Summary

Add Signal as a messaging channel for PicoClaw.

Motivation

Signal is a major privacy-focused messaging platform. Many users prefer it over Telegram/WhatsApp for self-hosted AI assistants due to its E2E encryption and privacy stance.

Proposed Solutions

Option A: signal-cli (Recommended)
Use signal-cli JSON-RPC API:

• Run signal-cli daemon --http as external dependency
• PicoClaw connects to local HTTP API to send/receive messages
• Pros: Mature, handles E2E encryption, minimal code to maintain
• Cons: Requires JVM (~50-100MB RAM) — documented as optional external dependency

Option B: libsignal
Use Signal's official libsignal library:

• Native Signal Protocol implementation
• Pros: No external JVM process, lower memory footprint
• Cons: More complex integration, requires maintaining crypto code

Configuration

{
  "channels": {
    "signal": {
      "enabled": true,
      "account": "+1234567890",
      "signal_cli_url": "http://localhost:8080",
      "allow_from": ["+0987654321"]
    }
  }
}

Notes

• Credentials stored in ~/.local/share/signal-cli/ (if using signal-cli)
• Supports text messages, with voice/attachments possible as follow-up

References

• signal-cli
• signal-cli-rest-api
• libsignal