Part 1: Your First Template

Build an API that runs code in sandboxes: a one-shot sandbox per request, and a sandbox per user that keeps their files.

The finished code is in examples/e2b-agent-sandbox.

Prerequisites

Finish E2B setup and Cloudflare setup.

Declare the template

src/Sandbox.ts

import * as Dockerfile from "@alchemy.run/docker/Dockerfile";
import * as E2B from "@alchemy.run/e2b";

export const Agent = E2B.Template("Agent", {
  dockerfile: Dockerfile.inline`
    FROM node:22-bookworm
    RUN apt-get update && apt-get install -y git ripgrep
  `,
  cpuCount: 2,
  memoryMB: 2048,
});

Every sandbox boots from this image, with 2 vCPUs and 2 GiB of memory.

Add it to the Stack

alchemy.run.ts

import * as Cloudflare from "@alchemy.run/cloudflare";
import * as E2B from "@alchemy.run/e2b";
import * as Alchemy from "alchemy";
import * as Effect from "effect/Effect";
import * as Layer from "effect/Layer";
import { Agent } from "./src/Sandbox.ts";

export default Alchemy.Stack(
  "E2BAgentSandboxExample",
  {
    providers: Layer.mergeAll(Cloudflare.providers(), E2B.providers()),
    state: Alchemy.localState(),
  },
  Effect.gen(function* () {
    const agent = yield* Agent;
    return { templateId: agent.templateId };
  }),
);

Deploy

alchemy deploy

E2B builds the template on its side; you don’t need Docker. The first build takes a minute or two. Later deploys rebuild only when the Dockerfile changes.

Next

Part 2 adds a Worker that creates sandboxes from this template.