A command that adds one automated hook to Claude Code's .claude/settings.json file. A hook runs a command when a specified tool event occurs.

Use it to add a pre-tool, post-tool, or stop hook triggered by tools such as Edit, Write, or Bash, optionally for matching file patterns.

It makes repeated actions, such as formatting or testing after edits, happen automatically without changing existing permissions.

add-hook — Command by ShipWithAI

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add commands/shipwithai/shipwithai-plugins/add-hook

Clone the repo

git clone --depth 1 https://github.com/ShipWithAI/shipwithai-plugins

Or install shipwithai-starter, the plugin that ships this one along with the rest of its 13 skills, 4 commands, 1 agent.

Per session 56 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 408 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5	$0.00056	$0.00408
Opus 5	$0.00028	$0.00204
Sonnet 5	$0.00011	$0.00082
Haiku 4.5	$0.00006	$0.00041

Measured 3d ago against content hash b344f8d6c8ae, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-hook scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/starter/commands/add-hook.md · 48 lines

What it actually says

/add-hook

Add a single hook to the .claude/settings.json hooks section. Stateless.

Steps

Check the plugin's hooks-catalog.json (located at skills/setup-hooks/hooks-catalog.json in the plugin directory) for a matching common pattern.
- Match found: show preset, confirm or customize.
- No match: ask:
  - Hook type: PreToolUse / PostToolUse / Stop?
  - Trigger on which tool: Edit / Write / Bash / * (all)?
  - File pattern (optional): *.ts, *.py, *.go?
  - Command to run?

Show preview before confirming:

This hook will run `[command]` every time Claude uses the [tool] tool
[on files matching [pattern]].

Preview:
{
  "PostToolUse": [{
    "matcher": "Edit",
    "hooks": [{"type": "command", "command": "[command]"}]
  }]
}

Check for duplicate: if an identical hook already exists in settings.json, skip.
If .claude/settings.json does not exist: create it with { "hooks": {} }.
Confirm → merge into .claude/settings.json hooks section. Do not overwrite the permissions section.
Update **Last updated:** date in the Harness config section of CLAUDE.md if the file exists.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

3d ago First seen · 48 lines · 56 tokens per session scan A b344f8d6c8ae

Subscribe to this mod's changes

add-hook is a command published in the GitHub repository ShipWithAI/shipwithai-plugins (10 stars, last pushed 21d ago), licensed MIT. It adds 56 tokens to every session and 408 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

ai-coding claude-code claude-code-plugin developer-tools shipwithai

add-hook

Getting it into your agent

What it costs to keep this loaded

Grade A, and why

Nothing flagged

What it actually says

/add-hook

Steps

What this file has done since we first saw it

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