Go Playground MCP Server

Instructions

Implementation Reference

• src/go-playground-client.ts:161-199 (handler)

  Core handler function that validates the Go code, sends a POST request to the Go Playground '/share' endpoint with the code, extracts the share ID from the response, and constructs the shareable frontend URL (https://go.dev/play/p/{shareId}). Returns the URL or null on failure.

  export const shareGoCode =
    (config: Partial<GoPlaygroundConfig> = {}) =>
    async (code: string): Promise<ShareUrl | null> => {
      // Validate input
      const validationResult = validateGoCode(code);
      if (!validationResult.success) {
        console.error(
          'Invalid Go code for sharing:',
          validationResult.error.message
        );
        return null;
      }
  
      const finalConfig = { ...createDefaultConfig(), ...config };
      const client = createHttpClient(finalConfig);
  
      try {
        const request: GoPlaygroundShareRequest = {
          body: validationResult.data,
        };
  
        const response = await client.post<GoPlaygroundShareResponse>(
          '/share',
          request.body,
          {
            headers: {
              'Content-Type': 'application/x-www-form-urlencoded',
            },
          }
        );
  
        const shareId = response.data;
        // Use the frontend URL for sharing, not the API URL
        return createShareUrl(`${finalConfig.frontendUrl}/p/${shareId}`);
      } catch (error) {
        console.error('Failed to share code:', error);
        return null;
      }
    };

• src/mcp-server.ts:69-82 (registration)

  Registers the 'share_go_code' tool in the MCP server with its name, description, and input schema (object with required 'code' string). This is returned by listTools.

  {
    name: TOOL_NAMES.SHARE_GO_CODE,
    description: 'Share Go code and get a shareable URL',
    inputSchema: {
      type: 'object',
      properties: {
        code: {
          type: 'string',
          description: 'The Go code to share',
        },
      },
      required: ['code'],
    },
  },

• src/mcp-server.ts:230-246 (handler)

  MCP-specific tool handler that extracts 'code' from args, calls the client's shareCode method, formats a success/error response with the share URL, and returns it as MCPToolResponse.

  const createShareGoCodeHandler =
    (client: ReturnType<typeof createGoPlaygroundClient>) =>
    async (args: ShareGoCodeArgs): Promise<MCPToolResponse> => {
      try {
        const { code } = args;
        const shareUrl = await client.shareCode(code);
  
        const responseText = shareUrl
          ? `✅ Code shared successfully!\n\n**Share URL:** ${shareUrl}`
          : '❌ Failed to share code. Please try again.';
  
        return createSuccessResponse(responseText);
      } catch (error) {
        console.error('Error in handleShareGoCode:', error);
        return createErrorResponse(error);
      }
    };

• src/types.ts:75-77 (schema)

  TypeScript type definition for the tool's input arguments: an object with a required 'code' field of type GoCode (branded string).

  export type ShareGoCodeArgs = {
    readonly code: GoCode;
  };

• src/types.ts:171-178 (schema)

  Runtime type guard/validator for ShareGoCodeArgs, checks if args is an object with non-null 'code' that is a valid GoCode (non-empty string). Used in the tool router for input validation.

  export const isShareGoCodeArgs = (args: unknown): args is ShareGoCodeArgs => {
    return (
      typeof args === 'object' &&
      args !== null &&
      'code' in args &&
      isGoCode((args as Record<string, unknown>).code)
    );
  };