---
summary: "Hooks: event-driven automation for commands and lifecycle events"
read_when:
  - You want event-driven automation for /new, /reset, /stop, and agent lifecycle events
  - You want to build, install, or debug hooks
title: "Hooks"
---

# Hooks

Hooks provide an extensible event-driven system for automating actions in response to agent commands and events. Hooks are automatically discovered from directories and can be managed via CLI commands, similar to how skills work in Gensparx.

## Getting Oriented

Hooks are small scripts that run when something happens. There are two kinds:

- **Hooks** (this page): run inside the Gateway when agent events fire, like `/new`, `/reset`, `/stop`, or lifecycle events.
- **Webhooks**: external HTTP webhooks that let other systems trigger work in Gensparx. See [Webhook Hooks](/automation/webhook) or use `gensparx webhooks` for Gmail helper commands.

Hooks can also be bundled inside plugins; see [Plugins](/tools/plugin#plugin-hooks).

Common uses:

- Save a memory snapshot when you reset a session
- Keep an audit trail of commands for troubleshooting or compliance
- Trigger follow-up automation when a session starts or ends
- Write files into the agent workspace or call external APIs when events fire

If you can write a small TypeScript function, you can write a hook. Hooks are discovered automatically, and you enable or disable them via the CLI.

## Overview

The hooks system allows you to:

- Save session context to memory when `/new` is issued
- Log all commands for auditing
- Trigger custom automations on agent lifecycle events
- Extend Gensparx's behavior without modifying core code

## Getting Started

### Bundled Hooks

gensparx ships with four bundled hooks that are automatically discovered:

- **💾 session-memory**: Saves session context to your agent workspace (default `~/.gensparx/workspace/memory/`) when you issue `/new`
- **📎 bootstrap-extra-files**: Injects additional workspace bootstrap files from configured glob/path patterns during `agent:bootstrap`
- **📝 command-logger**: Logs all command events to `~/.gensparx/logs/commands.log`
- **🚀 boot-md**: Runs `BOOT.md` when the gateway starts (requires internal hooks enabled)

List available hooks:

```bash
gensparx hooks list
```

Enable a hook:

```bash
gensparx hooks enable session-memory
```

Check hook status:

```bash
gensparx hooks check
```

Get detailed information:

```bash
gensparx hooks info session-memory
```

### Onboarding

During onboarding (`gensparx onboard`), you'll be prompted to enable recommended hooks. The wizard automatically discovers eligible hooks and presents them for selection.

## Hook Discovery

Hooks are automatically discovered from three directories (in order of precedence):

1. **Workspace hooks**: `<workspace>/hooks/` (per-agent, highest precedence)
2. **Managed hooks**: `~/.gensparx/hooks/` (user-installed, shared across workspaces)
3. **Bundled hooks**: `<gensparx>/dist/hooks/bundled/` (shipped with Gensparx)

Managed hook directories can be either a **single hook** or a **hook pack** (package directory).

Each hook is a directory containing:

```
my-hook/
├── HOOK.md          # Metadata + documentation
└── handler.ts       # Handler implementation
```

## Hook Packs (npm/archives)

Hook packs are standard npm packages that export one or more hooks via `gensparx.hooks` in
`package.json`. Install them with:

```bash
gensparx hooks install <path-or-spec>
```

Npm specs are registry-only (package name + optional version/tag). Git/URL/file specs are rejected.

Example `package.json`:

```json
{
  "name": "@acme/my-hooks",
  "version": "0.1.0",
  "gensparx": {
    "hooks": ["./hooks/my-hook", "./hooks/other-hook"]
  }
}
```

Each entry points to a hook directory containing `HOOK.md` and `handler.ts` (or `index.ts`).
Hook packs can ship dependencies; they will be installed under `~/.gensparx/hooks/<id>`.
Each `gensparx.hooks` entry must stay inside the package directory after symlink
resolution; entries that escape are rejected.

Security note: `gensparx hooks install` installs dependencies with `npm install --ignore-scripts`
(no lifecycle scripts). Keep hook pack dependency trees "pure JS/TS" and avoid packages that rely
on `postinstall` builds.

## Hook Structure

### HOOK.md Format

The `HOOK.md` file contains metadata in YAML frontmatter plus Markdown documentation:

```markdown
---
name: my-hook
description: "Short description of what this hook does"
homepage: https://docs.gensparx.com/automation/hooks#my-hook
metadata:
  { "gensparx": { "emoji": "🔗", "events": ["command:new"], "requires": { "bins": ["node"] } } }
---

# My Hook

Detailed documentation goes here...

## What It Does

- Listens for `/new` commands
- Performs some action
- Logs the result

## Requirements

- Node.js must be installed

## Configuration

No configuration needed.
```

### Metadata Fields

The `metadata.gensparx` object supports:

- **`emoji`**: Display emoji for CLI (e.g., `"💾"`)
- **`events`**: Array of events to listen for (e.g., `["command:new", "command:reset"]`)
- **`export`**: Named export to use (defaults to `"default"`)
- **`homepage`**: Documentation URL
- **`requires`**: Optional requirements
  - **`bins`**: Required binaries on PATH (e.g., `["git", "node"]`)
  - **`anyBins`**: At least one of these binaries must be present
  - **`env`**: Required environment variables
  - **`config`**: Required config paths (e.g., `["workspace.dir"]`)
  - **`os`**: Required platforms (e.g., `["darwin", "linux"]`)
- **`always`**: Bypass eligibility checks (boolean)
- **`install`**: Installation methods (for bundled hooks: `[{"id":"bundled","kind":"bundled"}]`)

### Handler Implementation

The `handler.ts` file exports a `HookHandler` function:

```typescript
const myHandler = async (event) => {
  // Only trigger on 'new' command
  if (event.type !== "command" || event.action !== "new") {
    return;
  }

  console.log(`[my-hook] New command triggered`);
  console.log(`  Session: ${event.sessionKey}`);
  console.log(`  Timestamp: ${event.timestamp.toISOString()}`);

  // Your custom logic here

  // Optionally send message to user
  event.messages.push("✨ My hook executed!");
};

export default myHandler;
```

#### Event Context

Each event includes:

```typescript
{
  type: 'command' | 'session' | 'agent' | 'gateway' | 'message',
  action: string,              // e.g., 'new', 'reset', 'stop', 'received', 'sent'
  sessionKey: string,          // Session identifier
  timestamp: Date,             // When the event occurred
  messages: string[],          // Push messages here to send to user
  context: {
    // Command events:
    sessionEntry?: SessionEntry,
    sessionId?: string,
    sessionFile?: string,
    commandSource?: string,    // e.g., 'whatsapp', 'telegram'
    senderId?: string,
    workspaceDir?: string,
    bootstrapFiles?: WorkspaceBootstrapFile[],
    cfg?: GensparxConfig,
    // Message events (see Message Events section for full details):
    from?: string,             // message:received
    to?: string,               // message:sent
    content?: string,
    channelId?: string,
    success?: boolean,         // message:sent
  }
}
```

## Event Types

### Command Events

Triggered when agent commands are issued:

- **`command`**: All command events (general listener)
- **`command:new`**: When `/new` command is issued
- **`command:reset`**: When `/reset` command is issued
- **`command:stop`**: When `/stop` command is issued

### Session Events

- **`session:compact:before`**: Right before compaction summarizes history
- **`session:compact:after`**: After compaction completes with summary metadata

Internal hook payloads emit these as `type: "session"` with `action: "compact:before"` / `action: "compact:after"`; listeners subscribe with the combined keys above.
Specific handler registration uses the literal key format `${type}:${action}`. For these events, register `session:compact:before` and `session:compact:after`.

### Agent Events

- **`agent:bootstrap`**: Before workspace bootstrap files are injected (hooks may mutate `context.bootstrapFiles`)

### Gateway Events

Triggered when the gateway starts:

- **`gateway:startup`**: After channels start and hooks are loaded

### Message Events

Triggered when messages are received or sent:

- **`message`**: All message events (general listener)
- **`message:received`**: When an inbound message is received from any channel. Fires early in processing before media understanding. Content may contain raw placeholders like `<media:audio>` for media attachments that haven't been processed yet.
- **`message:transcribed`**: When a message has been fully processed, including audio transcription and link understanding. At this point, `transcript` contains the full transcript text for audio messages. Use this hook when you need access to transcribed audio content.
- **`message:preprocessed`**: Fires for every message after all media + link understanding completes, giving hooks access to the fully enriched body (transcripts, image descriptions, link summaries) before the agent sees it.
- **`message:sent`**: When an outbound message is successfully sent

#### Message Event Context

Message events include rich context about the message:

```typescript
// message:received context
{
  from: string,           // Sender identifier (phone number, user ID, etc.)
  content: string,        // Message content
  timestamp?: number,     // Unix timestamp when received
  channelId: string,      // Channel (e.g., "whatsapp", "telegram", "discord")
  accountId?: string,     // Provider account ID for multi-account setups
  conversationId?: string, // Chat/conversation ID
  messageId?: string,     // Message ID from the provider
  metadata?: {            // Additional provider-specific data
    to?: string,
    provider?: string,
    surface?: string,
    threadId?: string,
    senderId?: string,
    senderName?: string,
    senderUsername?: string,
    senderE164?: string,
  }
}

// message:sent context
{
  to: string,             // Recipient identifier
  content: string,        // Message content that was sent
  success: boolean,       // Whether the send succeeded
  error?: string,         // Error message if sending failed
  channelId: string,      // Channel (e.g., "whatsapp", "telegram", "discord")
  accountId?: string,     // Provider account ID
  conversationId?: string, // Chat/conversation ID
  messageId?: string,     // Message ID returned by the provider
  isGroup?: boolean,      // Whether this outbound message belongs to a group/channel context
  groupId?: string,       // Group/channel identifier for correlation with message:received
}

// message:transcribed context
{
  body?: string,          // Raw inbound body before enrichment
  bodyForAgent?: string,  // Enriched body visible to the agent
  transcript: string,     // Audio transcript text
  channelId: string,      // Channel (e.g., "telegram", "whatsapp")
  conversationId?: string,
  messageId?: string,
}

// message:preprocessed context
{
  body?: string,          // Raw inbound body
  bodyForAgent?: string,  // Final enriched body after media/link understanding
  transcript?: string,    // Transcript when audio was present
  channelId: string,      // Channel (e.g., "telegram", "whatsapp")
  conversationId?: string,
  messageId?: string,
  isGroup?: boolean,
  groupId?: string,
}
```

#### Example: Message Logger Hook

```typescript
const isMessageReceivedEvent = (event: { type: string; action: string }) =>
  event.type === "message" && event.action === "received";
const isMessageSentEvent = (event: { type: string; action: string }) =>
  event.type === "message" && event.action === "sent";

const handler = async (event) => {
  if (isMessageReceivedEvent(event as { type: string; action: string })) {
    console.log(`[message-logger] Received from ${event.context.from}: ${event.context.content}`);
  } else if (isMessageSentEvent(event as { type: string; action: string })) {
    console.log(`[message-logger] Sent to ${event.context.to}: ${event.context.content}`);
  }
};

export default handler;
```

### Tool Result Hooks (Plugin API)

These hooks are not event-stream listeners; they let plugins synchronously adjust tool results before gensparx persists them.

- **`tool_result_persist`**: transform tool results before they are written to the session transcript. Must be synchronous; return the updated tool result payload or `undefined` to keep it as-is. See [Agent Loop](/concepts/agent-loop).

### Plugin Hook Events

Compaction lifecycle hooks exposed through the plugin hook runner:

- **`before_compaction`**: Runs before compaction with count/token metadata
- **`after_compaction`**: Runs after compaction with compaction summary metadata

### Future Events

Planned event types:

- **`session:start`**: When a new session begins
- **`session:end`**: When a session ends
- **`agent:error`**: When an agent encounters an error

## Creating Custom Hooks

### 1. Choose Location

- **Workspace hooks** (`<workspace>/hooks/`): Per-agent, highest precedence
- **Managed hooks** (`~/.gensparx/hooks/`): Shared across workspaces

### 2. Create Directory Structure

```bash
mkdir -p ~/.gensparx/hooks/my-hook
cd ~/.gensparx/hooks/my-hook
```

### 3. Create HOOK.md

```markdown
---
name: my-hook
description: "Does something useful"
metadata: { "gensparx": { "emoji": "🎯", "events": ["command:new"] } }
---

# My Custom Hook

This hook does something useful when you issue `/new`.
```

### 4. Create handler.ts

```typescript
const handler = async (event) => {
  if (event.type !== "command" || event.action !== "new") {
    return;
  }

  console.log("[my-hook] Running!");
  // Your logic here
};

export default handler;
```

### 5. Enable and Test

```bash
# Verify hook is discovered
gensparx hooks list

# Enable it
gensparx hooks enable my-hook

# Restart your gateway process (menu bar app restart on macOS, or restart your dev process)

# Trigger the event
# Send /new via your messaging channel
```

## Configuration

### New Config Format (Recommended)

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "entries": {
        "session-memory": { "enabled": true },
        "command-logger": { "enabled": false }
      }
    }
  }
}
```

### Per-Hook Configuration

Hooks can have custom configuration:

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "entries": {
        "my-hook": {
          "enabled": true,
          "env": {
            "MY_CUSTOM_VAR": "value"
          }
        }
      }
    }
  }
}
```

### Extra Directories

Load hooks from additional directories:

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "load": {
        "extraDirs": ["/path/to/more/hooks"]
      }
    }
  }
}
```

### Legacy Config Format (Still Supported)

The old config format still works for backwards compatibility:

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "handlers": [
        {
          "event": "command:new",
          "module": "./hooks/handlers/my-handler.ts",
          "export": "default"
        }
      ]
    }
  }
}
```

Note: `module` must be a workspace-relative path. Absolute paths and traversal outside the workspace are rejected.

**Migration**: Use the new discovery-based system for new hooks. Legacy handlers are loaded after directory-based hooks.

## CLI Commands

### List Hooks

```bash
# List all hooks
gensparx hooks list

# Show only eligible hooks
gensparx hooks list --eligible

# Verbose output (show missing requirements)
gensparx hooks list --verbose

# JSON output
gensparx hooks list --json
```

### Hook Information

```bash
# Show detailed info about a hook
gensparx hooks info session-memory

# JSON output
gensparx hooks info session-memory --json
```

### Check Eligibility

```bash
# Show eligibility summary
gensparx hooks check

# JSON output
gensparx hooks check --json
```

### Enable/Disable

```bash
# Enable a hook
gensparx hooks enable session-memory

# Disable a hook
gensparx hooks disable command-logger
```

## Bundled hook reference

### session-memory

Saves session context to memory when you issue `/new`.

**Events**: `command:new`

**Requirements**: `workspace.dir` must be configured

**Output**: `<workspace>/memory/YYYY-MM-DD-slug.md` (defaults to `~/.gensparx/workspace`)

**What it does**:

1. Uses the pre-reset session entry to locate the correct transcript
2. Extracts the last 15 lines of conversation
3. Uses LLM to generate a descriptive filename slug
4. Saves session metadata to a dated memory file

**Example output**:

```markdown
# Session: 2026-01-16 14:30:00 UTC

- **Session Key**: agent:main:main
- **Session ID**: abc123def456
- **Source**: telegram
```

**Filename examples**:

- `2026-01-16-vendor-pitch.md`
- `2026-01-16-api-design.md`
- `2026-01-16-1430.md` (fallback timestamp if slug generation fails)

**Enable**:

```bash
gensparx hooks enable session-memory
```

### bootstrap-extra-files

Injects additional bootstrap files (for example monorepo-local `AGENTS.md` / `TOOLS.md`) during `agent:bootstrap`.

**Events**: `agent:bootstrap`

**Requirements**: `workspace.dir` must be configured

**Output**: No files written; bootstrap context is modified in-memory only.

**Config**:

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "entries": {
        "bootstrap-extra-files": {
          "enabled": true,
          "paths": ["packages/*/AGENTS.md", "packages/*/TOOLS.md"]
        }
      }
    }
  }
}
```

**Notes**:

- Paths are resolved relative to workspace.
- Files must stay inside workspace (realpath-checked).
- Only recognized bootstrap basenames are loaded.
- Subagent allowlist is preserved (`AGENTS.md` and `TOOLS.md` only).

**Enable**:

```bash
gensparx hooks enable bootstrap-extra-files
```

### command-logger

Logs all command events to a centralized audit file.

**Events**: `command`

**Requirements**: None

**Output**: `~/.gensparx/logs/commands.log`

**What it does**:

1. Captures event details (command action, timestamp, session key, sender ID, source)
2. Appends to log file in JSONL format
3. Runs silently in the background

**Example log entries**:

```jsonl
{"timestamp":"2026-01-16T14:30:00.000Z","action":"new","sessionKey":"agent:main:main","senderId":"+1234567890","source":"telegram"}
{"timestamp":"2026-01-16T15:45:22.000Z","action":"stop","sessionKey":"agent:main:main","senderId":"user@example.com","source":"whatsapp"}
```

**View logs**:

```bash
# View recent commands
tail -n 20 ~/.gensparx/logs/commands.log

# Pretty-print with jq
cat ~/.gensparx/logs/commands.log | jq .

# Filter by action
grep '"action":"new"' ~/.gensparx/logs/commands.log | jq .
```

**Enable**:

```bash
gensparx hooks enable command-logger
```

### boot-md

Runs `BOOT.md` when the gateway starts (after channels start).
Internal hooks must be enabled for this to run.

**Events**: `gateway:startup`

**Requirements**: `workspace.dir` must be configured

**What it does**:

1. Reads `BOOT.md` from your workspace
2. Runs the instructions via the agent runner
3. Sends any requested outbound messages via the message tool

**Enable**:

```bash
gensparx hooks enable boot-md
```

## Best Practices

### Keep Handlers Fast

Hooks run during command processing. Keep them lightweight:

```typescript
// ✓ Good - async work, returns immediately
const handler: HookHandler = async (event) => {
  void processInBackground(event); // Fire and forget
};

// ✗ Bad - blocks command processing
const handler: HookHandler = async (event) => {
  await slowDatabaseQuery(event);
  await evenSlowerAPICall(event);
};
```

### Handle Errors Gracefully

Always wrap risky operations:

```typescript
const handler: HookHandler = async (event) => {
  try {
    await riskyOperation(event);
  } catch (err) {
    console.error("[my-handler] Failed:", err instanceof Error ? err.message : String(err));
    // Don't throw - let other handlers run
  }
};
```

### Filter Events Early

Return early if the event isn't relevant:

```typescript
const handler: HookHandler = async (event) => {
  // Only handle 'new' commands
  if (event.type !== "command" || event.action !== "new") {
    return;
  }

  // Your logic here
};
```

### Use Specific Event Keys

Specify exact events in metadata when possible:

```yaml
metadata: { "gensparx": { "events": ["command:new"] } } # Specific
```

Rather than:

```yaml
metadata: { "gensparx": { "events": ["command"] } } # General - more overhead
```

## Debugging

### Enable Hook Logging

The gateway logs hook loading at startup:

```
Registered hook: session-memory -> command:new
Registered hook: bootstrap-extra-files -> agent:bootstrap
Registered hook: command-logger -> command
Registered hook: boot-md -> gateway:startup
```

### Check Discovery

List all discovered hooks:

```bash
gensparx hooks list --verbose
```

### Check Registration

In your handler, log when it's called:

```typescript
const handler: HookHandler = async (event) => {
  console.log("[my-handler] Triggered:", event.type, event.action);
  // Your logic
};
```

### Verify Eligibility

Check why a hook isn't eligible:

```bash
gensparx hooks info my-hook
```

Look for missing requirements in the output.

## Testing

### Gateway Logs

Monitor gateway logs to see hook execution:

```bash
# macOS
./scripts/clawlog.sh -f

# Other platforms
tail -f ~/.gensparx/gateway.log
```

### Test Hooks Directly

Test your handlers in isolation:

```typescript
import { test } from "vitest";
import myHandler from "./hooks/my-hook/handler.js";

test("my handler works", async () => {
  const event = {
    type: "command",
    action: "new",
    sessionKey: "test-session",
    timestamp: new Date(),
    messages: [],
    context: { foo: "bar" },
  };

  await myHandler(event);

  // Assert side effects
});
```

## Architecture

### Core Components

- **`src/hooks/types.ts`**: Type definitions
- **`src/hooks/workspace.ts`**: Directory scanning and loading
- **`src/hooks/frontmatter.ts`**: HOOK.md metadata parsing
- **`src/hooks/config.ts`**: Eligibility checking
- **`src/hooks/hooks-status.ts`**: Status reporting
- **`src/hooks/loader.ts`**: Dynamic module loader
- **`src/cli/hooks-cli.ts`**: CLI commands
- **`src/gateway/server-startup.ts`**: Loads hooks at gateway start
- **`src/auto-reply/reply/commands-core.ts`**: Triggers command events

### Discovery Flow

```
Gateway startup
    ↓
Scan directories (workspace → managed → bundled)
    ↓
Parse HOOK.md files
    ↓
Check eligibility (bins, env, config, os)
    ↓
Load handlers from eligible hooks
    ↓
Register handlers for events
```

### Event Flow

```
User sends /new
    ↓
Command validation
    ↓
Create hook event
    ↓
Trigger hook (all registered handlers)
    ↓
Command processing continues
    ↓
Session reset
```

## Troubleshooting

### Hook Not Discovered

1. Check directory structure:

   ```bash
   ls -la ~/.gensparx/hooks/my-hook/
   # Should show: HOOK.md, handler.ts
   ```

2. Verify HOOK.md format:

   ```bash
   cat ~/.gensparx/hooks/my-hook/HOOK.md
   # Should have YAML frontmatter with name and metadata
   ```

3. List all discovered hooks:

   ```bash
   gensparx hooks list
   ```

### Hook Not Eligible

Check requirements:

```bash
gensparx hooks info my-hook
```

Look for missing:

- Binaries (check PATH)
- Environment variables
- Config values
- OS compatibility

### Hook Not Executing

1. Verify hook is enabled:

   ```bash
   gensparx hooks list
   # Should show ✓ next to enabled hooks
   ```

2. Restart your gateway process so hooks reload.

3. Check gateway logs for errors:

   ```bash
   ./scripts/clawlog.sh | grep hook
   ```

### Handler Errors

Check for TypeScript/import errors:

```bash
# Test import directly
node -e "import('./path/to/handler.ts').then(console.log)"
```

## Migration Guide

### From Legacy Config to Discovery

**Before**:

```json
{
  "hooks": {
    "internal": {
      "enabled": true,
      "handlers": [
        {
          "event": "command:new",
          "module": "./hooks/handlers/my-handler.ts"
        }
      ]
    }
  }
}
```

**After**:

1. Create hook directory:

   ```bash
   mkdir -p ~/.gensparx/hooks/my-hook
   mv ./hooks/handlers/my-handler.ts ~/.gensparx/hooks/my-hook/handler.ts
   ```

2. Create HOOK.md:

   ```markdown
   ---
   name: my-hook
   description: "My custom hook"
   metadata: { "gensparx": { "emoji": "🎯", "events": ["command:new"] } }
   ---

   # My Hook

   Does something useful.
   ```

3. Update config:

   ```json
   {
     "hooks": {
       "internal": {
         "enabled": true,
         "entries": {
           "my-hook": { "enabled": true }
         }
       }
     }
   }
   ```

4. Verify and restart your gateway process:

   ```bash
   gensparx hooks list
   # Should show: 🎯 my-hook ✓
   ```

**Benefits of migration**:

- Automatic discovery
- CLI management
- Eligibility checking
- Better documentation
- Consistent structure

## See Also

- [CLI Reference: hooks](/cli/hooks)
- [Bundled Hooks README](https://github.com/gensparx/gensparx/tree/main/src/hooks/bundled)
- [Webhook Hooks](/automation/webhook)
- [Configuration](/gateway/configuration#hooks)
