Implementation:Microsoft Playwright APIRequestContext Post

Knowledge Sources	Playwright Playwright API Testing Playwright APIRequestContext.post
Domains	API_Testing, HTTP, Test_Setup
Last Updated	2026-02-11 00:00 GMT

Overview

Concrete tool for creating test fixtures and preconditions by making POST API calls to set up required server-side state before tests run, provided by the Playwright library.

Description

Playwright's test.beforeAll() hook combined with request.post() enables API-driven test setup. The beforeAll hook runs once before all tests in a file or describe block, receiving the request fixture (an APIRequestContext) as an argument. The post() method sends HTTP POST requests to create resources on the server.

The post() method supports multiple body formats:

• JSON data: Pass a JavaScript object via the data option; Playwright automatically serializes it to JSON and sets the Content-Type: application/json header.
• Form data: Pass an object via the form option; Playwright URL-encodes it and sets Content-Type: application/x-www-form-urlencoded.
• Multipart data: Pass an object via the multipart option for file uploads; Playwright constructs the multipart/form-data body.

The response is returned as an APIResponse object that can be inspected for status codes and parsed for JSON body content, allowing the setup hook to extract created resource IDs for use in subsequent tests.

Usage

Use test.beforeAll() with request.post() when you need to create server-side resources (users, articles, orders, etc.) that multiple tests in the suite will operate on. Use test.beforeEach() when each test needs its own isolated setup.

Code Reference

Source Location

• Repository: playwright
• beforeAll hook: packages/playwright/types/test.d.ts:L6026-6067
• post() method: packages/playwright-core/src/client/fetch.ts:L152-157

Signature

// Test setup hook
test.beforeAll(
  inner: (args: { request: APIRequestContext }, testInfo: TestInfo) => Promise<any>
): void;

// POST request
request.post(url: string, options?: {
  data?: string | Buffer | Serializable;
  form?: { [key: string]: string | number | boolean };
  multipart?: {
    [key: string]: string | number | boolean | ReadStream | {
      name: string;
      mimeType: string;
      buffer: Buffer;
    };
  };
  headers?: { [key: string]: string };
  params?: { [key: string]: string | number | boolean };
  timeout?: number;
  failOnStatusCode?: boolean;
  ignoreHTTPSErrors?: boolean;
  maxRedirects?: number;
  maxRetries?: number;
}): Promise<APIResponse>;

Import

import { test, expect } from '@playwright/test';

I/O Contract

Inputs

Name	Type	Required	Description
url	string	Yes	The endpoint URL. If relative, it is combined with the context's baseURL. For example, /api/users with baseURL https://api.example.com becomes https://api.example.com/api/users.
options.data	Buffer | Serializable	No	Request body. Objects are auto-serialized to JSON with Content-Type: application/json header set automatically.
options.form	number | boolean }	No	Form data for URL-encoded submission. Sets Content-Type: application/x-www-form-urlencoded.
options.multipart	number | boolean | ReadStream | FilePayload }	No	Multipart form data for file uploads. Sets Content-Type: multipart/form-data.
options.headers	{ [key: string]: string }	No	Additional headers merged with context-level headers. Per-request headers override context headers for the same key.
options.params	number | boolean }	No	Query parameters appended to the URL.
options.timeout	number	No	Request timeout in milliseconds. Defaults to 30000 (30 seconds).
options.failOnStatusCode	boolean	No	Whether to throw an error if the response status code is not 2xx or 3xx. Defaults to false.
options.maxRedirects	number	No	Maximum number of redirects to follow. Defaults to 20. Set to 0 to disable redirect following.
options.maxRetries	number	No	Maximum number of retries for transient failures. Defaults to 0.

Outputs

Name	Type	Description
response	Promise<APIResponse>	The API response object containing status code, headers, and body. Use response.ok() to check for 2xx status, response.json() to parse the JSON body, response.status() for the numeric status code.

Usage Examples

Basic Example

import { test, expect } from '@playwright/test';

test.use({
  baseURL: 'https://api.example.com',
  extraHTTPHeaders: {
    'Authorization': 'Bearer my-token',
  },
});

let articleId: number;

test.beforeAll(async ({ request }) => {
  // Create a test article via POST
  const response = await request.post('/api/articles', {
    data: {
      title: 'Test Article',
      body: 'This article was created for testing.',
      status: 'published',
    },
  });
  expect(response.ok()).toBeTruthy();

  const body = await response.json();
  articleId = body.id;
});

test('can retrieve the created article', async ({ request }) => {
  const response = await request.get(`/api/articles/${articleId}`);
  expect(response.ok()).toBeTruthy();

  const article = await response.json();
  expect(article.title).toBe('Test Article');
});

test('can update the created article', async ({ request }) => {
  const response = await request.patch(`/api/articles/${articleId}`, {
    data: { title: 'Updated Title' },
  });
  expect(response.ok()).toBeTruthy();
});

Example: Form-Encoded Login Setup

import { test, expect } from '@playwright/test';

test.use({
  baseURL: 'https://app.example.com',
});

test.beforeAll(async ({ request }) => {
  // Create a test user via API
  await request.post('/api/admin/users', {
    data: {
      username: 'testuser',
      password: 'Test1234!',
      role: 'editor',
    },
  });

  // Verify login works with form-encoded POST
  const loginResponse = await request.post('/api/login', {
    form: {
      username: 'testuser',
      password: 'Test1234!',
    },
  });
  expect(loginResponse.ok()).toBeTruthy();
});

Example: Multipart File Upload Setup

import { test, expect } from '@playwright/test';
import fs from 'fs';
import path from 'path';

test.beforeAll(async ({ request }) => {
  const filePath = path.resolve(__dirname, 'fixtures/test-image.png');
  const fileBuffer = fs.readFileSync(filePath);

  const response = await request.post('/api/uploads', {
    multipart: {
      description: 'Test image for API tests',
      file: {
        name: 'test-image.png',
        mimeType: 'image/png',
        buffer: fileBuffer,
      },
    },
  });
  expect(response.ok()).toBeTruthy();
});

Related Pages

Implements Principle

• Principle:Microsoft_Playwright_Set_Up_Test_Resources