Function useConnection

packages/plugins/mcp/src/sdk/invoke.ts:358–432

(
  connection: McpConnection,
  toolName: string,
  args: Record<string, unknown>,
  elicit: Elicit,
  onToolListChanged: (() => void) | undefined,
)

// ---------------------------------------------------------------------------

const useConnection = (
  connection: McpConnection,
  toolName: string,
  args: Record<string, unknown>,
  elicit: Elicit,
  onToolListChanged: (() => void) | undefined,
): Effect.Effect<unknown, McpInvocationError | McpOAuthReauthorizationRequired> =>
  Effect.gen(function* () {
    const deadline = yield* Effect.acquireRelease(
      Effect.sync(() => makeActiveWorkDeadline()),
      (activeWork) => Effect.sync(activeWork.dispose),
    );
    installElicitationHandler(connection.client, elicit, deadline);
    installToolListChangedHandler(connection.client, onToolListChanged);
    return yield* Effect.tryPromise({
      try: () =>
        connection.client.callTool(
          { name: toolName, arguments: args },
          { signal: deadline.signal, timeout: MCP_SDK_TIMEOUT_BACKSTOP_MS },
        ),
      catch: (cause) => {
        if (Predicate.isTagged(cause, "McpOAuthReauthorizationRequired")) {
          return new McpOAuthReauthorizationRequired({
            message: "MCP OAuth re-authorization required",
          });
        }
        // Raised by the fetch adapter when the 403 carried an RFC 6750
        // insufficient_scope challenge (the authProvider path, where the SDK
        // would otherwise consume the challenge before we could see it).
        if (Predicate.isTagged(cause, "McpInsufficientScopeError")) {
          return new McpInvocationError({
            toolName,
            message: `MCP tool call failed for ${toolName}`,
            status: 403,
            insufficientScope: true,
            transportFailure: true,
          });
        }
        const status = httpStatusFromCause(cause);
        const protocolError = asProtocolError(cause);
        const sdkFailure = summarizeSdkFailure(cause);
        return new McpInvocationError({
          toolName,
          // The class and code ride in the message because the dispatch
          // defect log renders only `Error#toString()`: without them the
          // trace says which tool failed and nothing about how.
          message: `MCP tool call failed for ${toolName} (${[
            sdkFailure.name,
            ...(sdkFailure.code === undefined ? [] : [String(sdkFailure.code)]),
            ...(status === undefined ? [] : [`HTTP ${status}`]),
          ].join(" ")})`,
          sdkFailure,
          ...(status === undefined ? {} : { status }),
          ...(protocolError === undefined
            ? { transportFailure: true }
            : {
                // A JSON-RPC error is the server's answer to this call, written
                // for the caller (the same trust level as an `isError` result