Unleash MCP (Feature Toggle)

Instructions

Implementation Reference

• src/tools/get-project-feature.ts:19-67 (handler)

  Handler function that executes the getProjectFeature tool logic: calls the Unleash helper, handles errors, and formats the response as MCP content.

  export async function handleGetProjectFeature({ projectId, featureName }: { projectId: string, featureName: string }) {
    try {
      // Get the feature flag from the project
      const feature = await getProjectFeature(projectId, featureName);
      
      if (!feature) {
        return {
          content: [{ 
            type: "text", 
            text: JSON.stringify({ 
              success: false,
              projectId,
              featureName,
              error: `Feature '${featureName}' not found in project '${projectId}'` 
            }, null, 2)
          }],
          isError: true
        };
      }
      
      const statusInfo = feature.enabled !== undefined 
        ? `The ${featureName} flag is currently ${feature.enabled ? 'enabled' : 'disabled'}.` 
        : '';
      
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            success: true,
            feature,
            summary: `Feature '${featureName}' in project '${projectId}' retrieved successfully. ${statusInfo}`
          }, null, 2)
        }]
      };
    } catch (error: any) {
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            success: false,
            projectId,
            featureName,
            error: error.message || 'An unknown error occurred'
          }, null, 2)
        }],
        isError: true
      };
    }
  }

• src/tools/get-project-feature.ts:11-14 (schema)

  Zod schema defining the input parameters for the getProjectFeature tool: projectId and featureName.

  export const GetProjectFeatureParamsSchema = {
    projectId: z.string().describe('ID of the project'),
    featureName: z.string().describe('Name of the feature flag')
  };

• src/server.ts:151-155 (registration)

  Registration of the getProjectFeature tool on the MCP server using server.tool().

    getProjectFeatureTool.name,
    getProjectFeatureTool.description,
    getProjectFeatureTool.paramsSchema as any,
    getProjectFeatureTool.handler as any
  );

• src/unleash/get-project-feature.ts:10-23 (helper)

  Supporting function that performs the actual API request to retrieve a specific feature flag from Unleash.

  export async function getProjectFeature(projectId: string, featureName: string): Promise<any | null> {
    try {
      const response = await client.get(`/api/admin/projects/${projectId}/features/${featureName}`);
      logger.info(`Successfully fetched feature ${featureName} from project ${projectId}`);
      return response.data;
    } catch (error: any) {
      logger.error(`Error fetching feature ${featureName} from project ${projectId}:`, error);
      if (error.response && error.response.status === 404) {
        logger.info(`Feature ${featureName} not found in project ${projectId}`);
        return null;
      }
      throw error;
    }
  }