Validation

Axiom Core uses Rod for all schema validations. Rod is a high-performance, cross-platform validation library built by Axiom Core that ensures your data is valid before it ever leaves the client or enters your application logic.

The "Write-Once, Validate-Anywhere" Model

Traditionally, validation logic is duplicated across the Backend (Python) and Frontend (Flutter). This leads to Schema Drift.

Axiom solves this by moving validation into the Shared Rust Core. You define the validation rules once in your axiom.acore file, and the Generic Runtime enforces them natively on the client device.

Defining Validations in Acore

Validation is applied at the model level. You reference the model and field discovered during introspection and attach a validate block.

local User = Models.User

models {
  [User._model] {
    fields {
      [User.email] {
        validate {
          type = "string"
          email = true
        }
      }
      [User.age] {
        validate {
          type = "number"
          minimum = 18
          int = true
        }
      }
    }
  }
}

How it Works: RodSpec

Acore's validation syntax maps 1-to-1 with RodSpec—a serializable AST (Abstract Syntax Tree) for validation logic.

1. Contract Build: Your Acore rules are compiled into a RodSpec and embedded in the .axiom file.
2. Runtime Execution: The Rust runtime parses this spec into an executable validator.
3. Deterministic Enforcement:
   • Outgoing: Requests are validated against the spec before being sent.
   • Incoming: Server responses are validated before being returned to the Flutter SDK.

Why Rod?

• Native Speed: Validation happens in the Rust runtime, bypassing the overhead of high-level languages.
• Consistency: Because the same Rust core is used, a validation that passes in your test suite is guaranteed to behave identically in the production mobile app.
• Precision: Capture specific requirements like trim, uuid, or regex that standard JSON schemas often miss.