Deploy to Cloudflare Sandboxes

The backends/cloudflare/ directory implements the same execution contract as the local compose stack, running on Cloudflare Sandboxes (GA since April 2026). Sessions become Durable Object instances; the same ant beta:worker poll runs inside each one.

One-click deploy

Cloudflare Sandboxes require a Workers Paid plan with Containers enabled. Click the button to clone the repository into your connected GitHub or GitLab account, provide the required secrets, and deploy the backend.

Caution

The wrangler configuration lives in backends/cloudflare/, not the repository backends/cloudflare. When prompted, provide all three required secrets: ANTHROPIC_ENVIRONMENT_KEY, ANTHROPIC_ENVIRONMENT_ID, and SANDBOX_API_TOKEN, as described in step 2 below.

Manual deploy with wrangler

1. Authenticate and install dependencies.

   cd backends/cloudflare
   bun install
   bunx wrangler login

2. Add the required Worker secrets. These must be secrets, not plaintext vars — agent tool calls can read the worker environment.

   bunx wrangler secret put ANTHROPIC_ENVIRONMENT_KEY
   bunx wrangler secret put ANTHROPIC_ENVIRONMENT_ID
   bunx wrangler secret put SANDBOX_API_TOKEN

3. Deploy.

   bunx wrangler deploy

   The wrangler.jsonc instance_type defaults to lite. Raise it to a larger instance type if sessions require more memory or CPU.

Start a session

Note

Every route except /healthz requires an `Authorization: ****** header. The Worker returns 503 when the secret is not configured and 401 when the header is missing or wrong.

Once deployed, start the Anthropic worker inside a sandbox by posting to the session endpoint:

curl -X POST "https://claude-sandbox-cf.<your-subdomain>.workers.dev/sessions/<random-session-id>/ant" \
  -H "Authorization: ******"

MCP servers running inside the sandbox are reachable through the SDK’s native cloudflared quick tunnel; see sandbox.tunnels.get(port) in the Worker source.

Relationship to the local compose backend

Both backends implement the same contract. See the architecture explanation for a comparison.