Backend quickstart

This quickstart keeps FastAPI or Go as the executable backend and adds an Axiom contract boundary around it.

Diagnose and plan

axiom doctor
axiom onboard --role backend

Review the detected entrypoint and extractor. To create source explicitly for a FastAPI app:

axiom init main.py:app --module axiom-fastapi

Build and inspect

axiom build axiom.acore
axiom inspect axiom.axiom

The build evaluates Acore, invokes the configured extractor, validates the result, and writes a canonical .axiom artifact. It does not replace or deploy the backend.

Exercise the development boundary

axiom test axiom.acore
axiom serve axiom.acore --port 8080 --debug

Tests use configured suites. The mock server uses authored contract responses and state, so compare it with the real service before treating it as behavioral evidence.

Next, follow the full Backend contract lifecycle for semantic review and immutable release.