playwright_expect_response

Initiate waiting for HTTP responses in browser automation tests by specifying URL patterns and unique identifiers for later validation.

Instructions

Ask Playwright to start waiting for a HTTP response. This tool initiates the wait operation but does not wait for its completion.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`id`	Yes	Unique & arbitrary identifier to be used for retrieving this response later with `Playwright_assert_response`.
`url`	Yes	URL pattern to match in the response.

Implementation Reference

src/tools/browser/response.ts:21-37 (handler)

Implements the core execution logic for the 'playwright_expect_response' tool using Playwright's page.waitForResponse to start waiting for a HTTP response matching the URL pattern, storing the promise for later assertion.

export class ExpectResponseTool extends BrowserToolBase {
  /**
   * Execute the expect response tool
   */
  async execute(args: ExpectResponseArgs, context: ToolContext): Promise<ToolResponse> {
    return this.safeExecute(context, async (page) => {
      if (!args.id || !args.url) {
        return createErrorResponse("Missing required parameters: id and url must be provided");
      }

      const responsePromise = page.waitForResponse(args.url);
      responsePromises.set(args.id, responsePromise);

      return createSuccessResponse(`Started waiting for response with ID ${args.id}`);
    });
  }
}

src/tools.ts:307-318 (schema)

Defines the tool schema including name, description, input parameters (id and url), and validation requirements.

{
  name: "playwright_expect_response",
  description: "Ask Playwright to start waiting for a HTTP response. This tool initiates the wait operation but does not wait for its completion.",
  inputSchema: {
    type: "object",
    properties: {
      id: { type: "string", description: "Unique & arbitrary identifier to be used for retrieving this response later with `Playwright_assert_response`." },
      url: { type: "string", description: "URL pattern to match in the response." }
    },
    required: ["id", "url"],
  },
},

src/toolHandler.ts:508-509 (registration)
Registers the tool handler in the main tool dispatching switch statement, delegating execution to the ExpectResponseTool instance.
```
case "playwright_expect_response":
  return await expectResponseTool.execute(args, context);
```
src/toolHandler.ts:329-329 (registration)
Instantiates the ExpectResponseTool class instance used for handling tool calls.
```
if (!expectResponseTool) expectResponseTool = new ExpectResponseTool(server);
```

src/tools/codegen/generator.ts:125-130 (helper)

Generates equivalent Playwright test code for the tool action during codegen session recording.

private generateExpectResponseStep(parameters: Record<string, unknown>): string {
  const { url, id } = parameters;
  return `
  // Wait for response
  const ${id}Response = page.waitForResponse('${url}');`;
}

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