What is API automation testing?

API automation testing sends real requests to your endpoints from code or collections and checks the status, payload, schema and side effects of each one, without a browser or device. Because it skips the user interface, it runs in seconds and points straight at the service that broke.

How is this different from your API testing service?

This page is about building and running automated API suites that live in your pipeline. Our API testing service is broader, covering exploratory API testing, integration reviews, security and performance. Many clients use both.

What should we automate first?

Health checks for each service, then the calls behind your most valuable journeys, such as sign-in, orders and payments, then roles and error handling. The strategy and feasibility report ranks your endpoints and flags what should stay manual.

Code or Postman collections: which should we use?

Collections are quick to start and easy for the whole team to read. Code-based suites, with REST Assured, Supertest, Playwright or pytest, scale better for large, data-heavy suites. We often start with collections run by Newman and move high-value tests into code as the suite grows.

Can you automate GraphQL, SOAP, gRPC and event-driven APIs?

Yes. We automate REST, GraphQL, SOAP, gRPC and WebSocket APIs, webhooks, and messages flowing through Kafka and other queues, as well as calls between microservices.

What is contract testing, and do we need it?

Contract testing checks that a service and the clients that call it agree on request and response shapes, with each side verified on its own. It’s most useful when several teams own services that call each other. We use Pact, alongside OpenAPI schema checks.

How do you handle third-party APIs and unstable dependencies?

We test against provider sandboxes where they exist and are reliable, and use WireMock stubs or Testcontainers where they aren’t, so your suite doesn’t fail because someone else’s service is down.

How do you manage test data and environments?

Each test creates the data it needs through the API, checks the database where it matters, and cleans up afterwards. Docker and Testcontainers give repeatable environments for runs in CI.

Do you include security checks?

We add basic checks for common OWASP API Top 10 issues and OWASP ZAP scans to the suite. That doesn’t replace a penetration test, which our security team covers separately.

Can the same suite be used for load testing?

Key flows can be reused in k6, JMeter or Gatling for quick load checks before a release. Full load, stress and capacity testing is covered by our performance testing services.

How do you integrate with CI/CD?

We add test jobs to Jenkins, GitHub Actions, GitLab CI, Azure DevOps or CircleCI, usually with health checks on every deploy, regression on merge or nightly, and contract checks before services are released.

What reports will we get?

Allure or Extent reports after every run, with the request and response logged for each failure. Real defects are logged in Jira with the exact call, and results can go to TestRail.

You do. Frameworks and collections live in your repository, with documentation and a handover session, so your team can run and extend them without us.

How long does it take, and what does it cost?

It depends on the number of services and endpoints, the protocols involved and whether we start fresh or take over a suite. We agree the scope first, then send a timeline and a quote.

What happens in the free consultation?

You talk to an API automation engineer about your services, how you release and what you test today. We’ll suggest where automation pays off first and which approach fits, with no obligation.

API Automation Testing Services

Automated API suites that check every endpoint, contract and role on each merge, in seconds rather than hours.

We design, build and run API automation for REST, GraphQL, SOAP, gRPC and event-driven services, in code or collections, wired into your CI/CD pipeline and kept stable as your services change. Everything lives in your repository, so your team owns it.

Get in touch Plan your automation

Postman, REST Assured, Karate and more
REST, GraphQL, SOAP, gRPC, events
Contract and schema checks
Your repo, no lock-in

What we automate

Contract testingPact between services RegressionEvery merge Auth & rolesEvery role, every endpoint Chained workflowsReal call sequences CI/CD-integratedRuns in your pipeline Suite rescueStabilise or migrate

All 12 types →

[ Why API automation testing matters ]

Most of your product’s logic lives behind the API

API automation sends real requests to your endpoints and checks status, payloads, schemas and side effects, with no browser or device in the way. It runs in seconds and tells you which service broke, not just that something did.

UI tests still matter, but they’re slower and vaguer. A solid API suite underneath catches most logic and integration bugs earlier, and keeps your web and mobile suites short.

Need broader API testing, including security and performance reviews? See API testing services →

The problems it solves

Breaking changes between services

One team renames a field, another team’s service fails in production.

API bugs found late, through the UI

A UI test fails minutes into a run, and someone spends an hour finding which call was wrong.

Docs that drift from behaviour

Partners and client apps build against a spec the API no longer follows.

Edge cases nobody calls by hand

Every role, bad input and data combination is too many requests to check manually each release.

[ How it helps your product ]

What API automation changes in your product

Five outcomes engineering leads ask us about, and how a well-built API suite delivers each one.

Speed

API suites run in seconds to minutes, so they can run on every merge and developers hear about a break while the change is fresh.

Coverage

Endpoints, roles, inputs and error paths that no UI test reaches, checked on every run.

Release quality

Contracts and schemas are verified before deploy, so a breaking change is stopped in the pipeline, not found by a client.

Cost

Bugs found at the API layer are quicker to diagnose, and a strong API suite means fewer slow, expensive UI tests.

Regression stability

No rendering or timing issues, plus isolated data per test, keep results steady, so a red build means a real problem.

Aspect	Manual or UI-only API checks	Automated API suite
Time per run	Requests sent and checked by hand	Seconds to minutes, on every merge
Roles and error paths	A few samples when there’s time	Every role and error case, every run
Breaking changes between services	Found when a client or service fails	Caught by contract checks before deploy
Where a failure points	A UI step that stopped working	The exact call, payload and response
Docs vs behaviour	Checked occasionally, if at all	Responses validated against the spec
Where testers spend time	Replaying known requests	New endpoints, exploratory and edge-case testing

Honest note: automation suits stable, agreed behaviour. New endpoints and unclear requirements still benefit from exploratory testing first, and we’ll tell you which is which.

For Drop Delivery, 1,200+ automated Selenium and API checks run per regression cycle. For KORRA, 600+ automated Playwright and API checks run per release.

[ Types of API automation we deliver ]

Twelve kinds of API automation, matched to your services

Most teams start with health checks, functional and regression suites, then add contracts, roles and integrations as the suite proves itself.

Functional API automation

Endpoint behaviour

Each endpoint checked for the right status, payload and side effects when it gets a valid request.

What we cover

Status codes, headers and response bodies
The business rules behind each endpoint
Create, read, update and delete flows with real data

When it pays offOnce endpoints have agreed behaviour that won’t change every sprint.

Regression suites

Every release

The API checks you rely on before a release, run unattended, so a change in one service doesn’t quietly break another.

What we cover

Ordered by business risk
Extended as each sprint adds endpoints
Run on merge, nightly or on demand

When it pays offWhen manual API checks are what holds releases back.

Smoke & health checks per deploy

Seconds per deploy

View service

A short set of calls that confirms each environment is up and wired correctly right after deployment.

What we cover

Health and readiness endpoints
One key call per critical service
Fails the deploy with a clear reason

When it pays offWhen broken deployments are noticed by users before the team.Smoke & sanity testing →

End-to-end chained workflows

Real call sequences

Requests chained the way your clients really use them, passing tokens, IDs and state from one call to the next.

What we cover

Sign-up, order, payment and refund style flows
Values captured and reused between calls
Test data cleaned up after each run

When it pays offWhen bugs only appear once several calls happen in order.

Contract testing

Pact

Consumer and provider agree on request and response shapes, and each side is verified on its own, so a breaking change is caught before deployment.

What we cover

Consumer-driven contracts with Pact
Provider verification in CI
Breaking changes flagged per service

When it pays offWhen several teams own services that call each other.

Schema validation

OpenAPI & JSON Schema

Every response checked against your OpenAPI spec or JSON Schema, so missing fields, wrong types and undocumented changes show up straight away.

What we cover

Responses validated against the spec
Drift between docs and behaviour flagged
Required fields, types and formats

When it pays offWhen client apps or partners build against your documentation.

Data-driven tests

Many inputs, one test

One test run against many data sets: boundaries, locales, currencies, plans and roles.

What we cover

Inputs from CSV, JSON or the database
Boundary and equivalence values
A clear result for each data row

When it pays offFor pricing, eligibility and rules with many valid inputs.

Negative & error handling

Bad input on purpose

Invalid, missing and malformed input sent on purpose, to check the API refuses it cleanly and returns errors clients can act on.

What we cover

Validation, missing fields and wrong types
Correct 4xx and 5xx codes and messages
Rate-limit and timeout responses

When it pays offWhen unclear errors turn into support tickets and client-side guesswork.

Auth & role-based access

Tokens and roles

Every role tried against every protected endpoint, so users and tenants reach only what they should.

What we cover

Token, session and API-key flows
Role and tenant boundaries
Expired, revoked and missing credentials

When it pays offWhen your API serves several roles, plans or customers.

Integration & third-party APIs

Partners and providers

Calls to payment, messaging, CRM and other third-party services checked against their sandboxes, or stubbed when sandboxes aren’t reliable.

What we cover

Provider sandboxes where available
WireMock stubs for unstable dependencies
Webhook callbacks received and verified

When it pays offWhen a partner change can break your product without any change on your side.

CI/CD-integrated automation

Your pipeline

View service

Suites wired into Jenkins, GitHub Actions, GitLab CI, Azure DevOps or CircleCI, running in Docker, with the right tests at each stage.

What we cover

Smoke on deploy, regression on merge or nightly
Docker and Testcontainers for repeatable environments
Quality gates and results on the build

When it pays offWhen you deploy often and need a go/no-go you can trust.CI/CD & QAOps →

Suite maintenance & migration

Stabilise or move

We take over existing collections and frameworks, fix flaky tests at the cause, and move between tools, such as Postman collections into code, when there’s a clear reason.

What we cover

Root cause and fix for each flaky test
Shared clients, config and data clean-up
Phased migration, old and new suites side by side

When it pays offWhen the suite is slow, brittle or only runs on one person’s laptop.

[ API styles & extra layers ]

The APIs we automate, and what we add on top

Whatever your services speak, the suite covers it. Extra layers reuse the same requests for security, load, mocks and data.

API styles and protocols

REST

Methods, status codes, pagination, filtering and versioning.

GraphQL

Queries, mutations, variables, error shapes and field-level permissions.

SOAP

WSDL-based requests, envelopes and faults.

gRPC

Unary and streaming calls, status codes and message structure.

WebSocket

Connecting, subscribing, message order and reconnects.

Kafka & message queues

Messages produced and consumed, payloads, ordering and retries.

Webhooks

Delivery, signatures, retries and duplicate handling.

Microservices

Service-to-service calls, contracts and what happens when one service fails.

Extra layers in the suite

Basic security checks

Common OWASP API Top 10 issues, such as broken object-level authorisation and excessive data exposure, checked in the suite, with OWASP ZAP scans. Not a replacement for a penetration test.

Penetration testing →

Load checks from the same flows

Key API flows reused in k6, JMeter or Gatling for quick load checks before a release.

Load testing →

Mocking & service virtualization

WireMock stubs and Testcontainers stand in for services that are unstable, costly or not built yet.

Database state validation

Records checked after each call, so a 200 response really means the data was written, updated or removed.

Test data for UI suites

API helpers that create accounts and data for web and mobile suites, so UI tests stay short.

Web automation testing →

[ How you benefit from working with us ]

What you get from QAonTOP’s API automation service

Beyond the tests themselves: how we work with your team, and what you keep when the engagement ends.

Code or collections, your call

We work with Postman, REST Assured, Karate, Supertest, Playwright, pytest and more, so we recommend what your team will keep using, and explain why.

Code you own

Frameworks, collections and environment files live in your repository, with documentation. No proprietary layer, no lock-in.

Contracts teams agree on

Pact contracts and OpenAPI checks give separate teams a shared, tested definition of every request and response.

API, UI and load under one roof

The same engineers can feed data to your web and mobile suites and reuse flows for load checks.

Failures developers can act on

Every failure logs the request and response, and real defects go into Jira with the exact call to reproduce them.

Flexible ways to engage

A fixed-scope build, managed testing, a dedicated team or an engineer in your sprints. See all six.

[ Technology & tool stack ]

Our API automation technology stack

We pick each layer with your team, based on your language, your API styles and the pipeline you already run. On the right is an example layout.

API toolsPostman · Newman · REST Assured · Karate · SoapUI · Supertest · Playwright (API) · pytest + requests · Bruno · Insomnia

LanguagesJava · JavaScript · TypeScript · Python · C#

Test runnersTestNG · JUnit · pytest · Mocha · Jest · NUnit

BDDCucumber

Contracts & specsPact · OpenAPI / Swagger

Mocks & environmentsWireMock · Testcontainers · Docker

Performancek6 · JMeter · Gatling

SecurityOWASP ZAP

CI/CDJenkins · GitHub Actions · GitLab CI · Azure DevOps · CircleCI

Reporting & trackingAllure · Extent Reports · Jira · TestRail

Sample project layoutJava · REST Assured · Pact

src/test/java/
  clients/      OrdersClient.java  AuthClient.java
  smoke/        HealthTest.java
  orders/       CreateOrderTest.java  RefundFlowTest.java
  auth/         RoleAccessTest.java
  negative/     OrderValidationTest.java
  contracts/    OrdersConsumerPactTest.java
src/test/resources/
  schemas/      order.schema.json
  data/         orders.csv
  config/       staging.properties
openapi.yaml
docker-compose.yml
.github/workflows/api-tests.yml

Example only. Your layout follows your tools, language and team.

API tools, and where each fits best

Postman

Shareable collections with environments per stage, easy for the whole team to explore.

Newman

Runs Postman collections from the command line and in CI.

REST Assured

Java teams who want API tests in code alongside TestNG or JUnit.

Karate

Readable, Gherkin-style API tests with built-in assertions and little code.

SoapUI

SOAP and WSDL-based services.

Supertest

Node.js services tested in-process with Mocha or Jest.

Playwright (API)

Teams already on Playwright, mixing API and UI steps in one test.

Playwright testing services →

pytest + requests

Python teams who want lightweight, readable API tests.

Bruno

Git-friendly API collections stored as plain files.

Insomnia

Exploring and debugging REST and GraphQL requests.

Comparing tools in depth? See our tool-agnostic testing services →

[ How we work ]

Six steps from first call to a suite your team owns

You see working tests in your pipeline early, and you approve each stage before we build on it.

Step 1 of 6
Discovery

We review your services, API specs, release cycle and current tests, and rank the endpoints worth automating first.

You getStrategy & feasibility reportEndpoint coverage map
Step 2 of 6
Framework design

Tools, language, structure, test data, environments and reporting agreed with your team.

You getFramework code in your repoCollections and environment files
Step 3 of 6
Pilot in your pipeline

A first set of real tests running in your CI, so you can judge the approach before we scale.

You getCI pipeline integration
Step 4 of 6
Scale coverage

Critical calls first, then roles, errors, contracts, schemas and integrations.

You getContract tests & schemasUpdated coverage map
Step 5 of 6
Run and report

Suites run on agreed triggers. We triage failures and log real defects in your tracker.

You getExecution reportsDefect reports
Step 6 of 6
Maintain and hand over

Flaky tests fixed at the cause, the suite kept in step with your services, and a walkthrough for your team.

You getMaintenance logDocs and handover

[ Deliverables ]

What you receive

Everything below is yours to keep, whether we stay on to run the suite or hand it over to your team.

API automation strategy & feasibility report

What to automate, in what order and with which tools, and what should stay manual.

Endpoint coverage map

Every endpoint and the checks against it: happy path, roles, errors and contracts.

Framework source code in your repository

Committed to your repo, under your access controls, in your team’s language.

Postman collections & environment files

Organised collections with environments per stage, ready to run with Newman.

Contract tests & schemas

Pact contracts and OpenAPI or JSON Schema checks your teams agree on.

CI pipeline integration

Jobs and quality gates in Jenkins, GitHub Actions, GitLab CI, Azure DevOps or CircleCI.

Execution reports per run

Allure or Extent reports with the request and response logged for every failure.

Defect reports in your tracker

The exact call, payload, response and expected result, logged in Jira.

Maintenance & flaky-test log

Each unstable test, its cause and the fix, so suite health stays visible.

Documentation & handover session

Setup guide, conventions and a live walkthrough so your team can run and extend the suite.

[ Case Studies ]

APIs and integrations we’ve tested

Drop Delivery and KORRA run automated API checks on every cycle; DesignO and Workflo show our wider API and integration work.

{{ c.metric }}{{ c.label }}Read the case study

All case studies →

[ Ways to work ]

Six ways to work with our API automation engineers

A new suite, a rescue of an existing one, ongoing runs or an engineer in your team.

01Fixed-price projectChoose it for a new framework or a migration with a clear scope.02Managed testingChoose it when you want the suite built, run and maintained for you.03Dedicated QA teamChoose it when automation grows every sprint.04Staff augmentationChoose it when your team needs an API automation specialist for a while.05QA consultingChoose it for a review of your current suite and a plan to improve it.06On-demand testingChoose it for a one-off push, such as stabilising a flaky suite.

Hire our QAHire an automation engineerAn automation engineer who joins your sprints, works in your repository and grows coverage with your team.See the role → Start with no obligationFree API automation consultationTalk to an automation engineer about your services, your current tests and your pipeline. We’ll suggest where automation pays off first.Book the consultation →

Not sure which fits? Find your model in four questions, compare all six or estimate your cost.

[ FAQ ]

API automation testing questions, answered

[ Contact us ]

Talk to an API automation engineer

✓ Free one-week POC✓ NDA before access✓ A QA lead replies the same day

Book a free consultation

[ Keep exploring ]

Related testing services

All services →

API Automation Testing Services

Most of your product’s logic lives behind the API

Breaking changes between services

API bugs found late, through the UI

Docs that drift from behaviour

Edge cases nobody calls by hand

What API automation changes in your product

Speed

Coverage

Release quality

Cost

Regression stability

Twelve kinds of API automation, matched to your services

Functional API automation

Regression suites

Smoke & health checks per deploy

End-to-end chained workflows

Contract testing

Schema validation

Data-driven tests

Negative & error handling

Auth & role-based access

Integration & third-party APIs

CI/CD-integrated automation

Suite maintenance & migration

The APIs we automate, and what we add on top

REST

GraphQL

SOAP

gRPC

WebSocket

Kafka & message queues

Webhooks

Microservices

Basic security checks

Load checks from the same flows

Mocking & service virtualization

Database state validation

Test data for UI suites

What you get from QAonTOP’s API automation service

Code or collections, your call

Code you own

Contracts teams agree on

API, UI and load under one roof

Failures developers can act on

Flexible ways to engage

Our API automation technology stack

Postman

Newman

REST Assured

Karate

SoapUI

Supertest

Playwright (API)

pytest + requests

Bruno

Insomnia

Six steps from first call to a suite your team owns

Discovery

Framework design

Pilot in your pipeline

Scale coverage

Run and report

Maintain and hand over

What you receive

API automation strategy & feasibility report

Endpoint coverage map

Framework source code in your repository

Postman collections & environment files

Contract tests & schemas

CI pipeline integration

Execution reports per run

Defect reports in your tracker

Maintenance & flaky-test log

Documentation & handover session

APIs and integrations we’ve tested

{{ c.name }}

Six ways to work with our API automation engineers

API automation testing questions, answered

{{ f.q }}{{ f.sign }}