Adds support for Chatterbox TTS (https://github.com/resemble-ai/chatterbox),
a state-of-the-art open-source text-to-speech system that runs locally.

Features:
- OpenAI-compatible API endpoint support
- Voice cloning via voice library
- Multilingual support (23+ languages)
- Configurable parameters: exaggeration, CFG weight, speed
- Supports Chatterbox, Chatterbox-Turbo, and Chatterbox-Multilingual models

Configuration example:
```yaml
messages:
  tts:
    provider: chatterbox
    chatterbox:
      enabled: true
      baseUrl: http://localhost:4123
      voice: default
      model: chatterbox-turbo
```

Closes #XXX

Adds support for Piper TTS (https://github.com/rhasspy/piper),
a fast, local, and privacy-focused neural text-to-speech system.

Features:
- OpenAI-compatible API endpoint support
- High-quality neural voices (60+ languages)
- Lightweight and fast inference
- Runs completely offline/local
- Configurable voice parameters (speed, noise, etc.)

Configuration example:
```yaml
messages:
  tts:
    provider: piper
    piper:
      enabled: true
      baseUrl: http://localhost:8101
      voice: en_US-lessac-high
      lengthScale: 1.0
```

@vector-im/matrix-bot-sdk returns {data: Buffer, contentType: string}
instead of raw Buffer. Extract the data property and preserve contentType.

…ndpoint

- Full voice conversation loop (audio reception, STT, agent response, TTS, playback)
- Proactive speaking via HTTP endpoint (POST /mumble/speak)
- Voice parameter support for different TTS voices
- Sender allowlist for multi-bot environments
- High-quality audio (128kbps Opus, 10ms frames, 'audio' mode)
- Timeout-based silence detection (500ms)
- Comprehensive README with configuration examples

Technical details:
- Uses @tf2pickup-org/mumble-client (fork with full audio support)
- Whisper STT integration (OpenAI-compatible API)
- Kokoro TTS integration (67 voices, blending support)
- @discordjs/opus for native Opus encoding
- Linear interpolation resampling (24kHz → 48kHz)

Tested with Mumble v1.5.857, Node.js v24

Resolved conflicts:
- extensions/matrix/src/matrix/monitor/media.ts: accepted upstream's cleaner response handling
- src/media-understanding/providers/index.ts: merged both whisperProvider and zaiProvider

- Renamed skyline-mcp → mcp-client for generic MCP support
- Supports multiple simultaneous MCP server connections
- Compatible with any MCP server (filesystem, GitHub, Postgres, Slack, Skyline, etc.)
- Per-server tool prefixes to avoid naming conflicts
- Auto-reconnection support
- Updated plugin API for OpenClaw v2026.2.9 compatibility
  - Changed handler → execute method
  - Added toolCallId parameter
  - Fixed return format (content + details)

Tested with Skyline MCP server (31 tools loaded successfully).

Example config:
{
  "servers": {
    "skyline": { "command": "skyline-mcp", ... },
    "filesystem": { "command": "mcp-server-filesystem", ... }
  }
}

This enables OpenClaw to connect to the entire MCP ecosystem.

Major Features:
- Multi-server support with error isolation
- Auto ext_ prefix prevents native tool collisions
- Pre-flight command validation (no uncaught exceptions)
- Health monitoring with auto-recovery (60s intervals)
- Rate limiting (concurrent + per-minute)
- Metrics & observability (/mcp-metrics command)
- Protocol completeness (resources, prompts)
- Hot reload capability (/mcp-reload command)
- Comprehensive test suite (13 test cases)

P0 Features (Critical):
✅ Auto ext_ prefix for collision prevention
✅ MCP-to-MCP collision detection
✅ Pre-flight command check
✅ Error isolation (one bad server != crash)
✅ Tool discovery (/mcp command)
✅ Graceful degradation

P1 Features (Should Have):
✅ Expanded config validation
✅ Health monitoring & auto-restart
✅ Resource cleanup (no zombie processes)
✅ Basic test coverage

P2 Features (Nice to Have):
✅ Rate limiting (maxConcurrent, maxPerMinute)
✅ Metrics endpoint (/mcp-metrics)
✅ Resources & Prompts support
✅ Hot reload (/mcp-reload)

Testing:
- Crash-tested with invalid configurations
- Verified error isolation (3/4 servers working)
- Confirmed zombie process cleanup
- Production deployment verified (51 tools loaded)

Documentation:
- Comprehensive README (666 lines)
- Implementation summary with lessons learned
- Troubleshooting guide
- Configuration examples

Files:
- index.ts (995 lines)
- index.test.ts (219 lines, 13 tests)
- README.md (updated)
- IMPLEMENTATION-SUMMARY.md (new)

Status: Production Ready ✅

feat: Production-ready MCP client plugin

- Add duckduckgo as 4th search provider (no API key required)
- Uses official ddgs CLI (pip install ddgs)
- Supports Tor proxy with 'tor' convenience alias
- Add region, safesearch, and timelimit configuration options
- Maintain same caching and output format as other providers
- Auto-detects ddgs CLI in common installation paths

Configuration example:
  tools:
    web:
      search:
        provider: duckduckgo
        duckduckgo:
          proxy: tor
          region: wt-wt
          safesearch: moderate

Benefits:
- Zero-cost search option (vs Brave $5-15/month)
- Privacy-first with built-in Tor integration
- No API key registration required
- Same UX as existing providers

Technical details:
- Searches: ~/.local/bin/ddgs, ~/.openclaw/.venv/bin/ddgs, system paths
- Calls ddgs CLI with JSON output (-o flag)
- Maps ddgs output format to OpenClaw format
- Adds duckduckgo config schema validation

Use proper TypeScript types instead of 'as any' casts.

Keep both DuckDuckGo integration and upstream Grok improvements

Changes:
- extensions/mumble/package.json: @tf2pickup-org/mumble-client ^0.12.5
- Updated pnpm-lock.yaml

This makes the fork buildable without requiring a local mumble-client-fork directory.

Adds first-party support for Zulip, the open-source threaded team chat.

Features:
- Real-time message polling via Zulip event queue API
- Stream and DM support with topics
- Media upload and attachments
- Multiple account configuration
- DM/group allowlist policies
- @-mention requirement in streams
- Full config schema with environment variable support

Follows the same patterns as mattermost extension.