Flipt MCP Server

Implementation Reference

• src/index.ts:199-232 (handler)

  Primary handler, schema, and registration for the MCP 'get_flag' tool. Calls FliptClient.getFlag and returns formatted response.

  server.tool(
    'get_flag',
    {
      namespaceKey: z.string().min(1),
      flagKey: z.string().min(1),
    },
    async args => {
      try {
        const flag = await fliptClient.getFlag(args.namespaceKey, args.flagKey);
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(flag, null, 2),
            },
          ],
          _meta: {
            uri: `flipt://namespaces/${args.namespaceKey}/flags/${args.flagKey}`,
          },
        };
      } catch (error: any) {
        console.error(`Error getting flag ${args.flagKey} in namespace ${args.namespaceKey}:`, error);
        return {
          content: [
            {
              type: 'text',
              text: `Failed to get flag: ${error.message}`,
            },
          ],
          isError: true,
        };
      }
    }
  );

• src/services/fliptClient.ts:207-215 (helper)

  FliptClient helper method that wraps the generated FlagsServiceApi.getFlag to retrieve a specific flag.

  async getFlag(namespaceKey: string, key: string) {
    try {
      const response = await this.flagsApi.getFlag(namespaceKey, key);
      return response;
    } catch (error) {
      console.error(`Error getting flag ${key} in namespace ${namespaceKey}:`, error);
      throw error;
    }
  }

• src/handlers/resourceHandlers.ts:81-99 (helper)

  Resource handler for flags that uses FliptClient.getFlag, potentially related to tool responses.

  async handleFlag(uri: URL, { namespaceKey, flagKey }: { namespaceKey: string; flagKey: string }) {
    console.log('Handling flag resource:', uri.toString());
  
    try {
      const flag = await this.fliptClient.getFlag(namespaceKey, flagKey);
  
      return {
        contents: [
          {
            uri: `flipt://namespaces/${namespaceKey}/flags/${flag.key}`,
            text: flag.name,
          },
        ],
      };
    } catch (error) {
      console.error('Error handling flag resource:', error);
      throw error;
    }
  }