Runtime generations

A runtime generation is the immutable, compiled representation of every deployed artifact and environment-scoped resource a gateway needs to serve traffic.

Apply sequence

1. The control plane records deployment intent and emits an invalidation signal.
2. The gateway backend constructs the environment snapshot from durable state.
3. Gateway pods receive snapshot metadata and content-addressed resources.
4. Each pod verifies, parses, validates, and compiles the candidate generation.
5. The pod atomically swaps the active generation.
6. The previous generation becomes eligible for disposal only after in-flight requests release it.

Last-known-good behavior

If any candidate resource is missing, corrupt, invalid, or cannot compile, the gateway rejects the candidate and continues serving the previous generation. The failure is reported through runtime status; readiness remains tied to the ability to serve traffic, not to configuration freshness.

Request execution

Once a route is selected, the gateway executes ordered request policies, calls the upstream, then executes response policies. A policy failure with onError: fault enters the fault flow; onError: continue records the failure and advances to the next step.

Streaming traffic remains streaming. Steps that require a buffered body are skipped for opaque streaming requests or responses, while header-only and identity policies can continue.