ax-gen

AxGen Codegen Rules (@ax-llm/ax)

Use this skill to generate AxGen code. Prefer short, modern, copyable patterns. Do not write tutorial prose unless the user explicitly asks for explanation.

Use the ax-mcp skill when AxGen attaches native MCP clients or consumes MCP prompts, resources, tools, tasks, subscriptions, authentication, or events.

Use These Defaults

• Use ax(...) factory, not new AxGen(...).
• Always pass an AI instance from ai(...) as the first argument to forward().
• Streaming uses streamingForward(), not forward() with a stream option.
• Use schema validation for field shape and constraints.
• Use addAssert(...) for whole-output hard invariants with correction retries.
• Use addStreamingAssert(...) for partial streaming hard invariants with fail-fast per-attempt correction retries.
• Use bestOfN(...) / refine(...) for reward-scored complete outputs.
• Step hook mutations are applied at the next step boundary (pending pattern).
• stopFunction accepts a string or string[] for multiple stop functions.
• Multi-step continues until: all outputs filled, stop function called, or maxSteps reached.

Canonical Pattern

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

const llm = ai({
  name: 'openai',
  apiKey: process.env.OPENAI_APIKEY!,
});

// Inline signature
const gen = ax('input:string -> output:string, reasoning:string');

// Reusable signature
const sig = s('question:string, context:string[] -> answer:string');
const gen2 = ax(sig);

// With options
const gen3 = ax('input -> output', {
  description: 'A helpful assistant',
  maxRetries: 3,
  maxSteps: 10,
  modelConfig: { temperature: 0.7 },
});

const result = await gen.forward(llm, { input: 'Hello world' });
console.log(result.output);

Signatures from zod / valibot / arktype

ax() accepts any signature built with f(), and f().input() / .output() accept Standard Schema v1 validators directly — per-field or a whole z.object({...}):