How to Buy a Claude API Key
Step-by-step guide to purchasing a Claude API key through LLMsRelay — the fastest way to access Claude models via API.
Why You Need a Claude API Key
A Claude API key unlocks programmatic access to Anthropic's Claude models — including Claude Opus 4.8, Opus 4.7, Sonnet 4.6, and Haiku 4.5. Whether you're building AI-powered apps, integrating Claude into your IDE, or automating workflows, an API key is your starting point.
LLMsRelay provides instant access to Claude models without the complexity of managing Anthropic accounts directly. You get the same models, same capabilities, and pay-as-you-go pricing.
Step-by-Step: Getting Your API Key
1. Create a LLMsRelay Account
Visit llmsrelay.com and sign up. Registration is quick — you only need an email address.
2. Choose a Plan
LLMsRelay offers flexible credit-based plans. Choose a package that fits your needs:
- Starter — 1,000 credits, ideal for testing and small projects
- Pro — 5,000 credits with priority support
- Enterprise — 10,000+ credits with dedicated support
See full details on the Plans page.
3. Add Credits
Purchase credits through the dashboard. Payment is accepted via credit card or crypto.
4. Generate Your API Key
Navigate to API Keys in your dashboard and click Create Key. You can optionally set a name and credit limit per key.
5. Start Making Requests
Use your key with the Claude Code API endpoint:
curl https://api.llmsrelay.com/v1/messages \
-H "x-api-key: YOUR_API_KEY" \
-H "content-type: application/json" \
-H "anthropic-version: 2023-06-01" \
-d '{
"model": "claude-sonnet-4.6",
"max_tokens": 256,
"messages": [{"role": "user", "content": "Hello, Claude!"}]
}'Frequently Asked Questions
Can I use this key with Cursor, VS Code, or Claude Code?
Yes. LLMsRelay API keys are compatible with all major IDE integrations. See our IDE Integration guide for setup instructions.
Is there a pay-as-you-go starter ($5)?
LLMsRelay uses pay-as-you-go pricing. You only pay for what you use — start with the smallest credit package to test the service.
How is this different from Anthropic's direct API?
LLMsRelay proxies requests to the same Claude models. Benefits include simplified billing, flexible payment options (card & crypto), per-key limits, and instant setup. Read our detailed comparison.