A fallback chain tries one provider, then the next on failure, so a single provider outage doesn't take your app down. Declare it with the x-routeplane-provider header: a comma-separated list, most-preferred first.
Declare the chain
bashOpenAI → Anthropic → Gemini
curl -s https://<gateway-host>/v1/chat/completions \
-H 'content-type: application/json' \
-H 'x-routeplane-api-key: rp_...' \
-H 'x-routeplane-provider: openai,anthropic,gemini' \
-d '{"model":"gpt-4o-mini","messages":[{"role":"user","content":"hi"}]}'Drop the header to use the key's default provider. Routeplane advances to the next candidate on a retryable failure, and the per-provider circuit breaker keeps a failing upstream out of rotation.
Choose how candidates are ordered
By default the chain is honoured in priority order (left to right). Override it with x-routeplane-strategy:
| Strategy | Orders candidates by |
|---|---|
priority | The order you listed them (default). |
weighted | Configured weights. |
cost | Cheapest eligible candidate first. |
latency | Lowest observed latency first (per-provider EWMA). |
Note. Sovereign routing overrides any chain you specify: when a request carries regulated personal data, the residency lock wins. See Enforce data residency.
Want the whole policy, targets, retries, conditions, caching, saved server-side instead of in headers? See Routing configs.