A deterministic C runtime providing transport-level routing for ACP/MCP-style agent protocols.

Website · Workers · Docker Hub

stdio Bus kernel acts as a process supervisor and message router between external clients (IDEs, CLIs, services) and worker processes. It handles NDJSON-framed JSON-RPC messages with session-based routing, while remaining completely agnostic to protocol semantics.

• Zero AI logic: All routing is deterministic based on session identifiers
• Single-threaded: One event loop using epoll (Linux) or kqueue (macOS)
• No external dependencies: Only libc and POSIX APIs
• Protocol agnostic: Forwards messages unchanged, parsing only routing fields
• Session affinity: Messages with the same sessionId route to the same worker
• Backpressure management: Configurable limits prevent memory exhaustion

• C11-compliant compiler (GCC 4.9+ or Clang 3.4+)
• Make or CMake 3.10+
• Node.js 18+ (for running example workers)

Pre-compiled binaries for multiple platforms are available in the /releases directory. Each version contains ready-to-use stdio_bus binaries for different architectures:

Available platforms:

• macOS: darwin-amd64 | darwin-arm64
• Linux: linux-amd64 | linux-arm64 | linux-armv7
• Linux (musl): linux-musl-amd64 | linux-musl-arm64

Verification: SHA256 checksums available at checksums.sha256

Download the appropriate binary for your platform and make it executable:

# Example for Linux AMD64
curl -L -o stdio_bus https://github.com/stdiobus/stdiobus/releases/v2.0.3/linux-amd64/stdio_bus
chmod +x stdio_bus

Pre-built multi-architecture images available on Docker Hub:

docker pull stdiobus/stdiobus:latest

Supported platforms: linux/amd64, linux/arm64, linux/arm/v7

Available tags: latest, v2.0.3, main, develop

See Docker Hub for complete usage examples and configuration.

Embedded stdio_bus runtime for your application process — no external daemon, no Docker, no TCP hop.

Worker implementations for stdio Bus kernel: @stdiobus/workers-registry

Includes full ACP protocol agent, ACP Registry launcher for routing to any registered agent (Claude, Goose, Cline, GitHub Copilot and others), OpenAI-compatible endpoint bridge, MCP-to-ACP proxy for IDE integration, and echo/test workers for protocol validation.

See workers-registry for configuration and usage.

Apache License, Version 2.0