diff --git a/packages/views/agents/components/tabs/activity-tab.tsx b/packages/views/agents/components/tabs/activity-tab.tsx
index 9018b42fb0..44770704e4 100644
--- a/packages/views/agents/components/tabs/activity-tab.tsx
+++ b/packages/views/agents/components/tabs/activity-tab.tsx
@@ -37,6 +37,7 @@ import { useWorkspacePaths } from "@multica/core/paths";
 import { issueDetailOptions } from "@multica/core/issues/queries";
 import { AppLink } from "../../../navigation";
 import { TranscriptButton } from "../../../common/task-transcript";
+import { AttributionBadge } from "../../../issues/components/attribution-badge";
 import { taskStatusConfig } from "../../config";
 import { failureReasonLabel } from "./task-failure";
 import { Sparkline } from "../sparkline";
@@ -639,6 +640,14 @@ function TaskRow({
               <span className="text-destructive">{failureLabel}</span>
             </>
           )}
+          {/* Accountable member (MUL-4302 §9): whose behalf this run is on.
+              Avatar-only keeps the meta line tight; renders nothing when the
+              run has no resolved responsible member. */}
+          <AttributionBadge
+            attribution={task.attribution}
+            variant="avatar"
+            className="ml-0.5"
+          />
         </div>
       </div>
 
diff --git a/packages/views/common/task-transcript/agent-transcript-dialog.tsx b/packages/views/common/task-transcript/agent-transcript-dialog.tsx
index 4fa8078862..c44b60a580 100644
--- a/packages/views/common/task-transcript/agent-transcript-dialog.tsx
+++ b/packages/views/common/task-transcript/agent-transcript-dialog.tsx
@@ -34,6 +34,7 @@ import {
   DropdownMenuItem,
 } from "@multica/ui/components/ui/dropdown-menu";
 import { ActorAvatar } from "../actor-avatar";
+import { AttributionBadge } from "../../issues/components/attribution-badge";
 import { api } from "@multica/core/api";
 import {
   useTranscriptViewStore,
@@ -500,6 +501,9 @@ export function AgentTranscriptDialog({
 
             {statusBadge}
 
+            {/* Accountable member (MUL-4302 §9): whose behalf this run is on. */}
+            <AttributionBadge attribution={task.attribution} className="shrink-0" />
+
             <div className="flex w-full max-w-full flex-wrap items-center justify-end gap-1 sm:ml-auto sm:w-auto">
               {detailSeqs.length > 0 && (
                 <button
diff --git a/packages/views/issues/components/attribution-badge.test.tsx b/packages/views/issues/components/attribution-badge.test.tsx
index 1019886b10..6cb92cb8d5 100644
--- a/packages/views/issues/components/attribution-badge.test.tsx
+++ b/packages/views/issues/components/attribution-badge.test.tsx
@@ -86,4 +86,31 @@ describe("AttributionBadge", () => {
     // Unknown sources fall through to the raw label so nothing renders blank.
     expect(screen.getByTitle("future_source")).toBeInTheDocument();
   });
+
+  it("avatar variant renders just the accountable member's avatar", () => {
+    const attribution: TaskAttribution = {
+      source: "direct_human",
+      precise: true,
+      initiator: { id: "u1", name: "Ada Lovelace" },
+    };
+    renderWithI18n(
+      <AttributionBadge attribution={attribution} variant="avatar" />,
+    );
+
+    // Only the avatar (name plumbs through the stub) — no "on behalf of" chip.
+    expect(screen.getByTestId("actor-avatar")).toHaveTextContent("Ada Lovelace");
+    expect(screen.queryByText("on behalf of Ada Lovelace")).toBeNull();
+  });
+
+  it("avatar variant renders nothing without an accountable member", () => {
+    const attribution: TaskAttribution = {
+      source: "unattributed",
+      precise: false,
+    };
+    const { container } = renderWithI18n(
+      <AttributionBadge attribution={attribution} variant="avatar" />,
+    );
+
+    expect(container).toBeEmptyDOMElement();
+  });
 });
diff --git a/packages/views/issues/components/attribution-badge.tsx b/packages/views/issues/components/attribution-badge.tsx
index 9ffa57784b..469d84048a 100644
--- a/packages/views/issues/components/attribution-badge.tsx
+++ b/packages/views/issues/components/attribution-badge.tsx
@@ -3,6 +3,11 @@
 import type { TaskAttribution } from "@multica/core/types";
 import { Badge } from "@multica/ui/components/ui/badge";
 import { ActorAvatar } from "@multica/ui/components/common/actor-avatar";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+} from "@multica/ui/components/ui/tooltip";
 import { cn } from "@multica/ui/lib/utils";
 import { useT } from "../../i18n";
 
@@ -17,18 +22,29 @@ function initialsOf(name: string): string {
 }
 
 /**
- * AttributionBadge renders the "on behalf of <member>" chip for an agent run
- * (MUL-4302 §9): who the run is accountable to, with the resolution source as a
- * tooltip and a distinct warning tone for degraded (non-precise) attribution.
- * Renders nothing when the task has no attribution (older backends) — the caller
- * should optional-chain `task.attribution`.
+ * AttributionBadge renders who an agent run is accountable to (MUL-4302 §9):
+ * the "on behalf of <member>" provenance, with the resolution source and a
+ * distinct warning tone for degraded (non-precise) attribution.
+ *
+ * Two shapes:
+ *  - `variant="badge"` (default): the full "on behalf of <name>" chip, with an
+ *    explicit "unattributed" chip when no responsible member resolved.
+ *  - `variant="avatar"`: just the accountable member's avatar, with the name +
+ *    source in a hover tooltip. Compact enough for a dense task row. Renders
+ *    nothing when there's no accountable member — an avatar-only surface has
+ *    nothing meaningful to show for an unattributed run.
+ *
+ * Renders nothing when the task has no attribution at all (older backends) —
+ * the caller should optional-chain `task.attribution`.
  */
 export function AttributionBadge({
   attribution,
   className,
+  variant = "badge",
 }: {
   attribution?: TaskAttribution;
   className?: string;
+  variant?: "badge" | "avatar";
 }) {
   const { t } = useT("issues");
   if (!attribution) return null;
@@ -70,6 +86,52 @@ export function AttributionBadge({
   const degraded = attribution.precise === false;
   const initiator = attribution.initiator;
 
+  // Avatar-only shape: just the accountable member's face, with the name +
+  // source in a hover tooltip. Nothing to show without an accountable member.
+  if (variant === "avatar") {
+    if (!initiator) return null;
+    const name = initiator.name || t(($) => $.execution_log.attribution.someone);
+    return (
+      <Tooltip>
+        <TooltipTrigger
+          render={
+            <span
+              className={cn(
+                "inline-flex shrink-0",
+                // A subtle ring flags degraded attribution so an owner-fallback
+                // face never silently reads as a precise responsible member.
+                degraded && "rounded-full ring-1 ring-warning/60",
+                className
+              )}
+            >
+              <ActorAvatar
+                name={name}
+                initials={initialsOf(name)}
+                avatarUrl={initiator.avatar_url}
+                size="xs"
+              />
+            </span>
+          }
+        />
+        <TooltipContent>
+          <div className="flex flex-col">
+            <span>
+              {t(($) => $.execution_log.attribution.on_behalf_of, { name })}
+            </span>
+            <span
+              className={cn(
+                "text-[11px]",
+                degraded ? "text-warning" : "text-muted-foreground"
+              )}
+            >
+              {sourceLabel}
+            </span>
+          </div>
+        </TooltipContent>
+      </Tooltip>
+    );
+  }
+
   if (!initiator) {
     return (
       <Badge