API Spector vs Milkman
Short version: Milkman is an open-source, plugin-based API client built for extensibility and Git-friendly storage. API Spector shares the local-first, files in-Git approach but ships a broader, more polished workflow out of the box: mocking, contract testing, and test-code export.
What Milkman is
Milkman is an open-source, extensible API client (built on the JVM) whose features come largely from plugins. It stores requests as text you can keep in Git and appeals to developers who want a hackable, keyboard-driven tool they can extend. It is community-driven, and capabilities depend on which plugins you add.
Side by side
| API Spector | Milkman | |
|---|---|---|
| Local-first / offline | Yes | Yes |
| Account required | No | No |
| Storage | Files (Git-friendly) | Files (Git-friendly) |
| Out-of-the-box features | Client, mocks, contracts, code export | Core client; rest via plugins |
| Secret managers | Vault, AWS, Azure, GCP, 1Password (+ AES-256-GCM local) | Plugin-dependent |
| GraphQL query builder | Yes, introspection-driven | Plugin-dependent |
| SOAP + WSDL loader | Yes, load a WSDL and generate the envelope | Plugin-dependent |
| Export to test code | Robot Framework, Playwright, Karate, REST Assured, supertest | Plugin-dependent |
| Mock servers | Yes | Plugin-dependent |
| Contract testing | Built in, Pact-compatible | No |
| Protocols | HTTP/REST, GraphQL (+ subscriptions), SOAP/WSDL, WebSocket, Socket.IO, MQTT, SSE, gRPC (unary + server streaming) | HTTP/REST, GraphQL (plugins) |
| Visual flows | Yes, chain requests on a canvas | Plugin-dependent |
| Fuzz testing | Yes, spec-driven, built in | Plugin-dependent |
Where API Spector fits
- Batteries included. Mocking, visual flows, fuzz testing, contract testing, and code export work without assembling plugins, with a built-in Git client for the workspace.
- Consistent, polished UI. A single integrated experience rather than a core plus community add-ons.
- Secret management built in. Encrypted locally or referenced from an external manager.
API Spector is a European alternative: built in Europe, GDPR-first, and local-first (your API data stays on your machine), with the optional cloud hosted in the EU.
Pricing
API Spector's client is free; Cloud is Pro €12 or Team €19/user/mo, with SSO in Team. Compare the cost.
Choose Milkman if
- You want a hackable, plugin-driven client and enjoy extending your own tooling.
Choose API Spector if
- You want the local-first, Git-friendly model with mocking, contract testing, and code export ready out of the box.