Failover

A route may declare an ordered chain of targets. Each target is attempted in turn until one returns a successful response.

The chain

A chain is a list of targets attached to a route in the console. A target names a provider and, optionally, a model and a credential.

route  POST /v1/messages
  ├─ 1. anthropic   claude-sonnet-5-5
  ├─ 2. bedrock     claude-sonnet-5-5
  └─ 3. openai      gpt-6-sol

Targets are attempted in listed order. The first target that returns a 2xx response ends the chain. Reordering the list is a console action and applies to in-flight traffic.

Attempt budgets

Each attempt carries its own timeout. A slow primary cannot consume the whole request deadline, because the deadline is divided across the chain rather than shared by it.

Budget	Applies to	Where it is set
Per attempt	One target, including retries against it	On the target
Per request	The whole chain, including every attempt	On the route

When the per-request budget is exhausted, the request ends with 504 and the envelope describes each attempt that was made.

Retries and rotation

A failed attempt is classified before any decision is taken. The class decides whether the same target is retried, whether the credential is rotated, or whether the chain advances.

• Transient failures retry the same target with exponential backoff and jitter.
• Credential-bound failures rotate to another key in the pool instead of waiting.
• Request-shaped failures do not retry at all; they end the request, because the same failure will occur against every target.

The full table is on the circuit breaking page, which shares the same classification.

When every target fails

The client receives a 503 whose body lists each attempt: the target, the status, and a truncated copy of the upstream response. The chain is recorded in order, including retries, so the reason for the final failure is readable without correlating logs.

Next

• Load balancing
• Circuit breaking