Tool Compatibility
Which base URL should you paste into your tool? Almost every issue comes down to one of two answers:
- OpenAI-style tools need
https://synthorai.io/v1(include the/v1). - Anthropic-style tools need
https://synthorai.io(no/v1— the SDK appends it).
Dedicated step-by-step guides: Claude Code, OpenAI Codex CLI, and OpenClaw.
Quick reference
| Tool | Base URL to paste | Key field / env var |
|---|---|---|
| Claude Code (CLI) | https://synthorai.io | ANTHROPIC_API_KEY |
| Anthropic Python / Node SDK | https://synthorai.io | api_key= (constructor) |
| OpenAI Codex CLI | https://synthorai.io/v1 | OPENAI_API_KEY |
| OpenAI Python / Node SDK | https://synthorai.io/v1 | api_key= (constructor) |
| OpenClaw (provider.type=openai) | https://synthorai.io/v1 | providers.X.api_key |
| OpenClaw (provider.type=anthropic) | https://synthorai.io | providers.X.api_key |
| Cursor (OpenAI override) | https://synthorai.io/v1 | Settings → API Key |
| Continue (config.json) | https://synthorai.io/v1 | models[].apiKey |
| Aider | https://synthorai.io/v1 | OPENAI_API_KEY |
| LangChain ChatOpenAI | https://synthorai.io/v1 | openai_api_key |
| LangChain ChatAnthropic | https://synthorai.io | anthropic_api_key |
| LiteLLM proxy | see LiteLLM config | api_key per route |
| Raw curl (OpenAI-style) | https://synthorai.io/v1/... | Authorization: Bearer |
| Raw curl (Anthropic-style) | https://synthorai.io/v1/messages | x-api-key header |
Which protocol does each tool speak?
The protocol the tool uses determines which upstream models it can reach through the gateway:
- OpenAI Chat Completions (
/v1/chat/completions) — routes to any chat model: OpenAI, Anthropic, Google, Qwen, DeepSeek, and more. This is the universal path — the default for Codex, Aider, Cursor, Continue, OpenClaw-OpenAI, LangChain ChatOpenAI, etc. - Anthropic Messages (
/v1/messages) — routes only to Claude-family models via Anthropic or Bedrock-Anthropic channels. Used by Claude Code, the Anthropic SDKs, OpenClaw-Anthropic, and LangChain ChatAnthropic.
✦
If a tool isn't listed, try the OpenAI shape first (https://synthorai.io/v1 + any chat model). That covers 90% of community integrations.
Once your tool is wired up, pick a default model from the model price comparison — or estimate what a month of usage costs with the LLM cost calculator.