Visa Design System MCP Server

Instructions

Implementation Reference

• src/mcp-server.ts:397-417 (handler)

  MCP server handler for get-design-token-details tool: validates input arguments and calls DesignTokenService.getToken
  private async handleGetDesignTokenDetails(args: Record<string, any>): Promise<CallToolResult> { const { name } = args; if (!name || typeof name !== 'string') { throw new McpError( ErrorCode.InvalidParams, 'Design token name is required and must be a string' ); } const token = await this.designTokenService.getToken(name); return { content: [ { type: 'text', text: JSON.stringify(token, null, 2) } ] }; }
• src/services/design-token-service.ts:54-81 (handler)

  Core implementation of design token retrieval: performs case-insensitive search in cached data and returns token details or throws detailed error
  * Get a specific design token by name */ async getToken(name: string): Promise<DesignToken> { if (!name || typeof name !== 'string') { throw this.createError('INVALID_NAME', 'Token name must be a non-empty string'); } const cachedData = this.dataManager.getCachedData(); if (!cachedData) { throw this.createError('NO_DATA', 'No design token data available'); } const token = cachedData.designTokens.find( token => token.name.toLowerCase() === name.toLowerCase() ); if (!token) { const availableTokens = cachedData.designTokens.map(token => token.name); throw this.createError('TOKEN_NOT_FOUND', `Design token "${name}" not found`, [ `Available tokens: ${availableTokens.slice(0, 10).join(', ')}${availableTokens.length > 10 ? '...' : ''}`, 'Check token name spelling', 'Use search-tokens to find similar tokens' ]); } return token; }
• src/mcp-server.ts:147-160 (schema)

  Input schema and tool metadata definition used for registration and validation
  { name: 'get-design-token-details', description: 'Get detailed information about a specific design token', inputSchema: { type: 'object', properties: { name: { type: 'string', description: 'Design token name' } }, required: ['name'] } },
• src/mcp-server.ts:97-102 (registration)

  MCP server request handler for listing tools, which includes get-design-token-details via getToolDefinitions()
  this.server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: this.getToolDefinitions() }; });
• src/mcp-server.ts:294-295 (handler)

  Switch case routing tool calls to specific handlers
  case 'get-design-token-details': return await this.handleGetDesignTokenDetails(args);