The domain_tools.py module#

Summary#

DomainToolSpec

Metadata describing a domain tool to a MCP leaf.

DomainTool

A registered domain tool — spec plus typed async handler.

schema_from_signature

Derive a minimal JSON schema from a typed handler signature.

DomainToolHandler

Description#

Domain-tool registration framework.

A domain tool is one that does pure backend / catalog / product introspection work with no dependency on a plan builder, journal, learned constraints, or recipe registry. Every domain tool lives on an MCP leaf. When an optional higher-level agent layer is installed it reaches these tools over the MCP wire (an MCP client pool), not by direct Python import. This package never imports that agent layer — the dependency direction is strictly one-way (agent → this package).

The contract is intentionally small so that migrating a handler from the agent layer is a mechanical rewrite. A domain tool is a typed async function with the signature:

async def my_tool_impl(
    backend: Backend,
    *,
    arg1: int,
    arg2: str | None = None,
) -> dict[str, Any]: ...

paired with a name, description, and (optional) live-session flag:

DomainTool(
    spec=DomainToolSpec(name="my_tool", description="..."),
    handler=my_tool_impl,
)

The leaf calls FluidsLeafMCP._register_domain_tools() with a list of these. The helper synthesises a wrapper whose inspect.Signature mirrors the handler minus the backend parameter so FastMCP can extract the JSON input schema from the wrapper. There is no parallel JSON-schema-on-the-spec to keep in sync with the handler signature.

The handler receives the leaf’s active ansys.cfx.mcp.common.backend.Backend plus the validated keyword arguments; there is no loop state, no journal, no plan builder. A tool that needs the plan builder, journal, or recipe registry is agent-only by definition and lives in the optional agent layer instead — not in this package.

Module detail#

domain_tools.schema_from_signature(handler: DomainToolHandler) → dict[str, Any]#

Derive a minimal JSON schema from a typed handler signature.

Drops the leading backend parameter and emits one properties entry per keyword-only argument. The mapping is intentionally small: str -> "string", int -> "integer", float -> "number", bool -> "boolean", dict -> "object", list -> "array" plus None for Optional[...] arms. Anything else falls back to a parameter without a type constraint — the handler is still callable, the schema just documents fewer expectations.

Parameters:
handlerDomainToolHandler

Callable inspected or registered by the helper.

Returns:
dict[str, Any]

Mapping containing the operation result.

domain_tools.DomainToolHandler#