Unleash MCP (Feature Toggle)

Instructions

Implementation Reference

• src/tools/validate-feature-name.ts:18-62 (handler)

  The main handler function for the validateFeatureName tool, which calls the validation logic and formats the MCP response.

  export async function handleValidateFeatureName({ featureName }: { featureName: string }) {
    try {
      // Validate the feature name
      const result = await validateFeatureName(featureName);
      
      if (!result.isValid) {
        return {
          content: [{ 
            type: "text", 
            text: JSON.stringify({ 
              success: false,
              featureName,
              valid: false,
              error: result.error
            }, null, 2)
          }],
          isError: false // This is not a tool error, just a validation result
        };
      }
      
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            success: true,
            featureName,
            valid: true,
            message: `Feature name '${featureName}' is valid and available for use`
          }, null, 2)
        }]
      };
    } catch (error: any) {
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify({ 
            success: false,
            featureName,
            error: error.message || 'An unknown error occurred'
          }, null, 2)
        }],
        isError: true
      };
    }
  }

• src/tools/validate-feature-name.ts:11-13 (schema)

  Zod schema defining the input parameters for the validateFeatureName tool.

  export const ValidateFeatureNameParamsSchema = {
    featureName: z.string().describe('Name of the feature flag to validate')
  };

• src/server.ts:164-169 (registration)

  Registers the validateFeatureName tool with the MCP server.

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

• src/unleash/validate-feature-name.ts:17-44 (helper)

  Core validation logic that interacts with the Unleash API to check feature name validity, used by the tool handler.

  export async function validateFeatureName(featureName: string): Promise<FeatureNameValidationResult> {
    try {
      await client.post('/api/admin/features/validate', { name: featureName });
      logger.info(`Feature name '${featureName}' is valid`);
      return { isValid: true };
    } catch (error: any) {
      logger.error(`Error validating feature name '${featureName}':`, error);
      
      let errorMessage = 'An unknown error occurred during validation';
      
      if (error.response) {
        const { status } = error.response;
        
        if (status === 400) {
          errorMessage = 'Feature name is not URL friendly';
        } else if (status === 409) {
          errorMessage = 'Feature name already exists';
        } else if (status === 415) {
          errorMessage = 'Unsupported media type';
        }
      }
      
      return { 
        isValid: false, 
        error: errorMessage 
      };
    }
  } 

• src/tools/validate-feature-name.ts:67-72 (registration)

  Defines and exports the validateFeatureNameTool object for use in server registration.

  export const validateFeatureNameTool = {
    name: "validateFeatureName",
    description: "Validate if a feature flag name is valid and available for use",
    paramsSchema: ValidateFeatureNameParamsSchema,
    handler: handleValidateFeatureName
  };