API Spector vs Dredd
Short version: Dredd checks that a running API matches its OpenAPI (or API Blueprint) description. API Spector does that kind of provider verification too, and adds consumer-driven contracts, mocking, a request client, and test-code export. Dredd is a focused CLI; API Spector is a broader workflow.
What Dredd is
Dredd is an open-source, language-agnostic CLI that validates an API implementation against its API description. It reads your OpenAPI or API Blueprint spec, sends the described requests to your backend, and checks the responses, with hooks for setup and teardown. It is a solid tool for one job: spec-to-backend conformance in CI.
Side by side
| API Spector | Dredd | |
|---|---|---|
| Spec-to-backend conformance | Yes (provider verification) | Yes, its core purpose |
| Consumer-driven contracts | Yes | No |
| Bi-directional contracts | Yes | No |
| Pact-compatible | Yes | No |
| Provider states | Yes | Via hooks |
| Request client (GUI) | Yes | No, CLI only |
| Mock servers | Yes | No |
| Export to test code | Robot Framework, Playwright, Karate, REST Assured, supertest | No |
| Reports | HTML / JUnit | CLI / reporters |
Where API Spector fits
- More than conformance. Alongside checking a provider against a spec, API Spector supports consumer-driven and bi-directional contracts, so both sides of an integration are covered.
- Author interactively, run in CI. Build and explore requests in the app, then
run verification and the
deploy-checkgate from the CLI. - Mocks and code export included. Stand up a mock from a contract, and generate runnable tests for your framework.
Choose Dredd if
- You only need to verify a backend against an OpenAPI or API Blueprint spec from the CLI, and want a small, single-purpose tool.
Choose API Spector if
- You want consumer-driven and bi-directional contracts, not just spec conformance.
- You want a request client, mocking, and test-code export in the same tool.