TypeScript functions that answer questions about text

Pass the question and the text. Await the call, then read its .value.

Install

Channel
`npm install thinkthen`
`pnpm add thinkthen`
`bun add thinkthen`

Set THINKTHEN_API_KEY in the environment.

A first call

import assert from "node:assert/strict";
import * as tt from "thinkthen";

const complaintQuestion = "Is this a complaint?";
const reviews = [
  "Arrived a day early. Thank you!",
  "The zipper broke the first time I used it.",
  "The strap snapped on day two.",
];
const complaints = (await tt.filter(
  complaintQuestion,
  reviews,
)).value;
assert.deepEqual(complaints, [reviews[1], reviews[2]]);

const levels = ["Routine.", "Soon.", "Immediate."];
const urgencyScale = {
  score: "How urgent is this?",
  levels,
};
const outage = "Nobody can log in to the site right now.";
const urgency = (await tt.score(
  urgencyScale, outage,
)).value;
assert.equal(urgency, 2);

Not sure comes back as null. Branch on it and send those cases to a person. Each function page shows its TypeScript call.

Run facts

Call.facts counts this call.

Errors

A failure rejects with a ThinkThenError. Its kind is usage, backend, local, deadline, cancelled or defect.

Settings and recording

new Engine({...}) starts from the environment, and each key overrides one setting. record writes a recording to a folder. replay answers from that recording with no connection. The Settings page lists every setting.

Jev, Liquid d1 and Ollama from TypeScript

TypeScript reads its backend from the environment. Set THINKTHEN_BACKEND to the name below. Set the backend's key variable in the shell, and the same sample asks that backend.

Backend	Name	Key variable
TypeSafe Jev	`typesafe`	`TYPESAFE_API_KEY`
Liquid d1	`liquid`	`LIQUIDAI_API_KEY`, then `LIQUID_API_KEY`
Ollama	`ollama`	`OLLAMA_API_KEY`. A local address needs no key.

Ask TypeSafe Jev.

export THINKTHEN_BACKEND=typesafe
export TYPESAFE_API_KEY=...

Ask Liquid d1.

export THINKTHEN_BACKEND=liquid
export LIQUIDAI_API_KEY=...

Ask Ollama. This block names a second port, 11535, as the site's runs do. On the default port, leave THINKTHEN_BASE_URL out.

export THINKTHEN_BACKEND=ollama
export THINKTHEN_BASE_URL=http://localhost:11535/v1

import assert from "node:assert/strict";
import * as tt from "thinkthen";

const question = "Does the customer ask for a refund?";
const broken = "Please refund my order. It arrived broken.";
const thanks = "Thanks for the quick help yesterday!";
const brokenIsRefund = (await tt.decide(
  question, broken,
)).value;
const thanksIsRefund = (await tt.decide(
  question, thanks,
)).value;
assert.equal(brokenIsRefund, true);
assert.equal(thanksIsRefund, false);

The configuration file's backend names a default backend for every run. The Configuration page shows the file.

OpenAI Decisions API from TypeScript

OpenAI announced its Decisions API on 2026-09-29 in its DevDay 2026 recap. OpenAI has published no address, schema or price, so ThinkThen cannot call it. The OpenAI Decisions API page says what ThinkThen knows.

What is different in TypeScript

An AbortSignal cancels the call, and the promise rejects at once.
Every call returns a promise for a Call. An array crosses once.

On GitHub: github.com/botassembly/thinkthen