co-mono/packages/coding-agent/examples/hooks/README.md

Hooks Examples

Example hooks for pi-coding-agent.

Examples

permission-gate.ts

Prompts for confirmation before running dangerous bash commands (rm -rf, sudo, chmod 777, etc.).

git-checkpoint.ts

Creates git stash checkpoints at each turn, allowing code restoration when branching.

protected-paths.ts

Blocks writes to protected paths (.env, .git/, node_modules/).

Usage

# Test directly
pi --hook examples/hooks/permission-gate.ts

# Or copy to hooks directory for persistent use
cp permission-gate.ts ~/.pi/agent/hooks/

Writing Hooks

See docs/hooks.md for full documentation.

Key Points

Hook structure:

import type { HookAPI } from "@mariozechner/pi-coding-agent/hooks";

export default function (pi: HookAPI) {
  pi.on("session", async (event, ctx) => {
    // event.reason: "start" | "switch" | "clear"
    // ctx.ui, ctx.exec, ctx.cwd, ctx.sessionFile, ctx.hasUI
  });

  pi.on("tool_call", async (event, ctx) => {
    // Can block tool execution
    if (dangerous) {
      return { block: true, reason: "Blocked" };
    }
    return undefined;
  });

  pi.on("tool_result", async (event, ctx) => {
    // Can modify result
    return { result: "modified result" };
  });
}

Available events:

• session - startup, session switch, clear
• branch - before branching (can skip conversation restore)
• agent_start / agent_end - per user prompt
• turn_start / turn_end - per LLM turn
• tool_call - before tool execution (can block)
• tool_result - after tool execution (can modify)

UI methods:

const choice = await ctx.ui.select("Title", ["Option A", "Option B"]);
const confirmed = await ctx.ui.confirm("Title", "Are you sure?");
const input = await ctx.ui.input("Title", "placeholder");
ctx.ui.notify("Message", "info"); // or "warning", "error"

Sending messages:

pi.send("Message to inject into conversation");