Address review on the hook-bridges PR — two composability/compatibility bugs in both the CC and Codex bridges: 1. A hook that only attaches additionalContext (no block/deny) returned `allow`/`accept` WITHOUT calling next(), short-circuiting every later agent/prompt-submit / tools/post-execute listener. A policy/sandbox plugin registered after the bridge never saw the prompt. Now the context-only path delegates via next() and folds its context onto the downstream decision (concatContext): a downstream block/deny still wins and carries the bridge context; a downstream allow/accept keeps its own content rewrite and gains the context. Only a real hook deny/block short-circuits. 2. CLAUDE_PROJECT_DIR was empty in the default ACP wiring (no projectDir configured), breaking common unmodified hooks that reference $CLAUDE_PROJECT_DIR. It now defaults per-run to the agent's session workspace (the same cwd the hook runs in); an explicit config.projectDir still wins. Regression tests per bridge: a later listener blocks a prompt a context-only hook allowed; both contexts survive when the downstream also adds one; the default CLAUDE_PROJECT_DIR reaches the hook. Each proven red on the pre-fix code.
hooks/ — hook bridges + shared protocol
The hooks subsystem lets users extend the agent at lifecycle points the way Claude Code and Codex do — by pointing a bridge plugin at an existing hooks.json (or settings) so those external shell hooks run faithfully. The canonical extension surface itself is the harness's typed interception seams (the interception-seams RFC); a "native hook" is just an ordinary cordis plugin on those seams. These packages are the bridges that translate the external shell-hook protocol onto that same surface, plus the shared wire-protocol library they build on.
| Package | Role | Shape |
|---|---|---|
hook-protocol/ |
Shared wire-protocol core: matcher primitive, exit-code/stdout codec, runHook (via ctx.bash), most-restrictive merge, hook/* session events |
library (no plugin) |
hooks-claude/ |
Bridge for a Claude Code hooks.json / settings |
plugin |
hooks-codex/ |
Bridge for a Codex hooks.json |
plugin |
Codex deliberately reimplements a subset of the Claude Code protocol (same hooks.json shape, 5 events vs CC's many, command-only, regex-only matcher, no env/substitution), so hook-protocol owns the genuinely-identical primitives and each bridge owns only what differs (its per-event stdin payload, env, and the mapping of a hook's neutral outcome onto the harness's typed Decisions). See hook-protocol/README.md.