Flipt MCP Server

Implementation Reference

• src/index.ts:729-753 (handler)

  MCP tool handler function that calls FliptClient.evaluateBatch with the input requests, formats the JSON response, and handles errors.

  async args => {
    try {
      const response = await fliptClient.evaluateBatch(args.requests);
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify(response, null, 2),
          },
        ],
      };
    } catch (error: any) {
      console.error('Error evaluating batch:', error);
      return {
        content: [
          {
            type: 'text',
            text: `Failed to evaluate batch: ${error.message}`,
          },
        ],
        isError: true,
      };
    }
  }

• src/index.ts:719-728 (schema)

  Zod schema defining the input for the evaluate_batch tool: an array of requests each with namespaceKey, flagKey, entityId, and optional context.

  {
    requests: z.array(
      z.object({
        namespaceKey: z.string().min(1),
        flagKey: z.string().min(1),
        entityId: z.string().min(1),
        context: z.record(z.string()).optional(),
      })
    ),
  },

• src/index.ts:718-754 (registration)

  Registration of the 'evaluate_batch' MCP tool on the server using server.tool(name, schema, handler).

    'evaluate_batch',
    {
      requests: z.array(
        z.object({
          namespaceKey: z.string().min(1),
          flagKey: z.string().min(1),
          entityId: z.string().min(1),
          context: z.record(z.string()).optional(),
        })
      ),
    },
    async args => {
      try {
        const response = await fliptClient.evaluateBatch(args.requests);
  
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(response, null, 2),
            },
          ],
        };
      } catch (error: any) {
        console.error('Error evaluating batch:', error);
        return {
          content: [
            {
              type: 'text',
              text: `Failed to evaluate batch: ${error.message}`,
            },
          ],
          isError: true,
        };
      }
    }
  );

• src/services/fliptClient.ts:689-711 (helper)

  FliptClient helper method that maps the requests to API format and calls the generated evaluationApi.evaluateBatch.

  async evaluateBatch(
    requests: Array<{
      namespaceKey: string;
      flagKey: string;
      entityId: string;
      context?: Record<string, string>;
    }>
  ) {
    try {
      const response = await this.evaluationApi.evaluateBatch({
        requests: requests.map(req => ({
          namespaceKey: req.namespaceKey,
          flagKey: req.flagKey,
          entityId: req.entityId,
          context: req.context || {},
        })),
      });
      return response;
    } catch (error) {
      console.error('Error evaluating batch:', error);
      throw error;
    }
  }