API Keys, Scopes, and the Prepaid USD Wallet Explained
Every agent you deploy needs a key. That key needs limits so one account does not accidentally unlock the whole platform. The Coasty computer use API protects you with scoped keys and a prepaid USD wallet. You can grant read/write access only to specific endpoints, and you can only spend what you top up. No surprise monthly bills.
API keys and scopes
Keys live at https://coasty.ai/developers/keys. You create them there, and each key carries a set of scopes. Scopes gate access to resources, not just endpoints. For example, a key scoped to machines can provision cloud VMs but cannot submit task runs. This model prevents a misconfigured key from triggering expensive workflows.
- ●Create keys in the dashboard under /developers/keys.
- ●Scopes control which resources a key can access.
- ●403 INSUFFICIENT_SCOPE means your key lacks the right permission.
- ●Scopes are set per key and cannot be added retroactively.
Prepaid USD wallet
Coasty uses a prepaid USD wallet. One credit equals one cent. You top up the wallet, and the system deducts credits as you call endpoints. This gives you full visibility into usage and prevents unexpected charges. The wallet is separate from any account limits so you can cap spend at the credit level you choose.
- ●Wallet balance is in USD.
- ●1 credit = $0.01.
- ●You control spend by topping up.
- ●402 INSUFFICIENT_CREDITS triggers when the balance is too low.
# Create a key with scoped permissions (browser only) and check wallet balance
export COASTY_API_KEY="$COASTY_API_KEY"
# List runs (requires runs scope)
curl -X GET "https://coasty.ai/v1/runs" \
-H "X-API-Key: $COASTY_API_KEY" \
-H "Content-Type: application/json"Wallet balance endpoint
The wallet is managed via account-level calls, not per-key. You can check your current balance and see how many credits remain. This is useful for monitoring usage before you launch long-running workflows or commit to iterative task steps.
- ●Balance is reflected in the wallet, not per-key.
- ●Credits are deducted per step or endpoint call.
- ●402 INSUFFICIENT_CREDITS prevents new runs when the balance is exhausted.
- ●Reconciliation is as simple as checking the wallet balance.
Scope keys to what the agent actually needs and top up the wallet to match your budget.
Where this beats brittle automation
Traditional automation relies on brittle selectors like XPath or CSS classes that break every time a UI changes. The Coasty computer use API drives real desktops, browsers, and terminals by actually seeing the screen and acting like a human. You do not need to maintain fragile selectors, and you do not need to guess element positions. Just describe what you want in plain language, and the agent uses the computer use API to handle the rest. Scoped keys and prepaid credits let you scale that behavior safely across many machines.
Secure your computer use agents with scoped keys and spend only what you top up. Build reliable workflows, browsers, and desktop agents with the Coasty computer use API. Get your API key at https://coasty.ai/developers.