---
source_keys:
  - apm-cli-installed-source
  - apm-docs-llms-full
---

# Hook Flow

Steps 1 to 3 for an apm hook — the target Step 0 matched as a `.json` file directly under a
`hooks/` directory. Work them in order, then return to `SKILL.md` Step 4 to report.

## Gotchas

- apm checks almost nothing here. Invalid JSON is skipped without a word, an all-lowercase event deploys and never fires, and a missing script only warns — so `apm install` exiting 0 says nothing about whether the hook works. Never cite a clean install as evidence against a finding.
- Copilot receiving a Claude-shaped file is not a finding. apm renders one source for every target and documents that it owns the per-target shape; whether Copilot CLI honours a nested entry or `matcher` is unverified upstream, not a defect in the file.
- Quoting is not the fix for a script path with a space. apm rewrites a whole-token-quoted `"${PLUGIN_ROOT}/scripts/x.sh"`, but still stops reading the path at the space; the only fix is a path without one.

## Step 1 — Deterministic checks

Resolve the path against this skill's own directory. Run exactly:

```bash
bash scripts/validate.sh <hook-file>
```

Its findings become the `### Structure` dimension, FAILs and SUGGESTIONs both, at the tier the script assigned: JSON validity, the wrapped-or-naked shape, event lists and nested handler lists (the checks whose failure makes the Copilot install fail), a file contributing no entries (no events, only empty event lists, or an entry with no handler), event names that never fire, referenced scripts that are missing, outside the package, not executable when run directly, or referenced by an absolute, bare relative, `../`, split-quoted or space-containing path apm will not bundle correctly, deprecated filename routing, and `${CLAUDE_PLUGIN_ROOT}` where `${PLUGIN_ROOT}` would do. Script references are read with apm 0.28.0's own patterns: `${PLUGIN_ROOT}/…` only when the path follows the token directly, up to the first whitespace or quote, and `./…` anywhere in the command, including after an interpreter. A camelCase event outside Claude's rename map FAILs in a Claude-shaped file, and in a flat Copilot-shaped file too whenever the nearest `apm.yml` above the file targets Claude — no `target:`/`targets:` means every target. It exits **0** with no FAIL, **1** on real findings, **2** when it never ran — report that as `### Structure` unverified, quoting the stderr reason.

There is no provenance and no Vale step: a hook carries no `source_keys` and no prose.

Four tiers deliberately differ from `primitive-author`'s checklist or the research's. Do not re-tier them by judgment:

- A hook file directly under a package-root `hooks/` passes. apm discovers both `.apm/hooks/` and `hooks/`, and this audit may target a third-party package; `primitive-author` authors only in `.apm/hooks/`.
- Deprecated filename routing is a SUGGESTION, matching the author's Should: the research allows it when deprecated routing is intended.
- A non-executable script run as the command's first token is a FAIL, stricter than the research's Should, because it fails every time it fires.
- A split-quoted `"${PLUGIN_ROOT}"/x.sh` or a script path containing a space is a FAIL, stricter than the author's Should 10: apm leaves the first unrewritten and cuts the second at the space, so either deploys a hook that fails every time it fires.

## Step 2 — Read the hook and its scripts

Read the hook file, every script it references, and the package's `apm.yml` `targets:` — reach is narrowed there, never in the hook file.

## Step 3 — Qualitative audit

Cite file and line for every finding.

**purpose** — apm's own rule is to reach for a skill, instruction or prompt first; a hook is for "this must always happen at this event".

- FAIL: the script carries procedure the agent should follow — instructions printed to the model, a multi-step workflow — rather than a runtime callback. That is a skill.
- SUGGESTION: the behaviour is harness-specific (a Claude-only event, a Claude-only matcher value) in a package whose `targets:` includes other harnesses, and nothing records that the other targets receiving it was accepted. The apm-native fix is a separate package with its own `targets:`, not a routing filename.

**handlers** — the research checklist's Should and audit-only items, which apm never checks:

- SUGGESTION: a handler without `"type": "command"` or an explicit numeric `timeout` in seconds.
- SUGGESTION: a tool event (`PreToolUse`, `PostToolUse`) or `SessionStart` with no `matcher` — Claude receives `"*"`. A `matcher` on an event Claude ignores it for (`Stop`, `UserPromptSubmit`) is inert, not wrong.
- SUGGESTION: a PascalCase event name that is not a real Claude Code event (a misspelling deploys verbatim and never fires; the script cannot tell a typo from an event it does not know).
- SUGGESTION: `bash`/`powershell`/`timeoutSec` keys in a Claude-shaped file — they render, but leave stray keys in `settings.json`.
- SUGGESTION: a helper `.json` file in the hook directory without a `hooks` key — Copilot's loader scans the bundled scripts directory and rejects it. Keep helper configuration non-JSON.

Then return to `SKILL.md` Step 4, opening the report with this coverage line:

```text
Checked: structure · purpose · handlers
```