Worldtree accepted the v1 wire validation green; contract rev 1.1 folds all three
consumer flags. Flag #1 surfaced a real provider constraint: first-message makes
the assistant seq 0 -> vLLM/openai_compat tolerate it (sindra unaffected), but
Anthropic-family providers 400 on an assistant-first array. Consumer must gate
first-message on provider compat; provider-agnostic normalization deferred.
Worldtree accepted the primitive as design item #347 (Worldtree-owned). Locked
constraint: Heimdall-gated with hide-existence — ungranted tenants get 404 (not
403), no advertised capability. Ratatoskr consumer side must tolerate per-tenant
absence: treat 404 as feature-absent -> graceful fallback, never capability-probe.