The fragmentation of the AI agent ecosystem just got a little less painful. Botline, a new open-source project hosted on GitHub by sabotage-dev, introduces a unified mailbox interface for agents from different vendors. By leveraging a single Cloudflare Worker, the system allows agents like Anthropic’s Claude, xAI’s Grok Bot, and Meta’s Muse to exchange messages and files regardless of their native API constraints. The project, currently at version v0.4-pre, is designed to be self-hosted and remains unofficial, with no affiliation to the major AI providers it connects.

Interoperability and Measured Latency

Botline operates by assigning each agent a unique key, enabling them to send and receive data via REST or the Model Context Protocol (MCP). The architecture handles vendor-specific limitations gracefully; while Claude and Grok can be triggered via API webhooks, Meta’s Muse lacks push capabilities and must poll on a schedule. Conformance tests conducted on October 13, 2026, measured cross-vendor communication speeds. Messages sent to Claude and Grok were acknowledged in 15 to 58 seconds. In contrast, interactions involving Muse took longer, with round-trip times ranging from one minute to 13 minutes depending on the poll interval. A complete four-agent loop, including a relay of unchanged data, closed in as little as 1 minute and 3 seconds.

Security and Delegation Controls

Security is baked into the core design, treating message bodies as untrusted data wrapped in specific tags to prevent prompt injection attacks. The system enforces strict allowlists, ensuring that only authorized senders can deliver mail to a recipient. Version 0.4 introduces a delegation model, allowing owners to specify which agents can assign work to others and what capabilities, such as file access, they may use. Doorbell secrets, which trigger agent routines, are encrypted using AES-256-GCM and bound to specific agent rows, ensuring that even if a secret is leaked, it cannot be used by a different agent. The project also implements backoff and dead-letter mechanisms to prevent retry storms when an agent’s webhook fails.

Key Takeaways

  • Botline enables cross-vendor AI agent communication using a single Cloudflare Worker.
  • Latency varies by vendor: Claude and Grok respond in seconds, while Muse requires polling.
  • The system treats message bodies as untrusted data to mitigate prompt injection risks.
  • Version 0.4 adds delegation controls, allowing owners to restrict which agents can assign tasks.
  • Self-hosting is free via Cloudflare’s free tier, supporting a three-agent loop with 5-minute polling.

The Bottom Line

Botline is a pragmatic infrastructure play for the multi-model future, proving that a simple mailbox abstraction can bridge the gap between walled-garden AI ecosystems without requiring massive architectural overhauls.