Introduction

ai-effect wraps the Vercel AI SDK so its functions return Effects.

ai-effect wraps the AI SDK’s generateText, streamText, tool, ToolLoopAgent, embed, embedMany and rerank so they return Effects, and streams become Effect Streams. Callbacks and tool execute functions are Effects that can use your services, and a failed call fails with a typed AiError that says why. It also adds UI message streams for chat UIs and tracing of every call.

Use the AI SDK docs for options and result shapes: the wrapped functions take the same options, and return the same results except for streamText and ToolLoopAgent.stream. These docs cover only what changes.

Install

pnpm add ai-effect ai effect

ai (v7) and effect (v4) are peer dependencies, so your app shares one copy of each with this package. The package is ESM only, and its version tracks the AI SDK major: ai-effect@7 wraps ai@7.

First example

import { Ai, generateText } from 'ai-effect';
import { Effect } from 'effect';

const program = Effect.gen(function* () {
	const result = yield* generateText({
		model: 'openai/gpt-5',
		prompt: 'What is the capital of France?',
	});
	console.log(result.text);
});

program.pipe(Effect.provide(Ai.layer), Effect.runPromise);

result is the AI SDK’s own result object. Ai.layer is explained in Setup.