spine-envoy is a transport boundary. It assembles no recommendation and never interprets provider output. Use scripts/run.sh with a non-empty prompt and output path. The script probes the selected route, records its liveness outcome, and invokes an external CLI. It rejects recursion and malformed or empty output.

Auth and liveness probes run with stdin disconnected, TERM=dumb, and color disabled by default. When a provider still emits terminal decoration, the probe parser removes ANSI/VT control sequences before validating structured output. A malformed probe response is reported as a parse failure, separately from an unavailable or unauthenticated provider; an explicitly targeted healthy provider keeps its requested and actual route lineage.