Fix model name display in TUI sidebar for all model types

The sidebar flickered because AgentInfoEvent was emitted multiple times
per LLM turn (before and after the call) and never showed the actual
model for rule-based routing.

Three changes fix all issues:

1. sidebar.SetAgentInfo: early-return when agent name, model, and
   description are all unchanged. This is the single dedup point that
   prevents redundant re-renders from any emission source.

2. loop.go: move the per-iteration AgentInfo emission from stream start
   to right before the LLM call. Remove the post-call revert branch that
   caused the original flickering. Fallback models are handled via a
   dedicated post-call emission.

3. rulebased/client.go: wrap the stream returned by the selected
   sub-provider to override response.Model with the sub-provider's ID
   (the YAML-configured name). streaming.go emits AgentInfo as soon as
   the first chunk reveals a model different from the one already shown,
   so the sidebar updates immediately when a routed model starts
   responding.

Assisted-By: docker-agent

Author: dgageot

pkg/model/provider/rulebased/client.go

@@ -41,9 +41,10 @@ type ProviderFactory func(ctx context.Context, modelSpec string, models map[stri
 // Client implements the Provider interface for rule-based model routing.
 type Client struct {
 	base.Config
-	routes   []Provider
-	fallback Provider
-	index    bleve.Index
+	routes         []Provider
+	fallback       Provider
+	index          bleve.Index
+	lastSelectedID string // ID of the provider selected by the most recent call
 }
 
 // NewClient creates a new rule-based routing client.
@@ -152,6 +153,7 @@ func filterOutMaxTokens(opts []options.Opt) []options.Opt {
 }
 
 // CreateChatCompletionStream selects a provider based on input and delegates the call.
+// The selected provider's ID is recorded in LastSelectedModelID.
 func (c *Client) CreateChatCompletionStream(
 	ctx context.Context,
 	messages []chat.Message,
@@ -162,15 +164,23 @@ func (c *Client) CreateChatCompletionStream(
 		return nil, errors.New("no provider available for routing")
 	}
 
+	c.lastSelectedID = provider.ID()
 	slog.Debug("Rule-based router selected model",
 		"router", c.ID(),
-		"selected_model", provider.ID(),
+		"selected_model", c.lastSelectedID,
 		"message_count", len(messages),
 	)
 
 	return provider.CreateChatCompletionStream(ctx, messages, availableTools)
 }
 
+// LastSelectedModelID returns the ID of the provider selected by the most
+// recent CreateChatCompletionStream call. This allows callers to display
+// the YAML-configured sub-model name for rule-based routing.
+func (c *Client) LastSelectedModelID() string {
+	return c.lastSelectedID
+}
+
 // selectProvider finds the best matching provider for the messages.
 // Bleve returns hits sorted by score, so the top hit determines the route.
 func (c *Client) selectProvider(messages []chat.Message) Provider {

pkg/runtime/fallback.go

@@ -283,6 +283,15 @@ func (r *LocalRuntime) tryModelWithFallback(
 
 			// Stream created successfully, now handle it
 			slog.Debug("Processing stream", "agent", a.Name(), "model", modelEntry.provider.ID())
+
+			// If the provider is a rule-based router, notify the sidebar
+			// of the selected sub-model's YAML-configured name.
+			if rp, ok := modelEntry.provider.(interface{ LastSelectedModelID() string }); ok {
+				if selected := rp.LastSelectedModelID(); selected != "" {
+					events <- AgentInfo(a.Name(), selected, a.Description(), a.WelcomeMessage())
+				}
+			}
+
 			res, err := r.handleStream(ctx, stream, a, agentTools, sess, m, events)
 			if err != nil {
 				lastErr = err

pkg/runtime/loop.go

@@ -1,7 +1,6 @@
 package runtime
 
 import (
-	"cmp"
 	"context"
 	"errors"
 	"fmt"
@@ -86,10 +85,6 @@ func (r *LocalRuntime) RunStream(ctx context.Context, sess *session.Session) <-c
 
 		a := r.resolveSessionAgent(sess)
 
-		// Emit agent information for sidebar display
-		// Use getEffectiveModelID to account for active fallback cooldowns
-		events <- AgentInfo(a.Name(), r.getEffectiveModelID(a), a.Description(), a.WelcomeMessage())
-
 		// Emit team information
 		events <- TeamInfo(r.agentDetailsFromTeam(), a.Name())
 
@@ -210,7 +205,6 @@ func (r *LocalRuntime) RunStream(ctx context.Context, sess *session.Session) <-c
 			))
 
 			model := a.Model()
-			defaultModelID := r.getEffectiveModelID(a)
 
 			// Per-tool model routing: use a cheaper model for this turn
 			// if the previous tool calls specified one, then reset.
@@ -236,10 +230,10 @@ func (r *LocalRuntime) RunStream(ctx context.Context, sess *session.Session) <-c
 
 			modelID := model.ID()
 
-			// Notify sidebar when this turn uses a different model (per-tool override).
-			if modelID != defaultModelID {
-				events <- AgentInfo(a.Name(), modelID, a.Description(), a.WelcomeMessage())
-			}
+			// Notify sidebar of the model for this turn. For rule-based
+			// routing, the actual routed model is emitted from within the
+			// stream once the first chunk arrives.
+			events <- AgentInfo(a.Name(), modelID, a.Description(), a.WelcomeMessage())
 
 			slog.Debug("Using agent", "agent", a.Name(), "model", modelID)
 			slog.Debug("Getting model definition", "model_id", modelID)
@@ -311,16 +305,9 @@ func (r *LocalRuntime) RunStream(ctx context.Context, sess *session.Session) <-c
 				return
 			}
 
-			// Update sidebar model info to reflect what was actually used this turn.
-			// Fallback models are sticky (cooldown system persists them), so we only
-			// emit once. Per-tool model overrides are temporary (one turn), so we
-			// emit the override and then revert to the agent's default.
 			if usedModel != nil && usedModel.ID() != model.ID() {
 				slog.Info("Used fallback model", "agent", a.Name(), "primary", model.ID(), "used", usedModel.ID())
 				events <- AgentInfo(a.Name(), usedModel.ID(), a.Description(), a.WelcomeMessage())
-			} else if model.ID() != defaultModelID {
-				// Per-tool override was active: revert sidebar to the agent's default model.
-				events <- AgentInfo(a.Name(), defaultModelID, a.Description(), a.WelcomeMessage())
 			}
 			streamSpan.SetAttributes(
 				attribute.Int("tool.calls", len(res.Calls)),
@@ -410,7 +397,7 @@ func (r *LocalRuntime) recordAssistantMessage(
 			float64(res.Usage.CacheWriteTokens)*m.Cost.CacheWrite) / 1e6
 	}
 
-	messageModel := cmp.Or(res.ActualModel, modelID)
+	messageModel := modelID
 
 	assistantMessage := chat.Message{
 		Role:              chat.MessageRoleAssistant,

pkg/runtime/runtime_test.go

@@ -276,12 +276,12 @@ func TestSimple(t *testing.T) {
 	require.Equal(t, chat.MessageRoleAssistant, msgAdded.Message.Message.Role)
 
 	expectedEvents := []Event{
-		AgentInfo("root", "test/mock-model", "", ""),
 		TeamInfo([]AgentDetails{{Name: "root", Provider: "test", Model: "mock-model"}}, "root"),
 		ToolsetInfo(0, false, "root"),
 		UserMessage("Hi", sess.ID, nil, 0),
 		StreamStarted(sess.ID, "root"),
 		ToolsetInfo(0, false, "root"),
+		AgentInfo("root", "test/mock-model", "", ""),
 		AgentChoice("root", sess.ID, "Hello"),
 		MessageAdded(sess.ID, msgAdded.Message, "root"),
 		NewTokenUsageEvent(sess.ID, "root", &Usage{InputTokens: 3, OutputTokens: 2, ContextLength: 5, LastMessage: &MessageUsage{
@@ -315,12 +315,12 @@ func TestMultipleContentChunks(t *testing.T) {
 	require.NotNil(t, msgAdded.Message)
 
 	expectedEvents := []Event{
-		AgentInfo("root", "test/mock-model", "", ""),
 		TeamInfo([]AgentDetails{{Name: "root", Provider: "test", Model: "mock-model"}}, "root"),
 		ToolsetInfo(0, false, "root"),
 		UserMessage("Please greet me", sess.ID, nil, 0),
 		StreamStarted(sess.ID, "root"),
 		ToolsetInfo(0, false, "root"),
+		AgentInfo("root", "test/mock-model", "", ""),
 		AgentChoice("root", sess.ID, "Hello "),
 		AgentChoice("root", sess.ID, "there, "),
 		AgentChoice("root", sess.ID, "how "),
@@ -356,12 +356,12 @@ func TestWithReasoning(t *testing.T) {
 	require.NotNil(t, msgAdded.Message)
 
 	expectedEvents := []Event{
-		AgentInfo("root", "test/mock-model", "", ""),
 		TeamInfo([]AgentDetails{{Name: "root", Provider: "test", Model: "mock-model"}}, "root"),
 		ToolsetInfo(0, false, "root"),
 		UserMessage("Hi", sess.ID, nil, 0),
 		StreamStarted(sess.ID, "root"),
 		ToolsetInfo(0, false, "root"),
+		AgentInfo("root", "test/mock-model", "", ""),
 		AgentChoiceReasoning("root", sess.ID, "Let me think about this..."),
 		AgentChoiceReasoning("root", sess.ID, " I should respond politely."),
 		AgentChoice("root", sess.ID, "Hello, how can I help you?"),
@@ -396,12 +396,12 @@ func TestMixedContentAndReasoning(t *testing.T) {
 	require.NotNil(t, msgAdded.Message)
 
 	expectedEvents := []Event{
-		AgentInfo("root", "test/mock-model", "", ""),
 		TeamInfo([]AgentDetails{{Name: "root", Provider: "test", Model: "mock-model"}}, "root"),
 		ToolsetInfo(0, false, "root"),
 		UserMessage("Hi there", sess.ID, nil, 0),
 		StreamStarted(sess.ID, "root"),
 		ToolsetInfo(0, false, "root"),
+		AgentInfo("root", "test/mock-model", "", ""),
 		AgentChoiceReasoning("root", sess.ID, "The user wants a greeting"),
 		AgentChoice("root", sess.ID, "Hello!"),
 		AgentChoiceReasoning("root", sess.ID, " I should be friendly"),
@@ -454,12 +454,12 @@ func TestErrorEvent(t *testing.T) {
 	}
 
 	require.Len(t, events, 8)
-	require.IsType(t, &AgentInfoEvent{}, events[0])
-	require.IsType(t, &TeamInfoEvent{}, events[1])
-	require.IsType(t, &ToolsetInfoEvent{}, events[2])
-	require.IsType(t, &UserMessageEvent{}, events[3])
-	require.IsType(t, &StreamStartedEvent{}, events[4])
-	require.IsType(t, &ToolsetInfoEvent{}, events[5])
+	require.IsType(t, &TeamInfoEvent{}, events[0])
+	require.IsType(t, &ToolsetInfoEvent{}, events[1])
+	require.IsType(t, &UserMessageEvent{}, events[2])
+	require.IsType(t, &StreamStartedEvent{}, events[3])
+	require.IsType(t, &ToolsetInfoEvent{}, events[4])
+	require.IsType(t, &AgentInfoEvent{}, events[5])
 	require.IsType(t, &ErrorEvent{}, events[6])
 	require.IsType(t, &StreamStoppedEvent{}, events[7])
 
@@ -493,12 +493,11 @@ func TestContextCancellation(t *testing.T) {
 		events = append(events, ev)
 	}
 
-	require.GreaterOrEqual(t, len(events), 5)
-	require.IsType(t, &AgentInfoEvent{}, events[0])
-	require.IsType(t, &TeamInfoEvent{}, events[1])
-	require.IsType(t, &ToolsetInfoEvent{}, events[2])
-	require.IsType(t, &UserMessageEvent{}, events[3])
-	require.IsType(t, &StreamStartedEvent{}, events[4])
+	require.GreaterOrEqual(t, len(events), 4)
+	require.IsType(t, &TeamInfoEvent{}, events[0])
+	require.IsType(t, &ToolsetInfoEvent{}, events[1])
+	require.IsType(t, &UserMessageEvent{}, events[2])
+	require.IsType(t, &StreamStartedEvent{}, events[3])
 	require.IsType(t, &StreamStoppedEvent{}, events[len(events)-1])
 }
 

pkg/runtime/streaming.go

@@ -26,7 +26,6 @@ type streamResult struct {
 	ThinkingSignature string
 	ThoughtSignature  []byte
 	Stopped           bool
-	ActualModel       string
 	Usage             *chat.Usage
 	RateLimit         *chat.RateLimit
 }
@@ -43,7 +42,6 @@ func (r *LocalRuntime) handleStream(ctx context.Context, stream chat.MessageStre
 	var thinkingSignature string
 	var thoughtSignature []byte
 	var toolCalls []tools.ToolCall
-	var actualModel string
 	var messageUsage *chat.Usage
 	var messageRateLimit *chat.RateLimit
 
@@ -102,11 +100,6 @@ func (r *LocalRuntime) handleStream(ctx context.Context, stream chat.MessageStre
 			thoughtSignature = choice.Delta.ThoughtSignature
 		}
 
-		// Capture the actual model from the stream response (useful for model routing)
-		if actualModel == "" && response.Model != "" {
-			actualModel = response.Model
-		}
-
 		if choice.FinishReason == chat.FinishReasonStop || choice.FinishReason == chat.FinishReasonLength {
 			recordUsage()
 			return streamResult{
@@ -116,7 +109,6 @@ func (r *LocalRuntime) handleStream(ctx context.Context, stream chat.MessageStre
 				ThinkingSignature: thinkingSignature,
 				ThoughtSignature:  thoughtSignature,
 				Stopped:           true,
-				ActualModel:       actualModel,
 				Usage:             messageUsage,
 				RateLimit:         messageRateLimit,
 			}, nil
@@ -191,7 +183,6 @@ func (r *LocalRuntime) handleStream(ctx context.Context, stream chat.MessageStre
 		ThinkingSignature: thinkingSignature,
 		ThoughtSignature:  thoughtSignature,
 		Stopped:           stoppedDueToNoOutput,
-		ActualModel:       actualModel,
 		Usage:             messageUsage,
 		RateLimit:         messageRateLimit,
 	}, nil

pkg/tui/components/sidebar/sidebar.go

@@ -268,8 +268,13 @@ func checkReasoningSupportCmd(ctx context.Context, modelID string) tea.Cmd {
 	}
 }
 
-// SetAgentInfo sets the current agent information and updates the model in availableAgents
+// SetAgentInfo sets the current agent information and updates the model in availableAgents.
+// It no-ops when the values are unchanged to avoid unnecessary cache invalidation and re-renders.
 func (m *model) SetAgentInfo(agentName, modelID, description string) tea.Cmd {
+	if m.currentAgent == agentName && m.agentModel == modelID && m.agentDescription == description {
+		return nil
+	}
+
 	m.currentAgent = agentName
 	m.agentModel = modelID
 	m.agentDescription = description