Ax Signatures For Rust

Use when writing Rust code with axllm for string signatures, field descriptors, JSON schema output, validation, and typed tool argument shapes.

Install

Install only this skill for Rust:

Shell

npx skills add https://ax-llm.github.io/ax/rust/ --skill 'ax-rust-signature'

Published skill file: ax-rust-signature/SKILL.md.

Source

Source: packages/rust/skills/ax-rust-signature/SKILL.md
Version: 23.0.5

Skill Instructions

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.