RSS3 MCP Server

Instructions

Implementation Reference

• index.js:150-223 (handler)

  Generic handler executing all dynamic API tools (including "API-getFederatedActivityById") by looking up the OpenAPI operation and calling the HttpClient.
  server.setRequestHandler(CallToolRequestSchema, async (request) => { // console.error("call tool", request.params); const { name, arguments: params } = request.params; console.error("name", name); if (name === "API-get-input-schema") { for (const mcpToolWithClient of mcpToolWithClients) { for (const [toolName, def] of Object.entries( mcpToolWithClient.mcpTools.tools, )) { for (const method of def.methods) { const toolNameWithMethod = `${toolName}-${method.name}`; const truncatedToolName = toolNameWithMethod.slice(0, 64); if (truncatedToolName === params.toolName) { return { content: [ { type: "text", text: JSON.stringify(method.inputSchema) }, ], }; } } } } throw new Error(`Method ${params.toolName} not found`); } // find operation const mcpToolWithClient = mcpToolWithClients.find( (t) => t.mcpTools.openApiLookup[name], ); if (!mcpToolWithClient) { throw new Error(`Method ${name} not found`); } const operation = mcpToolWithClient.mcpTools.openApiLookup[name]; // execute try { const response = await mcpToolWithClient.client.executeOperation( operation, params, ); return { content: [ { type: "text", // currently this is the only type that seems to be used by mcp server text: JSON.stringify(response.data), // TODO: pass through the http status code text? }, ], }; } catch (error) { console.error("Error in tool call", error); if (error instanceof HttpClientError) { console.error( "HttpClientError encountered, returning structured error", error, ); const data = error.data?.response?.data ?? error.data ?? {}; return { content: [ { type: "text", text: JSON.stringify({ status: "error", // TODO: get this from http status code? ...(typeof data === "object" ? data : { data: data }), }), }, ], }; } throw error; } });
• index.js:100-147 (registration)

  Dynamic tool registration: generates list of all API tools from OpenAPI specs using names like `${toolName}-${method.name}` (e.g., "API-getFederatedActivityById").
  server.setRequestHandler(ListToolsRequestSchema, async () => { console.error("list tools"); /** * @typedef {import("@modelcontextprotocol/sdk/types.js").Tool} Tool * @type {Tool[]} */ const tools = []; for (const mcpToolWithClient of mcpToolWithClients) { for (const [toolName, def] of Object.entries( mcpToolWithClient.mcpTools.tools, )) { for (const method of def.methods) { console.error("method", method); const toolNameWithMethod = `${toolName}-${method.name}`; const truncatedToolName = toolNameWithMethod.slice(0, 64); const trimmedDescription = method.description.split("Error")[0].trim(); tools.push({ name: truncatedToolName, description: trimmedDescription, inputSchema: { type: "object", properties: {}, }, }); } } } tools.unshift({ name: "API-get-input-schema", description: "Get the input schema for a given API. We should always use this tool to get the input schema for a given API before calling the API.", inputSchema: { type: "object", properties: { toolName: { type: "string", description: "The name of the tool to get the input schema for", }, }, }, }); console.error("tools", tools); return { tools }; });
• index.js:156-175 (schema)

  Dynamic schema retrieval for any API tool (including "API-getFederatedActivityById"), returns the input schema from the OpenAPI method.
  if (name === "API-get-input-schema") { for (const mcpToolWithClient of mcpToolWithClients) { for (const [toolName, def] of Object.entries( mcpToolWithClient.mcpTools.tools, )) { for (const method of def.methods) { const toolNameWithMethod = `${toolName}-${method.name}`; const truncatedToolName = toolNameWithMethod.slice(0, 64); if (truncatedToolName === params.toolName) { return { content: [ { type: "text", text: JSON.stringify(method.inputSchema) }, ], }; } } } } throw new Error(`Method ${params.toolName} not found`); }
• index.js:78-84 (helper)

  Converts OpenAPI specs to MCP tools structures used for lookup, execution, and listing (key for dynamic tools like "API-getFederatedActivityById").
  const mcpToolWithClients = converterWithClients.map((cwc) => { const mcpTools = cwc.converter.convertToMCPTools(); return { mcpTools, client: cwc.client, }; });
• index.js:40-70 (helper)

  Fetches OpenAPI specifications from RSS3 endpoints, which define the APIs (including getFederatedActivityById) proxied as MCP tools.
  const openApiSpecs = ( await Promise.allSettled([ fetch("https://gi.rss3.io/docs/openapi.json").then(async (res) => { if (!res.ok) throw new Error(`HTTP error! status: ${res.status}`); return res.json(); }), fetch("https://ai.rss3.io/openapi.json").then(async (res) => { if (!res.ok) throw new Error(`HTTP error! status: ${res.status}`); return res.json(); }), ]).then((results) => { return results.map((result) => { if (result.status === "fulfilled") { const client = new HttpClient( { baseUrl: result.value.servers[0].url, }, result.value, ); return { spec: result.value, client, }; } console.error("Failed to fetch openapi spec", result.reason); return null; }); }) ).filter(Boolean);