Quick Start

Ax gives Java one typed contract for LLM programs: signatures for data shape, ai() for model access, ax() for structured generation, agent() for tool-using runtime loops, and AxGEPA for improving programs with examples.

Install

git clone https://github.com/ax-llm/ax && cd ax/packages/java
javac -cp . dev/axllm/ax/*.java examples/SignatureSchemaExample.java
java -cp .:examples SignatureSchemaExample

First Program

Start with a small typed task. The signature declares the fields the model receives and the fields Ax must parse back out.

import dev.axllm.ax.Ax;

var llm = Ax.ai("openai", Map.of("apiKey", System.getenv("OPENAI_API_KEY")));
var classify = Ax.ax("review:string -> sentiment:class \"positive, negative, neutral\"");

That is the core loop:

• create a provider client
• declare the input and output contract
• run the program with typed inputs
• read typed outputs instead of scraping prose

flowchart LR
  A["ai() client"] --> C["forward() with typed inputs"]
  B["Signature"] --> C
  C --> D["Validate + retry"]
  D --> E["Typed output"]

The rest of the site keeps the same concepts but swaps install commands, imports, examples, and API names for Java.

Where To Go Next

Use Examples when you want runnable files. Use Concepts when you want the mental model. Use Subsystems when you know which surface you are trying to use and want the practical call shape.

What To Read Next

• Examples
• DSPy concepts
• ai() LLM models
• ax() generation
• AxGEPA GEPA