Cortex · guide

An answer as it arrives

A model writes its answer a few characters at a time. Cortex hands you what there is of it so far, each time it changes.

Install it

pnpm add @niscorp/cortex @niscorp/signal zod openai

Step 1 of 4

The model

createSignal makes the client that calls the model. Cortex is handed this client, here for Groq, and Signal reads the key from GROQ_API_KEY.

The model

import { z } from 'zod';
import { createSignal } from '@niscorp/signal';
import { defineAgent } from '@niscorp/cortex';

const llm = createSignal('groq');

Step 2 of 4

An answer with a list in it

The longer the answer, the more there is to gain from reading it early. This one is a list of what was ordered.

An answer with a list in it

const Orders = z.object({
  items: z.array(z.object({ item: z.string(), quantity: z.number() })),
});

const reader = defineAgent({
  id: 'order-reader',
  instructions: 'Read every item of the order out of the message.',
  output: { schema: Orders },
});

Step 3 of 4

What there is so far

An output-partial event carries the answer as far as it has been written, under data: first an empty list, then one item with only its name, then the item whole, and so on.

What it carries is not checked yet. It is there to be shown: a list that grows, a screen that fills in.

What there is so far

const run = reader.run('Two coffees and a cake, please.', { llm });
run.onEvent((event) => {
  if (event.type === 'output-partial') console.log('so far:', JSON.stringify(event.output));
});

Step 4 of 4

The whole answer

The result is the answer once it is whole and has passed the schema. Use the partial ones to draw, and this one to act on.

The whole answer

const result = await run.result;
console.log('whole:', result.ok ? JSON.stringify(result.output.data) : result.error.message);

Then

Run it.

This file asks a model, so it is not run on this site. It prints a line of so far: each time more of the answer can be read, the list growing by an item or part of one, and then whole: with both items.

Run it

GROQ_API_KEY=your-key npx tsx arrives.mts