Reuse the same contract everywhere You keep a field’s meaning stable as it moves through generators, tools, flows, agents, and events. That makes composed systems easier to validate and evaluate. typescript academy academy/topics/typed-contracts-everywhere website/content-src/academy/course.mjs academy Reuse the same contract everywhere
ax
TypeScript @ax-llm/ax
TypeScript Python Java C++ Go Rust
Unit 2 · Make AI outputs predictable

Reuse the same contract everywhere

You keep a field’s meaning stable as it moves through generators, tools, flows, agents, and events. That makes composed systems easier to validate and evaluate.

6 focused minutesNot started
Worked example

See the idea in context

const lookup = fn('lookup').arg('ticketId', f.string()).returns(f.json()).handler(loadTicket).build();
  1. Name the capability

    lookup gives the model and traces a stable tool name.

  2. Type the boundary

    ticketId and the JSON result use the same field vocabulary as Ax programs.

  3. Keep execution in your app

    The handler owns the real lookup and returns the declared result.

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/structured.ts
Active practice

Show that you can use it

Answer 2 in a row to learn this · attempt 1
Keep exploring

Source-backed follow-up