Unit 3 · Build a reliable AI-powered feature

Run your first typed AI call

You run a declared program with a provider and typed input. The returned object follows the output side of your signature.

forward()6 focused minutesNot started

Worked example

See the idea in context

const answer = ax('question:string -> answer:string, confidence:number');
const result = await answer.forward(llm, { question: 'What is Ax?' });

Create the program
The signature asks for an answer and a numeric confidence.
Pass a provider and input
forward() runs the program with llm and the required question.
Use the typed result
result exposes the declared output fields instead of raw model text.

Run itIn your own project

npm install @ax-llm/ax

import { ai, ax } from '@ax-llm/ax';

const llm = ai({ name: 'openai', apiKey: process.env.OPENAI_APIKEY! });
const classify = ax('review:string -> sentiment:class "positive, negative, neutral"');

const result = await classify.forward(llm, {
  review: 'Useful and boring in the best way.',
});

Set OPENAI_APIKEY in your environment before running provider-backed code.

In the ax repo

From a clone of the ax repo:

npm run example -- typescript src/examples/typescript/generation/axgen-openai.ts

Active practice

Show that you can use it

Answer 2 in a row to learn this · attempt 1

Keep exploring

See the idea in context

Show that you can use it

Source-backed follow-up