Troubleshooting

Common errors and how to diagnose them.

"My hook didn't fire"

Four things to check, in order:

1. Run capt-hook --hooks <dir> test with the inline tests in place. If the test fails, the hook's conditions aren't matching the input you expect — fix the condition before debugging dispatch.
2. Confirm the --hooks argument points at the directory that actually contains your hook file. Captain-hook loads .py files under that root and nothing else.
3. Inspect the events= argument. A primitive defaults to one event (block_command → PreToolUse, nudge → PostToolUse); if you want a different event, pass it explicitly.
4. View the recent dispatch logs with capt-hook logs. By default it prints the most recent session's per-event log file, written under the cache log dir (default ~/.cache/captain-hook/logs, see Configuration). Pass --tail N to limit lines, or --session <id-or-transcript-path> to target a specific session. If your hook never appears in the log, dispatch never reached it — recheck steps 1–3.

Settings not picked up

Captain-hook reads settings from environment variables with the HOOKS_ prefix. A HooksSettings subclass only auto-loads if you build it through build_settings(YourSettings) or expose it from your conf.py so the dispatch CLI can discover it.

• Run printenv | rg HOOKS_ to confirm the variable is set.
• If you changed the prefix via model_config = SettingsConfigDict(env_prefix="MYAPP_"), double-check that nothing else still expects HOOKS_.
• See Configuration for the full settings surface.

RuntimeError: spaCy model is not installed

NLP signals refuse to auto-download the spaCy model at hook execution time (it's a ~100MB silent fetch). Install it once, explicitly:

python -m spacy download en_core_web_sm

Or, if you want the model cached at the location captain-hook expects:

python -c "from captain_hook.util.model_cache import ensure_spacy_model; ensure_spacy_model()"

Hook fired twice

If a primitive emits the same nudge / block twice for one event:

• Inspect events= on every registration. A hook registered with Event.Stop | Event.SubagentStop fires on both — confirm that's what you want.
• For nudge, add max_fires=N to cap how many times it can emit in a session.
• For signal-driven nudges, the same trigger phrase may live in multiple Signal patterns. Run capt-hook --hooks <dir> test — each test prints the Input it built and a PASS/FAIL, so you can confirm whether the phrase matched.

"Inline test failed but I can't tell why"

capt-hook test

The default output prints the Input it built and a PASS/FAIL for each test. Add --json to emit one record per test (id, status, expected, reason) for structured inspection. If the test still looks correct, dump the Input you're constructing — the most common mistake is leaving a field off (e.g. file= for an Edit test) so the hook's condition can't match.

"How do I see what events look like?"

Drop an audit() into your hooks directory for one session:

from captain_hook import Event, audit

audit(Event.PreToolUse | Event.PostToolUse | Event.Stop)

It writes one JSONL line per event under the log directory (see Configuration). Tail the file while the agent runs to see the exact tool_input, tool_name, and metadata your hooks will receive.

Diagnostic commands

capt-hook --hooks <dir> test                   # Run inline tests
capt-hook --hooks <dir> test --json            # Machine-readable output for CI
capt-hook --hooks <dir> run <Event> < event.json   # Replay an event JSON payload
capt-hook --hooks <dir> generate-settings      # Emit the .claude/settings.local.json fragment