Unleash MCP (Feature Toggle)

Instructions

Implementation Reference

• src/tools/get-flag.ts:18-61 (handler)

  The main handler function that implements the core logic of the 'getFlag' tool. It retrieves feature flag details using getFeatureFlag, handles errors, and returns a structured JSON response.

  export async function handleGetFlag({ flagName }: { flagName: string }) {
    try {
      // Get the feature flag
      const flag = await getFeatureFlag(flagName);
      
      if (!flag) {
        return {
          content: [{ 
            type: "text", 
            text: JSON.stringify({ 
              success: false,
              flagName,
              error: `Feature flag '${flagName}' not found` 
            }, null, 2)
          }],
          isError: true
        };
      }
      
      const summary = `The ${flagName} flag is currently ${flag.enabled ? 'enabled' : 'disabled'}.`;
      
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            flag,
            summary
          }, null, 2)
        }]
      };
    } catch (error: any) {
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            success: false,
            flagName,
            error: error.message 
          }, null, 2)
        }],
        isError: true
      };
    }
  }

• src/tools/get-flag.ts:11-13 (schema)

  Zod schema defining the input parameters for the getFlag tool, specifically the required 'flagName' string parameter.

  export const GetFlagParamsSchema = {
    flagName: z.string()
  };

• src/server.ts:87-92 (registration)

  The registration of the getFlag tool on the MCP server instance using server.tool(), referencing the tool's name, description, schema, and handler.

  server.tool(
    getFlagTool.name,
    getFlagTool.description,
    getFlagTool.paramsSchema as any,
    getFlagTool.handler as any
  );

• src/tools/get-flag.ts:66-71 (helper)

  The tool definition object that bundles the name, description, schema, and handler for easy import and registration.

  export const getFlagTool = {
    name: "getFlag",
    description: "Get detailed information about a feature flag",
    paramsSchema: GetFlagParamsSchema,
    handler: handleGetFlag
  };