Gives the assistant three new ACTION tools to change its own playbooks,
runtime settings, and (source checkout only) its own source code, all
reusing the existing run_snippet/remember approval framework — but with
a hardcoded floor (self_edit.ALWAYS_ASK_TOOLS) so these three always pause
for per-call human approval regardless of the global action_tool_policy
setting. Flipping that policy for an unrelated tool must never silently
also unlock unattended self-modification.
synapse/self_edit.py is the new module doing the actual work, documented
in the same explicit "here's what is and isn't a security boundary" style
as code_run.py:
- edit_source is confined to settings.project_root via the same
realpath + Path.parents boundary check that just closed a sibling-
directory bypass in /icons/image, plus a denylist of dangerous
subtrees (.git, the venv, node_modules, build output, runtime state).
Gated on settings.source_checkout — refuses cleanly in a wheel
install, where there's no live repo to edit or commit into.
- The model sends full file content, never a diff; the server computes
the diff itself via difflib against what's actually on disk, so a
human reviews ground truth, not a description the model wrote.
- Every applied source edit best-effort commits to git as an audit
trail — independent of, not a substitute for, the approval gate.
- edit_playbook merges instead of replacing (main.py's prior
_persist_playbook did a raw replace, which was only safe because the
frontend form always sent a complete object — unsafe for a tool a
model calls with a partial argument set, so this also fixes that
latent bug). Becoming the active system prompt requires an explicit
make_active flag, never a side effect of an ordinary edit.
- edit_settings reuses the existing _SETTINGS_DEFAULTS allowlist.
The approval UI (Chatbot.jsx) previously rendered a tool call's arguments
as Object.values(args).join(", ") in a single-line badge — unusable for
reviewing a diff. It now renders a real, server-computed preview (diff
for source, before/after for playbook/settings) via a new shared
diff-view.js helper, with a loud banner when a change would become the
active system prompt or touch action_tool_policy/system_prompt. A new
nexus-edit fence (self-edit-langs.js + Markdown.jsx's EditBlock) shows
the same diff after an edit is applied, mirroring nexus-run.
Verified: 212 backend tests pass (29 new in test_self_edit.py; the 12
pre-existing C/C++/Rust toolchain failures are unrelated and unchanged),
57 frontend node:test cases pass (15 new), eslint and vite build clean,
and the full approval-preview render path was exercised against the real
built UI with a mocked SSE stream covering all four preview branches
(source diff, playbook becomes-main, settings policy-change, and a
rejected/failing preview).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
GitNexus · part of the Nexus stack