API testing

API test automation for REST, SOAP and GraphQL, beside your UI tests.

API test automation in ZeuZ generates, chains and asserts REST, SOAP and GraphQL tests from a plain-English description or an OpenAPI spec, and runs them on every build in the same suite as your UI tests. Response values feed the next step; the same requests become load tests when you need them.

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RESTSOAPGraphQLWebSocket & SSEOpenAPI & Postman importChained with UI

node-toronto-01atlas-crmrelease/2026.09

Test case · Create order via API, verify in UI

Passed

POST/api/orders✓ 201

{ "customer": "acme-3312",
"sku": "SKU-2214", "qty": 2 }

✓ status 201✓ schema order.v2

order_id → ${order_id} = 88012

BrowserOpen /orders/${order_id}✓ Passed

Assert status badge = Confirmed · Chrome

Run history · hourly

10:00✓ 2.1s

09:00✓ 2.0s

08:00✓ 2.2s

07:00✓ 2.0s

06:00✓ 2.3s

05:00✓ 2.1s

Response values chained into the UI steprelease/2026.09

In one paragraph

API test automation is the automated sending of requests to an application's interfaces and the checking of the responses, status, schema, values and timing, without a user interface in the loop. ZeuZ covers REST, SOAP, GraphQL, WebSocket and server-sent events, with authorization, certificates, schema validation and response chaining, and runs API steps in the same case as web, mobile, desktop and database steps.

Part of ZeuZ Test Studio · REST, SOAP, GraphQL, WebSocket and SSE, in the same case as web, mobile, desktop and database

The problem

Where API testing breaks today.

API tests live in a separate tool from the UI tests, so the journey that starts in the API and ends on screen is never one test.

Auth, certificates and environment differences get hard-coded per request, and the collection stops working the day a token rotates.

The load test is a different tool again, with the same requests rewritten a third time.

The six steps

How ZeuZ automates API test automation.

01Test designProposes the endpoints and cases a change needs from the changed files, the spec and the tickets, ranked by importance.
02Test case creationDescribe the request and the expected response in plain English, or import an OpenAPI spec or Postman collection to scaffold the cases.
03Test automationRequests compile into readable steps with headers, auth, payload and assertions, and response fields save into variables for the next step.
04Test executionRuns on every build from a CI webhook, on a schedule or manually, with parallel isolated sessions for multi-user scenarios.
05Reporting and analysisEvery request returns status, headers, body and timing, and a failed assertion names the field that differed.
06Test maintenanceA changed schema or field path comes back as a proposed repair to the case, not a broken collection.

Your team reviews what ZeuZ produced. Nothing joins the suite or runs without a person accepting it.

See it in the demo lab or in your own environment

See it run on your application.

Watch an API test chain straight into the UI steps that depend on it.

Book a demo Download the solution brief →

What is covered

API testing tools that reach past the endpoint.

ZeuZ sends REST, SOAP, GraphQL and Mirth requests with every HTTP verb, plus WebSocket and server-sent-event checks, and custom protocols through Python. Payloads can be JSON, XML, GraphQL, form-data, URL-encoded, raw, binary or multipart with file upload, and an existing cURL command runs as-is. Authentication is handled through authorization headers, custom and inherited headers, stored cookies, client-side certificates and root certificate validation, with an optional bypass for internal tools.

Responses are validated against a JSON schema, compared structurally, and mined with deep field extraction into variables; test data comes from JSON, XML, CSV or XLSX. Loops, conditions, retries, timeouts and teardown logic are built in, and sessions run in parallel with isolation. Postman collections and OpenAPI specifications import to scaffold cases, and the same request steps drive the load tests, which is where API test automation stops being a separate tool and becomes part of the suite.

Protocols: REST, SOAP, GraphQL, Mirth, WebSocket, SSE; custom via Python
Payloads: JSON, XML, form, URL-encoded, raw, binary, multipart, file upload, cURL
Auth: Headers, cookies, client certificates, root validation, optional bypass
Validation: Status, JSON schema, structural compare, deep extraction
Data: JSON, XML, CSV, XLSX; variables between steps
Import: Postman, OpenAPI