Postman

Collections and Requests

• Collection — a saved group of requests, organized in folders, shareable and exportable as JSON.
• Request — method + URL + headers/body, saved inside a collection for reuse.
• Cmd+S / Ctrl+S — save the current request.
• Cmd+Enter / Ctrl+Enter — send the current request.
• Runner — runs every request in a collection in sequence, useful for smoke-testing an API end to end.
• Right-click a request → “Generate Code” — export a request as a curl command or a snippet in another language.

Environments and Variables

• Environment — a named set of key/value variables (e.g. baseUrl, token) swappable via the environment dropdown, top-right.
• {{variableName}} — reference a variable inside a URL, header, or body.
• Variable scopes (narrowest wins): local → data → environment → collection → global.
• pm.environment.set('token', value) — set an environment variable from a script.
• pm.environment.get('token') — read an environment variable from a script.

Common Features

• Pre-request Script tab — runs before the request is sent (e.g. to compute a signature or refresh a token).
• Tests tab — runs after the response arrives, for assertions.
• Mock Servers — simulate an API’s responses before the real backend exists, from a collection’s example responses.
• Postman Console (bottom-left icon) — inspect the raw request/ response, including redirects and headers.

Testing Scripts Basics

// In a request's "Tests" tab:
pm.test('Status code is 200', () => {
  pm.response.to.have.status(200);
});

pm.test('Response has an id', () => {
  const body = pm.response.json();
  pm.expect(body.id).to.exist;
});

// Chain requests by passing data forward:
pm.environment.set('userId', pm.response.json().id);

• pm.response.json() — parse the response body as JSON.
• pm.response.to.have.status(code) — assert the status code.
• pm.expect(value).to.equal(expected) — Chai-style assertions.
• Tests in a collection run automatically in the Runner, making a collection double as an API test suite.

References

• Postman Learning Center
• Writing Scripts
• Postman Sandbox API Reference