Introduction
Set up the LLMsRelay developer gateway with Anthropic-compatible and OpenAI-compatible API formats.
LLMsRelay is an independently operated API gateway. It is not affiliated with or endorsed by Anthropic, PBC. Product and model names are used only to describe compatibility.
Base URL: https://api.llmsrelay.com. Models: Returned by GET /v1/models for your key. API formats: Anthropic Messages + OpenAI Chat Completions. Auth: API3 key. Setup time: ~2 minutes.
LLMsRelay is an independently operated developer gateway. It supports Anthropic-compatible Messages API requests and OpenAI-compatible Chat Completions requests at https://api.llmsrelay.com. Use GET /v1/models with your key to retrieve currently available model IDs. The dashboard provides per-key allowed-model settings, request-rate limits, usage caps, and token-level usage reporting.
What the LLMsRelay Gateway Provides
The LLMsRelay gateway gives you compatible API access through one API key from the dashboard. It works with both the Anthropic Messages API and the OpenAI Chat Completions API, so you can plug it into SDKs, editors, agents, and automation tools that support a custom base URL.
| Area | What you get |
|---|---|
| Anthropic-compatible | POST /v1/messages with Anthropic-style request and SSE streaming |
| OpenAI-compatible | POST /v1/chat/completions and GET /v1/models |
| Model IDs | Returned by GET /v1/models for the authenticated key |
| Tooling | Works with Cursor, Claude Code, VS Code extensions, SDKs, and cURL |
| Billing | Platform usage is deducted according to the published rate card |
| Key controls | Allowed models, per-key rate limit (requests/min), and monthly credit cap |
Recommended Model IDs
These are the stable IDs we recommend in docs and clients:
claude-opus-4.8— newest Opus model for long, complex coding and agent sessionsclaude-opus-4.7claude-sonnet-4.6claude-haiku-4.5
Use the IDs returned by GET /v1/models for new setups. Do not depend on an assumed catalogue in production.
Short Aliases
For quick CLI experiments you can use short aliases that always resolve to the latest version of each tier:
opus→claude-opus-4.8sonnet→claude-sonnet-4.6haiku→claude-haiku-4.5
For production use pinned IDs — aliases will silently upgrade across major versions. See Models for full table.
Base URL Rules
- Anthropic SDK / raw Anthropic API: use
https://api.llmsrelay.com/v1 - OpenAI SDK / Cursor / VS Code OpenAI-compatible tools: use
https://api.llmsrelay.com/v1 - Claude Code: use
https://api.llmsrelay.comforANTHROPIC_BASE_URL(without/v1)