Buying a key
Set up the Claude API in two minutes
This is the fastest path from zero to a working Claude API call. Everything below uses the standard Anthropic Messages API, so it drops straight into your existing code.
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1. Create a key
Sign up, open the dashboard, and generate a key. It looks like sk-pool-… and works across every supported model.
See also: Use a Claude API key in Cursor
2. Set your endpoint
Point any Anthropic-compatible client at the gateway:
Base URL: https://api.apitoken.sale
Endpoint: POST /v1/messages
Headers: x-api-key: sk-pool-•••
anthropic-version: 2023-06-013. Send your first request
curl https://api.apitoken.sale/v1/messages \
-H "x-api-key: sk-pool-•••" \
-H "anthropic-version: 2023-06-01" \
-H "content-type: application/json" \
-d '{
"model": "claude-opus-4-8",
"max_tokens": 1024,
"messages": [{"role":"user","content":"Hello"}]
}'Common first-call errors
- 401 Unauthorized — missing or wrong x-api-key, or wrong base URL.
- 400 Bad Request — check the model ID and that max_tokens is set.
- 429 Too Many Requests — respect Retry-After and lower concurrency.
- 402 / insufficient balance — top up any whole-dollar amount.
Frequently asked questions
What base URL do I use?
Use https://api.apitoken.sale with any Anthropic-compatible tool and send requests to /v1/messages.
Which auth header is required?
Send x-api-key with your key and anthropic-version, exactly like the official Anthropic API.
Use Google or GitHub to create your key and get $10 of Claude usage before you top up.