From 5841b04fe73dae63ff18714a22e19804f029e87c Mon Sep 17 00:00:00 2001
From: Simon Klee <hello@simonklee.dk>
Date: Wed, 22 Jul 2026 15:42:12 +0200
Subject: [PATCH] tui: resolve default mini footer agent (#38315)

---
 packages/tui/src/mini/footer.ts       | 17 ++++++++++++-----
 packages/tui/test/mini/footer.test.ts | 17 +++++++++++++++--
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/packages/tui/src/mini/footer.ts b/packages/tui/src/mini/footer.ts
index 54b50953bf2..a403542219c 100644
--- a/packages/tui/src/mini/footer.ts
+++ b/packages/tui/src/mini/footer.ts
@@ -102,6 +102,11 @@ type RunFooterOptions = {
   subscribeThemeSignal: (listener: () => void) => () => void
 }
 
+export function resolveRunAgent(agents: RunAgent[], current: string | undefined) {
+  const selectable = agents.filter((agent) => agent.mode !== "subagent" && !agent.hidden)
+  return selectable.find((agent) => agent.id === current) ?? selectable.at(0)
+}
+
 const PERMISSION_ROWS = 12
 const FORM_ROWS = 14
 const SUBAGENT_ROWS = RUN_SUBAGENT_PANEL_ROWS
@@ -252,13 +257,15 @@ export class RunFooter implements FooterApi {
     const [providers, setProviders] = createSignal<RunProvider[] | undefined>()
     this.providers = providers
     this.setProviders = setProviders
-    const [currentAgentID, setCurrentAgentID] = createSignal(options.agent)
-    this.currentAgentID = currentAgentID
+    const [selectedAgentID, setCurrentAgentID] = createSignal(options.agent)
+    const currentAgent = () => resolveRunAgent(this.agents(), selectedAgentID())
+    this.currentAgentID = () => currentAgent()?.id ?? selectedAgentID()
     this.setCurrentAgentID = setCurrentAgentID
     this.currentAgent = () => {
-      const agent = currentAgentID()
-      if (!agent) return "Default"
-      return this.agents().find((item) => item.id === agent)?.name ?? Locale.titlecase(agent)
+      const agent = currentAgent()
+      if (agent) return agent.name
+      const selected = selectedAgentID()
+      return selected ? Locale.titlecase(selected) : "Default"
     }
     const [currentModel, setCurrentModel] = createSignal<RunInput["model"]>(options.model)
     this.currentModel = currentModel
diff --git a/packages/tui/test/mini/footer.test.ts b/packages/tui/test/mini/footer.test.ts
index e59813f9f7f..8fbf7fc686b 100644
--- a/packages/tui/test/mini/footer.test.ts
+++ b/packages/tui/test/mini/footer.test.ts
@@ -1,6 +1,6 @@
 import { expect, test } from "bun:test"
-import { coalesceProgressCommit } from "../../src/mini/footer"
-import type { StreamCommit } from "../../src/mini/types"
+import { coalesceProgressCommit, resolveRunAgent } from "../../src/mini/footer"
+import type { RunAgent, StreamCommit } from "../../src/mini/types"
 
 function progress(input: Partial<StreamCommit> = {}): StreamCommit {
   return {
@@ -23,3 +23,16 @@ test("coalesces progress only within the same message and tool state", () => {
     progress({ text: "onetwo", directory: "/latest" }),
   )
 })
+
+test("resolves the first selectable agent when none is selected", () => {
+  const agents: RunAgent[] = [
+    { id: "task", name: "Task", mode: "subagent", hidden: false },
+    { id: "secret", name: "Secret", mode: "primary", hidden: true },
+    { id: "build", name: "Build", mode: "primary", hidden: false },
+    { id: "plan", name: "Plan", mode: "primary", hidden: false },
+  ]
+
+  expect(resolveRunAgent(agents, undefined)?.id).toBe("build")
+  expect(resolveRunAgent(agents, "plan")?.id).toBe("plan")
+  expect(resolveRunAgent(agents, "missing")?.id).toBe("build")
+})