Guides

Anthropic API

The gateway serves the Anthropic Messages API at /v1/messages, so the Anthropic SDKs and Claude Code work against it unchanged. It is a translation onto the same chat surface, so every catalog model is reachable, not just Claude.

The endpoint

POST https://api-pr-683.preview.experientiallabs.ai/v1/messages speaks the Anthropic Messages wire protocol. Authenticate with the Anthropic-style x-api-key header or with Authorization: Bearer — either carries the same xpl_ key. Name any slug from GET https://api-pr-683.preview.experientiallabs.ai/v1/models as the model.

POST /v1/messages

curl "https://api-pr-683.preview.experientiallabs.ai/v1/messages" \
  -H "x-api-key: $EXPLABS_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-opus-5", "max_tokens": 1024, "messages": [{"role": "user", "content": "Hello"}]}'

Streaming

Set stream: trueto receive Anthropic's server-sent event stream (message_start, content_block_delta, message_stop, and the rest), exactly as the Anthropic SDKs expect.

Streaming

curl -N "https://api-pr-683.preview.experientiallabs.ai/v1/messages" \
  -H "x-api-key: $EXPLABS_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-opus-5", "max_tokens": 1024, "stream": true, "messages": [{"role": "user", "content": "Hello"}]}'

What the translation lane drops

Because the lane maps onto the gateway's text-only chat surface, a few Anthropic features are deliberately unavailable:

Extended thinking is not available. A thinking config and thinking blocks are accepted and dropped, never returned.
Image and document blocks are rejected with 400; the chat surface is text-only.
Idempotency-Key is not honored on this lane (Anthropic defines none).
/v1/messages/count_tokens is not served.

Errors on /v1/messages use Anthropic's envelope, {"type":"error","error":{"type":"invalid_request_error","message":"..."}}, at the same HTTP statuses as the OpenAI routes. Branch on the status and the Anthropic error type; the underlying meanings match the Errors table.

Claude Code and other agents

Claude Code connects through this same lane by pointing ANTHROPIC_BASE_URL at the gateway and passing an xpl_ key as ANTHROPIC_AUTH_TOKEN. The per-agent configuration is in Coding agents.

The endpoint

Streaming

What the translation lane drops

Claude Code and other agents

See also