Get started with CoreWeave Sandboxes

Run a command in a sandbox on serverless capacity and print its output. No cluster setup is required.

Before you begin

Serverless sandboxes are generally available, and usage is billed. Access is enabled per organization. To request access for your organization, contact support. If your organization uses W&B Dedicated Cloud, follow Use sandboxes with W&B Dedicated Cloud.

Run your first sandbox

Choose the credential for the account that owns and is billed for your sandbox. A Forge API key supports serverless placement. A CoreWeave API access token supports serverless and CoreWeave Kubernetes Service (CKS) placement. For account requirements, see Choose and get credentials. Choose a credential tab, then verify the result.

Forge API key
CoreWeave API access token

Get your Forge API key. If you don’t have an account, sign up through the same link. Then set the key in your terminal. These examples explicitly select W&B authentication:

export WANDB_API_KEY="[WANDB-API-KEY]"

Python
TypeScript

With uv installed, save this as hello.py:

hello.py

from cwsandbox import AuthStrategy, Sandbox

with Sandbox.run(
    auth=AuthStrategy.WANDB,
    resources={"cpu": "1", "memory": "1Gi"},
) as sandbox:
    print(sandbox.exec(["echo", "Hello!"]).result().stdout)

Run it with Python 3.11 and the sandbox client. The command installs them if needed:

uv run --python 3.11 --with 'cwsandbox[wandb]>=1.14.2' hello.py

With Node.js 22 or later installed, install the client:

npm install @coreweave/cwsandbox

Save this as hello.mts:

hello.mts

import { createSandboxClient } from "@coreweave/cwsandbox/wandb";

const client = createSandboxClient({
  apiKey: process.env.WANDB_API_KEY,
});
const result = await client.withSandbox(
  async (sandbox) => sandbox.commands.run(["echo", "Hello!"]),
  { resources: { cpu: "1", memory: "1Gi" } },
);
console.log(result.stdout);

Run it with tsx:

npx --yes --package=tsx tsx hello.mts

The Forge API key uses the SDK’s existing W&B identifiers: WANDB_API_KEY, AuthStrategy.WANDB, and the TypeScript /wandb entry point.

Ask your administrator to create or update an Access Policy granting you the Sandbox User role. See Create an access policy for the steps.Create an API access token on the Tokens page, copy its Token Secret, and set it in your terminal:

export CWSANDBOX_API_KEY="[API-ACCESS-TOKEN]"

Python
TypeScript

With uv installed, save this as hello.py:

hello.py

from cwsandbox import AuthStrategy, Sandbox

with Sandbox.run(
    auth=AuthStrategy.COREWEAVE_API_KEY,
    resources={"cpu": "1", "memory": "1Gi"},
) as sandbox:
    print(sandbox.exec(["echo", "Hello!"]).result().stdout)

Run it with Python 3.11 and the sandbox client. The command installs them if needed:

uv run --python 3.11 --with 'cwsandbox>=1.10.0' hello.py

With Node.js 22 or later installed, install the client:

npm install @coreweave/cwsandbox

Save this as hello.mts:

hello.mts

import { createSandboxClientFromEnv } from "@coreweave/cwsandbox/node";

const client = createSandboxClientFromEnv();
const result = await client.withSandbox(
  async (sandbox) => sandbox.commands.run(["echo", "Hello!"]),
  { resources: { cpu: "1", memory: "1Gi" } },
);
console.log(result.stdout);

Run it with tsx:

npx --yes --package=tsx tsx hello.mts

Verify the result

The example prints the following output and stops the sandbox when it finishes:

Output

Hello!

The sandbox has 1 CPU and 1 GiB of memory. Serverless sets resource limits equal to requests. Change resources to choose its CPU and memory. For concurrent quotas, rate limits on create requests, and quota errors, see Limits and quotas.

Next steps

Continue with the guide for your workload:

Use your own compute: enable a runner on your cluster and run a sandbox there.
Sandbox placement and spillover: compare serverless and CKS capacity and configure fallback.
Run coding agents: connect a coding agent to a sandbox.
GPU sandboxes: request GPU access and run a GPU workload.
Python client: execute commands, work with files, and configure sandboxes.

Sandboxes

Use sandboxes

Manage sandboxes

Reference

Get started with CoreWeave Sandboxes

Before you begin

Run your first sandbox

Verify the result

Next steps

​Before you begin

​Run your first sandbox

​Verify the result

​Next steps

Before you begin

Run your first sandbox

Verify the result

Next steps