API Testing

We test the layer where integrations actually break

Home API Testing

Your UI Is Tested. The Layer Underneath It Probably Isn’t

Most teams test what they can see – the interface – and assume the API beneath it is fine. It usually isn’t. The API layer is where data leaks, where one service quietly breaks another, and where the failures that take down a release actually originate. The numbers prove it: more teams use automated API testing than ever, yet API downtime keeps climbing – because teams buy tools without building a testing strategy. We close that gap. Incisive tests your APIs the way attackers and broken integrations find them: every endpoint, every contract between services, every edge case the happy-path test never touches.

What We Test

We validate REST, GraphQL, and gRPC APIs across the full surface: functional correctness of every endpoint, business logic, status codes, and schema conformance. We test contracts between microservices so a change in one service can’t silently break another. We probe the failure paths – timeouts, malformed payloads, partial responses, downstream outages – that most suites skip entirely. And we run security checks against the OWASP API Top 10 and performance validation under realistic load, because a correct API that leaks data or buckles under traffic still fails in production. Our stack: Postman and REST Assured as primary, Karate and SoapUI where they fit, k6 and JMeter for the performance layer – all wired into your CI/CD pipeline.

AI SCENARIO GENERATION

Exhaustive Coverage, Including the Cases Nobody Thinks To Write

Manual API test design covers the obvious paths and runs out of patience before the edge cases. We feed your API specs – OpenAPI, GraphQL schemas – into AI-assisted generation that produces exhaustive test scenarios: boundary values, malformed inputs, unexpected types, injection patterns, and the awkward combinations real clients actually send. A senior engineer reviews and curates what matters. You get coverage that’s both broader and sharper than hand-written suites, in a fraction of the time.

CONTRACT TESTING

Stop One Service From Silently Breaking Another

In a microservices architecture, the most expensive failures happen at the seams – one team ships a change, and a service they’ve never heard of breaks in production. Contract testing fixes this. Each consumer defines what it expects; each provider verifies it still delivers it. Before anything deploys, we confirm every contract still holds – so a breaking change is caught in the pipeline, not in an incident channel at 2 a.m. This is where API testing earns its keep when multiple teams own interdependent services.

INTEGRATION & FAILURE PATHS

We Test What Happens When Things Go Wrong

Any test can confirm an API works when everything cooperates. The real risk lives in the failure paths: a downstream service times out, a payload arrives malformed, a third party returns a partial or inconsistent response. These are exactly the scenarios that take systems down – and exactly the ones under-tested suites skip. We deliberately break things in a controlled way, validating that your system degrades gracefully, retries correctly, and never corrupts data when a dependency misbehaves.

API SECURITY

The API Is Where Your Data Actually Leaks

Modern applications move their most sensitive data through APIs, which makes the API layer the single most common source of real breaches. We test against the OWASP API Security Top 10: broken object-level authorization, excessive data exposure, broken authentication, and injection through the API itself. We attempt to access data across user boundaries, verify sensitive fields never leak in responses or logs, and confirm every endpoint enforces authorization server-side – not just in the UI.

CI/CD & RELEASE OWNERSHIP

Every Endpoint Validated Before Anything Ships

API tests run in your CI/CD pipeline on every commit, so a regression in the data layer is caught before it reaches staging. But running tests is the tool, not the goal — the goal is a release you can ship with confidence. We commit contractually: a minimum of 80% automated coverage of critical functions, at least 30 new automated tests every month, defects reported within 24 hours, and a written readiness report on a cadence that matches your release rhythm — weekly, per sprint, or before each deploy window. CI/CD-integrated API testing is how you stop the API layer from being your release bottleneck.

FAQ

We have end-to-end tests already. Do we still need dedicated API testing?

Yes. End-to-end tests validate complete workflows but are slow, expensive to maintain, and terrible at pinpointing why something failed. API tests are faster, more stable, and tell you exactly which service and which contract broke. The two work together – E2E proves the journey, API testing proves the layer underneath it.

Which protocols do you support - REST, GraphQL, gRPC?

All three, plus SOAP where legacy systems require it. We validate each against its specification – OpenAPI for REST, schema validation for GraphQL – so tests check documented behavior, not brittle implementation details.

What is contract testing and do we need it?

Contract testing verifies that the agreement between two services still holds – what one sends, the other still accepts. You need it most when multiple teams own interdependent services or deploy independently, which is nearly every microservices setup. It catches breaking changes in the pipeline instead of in production.

How does AI improve API testing specifically?

AI generates exhaustive test scenarios from your API specs – edge cases, malformed inputs, injection patterns, and combinations a human would take days to enumerate. The engineer reviews and curates. You get broader, sharper coverage faster, without AI ever making the final call on what ships.

Do you test API security and performance, or just functionality?

All three. Functional correctness, security against the OWASP API Top 10, and performance under realistic load – at both the individual microservice level and the full system level. A correct API that leaks data or collapses under traffic still fails in production.

How is this priced?

Never per hour. API testing is part of a dedicated QA engagement at a fixed monthly rate with contractual deliverables: coverage targets, 30+ new tests a month, defect reporting within 24 hours, and weekly reports. You pay for a reliably tested API layer and a guaranteed output, not for clocked hours.

Do we own the test suite?

Entirely. Tests are built in standard, open tooling – Postman, REST Assured, Karate – documented and exportable. If we part ways, you keep the full suite and the framework. No proprietary platform, no lock-in.

Testimonials

Ava

CTO, Logistics

“Our frontend was tested; the API layer between our systems basically wasn’t. They built contract tests across our microservices and caught three breaking changes in the first month – before any of them shipped.”

4.0 rating
Sophie

VP Engineering, B2B SaaS

“AI-generated edge cases found input-handling bugs we’d been carrying for over a year. Our API response failures in production dropped to almost nothing.”

5.0 rating
Amelia

Head of Engineering, FinTech

“They tested the failure paths we never had time to – timeouts, malformed payloads, downstream outages. Our system now degrades gracefully instead of corrupting data when a dependency hiccups.”

5.0 rating