How to run a provision via MCP¶

This recipe runs a single provision on demand from an MCP client, without bringing the rest of the stack up or down. It assumes you already know the basics of Alphasfile and provisions; for the full tool reference see zordon mcp.

1. Expose a provision¶

Declare the provision in your Alphasfile. A latent provision (after = never) never auto-runs at bringup — it exists purely to be invoked on demand:

service "go" "app" {
  runtime {
    provision "seed-data" {
      after = never
      argument "key" {
        type     = "string"
        required = true
      }
      cmd = "echo ${self.runtime.provision.seed-data.arguments.key} > ${self.vars.seed}"
    }
  }
}

Declared argument blocks become typed fields on the MCP tool, so the agent sees exactly what to pass; see the reference for the full rules. Any provision can be invoked over MCP, latent or not; latent ones are the natural fit for "run like a script".

2. Start alpha¶

Provisions run inside the live alpha, so bring the stack up first:

zordon start

3. Point your MCP client at `zordon mcp`¶

Configure your client to launch the server as a subprocess from the project directory. For a client that reads a JSON server config:

{
  "mcpServers": {
    "zordon": {
      "command": "zordon",
      "args": ["mcp"],
      "cwd": "/path/to/your/project"
    }
  }
}

Set the same ZORDON_HOME the project uses if it is not the default, so the server resolves the same alpha.

4. Discover the provision tool¶

List the tools and find the one named provision__<toolchain>_<service>__<step>. For the service above that is provision__go_app__seed-data.

5. Invoke it¶

Call the tool, passing its declared arguments (and, if needed, undeclared overrides via env):

{"name": "provision__go_app__seed-data", "arguments": {"key": "abc"}}

The tool result contains the provision's shell output. If it fails, the result is marked as an error — but alpha keeps running (see the invariant).

6. Verify¶

The provision ran inside alpha, so its side effects are real: the file written above now contains abc. Calling status (the command tool, or zordon status on the CLI) confirms the stack is still up.