Ax Signatures For Rust

This skill helps an agent write Rust code with the generated Ax package axllm. Use the generated package API, examples, and manifests; do not import TypeScript-only APIs unless you are editing the TypeScript package.

When To Use

• Declare input and output contracts with native generated-package APIs.
• Generate JSON-schema-compatible shapes for outputs, tools, prompts, and validation.
• Keep Standard Schema and TypeScript-only helper libraries out of generated-language code.

Package Facts

• Language: Rust.
• Package: axllm.
• Package API docs: API.md and axir-api.json.
• Capability manifest: axir-capabilities.json.
• Runnable examples: examples/.
• Real network support: yes.
• Scripted no-key transport support: yes.
• Runtime profiles: javascript-quickjs.

Core Pattern

rust
use axllm::s;

let sig = s("question:string -> answer:string")?;
let schema = sig.to_json_schema("outputs");

More Patterns

Simple string contract

Use the string form when field names and types are enough.

rust
let mut program = axllm::ax("questionText:string -> answerText:string")?;

Bounded class output

A class field constrains the model to a known label set.

rust
let router = axllm::ax(
    "messageText:string -> routeClass:class \"support, sales, engineering\"",
)?;

Native constraints

Rust combines FieldType constraints with the generated signature builder.

rust
let mut party_type = FieldType::number();
party_type.minimum = Some(1.0);
party_type.maximum = Some(12.0);

let mut code_type = FieldType::string();
code_type.pattern = Some(r"^[A-Z]{3}-\d{4}$".to_string());

let signature = f()
    .output("partySize", party_type)
    .output("bookingCode", code_type)
    .build();

JSON schema

Render the output contract for tools, validators, or external consumers.

rust
let schema = signature.to_json_schema("outputs");

Reuse the signature

Attach the native signature to AxGen before the forward call.

rust
let mut program = axllm::ax("requestText:string -> partySize:number, bookingCode:string")?;
program.signature = signature;
let output = program.forward(&mut client, inputs)?;

Start from the complete programs under examples/, then browse the larger gallery at https://axllm.dev/rust/subsystems/s/.

Relevant API Surface

• Signatures: s, f, AxSignature
• Tools: tool, Tool

Guardrails

• Start from package examples for exact native syntax before inventing a new call shape.
• Use provider-api examples only when the user explicitly has provider credentials available.
• Use no-key examples for deterministic local checks and provider request mapping.
• Treat AxIR as the source of generated package truth: if package docs disagree with source code, update the compiler and regenerate packages.
• Do not copy repo-maintainer skills from tools/*/skills/ into user packages.