From 509017eda9ec7a183e5362eecef727b233ded33a Mon Sep 17 00:00:00 2001
From: roboomp <omp@can.ac>
Date: Wed, 22 Jul 2026 19:24:32 +0000
Subject: [PATCH] fix(tui): honored observed fallback flag on live hub rows

- Merged the executor-reported fallback flag into the live-session badge path so a Fireworks Fast to base degrade (which arms no session retry state) keeps its provenance.
- Added a live-row regression test for a fallback that populates no retryFallbackModel.

Fixes #6316
---
 .../src/modes/components/agent-hub.ts         | 21 ++++++----
 .../test/agent-hub-ordering.test.ts           | 42 +++++++++++++++++++
 2 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/packages/coding-agent/src/modes/components/agent-hub.ts b/packages/coding-agent/src/modes/components/agent-hub.ts
index 6c22cd764..07fb449bb 100644
--- a/packages/coding-agent/src/modes/components/agent-hub.ts
+++ b/packages/coding-agent/src/modes/components/agent-hub.ts
@@ -95,21 +95,24 @@ function formatResolvedModelBadge(resolved: string, preserveProvider = false): s
  * (e.g. a parked historical agent restored from disk).
  */
 function modelBadge(ref: AgentRef, observed: ObservableSession | undefined): string | undefined {
-	const fallback = ref.session?.retryFallbackModel;
-	if (fallback) {
-		return `${theme.fg("warning", "fallback →")} ${formatResolvedModelBadge(fallback, true)}`;
+	const progress = observed?.progress;
+	// Prefer the live session's own resolved fallback selector; else honor the
+	// executor-reported fallback flag. The latter covers observer-only rows (no
+	// live session) AND live rows whose fallback armed no session retry state —
+	// e.g. the Fireworks Fast → base degrade, which emits `retry_fallback_applied`
+	// without populating `#activeRetryFallback`, so `retryFallbackModel` is undefined.
+	const fallbackSelector =
+		ref.session?.retryFallbackModel ?? (progress?.resolvedModelIsFallback ? progress.resolvedModel : undefined);
+	if (fallbackSelector) {
+		return `${theme.fg("warning", "fallback →")} ${formatResolvedModelBadge(fallbackSelector, true)}`;
 	}
 	const model = ref.session?.model;
 	if (model) {
 		const level = model.thinking ? ref.session?.thinkingLevel : undefined;
 		return formatModelBadge(model.id, level);
 	}
-	const resolved = observed?.progress?.resolvedModel;
-	if (!resolved) return undefined;
-	if (observed?.progress?.resolvedModelIsFallback) {
-		return `${theme.fg("warning", "fallback →")} ${formatResolvedModelBadge(resolved, true)}`;
-	}
-	return formatResolvedModelBadge(resolved);
+	const resolved = progress?.resolvedModel;
+	return resolved ? formatResolvedModelBadge(resolved) : undefined;
 }
 
 /** Result of one host-backed transcript read for the Agent Hub viewer. */
diff --git a/packages/coding-agent/test/agent-hub-ordering.test.ts b/packages/coding-agent/test/agent-hub-ordering.test.ts
index c1ea67112..2588dd3eb 100644
--- a/packages/coding-agent/test/agent-hub-ordering.test.ts
+++ b/packages/coding-agent/test/agent-hub-ordering.test.ts
@@ -204,4 +204,46 @@ describe("Agent hub row ordering", () => {
 			hub.dispose();
 		}
 	});
+
+	it("flags a fallback badge for a live row whose fallback armed no session retry state", () => {
+		geometry = stubStdoutGeometry(120);
+		const agents = new AgentRegistry();
+		// Live session with a resolved model but no `retryFallbackModel` — the
+		// Fireworks Fast → base degrade emits `retry_fallback_applied` without
+		// arming `#activeRetryFallback`, so the badge must fall back to the
+		// executor-reported progress flag.
+		const session = { model: { id: "kimi-k2" }, retryFallbackModel: undefined } as unknown as AgentSession;
+		agents.register({ id: "FastAgent", displayName: "Fast Agent", kind: "sub", session });
+
+		const observers = new SessionObserverRegistry();
+		vi.spyOn(observers, "getSessions").mockReturnValue([
+			{
+				id: "FastAgent",
+				kind: "subagent",
+				label: "Subagent",
+				status: "active",
+				lastUpdate: Date.now(),
+				progress: {
+					resolvedModel: "fireworks/kimi-k2",
+					resolvedModelIsFallback: true,
+				} as never,
+			},
+		]);
+
+		const hub = new AgentHubOverlayComponent({
+			observers,
+			hubKeys: [],
+			onDone: () => {},
+			requestRender: () => {},
+			registry: agents,
+			irc: new IrcBus(agents),
+			focusAgent: async () => {},
+		});
+
+		try {
+			expect(Bun.stripANSI(hub.render(120).join("\n"))).toContain("fallback → fireworks/kimi-k2");
+		} finally {
+			hub.dispose();
+		}
+	});
 });