Filenames in forwardAttachedFiles arrived from the source agent's
messages_out content and were used directly in path.join on both
source outbox read and target inbox write. A value like `../evil.sh`
could escape `inbox/<a2a-id>/` on the target session (and similarly
the source outbox on read), breaking session isolation — an
adversarial or hallucinating sub-agent could overwrite files in
a sibling session.
Adds isSafeAttachmentName(name) — exported so it's unit-testable —
which rejects empty, `.`, `..`, anything containing `/`, `\`, or
NUL, and anything path.basename would strip. Guard runs before any
I/O. Unsafe names are dropped with a warning log, same pattern as
missing-source-file handling; a bad filename in one attachment
doesn't kill the whole route's text delivery.
Addresses Codex Review P1 on qwibitai/nanoclaw#1967.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Before: `send_file(to='parent')` from a sub-agent wrote the bytes to
the sub-agent's own session outbox, but agent-to-agent routing copied
only the content JSON — the target's inbound message referenced
`files: ['x.png']` but the bytes lived in a session directory the
target couldn't mount. Parent agents orchestrating sub-agents (e.g.
Design Team delegating illustration work to an Illustrator sub-agent
on Codex) received file-reference messages with nothing to forward.
Fix: on route, if the source's content has `files`, copy each referenced
file from `<source>/outbox/<src-msg-id>/` to
`<target>/inbox/<a2a-msg-id>/`, and emit `attachments` (the existing
formatter convention — see formatter.ts:223) with `localPath` relative
to `/workspace/`. The target formatter already renders these as
`[file: <name> — saved to /workspace/inbox/<a2a-id>/<name>]`, so the
target agent sees the path and can call `send_file(path=…, to=…)` to
forward onward.
Convention matches what session-manager.ts:256 already does for
base64-encoded channel-inbound attachments — same inbox layout, same
content shape. Nothing on the formatter/agent side needed to change.
## Scope
- `forwardAttachedFiles(source, target)` — pure-ish helper that copies
files and returns the attachments array.
- `forwardFileAttachments(msg, …)` — wraps the helper for the route
path: parses content, copies files if present, merges into any
existing `attachments`, re-serialises.
- `routeAgentMessage` — uses the rewritten content when writing the
target's inbound row.
- Log line now includes `forwardedFileCount` for observability.
Missing source files are skipped with a warning rather than killing
the route — a bad filename in a batch shouldn't drop the
accompanying text.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Last extraction of Phase 3. Moves inter-agent messaging + create_agent +
destination projection into src/modules/agent-to-agent/. Core retains:
- `channel_type === 'agent'` dispatch in delivery.ts, guarded by
hasTable('agent_destinations') + dynamic import into module.
- Channel-permission ACL in delivery.ts, guarded by hasTable, with
inlined SQL (no module import from core).
- writeDestinations call in container-runner.ts, guarded by hasTable +
dynamic import into module.
- createMessagingGroupAgent's destination side effect in db/messaging-groups.ts,
guarded by hasTable. This is a documented transitional tier violation
(core imports from optional module), analogous to src/access.ts.
Migration `004-agent-destinations.ts` renamed to `module-agent-to-agent-
destinations.ts` preserving `name: 'agent-destinations'` so existing DBs
don't re-run it.
delivery.ts: 600 → 449 lines. handleSystemAction's last switch case gone
(just registry + default log-and-drop). notifyAgent helper removed (only
create_agent used it).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
