mcp-playwright

Instructions

Implementation Reference

• src/tools/api/requests.ts:78-112 (handler)

  The PutRequestTool.execute method implements the core logic for performing HTTP PUT requests using Playwright's APIRequestContext.put()

  export class PutRequestTool extends ApiToolBase {
    /**
     * Execute the PUT request tool
     */
    async execute(args: any, context: ToolContext): Promise<ToolResponse> {
      return this.safeExecute(context, async (apiContext) => {
        // Check if the value is valid JSON if it starts with { or [
        if (args.value && typeof args.value === 'string' && 
            (args.value.startsWith('{') || args.value.startsWith('['))) {
          try {
            JSON.parse(args.value);
          } catch (error) {
            return createErrorResponse(`Failed to parse request body: ${(error as Error).message}`);
          }
        }
        
        const response = await apiContext.put(args.url, {
          data: args.value
        });
        
        let responseText;
        try {
          responseText = await response.text();
        } catch (error) {
          responseText = "Unable to get response text";
        }
        
        return createSuccessResponse([
          `PUT request to ${args.url}`,
          `Status: ${response.status()} ${response.statusText()}`,
          `Response: ${responseText.substring(0, 1000)}${responseText.length > 1000 ? '...' : ''}`
        ]);
      });
    }
  }

• src/tools.ts:272-283 (schema)

  Tool definition including name, description, and input schema for 'playwright_put'.

  {
    name: "playwright_put",
    description: "Perform an HTTP PUT request",
    inputSchema: {
      type: "object",
      properties: {
        url: { type: "string", description: "URL to perform PUT operation" },
        value: { type: "string", description: "Data to PUT in the body" },
      },
      required: ["url", "value"],
    },
  },

• src/toolHandler.ts:530-531 (registration)

  Switch case dispatching 'playwright_put' tool calls to the PutRequestTool handler.

  case "playwright_put":
    return await putRequestTool.execute(args, context);

• src/tools.ts:476-482 (registration)

  'playwright_put' listed in API_TOOLS array, used to determine API context initialization.

  export const API_TOOLS = [
    "playwright_get",
    "playwright_post",
    "playwright_put",
    "playwright_delete",
    "playwright_patch"
  ];

• src/tools/api/base.ts:8-63 (helper)

  ApiToolBase abstract class providing safeExecute wrapper and API context validation used by PutRequestTool.

  export abstract class ApiToolBase implements ToolHandler {
    protected server: any;
  
    constructor(server: any) {
      this.server = server;
    }
  
    /**
     * Main execution method that all tools must implement
     */
    abstract execute(args: any, context: ToolContext): Promise<ToolResponse>;
  
    /**
     * Ensures an API context is available and returns it
     * @param context The tool context containing apiContext
     * @returns The apiContext or null if not available
     */
    protected ensureApiContext(context: ToolContext): APIRequestContext | null {
      if (!context.apiContext) {
        return null;
      }
      return context.apiContext;
    }
  
    /**
     * Validates that an API context is available and returns an error response if not
     * @param context The tool context
     * @returns Either null if apiContext is available, or an error response
     */
    protected validateApiContextAvailable(context: ToolContext): ToolResponse | null {
      if (!this.ensureApiContext(context)) {
        return createErrorResponse("API context not initialized");
      }
      return null;
    }
  
    /**
     * Safely executes an API operation with proper error handling
     * @param context The tool context
     * @param operation The async operation to perform
     * @returns The tool response
     */
    protected async safeExecute(
      context: ToolContext,
      operation: (apiContext: APIRequestContext) => Promise<ToolResponse>
    ): Promise<ToolResponse> {
      const apiError = this.validateApiContextAvailable(context);
      if (apiError) return apiError;
  
      try {
        return await operation(context.apiContext!);
      } catch (error) {
        return createErrorResponse(`API operation failed: ${(error as Error).message}`);
      }
    }
  }