ADR-0003: One Switchyard binary with daemon, CLI, and MCP subcommands

• Status: Accepted
• Date: 2026-07-15

Context

Separate executables would complicate versioning, installation, local protocol compatibility, and desktop sidecar packaging.

Decision

Ship one primary executable named switchyard. cmd/switchyard is a small composition root; command groups delegate to client or application packages. The binary exposes daemon, CLI, UI, doctor, and MCP entry points without centralizing their behavior in one package.

Consequences

Users install and update one version. Internal packages must remain cohesive so the deployment unit does not become a god binary. The desktop app bundles or attaches to a compatible copy of the same executable.