Previously only retried on network errors (fetch exceptions). Now also
rotates to next proxy when upstream returns non-2xx (429 rate limit,
5xx, etc). Applies to both OpenAI and Anthropic endpoints.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- Create src/lib/anthropic-proxy.ts: accepts Anthropic Messages API
format (POST /v1/messages) and routes to the same backend providers
- Anthropic model names (claude-sonnet-4, claude-3-haiku, claude-opus-4)
map to backend models with full request/response translation
- Streaming (SSE) via Anthropic protocol: message_start,
content_block_delta, message_stop events
- Add /v1/messages route to server with CORS and proxy pool fallback
- Reuses MODEL_ROUTES from ai-proxy.ts for consistent backend routing
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
