ax-java-signature

name	ax-java-signature
description	Use when writing Java code with `dev.axllm:ax` for string signatures, field descriptors, JSON schema output, validation, and typed tool argument shapes.
version	23.0.14

Ax Signatures For Java

This skill helps an agent write Java code with the generated Ax package dev.axllm:ax. 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: Java.
• Package: dev.axllm:ax.
• 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, python-pyodide.

Core Pattern

import dev.axllm.ax.*;

AxSignature sig = Ax.s("question:string -> answer:string");
var schema = sig.toJsonSchema("outputs", java.util.Map.of());

More Patterns

Simple string contract

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

AxGen program = Ax.ax("questionText:string -> answerText:string");

Bounded class output

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

AxGen router = Ax.ax(
    "messageText:string -> routeClass:class \"support, sales, engineering\"");

Fluent constraints

Java exposes the native fluent builder for validation constraints and objects.

AxSignature signature = Ax.f().call()
    .input("contactEmail", Ax.f().string("Contact email").email())
    .output("partySize", Ax.f().number("Guests").min(1).max(12))
    .output("bookingCode", Ax.f().string().regex("^[A-Z]{3}-\\d{4}$", "ABC-1234"))
    .build();

JSON schema

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

var schema = signature.toJsonSchema("outputs", java.util.Map.of());

Reuse the signature

Pass one built signature into AxGen and call it like any other program.

AxGen program = Ax.ax(signature);
var output = program.forward(client, inputs);

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

Relevant API Surface

• Signatures: Ax.s, Ax.f, AxSignature
• Tools: Ax.fn, 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.