AI

Source: src/Cloudflare/Workers/AI.ts

The native Cloudflare Workers AI binding — run inference on Workers AI models directly from a Worker, with no AI Gateway (or any other cloud resource) required. This is the plain { type: "ai" } Worker binding: the runtime value is the same env.AI handle you would declare in wrangler.json.

AI is a single value that is at once the Binding.Service tag, the callable that produces an AIBinding, and the type. Declare it on a Worker’s env (it flows through InferEnv → the runtime Ai handle) or yield* it inside an Effect-native Worker to attach the binding and obtain the AIClient.

Use Cloudflare.AI.Gateway + QueryGateway instead when you want requests routed through an AI Gateway (caching, rate limiting, logs); use AI when you just want to call Workers AI models.

Effect-style Worker (recommended)

Cloudflare.Worker("AiWorker", { main: import.meta.url },
  Effect.gen(function* () {
    const ai = yield* Cloudflare.Workers.AI();
    return {
      fetch: Effect.gen(function* () {
        const result = yield* ai.run("@cf/meta/llama-3.3-70b-instruct-fp8-fast", {
          prompt: "What is the origin of the phrase Hello, World?",
        }).pipe(Effect.orDie);
        return yield* HttpServerResponse.json(result);
      }),
    };
  }).pipe(Effect.provide(Cloudflare.Workers.AIBinding)),
);

Effect AI LanguageModel

model(options) produces a Layer<LanguageModel, never, RuntimeContext> that translates LanguageModel.generateText / streamText calls (including tool calls) into ai.run(...) against the bound Workers AI model — the same adapter AI Gateway’s QueryGateway uses, minus the gateway routing.

const ai = yield* Cloudflare.Workers.AI();

const languageModel = ai.model({
  model: "@cf/meta/llama-3.3-70b-instruct-fp8-fast",
  parameters: { temperature: 0.7, maxTokens: 1024 },
});

const response = yield* LanguageModel.generateText({ prompt }).pipe(
  Effect.provide(languageModel),
);

Binding to an Async Worker

export const Worker = Cloudflare.Worker("Worker", {
  main: "./src/worker.ts",
  env: { AI: Cloudflare.Workers.AI() },
});

export type WorkerEnv = Cloudflare.InferEnv<typeof Worker>;
//   { AI: Ai }