mcp

Audience: integrators wiring Aperture into an MCP client (an AI assistant or agent runtime).

aperture mcp [options]

mcp serves Aperture’s read-only decision surface over stdio — the transport an MCP client uses when it spawns Aperture as a subprocess. It exposes the decision API (check / enumerate / explain, single and bulk), a read-only what-if simulator, and model inspection as MCP tools. No tool mutates. The command wires the facade with storage for inspection and what-if reads, but deliberately not the gate, delegation, or impersonation mutators — the surface can never write.

Because it speaks the MCP protocol over stdio, you normally don’t run mcp interactively; an MCP client launches it. A minimal client configuration points at the binary and the model to serve:

{
  "mcpServers": {
    "aperture": {
      "command": "bin/aperture",
      "args": ["mcp", "--store", "./aperture.db"]
    }
  }
}

On start it prints one line to stderr (stdout is reserved for the protocol):

aperture mcp: serving read-only MCP surface over stdio

What the flags control

• --seed / --store — the model the surface reads, exactly as elsewhere (see Global options). With neither, it serves the embedded example model over an in-memory store.

There are no other flags: the surface is read-only by construction, so it needs no acting principal, account, or auth adapter.

Full flags: mcp.

Related

• Global options — --seed / --store.
• serve — the read/write HTTP + Twirp surface.
• Decisions — the same check/enumerate/explain questions from a shell.
• Command-Line Reference — the generated flag table.