diff --git a/apps/web/src/components/Sidebar.logic.test.ts b/apps/web/src/components/Sidebar.logic.test.ts
index e4fa68a65201b..e51ceae551ba6 100644
--- a/apps/web/src/components/Sidebar.logic.test.ts
+++ b/apps/web/src/components/Sidebar.logic.test.ts
@@ -15,6 +15,7 @@ import {
   pinOrderKeyBetween,
   resolveProjectStatusIndicator,
   resolveSidebarSweepKeys,
+  resolveSidebarRowStatus,
   resolveSidebarThreadStatus,
   resolveThreadStatusPill,
   resolveWorkingStartedAt,
@@ -339,6 +340,55 @@ describe("resolveSidebarThreadStatus", () => {
   });
 });
 
+describe("resolveSidebarRowStatus", () => {
+  const failedRuntime = {
+    status: "failed" as const,
+    activeRunId: null,
+    providerInstanceId: ProviderInstanceId.make("codex"),
+    providerName: "Codex",
+    lastError: "Provider turn failed.",
+    updatedAt: "2026-03-09T10:05:00.000Z",
+  };
+  const failed = {
+    hasActionableProposedPlan: false,
+    hasPendingApprovals: false,
+    hasPendingUserInput: false,
+    interactionMode: "default" as const,
+    runtime: failedRuntime,
+    latestRun: { ...makeLatestRun(), status: "failed" as const },
+  };
+
+  it("clears a failure once opened, without showing Done, and shows the next failure", () => {
+    expect(resolveSidebarRowStatus({ ...failed, lastVisitedAt: undefined })).toBe("failed");
+
+    const opened = { ...failed, lastVisitedAt: "2026-03-09T10:06:00.000Z" };
+    expect(resolveSidebarRowStatus(opened)).toBe("ready");
+    expect(hasUnseenCompletion(opened)).toBe(false);
+
+    const failedAgain = {
+      ...opened,
+      latestRun: { ...opened.latestRun, completedAt: "2026-03-09T10:10:00.000Z" },
+    };
+    expect(resolveSidebarRowStatus(failedAgain)).toBe("failed");
+  });
+
+  it("dates a failure without a completed run by the runtime update", () => {
+    const visitedAfter = "2026-03-09T10:06:00.000Z";
+    const visitedBefore = "2026-03-09T10:00:00.000Z";
+    const noCompletedAt = {
+      ...failed,
+      latestRun: { ...failed.latestRun, completedAt: null },
+    };
+    expect(resolveSidebarRowStatus({ ...noCompletedAt, lastVisitedAt: visitedAfter })).toBe(
+      "ready",
+    );
+
+    const noRun = { ...failed, latestRun: null };
+    expect(resolveSidebarRowStatus({ ...noRun, lastVisitedAt: visitedBefore })).toBe("failed");
+    expect(resolveSidebarRowStatus({ ...noRun, lastVisitedAt: visitedAfter })).toBe("ready");
+  });
+});
+
 describe("searchSidebarThreads", () => {
   const searchThread = (id: string, title: string, latestUserMessageAt: string) => ({
     environmentId: localEnvironmentId,
@@ -1445,5 +1495,11 @@ describe("resolveSidebarFolderDot", () => {
     expect(resolveSidebarFolderDot([idle, working])).toBe("working");
     expect(resolveSidebarFolderDot([working, unread])).toBe("unread");
     expect(resolveSidebarFolderDot([unread, limited])).toBe("attention");
+    // A failure the user already opened clears, like its row.
+    const failed = { ...idle, runtime: { ...runtime, status: "failed" as const } };
+    expect(resolveSidebarFolderDot([failed])).toBeNull();
+    expect(
+      resolveSidebarFolderDot([{ ...failed, lastVisitedAt: "2026-03-09T09:00:00.000Z" }]),
+    ).toBe("failed");
   });
 });
diff --git a/apps/web/src/components/Sidebar.logic.ts b/apps/web/src/components/Sidebar.logic.ts
index efd8244f8c2b2..966601616825b 100644
--- a/apps/web/src/components/Sidebar.logic.ts
+++ b/apps/web/src/components/Sidebar.logic.ts
@@ -697,13 +697,22 @@ export function hasUnseenCompletion(thread: ThreadStatusInput): boolean {
 }
 
 /** Unopened threads' failures still count as unseen, unlike completions. */
-function hasUnseenFailure(thread: ThreadStatusInput): boolean {
-  if (thread.latestRun?.status !== "failed") return false;
+function hasUnseenFailure(
+  thread: Pick<ThreadStatusInput, "latestRun" | "runtime" | "lastVisitedAt">,
+): boolean {
+  // Failed runs can lack completedAt, and a session can fail before any run.
+  const failedAt =
+    thread.latestRun?.status === "failed"
+      ? (thread.latestRun.completedAt ?? thread.runtime?.updatedAt)
+      : thread.runtime?.status === "failed"
+        ? thread.runtime.updatedAt
+        : undefined;
+  if (failedAt === undefined) return false;
   if (!thread.lastVisitedAt) return true;
-  const completedAt = Date.parse(thread.latestRun.completedAt ?? "");
-  const lastVisitedAt = Date.parse(thread.lastVisitedAt);
-  if (Number.isNaN(completedAt) || Number.isNaN(lastVisitedAt)) return true;
-  return completedAt > lastVisitedAt;
+  const failedAtMs = Date.parse(failedAt ?? "");
+  const lastVisitedAtMs = Date.parse(thread.lastVisitedAt);
+  if (Number.isNaN(failedAtMs) || Number.isNaN(lastVisitedAtMs)) return true;
+  return failedAtMs > lastVisitedAtMs;
 }
 
 // Suppress trailing double-click navigation; keyboard and synthetic clicks use detail 0.
@@ -872,6 +881,14 @@ export function resolveSidebarThreadStatus(thread: SidebarThreadStatusInput): Si
   return "ready";
 }
 
+/** Sidebar row status: a failure the user has already opened settles to ready, like Done. */
+export function resolveSidebarRowStatus(
+  thread: SidebarThreadStatusInput & Pick<ThreadStatusInput, "latestRun" | "lastVisitedAt">,
+): SidebarThreadStatus {
+  const status = resolveSidebarThreadStatus(thread);
+  return status === "failed" && !hasUnseenFailure(thread) ? "ready" : status;
+}
+
 /**
  * The dot on a closed boring-sidebar folder: the most urgent state among its
  * hidden threads. Waiting threads stay quiet, like their rows.
@@ -879,7 +896,7 @@ export function resolveSidebarThreadStatus(thread: SidebarThreadStatusInput): Si
 export function resolveSidebarFolderDot(
   threads: ReadonlyArray<ThreadStatusInput & SidebarThreadStatusInput>,
 ): "attention" | "failed" | "unread" | "working" | null {
-  const statuses = new Set(threads.map(resolveSidebarThreadStatus));
+  const statuses = new Set(threads.map(resolveSidebarRowStatus));
   if (
     statuses.has("input") ||
     statuses.has("approval") ||
@@ -891,7 +908,7 @@ export function resolveSidebarFolderDot(
   if (statuses.has("failed")) return "failed";
   // Rows show Done only for ready threads, so the dot follows the same rule.
   const hasUnread = threads.some(
-    (thread) => resolveSidebarThreadStatus(thread) === "ready" && hasUnseenCompletion(thread),
+    (thread) => resolveSidebarRowStatus(thread) === "ready" && hasUnseenCompletion(thread),
   );
   if (hasUnread) return "unread";
   if (statuses.has("working")) return "working";
diff --git a/apps/web/src/components/sidebar/SidebarThreadRow.tsx b/apps/web/src/components/sidebar/SidebarThreadRow.tsx
index eac7c8591fa1c..28431c0059970 100644
--- a/apps/web/src/components/sidebar/SidebarThreadRow.tsx
+++ b/apps/web/src/components/sidebar/SidebarThreadRow.tsx
@@ -79,7 +79,7 @@ import {
   hasUnseenCompletion,
   resolveSidebarRowAccessibility,
   type SidebarDropVerb,
-  resolveSidebarThreadStatus,
+  resolveSidebarRowStatus,
   resolveThreadLastVisitedAt,
   shouldRecedeSidebarThread,
   resolveWorkingStartedAt,
@@ -705,7 +705,7 @@ const SidebarThreadRow = memo(function SidebarThreadRow(props: SidebarThreadRowP
     : null;
 
   const isUnread = hasUnseenCompletion({ ...thread, lastVisitedAt });
-  const status = resolveSidebarThreadStatus(thread);
+  const status = resolveSidebarRowStatus({ ...thread, lastVisitedAt });
   const lastVisitedDate = lastVisitedAt === undefined ? null : parseTimestampDate(lastVisitedAt);
   const wokeAtDate = props.wokeAt === null ? null : parseTimestampDate(props.wokeAt);
   const isWoke =