polyhook — TypeScript / JavaScript SDK

Write AI coding agent hooks once. Run them everywhere.

polyhook detects which AI coding tool invoked your hook binary, deserializes the event into a normalized struct, and serializes your response back in the format that tool expects. Your hook runs unchanged whether Claude Code, Cursor, Windsurf, Cline, or Amp invoked it.

Ships as dual ESM + CJS — works with import (ESM) and require (CJS) out of the box.

Install

npm install @polyhook/sdk
# or
pnpm add @polyhook/sdk
# or
yarn add @polyhook/sdk

Quick Start

// ESM ("type": "module" or .mts)
import { read, respond, block, approve } from "@polyhook/sdk";

const event = await read();

if (
  event.tool === "bash" &&
  /rm\s+-rf\s+\//.test((event.input?.command as string) ?? "")
) {
  await respond(block("Refusing to delete from root"));
} else {
  await respond(approve());
}

// CJS (require)
const { read, respond, block, approve } = require("@polyhook/sdk");

async function main() {
  const event = await read();
  await respond(approve());
}
main();

More examples: examples/

API

Function	Description
`read()`	Read and parse the hook event from stdin
`respond(r)`	Serialize and write a response to stdout
`approve()`	Build an approve response
`block(message)`	Build a block response with a message
`modify(input)`	Build a modify response with replacement fields

Supported Tools

Tool	Status
Claude Code	✅ Supported
Cursor	✅ Supported
Windsurf	✅ Supported
Cline	✅ Supported
Amp	✅ Supported
Continue	🚧 In progress
Aider	🚧 In progress
Copilot	📋 Planned

Documentation

Full docs and API reference: https://github.com/tupe12334/polyhook

License

MIT