Claude API Gateway — Unified Access to All Claude Models
LLMsRelay API gateway provides unified access to Claude models via Anthropic-compatible and OpenAI-compatible endpoints. Choose Basic or Pro for Claude models.
TL;DR
LLMsRelay acts as an API gateway for Claude models — providing both Anthropic-native and OpenAI-compatible endpoints. Use a Basic or Pro key for Claude models; use a Codex key for OpenAI/GPT models.
What Is a Claude API Gateway?
A Claude API gateway is a proxy service that routes your requests to Anthropic's Claude models while adding convenience features: dual-format endpoints (Anthropic + OpenAI), instant signup, credit-based billing, and crypto payments.
The account balance is shared across keys. The key group determines the model family: Basic/Pro for Claude and Codex for OpenAI/GPT.
Two Endpoints, Matching Key Groups
| Endpoint | Base URL | Format | Best For |
|---|---|---|---|
| Anthropic Messages | https://api.llmsrelay.com/v1/messages | Anthropic SDK | Python/TS Anthropic SDK, Claude Code |
| OpenAI Compatible | https://api.llmsrelay.com/v1 | OpenAI SDK | Cursor, VS Code, any OpenAI-compatible tool |
Quick Examples
Anthropic Format
Anthropic-compatible requestbash
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!"}]
}'OpenAI Format
OpenAI-compatible requestbash
curl https://api.llmsrelay.com/v1/chat/completions \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-sonnet-4.6",
"max_tokens": 256,
"messages": [{"role": "user", "content": "Hello!"}]
}'Why Use a Gateway?
- No instant access or approval — sign up and get your API key in minutes
- OpenAI-compatible — use Claude in any tool that supports OpenAI format
- Flexible credit billing — one-time usage packs with no recurring charge
- Crypto payments — pay with Bitcoin, ETH, USDT — no credit card needed
- Global access — available worldwide, no regional restrictions
- Same models — Claude Opus 4.7, Sonnet 4.6, Haiku 4.5 at identical per-token rates
Gateway vs Direct Anthropic API
| Feature | LLMsRelay Gateway | Anthropic Direct |
|---|---|---|
| Signup | Instant | May require approval |
| OpenAI-compatible endpoint | ✅ Yes | ❌ No |
| Credit card required | No (crypto accepted) | Yes |
| Per-token pricing | Same rates | Same rates |
| IDE support | Cursor, VS Code, Claude Code | Cursor, VS Code, Claude Code |
| Regional availability | Worldwide | Limited regions |
| Billing model | Credits (pay as you go) | Monthly billing |
Supported Tools & Integrations
- Cursor IDE — AI-powered code editor
- VS Code Extensions — Continue, Cline, Roo Code
- Claude Code CLI — terminal AI assistant
- Python SDK — Anthropic & OpenAI libraries
- TypeScript SDK — Node.js integration
- Any OpenAI-compatible tool — LangChain, LlamaIndex, etc.