Backend Setup

Axiom Core turns your backend into the absolute source of truth. You can iterate locally for rapid development or release to the Axiom Hub for production-grade signed contracts.

Initialize the Project

Navigate to your FastAPI root and run:

axiom init

This creates an axiom.acore file. Axiom automatically detects your entry point (e.g., main.py:app) and populates the initial configuration.

Build Locally

To generate your first behavioral contract, run the build command:

axiom build

Outcome: A .axiom file is generated in your project root. At this stage, the contract is unsigned, meaning it is perfect for local testing but will trigger a warning in the client-side runtime logs.

Inspect Structure & Behavior

Before releasing, use the built-in TUI to verify that your routes, models, and behavioral policies (caching, retries) are correct. You can inspect specific variants defined in your .acore file:

# Inspect the default variant
axiom inspect

# Inspect a specific variant
axiom inspect mobile
axiom inspect web

Use the TUI to browse models and routes. If something looks wrong, update your Python code or .acore configuration and rebuild.

Release to the Hub

Once you are satisfied with the contract, you can release it to the Axiom Hub. This process cryptographically signs the contract and makes it available for the frontend team to pull.

If you have already built and inspected your .axiom file:

axiom release

To build and release in a single step:

axiom build --release

Note: You must be logged in (axiom login) and have a linked project (axiom project link) to perform a release. If you haven't logged in, the CLI will prompt you to do so before the release can proceed.

Manage Projects

If this is a new service, you'll need to create and link a project in the Hub:

# 1. Create the project
axiom project create --name "My-Service"

# 2. Link the current folder to that project
axiom project link

Backend as Source of Truth: You never have to manually update a Swagger/OpenAPI file or rewrite your data structures in a separate config. Every time you change your Pydantic models or FastAPI routes, the structure is automatically synchronized during the next build.