Unleash Feature Flag MCP Server

Instructions

Implementation Reference

• src/tools/index.ts:38-53 (handler)

  Core handler function that fetches and returns the list of features for the specified projectId from the Unleash API.

  async function getFeatures(params: z.infer<typeof GetFeaturesSchema>) {
    const { projectId } = GetFeaturesSchema.parse(params);
    try {
      const response = await axios.get(
        `${UNLEASH_API_URL}/api/admin/projects/${projectId}/features`,
        {
          headers: {
            Authorization: `Bearer ${UNLEASH_AUTH_TOKEN}`,
          },
        }
      );
      return response.data;
    } catch (error) {
      console.error('Error fetching features:', error);
      throw error;
    }

• src/index.ts:31-39 (registration)

  Registers the MCP tool named 'getFeatures' with its description, input schema (RawGetFeaturesShape), and a thin wrapper handler that invokes the core getFeatures function and formats the response as MCP content.

  server.tool(
    'getFeatures',
    'Retrieve features for a specific project',
    RawGetFeaturesShape,
    async (args) => {
      const data = await getFeatures(args);
      return { content: [{ type: 'text', text: JSON.stringify(data) }] };
    }
  );

• src/tools/schema.ts:4-6 (schema)

  Zod input schema definition for the getFeatures tool, specifying the required 'projectId' parameter. This raw shape is used directly in the MCP tool registration.

  const RawGetFeaturesShape = {
    projectId: z.string(),
  };

• src/tools/schema.ts:48-48 (schema)

  Full Zod schema for getFeatures input validation, wrapping the raw shape and used within the handler for parsing params.

  const GetFeaturesSchema = z.object(RawGetFeaturesShape);