Playwright API testing: a practical guide with TypeScript examples
Playwright API testing in practice: when API tests beat UI tests, the request fixture, a create to delete example with cleanup, faster UI setup and token auth.
API testing
API testing, done for you
Tests for single endpoints and multistep journeys, written in TypeScript with Playwright and run in the same pipeline as your web tests. Claude agents write and maintain them, and a QA engineer reviews every change.
What we test in your API
- Status codes and response bodies for the endpoints your product depends on.
- Authentication and permissions: what each role and token can and cannot reach.
- Validation and error handling for missing, invalid and duplicate input.
- Multistep journeys, such as create, read, update and delete, with clean test data.
- Changes that would break a client: renamed fields, removed values, new required input.
Leaner web tests too. API calls set up the state a web test needs (an account, an order, a team) directly, so web tests skip the setup screens and stay focused on the flow they test.
Plain TypeScript, in your repository
Tests for single endpoints and multistep journeys, written in TypeScript and run in the same pipeline as the web tests.
The tests are plain code your developers can read and keep, and they run on every pull request with no fees per run. A person looks at every failure before it becomes a bug report or a test fix. The guide to API testing with Playwright shows the approach with examples.
Who does what
The agents write and run, a person reviews and decides
Claude agents
- Draft test plans from your specs, tickets and code
- Write new tests and update tests the product has outgrown
- Run the suites and collect evidence for each failure
- Propose fixes for broken tests
The QA engineer
- Sets the strategy and the priorities with you
- Reviews every change before it is merged
- Confirms each bug and its severity
- Signs the Go or No-Go call before each release
What it costs
US$2,000 a month for up to 500 user flows, across web, API and mobile. Each platform counts on its own, so checkout on web and on iOS is two flows. An API journey counts as one flow. Test runs, AI credits and hours are never billed. New clients start with a 60-day pilot at half price. The pricing page has the calculator and every term.
What kinds of API do you test?
APIs your product exposes over HTTP, such as REST and GraphQL endpoints, including the ones only your own web and mobile apps call. Tests are written in TypeScript with Playwright and run in the same pipeline as the web tests.
How is an API journey counted?
Each platform counts on its own, so checkout on web and on iOS is two flows. An API journey counts as one flow. We list your flows together when we write the test plan, and the number goes into the written agreement.
Do you do load or performance testing?
Not as part of the standard service. Load testing, security penetration testing and formal accessibility audits are separate specialist work. Ask, and you will get a straight answer on whether we can help.
Do you need production credentials?
No. API tests run against a staging or preview environment with test accounts and tokens kept in your CI secrets. See security and data handling.
Guides
Guides for API and web testing
Playwright GitHub Actions setup: a fast CI pipeline you can trust
A complete Playwright GitHub Actions workflow to copy: sharding, merged HTML reports, retries with traces, secrets for test accounts and what not to cache.
Regression testing checklist: what to retest before every release
A regression testing checklist for small teams: what to retest before each release, layer by layer, how to keep the suite small and trusted, and a template to copy.
Get your API tested on every pull request
One email is enough to start: your product, your platforms and how often you release. You get a plain answer on fit and, if it fits, a written proposal for the 60-day pilot with a short video of how we would test your product.
Or write to qa@releaseworthy.app. Still deciding after the proposal? We book a Google Meet call for your questions.