mcp serve

The invocation topaz mcp serve main.tpz --language-version 5.21 is expected to exit with 1.

Arguments and rejection

The complete startup form is topaz mcp serve. It accepts no positional operand and no options. Reject every additional argument before executable discovery or worker startup.

The service uses the installed Topaz executable and its admitted default compiler. Source text and supported profile choices are request fields rather than CLI paths or environment based compiler substitutions.

Validate request methods and each advertised tool schema before starting work. Reject unknown tool names, unlisted argument fields, wrong JSON types and request values beyond the advertised size limits.

Output

Standard input and standard output carry newline delimited MCP JSON-RPC messages. Standard output contains only protocol messages and no usage text, progress banner or worker output outside a tool response.

The initialization response advertises the supported protocol version and tool capabilities. Tool calls return MCP content and structured content according to the advertised result schema. Checker diagnostics and evaluator outcomes are tool results rather than CLI report text.

Human startup and fatal transport errors use standard error. The command has no human report mode and rejects --format human, --format json and --json. Protocol JSON is the transport format and does not need a report selector.

Exit status

Exit 0 when the stdio service closes normally after its input channel ends and outstanding work is cancelled or completed.

Exit 1 for invalid startup arguments, unavailable installed executable, failed service initialization or fatal transport or service failure. A rejected tool request or a program diagnostic does not alone change the server exit status.

Filesystem effects

Read reference assets from the installed product. Keep submitted source and intermediate worker state private to the request and remove temporary worker files at completion or cancellation.

Do not save submitted source, append source to a log, retain state between tool calls, write a caller workspace or load a user supplied component.

Tool execution uses the built in evaluator without filesystem capabilities. A request cannot grant itself filesystem authority by containing a path.

Network access

The server has only stdio transport. It opens no HTTP endpoint and performs no registry access, component download or outbound request. The built in evaluator has no network capability.

Reproducibility

Identical admitted tool requests under the same installed assets, compiler and resource profile produce the same semantic results. Response identifiers follow their requests.

Concurrent response arrival and wall clock timeout outcomes are not byte stable. Cancellation does not create a retained result or state for the next request.

Packages and locks

The stdio service does not discover a package from the current directory. Source checking is a stateless request and does not load caller package manifests, rewrite locks or materialize dependencies.

Reference and evaluator identities come from the installed product. No package or component fallback is selected after a request fails.