API Keys, Scopes, and the Prepaid USD Wallet Explained
Every computer use agent needs secure credentials. You must generate an API key, define the scopes you need, and fund a prepaid USD wallet so calls to endpoints like POST /v1/runs and POST /v1/sessions are charged correctly. This guide shows how to set up keys, assign scopes, and manage credits so you stay in control of costs.
How it works
Generate a key from the keys page (https://coasty.ai/developers/keys) and store it securely. Use the key in the X-API-Key header or Authorization: Bearer header for all requests to https://coasty.ai/v1. Scopes gate which operations the key can perform. Billing happens via a prepaid USD wallet where 1 credit equals $0.01. You can check your wallet balance via GET /v1/runs (no auth required) or monitor billing events through webhooks like the mentioned Coasty-Signature header. Idempotency-Key only provides replay safety for the 18 documented reserve-and-replay operations.
curl -X GET https://coasty.ai/v1/runs \
-H "X-API-Key: $COASTY_API_KEY"Scopes and access control
- ●Scopes gate which endpoints a key can access. Common scopes include machine management, workflow execution, and session prediction.
- ●A key with insufficient scope returns 403 INSUFFICIENT_SCOPE.
- ●You can create multiple keys with different scopes for different environments or teams.
- ●Scopes are enforced server-side and cannot be bypassed by the client.
Assign only the scopes you need to each key to minimize attack surface.
Where this beats brittle automation
Traditional automation relies on fragile selectors and explicit API calls. With a computer use API and agent, you generate credentials once, define scopes, and let the agent navigate UIs and react to real screen changes. You can fund the wallet, set webhooks, and monitor billing events in real time. This gives you full visibility and control over every dollar spent on agent steps, retries, and workflows.
Start building secure, billable computer use agents today. Generate a key, assign scopes, and fund your prepaid USD wallet at https://coasty.ai/developers.