A guide for creating Cursor hooks, which are scripts or checks that run around coding-agent events and can observe, block, change, or follow up on actions.

Use it to create project or user hooks, configure event filters, and choose between command-based and prompt-based behavior.

It helps define when automation should run, what it should inspect or change, and whether failures should stop the workflow.

create-hook — Skill for Claude Code by XyrusCode/ai-sync

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.

Any agent

npx skills add XyrusCode/ai-sync --skill create-hook

Clone the repo

git clone --depth 1 https://github.com/XyrusCode/ai-sync

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/xyruscode/ai-sync/create-hook/github.svg)](https://agentmods.dev/skills/xyruscode/ai-sync/create-hook)

Your own site

<a href="https://agentmods.dev/skills/xyruscode/ai-sync/create-hook"><img src="https://agentmods.dev/badge/skills/xyruscode/ai-sync/create-hook/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/xyruscode/ai-sync/create-hook"><img src="https://agentmods.dev/badge/skills/xyruscode/ai-sync/create-hook.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,178 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin 100% copy Near-identical to another mod 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 5.1	$0.00031	$0.02178
Opus 5.5	$0.00012	$0.00871
Sonnet 5.5	$0.00006	$0.00436
Haiku 4.5	$0.00003	$0.00218

Measured 1mo ago against content hash 28bfa0c6cd13, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

create-hook scanned grade A with 1 finding 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 1mo 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

"matcher": "curl|wget|nc ",

Origin

This is a copy

100% identical to create-hook — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/create-hook/SKILL.md · 240 lines

How it starts

The opening of the file, as written. The whole thing — 240 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Creating Cursor Hooks

Create hooks when you want Cursor to run custom logic before or after agent events. Hooks are scripts or prompt-based checks that exchange JSON over stdin/stdout and can observe, block, modify, or follow up on behavior.

When the user asks for a hook, don't stop at describing the format. Gather the missing requirements, then create or update the hook files directly.

Gather Requirements

Before you write anything, determine:

Scope: Should this be a project hook or a user hook?
Trigger: Which event should run the hook?
Behavior: Should it audit, deny/allow, rewrite input, inject context, or continue a workflow?
Implementation: Should it be a command hook (script) or a prompt hook?
Filtering: Does it need a matcher so it only runs for certain tools, commands, or subagent types?
Safety: Should failures fail open or fail closed?

Infer these from the conversation when possible. Only ask for the missing pieces.

Choose the Right Location

Project hooks: .cursor/hooks.json and .cursor/hooks/*
User hooks: ~/.cursor/hooks.json and ~/.cursor/hooks/*

Path behavior matters:

Project hooks run from the project root, so use paths like .cursor/hooks/my-hook.sh
User hooks run from ~/.cursor/, so use paths like ./hooks/my-hook.sh or hooks/my-hook.sh

Prefer project hooks when the behavior should be shared with the repository and checked into version control.

Choose the Hook Event

Use the narrowest event that matches the user's goal.

Common Agent events

sessionStart, sessionEnd: set up or audit a session
preToolUse, postToolUse, postToolUseFailure: work across all tools
subagentStart, subagentStop: control or continue Task/subagent workflows
beforeShellExecution, afterShellExecution: gate or audit terminal commands
beforeMCPExecution, afterMCPExecution: gate or audit MCP tool calls
beforeReadFile, afterFileEdit: control file reads or post-process edits
beforeSubmitPrompt: validate prompts before they are sent
preCompact: observe context compaction
stop: handle agent completion
afterAgentResponse, afterAgentThought: track agent output or reasoning

Read the full file on GitHub · 240 lines

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.

1mo ago First seen · 240 lines · 31 tokens per session scan A 28bfa0c6cd13

Subscribe to this mod's changes

create-hook is a skill published in the GitHub repository XyrusCode/ai-sync (2 stars, last pushed 18d ago), licensed MIT. It adds 31 tokens to every session and 2,178 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to create-hook, differing in 0 lines, and is treated as a copy.

Building agents

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

insight-error-page

Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…

vercel/next.js · 83 tokens

create-hook