mathiasandClaude Opus 5
36b757fabf
brain_read returns a note verbatim; brain_edit is str_replace with an exactly-once match. Both operate on INGEST_BRAIN_DIR, which is the pod's mount of /var/lib/supervisor/brain — the tree brain-sync commits from, so an edit reaches gitea on the next cycle rather than landing somewhere the sync cannot see it (brain#2). An adversarial design review before implementation changed three things, each of which would otherwise have shipped: 1. Governance files are NOT in the model-facing tool. The original plan allowed root *.md so CLAUDE.md had an MCP path at all — the absence of one is what pushed a session to edit via the gitea REST API on 2026-06-16 and wedge the sync. But brain content is ingested from the outside world, reaches a model's context via brain_query, and that model would hold the editor: one poisoned page could rewrite the CLAUDE.md a .dispatch-allow agent later loads as instructions. Worse, brain-sync merges with --strategy-option=ours, so the live tree wins against a human's corrective push on exactly the conflicting lines. CLAUDE.md now goes through brain_edit_root: de-surfaced from tools/list (the brain_index precedent, ADR-0012 rule 4) and gated on the local static principal, so a claude.ai-origin session is refused. The two scopes are disjoint — the privileged door has the smaller reach. 2. Reads needed the same allowlist, and brain_get already lacked it. api.ReadNote resolves any brain-relative path and parseFrontmatter returns the whole file when there is no fence, so brain_get reads verbatim session transcripts under archive/ (up to 500 KB, never BM25-indexed, so nobody thinks of them as reachable). A test proves the exposure was live; the same Resolve now gates brain_get. 3. Canonicalise before allowlisting. A prefix check on the raw argument accepts knowledge/../.git/hooks/post-commit, which Clean collapses to a git hook that brain-sync executes inside a pod holding the Gitea push credentials. Traversal, symlink escape, dotfiles, .git/, archive/, sessions/ and raw/ are refused by a static backstop that does not depend on the allowlist being right. There were no traversal tests in this repo before. Also from the review: overlapping match counting (bytes.Count says "aa" occurs once in "aaa", so a Count-based uniqueness check accepts an ambiguous edit); UTF-8 validation on both sides, because encoding/json substitutes U+FFFD and would hand back bytes the file does not contain, making every derived old_str unmatchable; refusal while .git/MERGE_HEAD or index.lock exists, since an edit racing brain-sync's merge is either hard-reset away or committed as a wrongly resolved conflict; flock plus a per-path mutex with the read taken inside the lock, because two pods share the hostPath during a RollingUpdate and uniqueness evaluated against a stale read loses an update while reporting success; same-dir *.tmp + rename + chmod 0644 + fsync of file and parent; and reindex only when the edit touches frontmatter, since BM25 walks live and embeddings are mtime-driven. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BeAp5LTscnz2W7Ubt4eJ6m