Canary of a model's newer weights: ctl model canary, promote and canaries, rolled back by itself when it serves worse

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/control/adminapi/api.go

@@ -154,6 +154,7 @@ func (a *API) Register(mux *http.ServeMux) {
 	mux.HandleFunc("POST /api/v1/updates/check", a.checkUpdates)
 	mux.HandleFunc("POST /api/v1/models/{name}/update", a.updateModel)
 	mux.HandleFunc("POST /api/v1/models/{name}/rollback", a.rollbackModel)
+	a.registerCanary(mux)
 	mux.HandleFunc("POST /api/v1/models/{name}/origin", a.setOrigin)
 	mux.HandleFunc("GET /api/v1/plan", a.planModel)
 	mux.HandleFunc("POST /api/v1/metrics/range", a.metricsBatch)
@@ -330,6 +331,10 @@ func loadView(l *inventory.Load, now time.Time) *LoadView {
 // ModelView is a model as `ctl models` shows it.
 type ModelView struct {
 	Name string `json:"name"`
+	// Canary is a share of its requests sent to a candidate; CanaryOf is
+	// set on the candidate, naming the model it is a canary of.
+	Canary   *catalog.Canary `json:"canary,omitempty"`
+	CanaryOf string          `json:"canary_of,omitempty"`
 	// Description is what the model is for, when somebody said.
 	Description string   `json:"description,omitempty"`
 	Aliases     []string `json:"aliases,omitempty"`
@@ -651,6 +656,7 @@ func (a *API) Models() []ModelView {
 			Parked: h.Parked, Reason: h.Reason, Unplaceable: h.Unplaceable,
 			Class: m.EffectiveClass(), Owner: m.Owner, Preempted: h.Preempted, HeldFor: h.HeldFor,
 			External: externalLabel(m), Adapters: m.Adapters,
+			Canary: m.Canary, CanaryOf: a.ctl.Catalog().CanaryOf(m.Name),
 		}
 		for _, p := range m.Profiles {
 			v.Profiles = append(v.Profiles, p.Name)