diff --git a/.changeset/board-post-sending-route.md b/.changeset/board-post-sending-route.md
new file mode 100644
index 000000000000..ee7269f50f7a
--- /dev/null
+++ b/.changeset/board-post-sending-route.md
@@ -0,0 +1,5 @@
+---
+"kilo-code": patch
+---
+
+Resolve agent board route metadata from the session store while a message is still being written, so sender and recipient avatars and titles appear without waiting for the completed tool result.
diff --git a/packages/kilo-docs/public/img/screenshot-tests/kilo-vscode/visual-regression/composite-webview/agent-message-pending-chromium-linux.png b/packages/kilo-docs/public/img/screenshot-tests/kilo-vscode/visual-regression/composite-webview/agent-message-pending-chromium-linux.png
new file mode 100644
index 000000000000..6145eb763a5b
--- /dev/null
+++ b/packages/kilo-docs/public/img/screenshot-tests/kilo-vscode/visual-regression/composite-webview/agent-message-pending-chromium-linux.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:13354cd75ccb15dea7149f1fac7b8f8ec34cf38489a0ec473365274a4ed2bbc0
+size 5469
diff --git a/packages/kilo-ui/src/components/board-message.css b/packages/kilo-ui/src/components/board-message.css
index 28a4d7a94230..3e99183034bc 100644
--- a/packages/kilo-ui/src/components/board-message.css
+++ b/packages/kilo-ui/src/components/board-message.css
@@ -23,26 +23,52 @@
     max-width: none;
   }
 
-  > [data-component="icon"],
+  [data-slot="board-route-arrow"],
   [data-slot="board-route-recipient-icon"] {
     flex: 0 0 auto;
-  }
-
-  [data-slot="board-route-recipient-icon"] {
     display: inline-flex;
   }
 
-  /* Parent session marker: the spinner grid, static, in the avatar slot size. */
+  /* Parent session marker, in the avatar slot size. */
   .board-route-parent {
     width: 18px;
     color: var(--text-weak);
+  }
 
-    > rect {
-      animation: none !important;
+  /* While the post is still being written or stored, the sender glyph
+     pulses (see agent-avatar.css) and the arrow travels toward the
+     recipient in the same 1.4s rhythm, so the row reads as "sending". */
+  &[data-pending="true"] [data-slot="board-route-arrow"] {
+    color: var(--text-base);
+
+    > [data-component="icon"] {
+      animation: board-route-send 1.4s ease-in-out infinite both;
     }
   }
 }
 
+@keyframes board-route-send {
+  0% {
+    transform: translateX(-4px);
+    opacity: 0;
+  }
+  35%,
+  65% {
+    transform: translateX(0);
+    opacity: 1;
+  }
+  100% {
+    transform: translateX(4px);
+    opacity: 0;
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  [data-component="board-route"][data-pending="true"] [data-slot="board-route-arrow"] > [data-component="icon"] {
+    animation: none;
+  }
+}
+
 /* Clickable avatars appear both inside a route and as a tool-header stack, so
    these rules stay outside the route block. */
 [data-slot="board-route-avatar"][data-clickable="true"] {
diff --git a/packages/kilo-ui/src/components/board-message.tsx b/packages/kilo-ui/src/components/board-message.tsx
index f2a11c27acf0..b59697dc4684 100644
--- a/packages/kilo-ui/src/components/board-message.tsx
+++ b/packages/kilo-ui/src/components/board-message.tsx
@@ -7,7 +7,13 @@ import { Markdown } from "./markdown"
 import { Tooltip } from "./tooltip"
 
 // The parent session keeps the plain spinner grid; only subagents get a glyph.
-function Member(props: { id: string; label?: string; onSessionClick?: BoardSessionNavigation; semantic?: boolean }) {
+function Member(props: {
+  id: string
+  label?: string
+  onSessionClick?: BoardSessionNavigation
+  semantic?: boolean
+  active?: boolean
+}) {
   const open = () => props.onSessionClick
   const semantic = () => props.semantic !== false
   const clickable = () => props.id !== "main" && !!open()
@@ -29,7 +35,7 @@ function Member(props: { id: string; label?: string; onSessionClick?: BoardSessi
 
   return (
     <Show when={props.id !== "main"} fallback={<Icon class="board-route-parent" name="task" size="small" />}>
-      <Show when={clickable()} fallback={<AgentAvatar id={props.id} />}>
+      <Show when={clickable()} fallback={<AgentAvatar id={props.id} status={props.active ? "running" : undefined} />}>
         <span
           data-slot="board-route-avatar"
           data-clickable="true"
@@ -40,7 +46,7 @@ function Member(props: { id: string; label?: string; onSessionClick?: BoardSessi
           onClick={click}
           onKeyDown={semantic() ? key : undefined}
         >
-          <AgentAvatar id={props.id} />
+          <AgentAvatar id={props.id} status={props.active ? "running" : undefined} />
         </span>
       </Show>
     </Show>
@@ -72,7 +78,8 @@ type Route = {
   semantic?: boolean
 }
 
-export function BoardRoute(props: Route) {
+/** `pending` animates the route while the post is still being written or stored. */
+export function BoardRoute(props: Route & { pending?: boolean }) {
   const i18n = useI18n()
   const ids = useAgentAvatarIds()
   const open = () => props.onSessionClick
@@ -105,10 +112,11 @@ export function BoardRoute(props: Route) {
     <span
       data-component="board-route"
       data-broadcast={to() === "ALL"}
+      data-pending={props.pending ? "true" : undefined}
       role="group"
       aria-label={i18n.t("ui.messagePart.board.route", { from: sender(), to: recipient() })}
     >
-      <Member id={from()} label={sender()} onSessionClick={open()} semantic={props.semantic} />
+      <Member id={from()} label={sender()} onSessionClick={open()} semantic={props.semantic} active={props.pending} />
       <Tooltip
         class="board-route-member board-route-sender"
         contentClass="board-route-tooltip"
@@ -116,11 +124,21 @@ export function BoardRoute(props: Route) {
       >
         {sender()}
       </Tooltip>
-      <Icon name="arrow-right" size="small" />
+      <span data-slot="board-route-arrow">
+        <Icon name="arrow-right" size="small" />
+      </span>
       <span data-slot="board-route-recipient-icon" data-broadcast={to() === "ALL"}>
         <Show
           when={to() === "ALL"}
-          fallback={<Member id={to()} label={recipient()} onSessionClick={open()} semantic={props.semantic} />}
+          fallback={
+            <Member
+              id={to()}
+              label={recipient()}
+              onSessionClick={open()}
+              semantic={props.semantic}
+              active={props.pending && !to()}
+            />
+          }
         >
           <Show
             when={broadcast().length > 0}
diff --git a/packages/kilo-ui/src/components/board-route.test.ts b/packages/kilo-ui/src/components/board-route.test.ts
new file mode 100644
index 000000000000..01ab2647396a
--- /dev/null
+++ b/packages/kilo-ui/src/components/board-route.test.ts
@@ -0,0 +1,55 @@
+import { describe, expect, test } from "bun:test"
+import { preview } from "./board-route"
+
+const sessions = [
+  { id: "root", title: "Fix comment UI cutoff issue" },
+  { id: "child", parentID: "root", title: "Find PR comment overflow (@explore subagent)" },
+  { id: "sibling", parentID: "root", title: "Check serializer compatibility" },
+  { id: "orphan", parentID: "missing", title: "Detached" },
+]
+
+describe("board route preview", () => {
+  test("maps the root session to main and resolves titles", () => {
+    expect(preview(sessions, "child", "main")).toEqual({
+      from: "child",
+      fromLabel: "Find PR comment overflow (@explore subagent)",
+      to: "main",
+      toLabel: "Fix comment UI cutoff issue",
+    })
+    expect(preview(sessions, "root", "child")).toEqual({
+      from: "main",
+      fromLabel: "Fix comment UI cutoff issue",
+      to: "child",
+      toLabel: "Find PR comment overflow (@explore subagent)",
+    })
+  })
+
+  test("aliases a recipient given by root ID to main", () => {
+    expect(preview(sessions, "child", "root")).toMatchObject({ to: "main", toLabel: "Fix comment UI cutoff issue" })
+  })
+
+  test("keeps broadcasts and hides unknown or partial recipient IDs", () => {
+    expect(preview(sessions, "child", "ALL")).toMatchObject({ to: "ALL", toLabel: undefined })
+    expect(preview(sessions, "child", "sib")).toMatchObject({ to: "", toLabel: undefined })
+    expect(preview(sessions, "child", undefined)).toMatchObject({ to: "", toLabel: undefined })
+    expect(preview(sessions, "child", "sibling")).toMatchObject({
+      to: "sibling",
+      toLabel: "Check serializer compatibility",
+    })
+  })
+
+  test("does not guess main when the lineage is incomplete", () => {
+    expect(preview(sessions, "orphan", "main")).toEqual({
+      from: "orphan",
+      fromLabel: "Detached",
+      to: "",
+      toLabel: undefined,
+    })
+    expect(preview([], "unknown", "main")).toEqual({
+      from: "unknown",
+      fromLabel: undefined,
+      to: "",
+      toLabel: undefined,
+    })
+  })
+})
diff --git a/packages/kilo-ui/src/components/board-route.ts b/packages/kilo-ui/src/components/board-route.ts
new file mode 100644
index 000000000000..4bee46badb37
--- /dev/null
+++ b/packages/kilo-ui/src/components/board-route.ts
@@ -0,0 +1,33 @@
+type Node = { id: string; parentID?: string; title?: string }
+
+const LIMIT = 32
+
+/**
+ * Optimistic route for a board_post that is still pending. The stored route
+ * (from, to, labels) only arrives with the tool result, but the sender and the
+ * usual recipients are already in the session store, so the trigger can show
+ * the real avatars and titles while the model still streams the message body.
+ * Unknown or partially streamed recipient IDs resolve to "" so the avatar does
+ * not flicker through hash colors.
+ */
+export function preview(sessions: readonly Node[], sessionID: string, to: unknown) {
+  const byID = new Map(sessions.map((node) => [node.id, node]))
+  const root = (id: string, depth = 0): string | undefined => {
+    const node = byID.get(id)
+    if (!node) return undefined
+    if (!node.parentID) return node.id
+    if (depth >= LIMIT) return undefined
+    return root(node.parentID, depth + 1)
+  }
+  const top = root(sessionID)
+  const alias = (id: string) => (top && id === top ? "main" : id)
+  const label = (id: string) => byID.get(id)?.title?.trim() || undefined
+  const value = typeof to === "string" ? to.trim() : ""
+  const target = (() => {
+    if (value === "ALL") return { id: "ALL", label: undefined }
+    if (value === "main") return { id: top ? "main" : "", label: top ? label(top) : undefined }
+    if (!byID.has(value)) return { id: "", label: undefined }
+    return { id: alias(value), label: label(value) }
+  })()
+  return { from: alias(sessionID), fromLabel: label(sessionID), to: target.id, toLabel: target.label }
+}
diff --git a/packages/kilo-ui/src/components/message-part.tsx b/packages/kilo-ui/src/components/message-part.tsx
index 7017df50d50a..f13230c25924 100644
--- a/packages/kilo-ui/src/components/message-part.tsx
+++ b/packages/kilo-ui/src/components/message-part.tsx
@@ -38,6 +38,7 @@ import { useClipboard } from "../context/clipboard"
 import { type UiI18n, useI18n } from "../context/i18n"
 import { BasicTool, useToolApprovalLine } from "./basic-tool"
 import { BoardMessage, BoardParticipantStack, BoardRoute } from "./board-message"
+import { preview } from "./board-route"
 import { AgentAvatar, taskStatus } from "./agent-avatar"
 import { Accordion } from "./accordion"
 import { StickyAccordionHeader } from "./sticky-accordion-header"
@@ -1096,6 +1097,7 @@ export interface ToolProps {
   tool: string
   partID?: string
   callID?: string
+  sessionID?: string
   output?: string
   status?: string
   attachments?: FilePart[]
@@ -1199,6 +1201,15 @@ function McpTool(props: ToolProps) {
     )
     return items.length === rows.length ? items : undefined
   })
+  // The stored route only arrives with the result. While the model still
+  // streams the post, derive the sender and recipient from the session store
+  // so the trigger shows the real avatars and titles from the first frame.
+  const data = props.tool === "board_post" ? useData() : undefined
+  const live = () => props.status === "pending" || props.status === "running"
+  const guess = createMemo(() => {
+    if (!data || !live() || !props.sessionID) return undefined
+    return preview(data.store.session, props.sessionID, props.input.to)
+  })
   const participants = createMemo(() => {
     const seen = new Set<string>()
     const ids: string[] = []
@@ -1220,10 +1231,11 @@ function McpTool(props: ToolProps) {
     if (props.tool === "board_post")
       return (
         <BoardRoute
-          from={props.metadata.from ?? result()?.from}
-          to={props.metadata.to ?? result()?.to ?? props.input.to}
-          fromLabel={props.metadata.fromLabel ?? result()?.fromLabel}
-          toLabel={props.metadata.toLabel ?? result()?.toLabel}
+          from={props.metadata.from ?? result()?.from ?? guess()?.from}
+          to={props.metadata.to ?? result()?.to ?? guess()?.to ?? props.input.to}
+          fromLabel={props.metadata.fromLabel ?? result()?.fromLabel ?? guess()?.fromLabel}
+          toLabel={props.metadata.toLabel ?? result()?.toLabel ?? guess()?.toLabel}
+          pending={live()}
           onSessionClick={navigate}
           semantic={false}
         />
@@ -1463,6 +1475,7 @@ PART_MAPPING["tool"] = function ToolPartDisplay(props) {
                 tool={part.tool}
                 partID={part.id}
                 callID={part.callID}
+                sessionID={part.sessionID}
                 metadata={meta()}
                 partMetadata={top()}
                 // @ts-expect-error
diff --git a/packages/kilo-vscode/webview-ui/src/stories/composite.stories.tsx b/packages/kilo-vscode/webview-ui/src/stories/composite.stories.tsx
index b811a51ba7e1..f21dd3f20d67 100644
--- a/packages/kilo-vscode/webview-ui/src/stories/composite.stories.tsx
+++ b/packages/kilo-vscode/webview-ui/src/stories/composite.stories.tsx
@@ -1410,6 +1410,53 @@ export const AgentMessages200: Story = {
   name: "Agent messages with long titles (200px)",
 }
 
+// A post that is still streaming: the route is derived from the session store
+// (sender title, recipient resolved to main) and the arrow animates.
+export const AgentMessagePending: Story = {
+  name: "Agent message, sending",
+  render: () => {
+    const parts: ToolPart[] = [
+      {
+        id: "part_board_pending",
+        sessionID: SESSION_ID,
+        messageID: ASST_MSG_ID,
+        type: "tool",
+        callID: "call_board_pending",
+        tool: "board_post",
+        state: {
+          status: "running",
+          input: { to: "main", type: "RESULT", body: "Parser checks are complete." },
+          title: "Post agent message",
+          metadata: {},
+          time: { start: now - 1000 },
+        },
+      },
+      {
+        id: "part_board_partial",
+        sessionID: SESSION_ID,
+        messageID: ASST_MSG_ID,
+        type: "tool",
+        callID: "call_board_partial",
+        tool: "board_post",
+        state: { status: "pending", input: { to: "ses_ser" }, raw: "" },
+      },
+    ]
+    const data = {
+      ...dataWith(parts),
+      session: [
+        { id: "ses_root", title: "Fix comment UI cutoff issue" },
+        { id: SESSION_ID, parentID: "ses_root", title: "Find PR comment overflow (@explore subagent)" },
+        { id: "ses_serializer", parentID: "ses_root", title: "Check serializer compatibility" },
+      ],
+    }
+    return (
+      <StoryProviders data={data} sessionID={SESSION_ID}>
+        <For each={parts}>{(part) => <Part part={part} message={baseAssistantMessage} />}</For>
+      </StoryProviders>
+    )
+  },
+}
+
 export const McpToolCards: Story = {
   name: "MCP Tool Cards — collapsed",
   render: () => {