fix(app): name and link the channel that sent an agent handoff

.lane/memory/apps/app/src/timeline.ts/01M4YQXGSB8HYNWEWT8HE54FVA-resolve-agent-prefix-only-am.md

@@ -0,0 +1,12 @@
+---
+id: 01M4YQXGSB8HYNWEWT8HE54FVA
+anchor: function sources
+created: 2026-10-15T02:58:00Z
+norm: '1'
+sig: 0ad9c2d0c83208a4
+body_hash: caee764965f73057
+raw_hash: cacc75e92aa998c6
+lines: 13-19
+---
+
+resolve agent@<prefix> only among channels on the viewed channel's host; prefixes are unique per host, not across hosts

.lane/memory/apps/host/src/worker.ts/01M4YQXGS3RQSHX8N6GH99R7D4-the-directory-s-self-name-st.md

@@ -0,0 +1,12 @@
+---
+id: 01M4YQXGS3RQSHX8N6GH99R7D4
+anchor: '@file'
+created: 2026-10-15T02:58:00Z
+norm: '1'
+sig: 1a43097a4e1ad24c
+body_hash: d306f7381f78d80e
+raw_hash: ddf38f30d6808a36
+lines: 1-194
+---
+
+the directory's self.name stays the channel's prefix, which the app resolves agent@<prefix> authors by

apps/app/src/app.tsx

@@ -654,11 +654,13 @@ export function App() {
 								<Channel
 									key={channel.id}
 									channel={channel}
+									channels={channels}
 									user={hello.user}
 									remote={channel.host !== hello.host}
 									draft={draft}
 									onDraftLoaded={() => setDraft(undefined)}
 									onSettings={() => setSettings(true)}
+									onOpen={select}
 								/>
 							)
 							: (

apps/app/src/channel.tsx

@@ -28,11 +28,13 @@ export type ChannelDraft = { channel: string; text: string };
 
 type Props = {
 	channel: Listing;
+	channels: Listing[];
 	user: string;
 	remote: boolean;
 	draft?: ChannelDraft;
 	onDraftLoaded: () => void;
 	onSettings?: () => void;
+	onOpen: (channel: Listing) => void;
 };
 
 const LINK = /https?:\/\/[^\s<>()[\]{}"'`]+/g;
@@ -197,7 +199,9 @@ export function ChannelDetails({ channel }: { channel: Listing }) {
 }
 
 /** A channel's tabs: its chat, plus Diff and Terminal views of that chat's lane. */
-export function Channel({ channel, user, remote, draft, onDraftLoaded, onSettings }: Props) {
+export function Channel(
+	{ channel, channels, user, remote, draft, onDraftLoaded, onSettings, onOpen }: Props,
+) {
 	const [changed, setChanged] = useState<boolean>();
 	const check = useRef({ busy: false, again: false });
 
@@ -242,11 +246,13 @@ export function Channel({ channel, user, remote, draft, onDraftLoaded, onSetting
 					return (
 						<Conversation
 							channel={channel}
+							channels={channels}
 							chat={chat}
 							user={user}
 							draft={draft?.channel === channel.id ? draft.text : undefined}
 							onDraftLoaded={onDraftLoaded}
 							onSettings={!remote && !channel.hosted ? onSettings : undefined}
+							onOpen={onOpen}
 							onWork={inspect}
 						/>
 					);

apps/app/src/conversation.tsx

@@ -7,24 +7,27 @@ import { Composer } from "./composer";
 import { publish } from "./details";
 import { host } from "./host";
 import { MessageQueue } from "./message-queue";
-import { toEvents } from "./timeline";
+import { sources, toEvents } from "./timeline";
 import { useTranscript } from "./transcript";
 import { Usage } from "./usage";
 
 type Props = {
 	channel: Listing;
+	/** Every listed channel, to name and open the channels that message this one. */
+	channels: Listing[];
 	chat: number;
 	user: string;
 	draft?: string;
 	onDraftLoaded: () => void;
 	onSettings?: () => void;
+	onOpen: (channel: Listing) => void;
 	/** Called once the chat loads and whenever its agent may have changed files since. */
 	onWork?: () => void;
 };
 
 /** One chat's timeline and composer over its transcript; the content of a Chat tab. */
 export function Conversation(
-	{ channel, chat: id, user, draft, onDraftLoaded, onSettings, onWork }: Props,
+	{ channel, channels, chat: id, user, draft, onDraftLoaded, onSettings, onOpen, onWork }: Props,
 ) {
 	const transcript = useTranscript(
 		channel.id,
@@ -35,6 +38,7 @@ export function Conversation(
 	const chat = transcript.info?.chats.find((value) => value.id === id);
 	const model = chat?.model || channel.model;
 	const people = useSyncExternalStore(host.subscribe, () => host.people);
+	const senders = useMemo(() => sources(channels, channel.host), [channels, channel.host]);
 	const events = useMemo(
 		() =>
 			toEvents(
@@ -46,6 +50,7 @@ export function Conversation(
 					model: model?.modelId,
 				},
 				people,
+				senders,
 				transcript.captions,
 				transcript.recaps,
 			),
@@ -56,6 +61,7 @@ export function Conversation(
 			transcript.draft,
 			model,
 			people,
+			senders,
 			transcript.captions,
 			transcript.recaps,
 		],
@@ -111,6 +117,10 @@ export function Conversation(
 							working={transcript.busy || undefined}
 							currentUser={{ login: user }}
 							avatars={avatars}
+							openSender={(sender) => {
+								const source = senders.get(sender);
+								return source && (() => onOpen(source));
+							}}
 							intro={{ name: channel.name, createdAt: Math.floor(channel.created / 1000) }}
 						/>
 					)
@@ -128,7 +138,9 @@ export function Conversation(
 					)}
 			</div>
 			<div className="utils:max-width relative z-20 shrink-0 px-3 pb-3">
-				{transcript.live && <MessageQueue messages={transcript.queue} people={people} />}
+				{transcript.live && (
+					<MessageQueue messages={transcript.queue} people={people} channels={senders} />
+				)}
 				<Composer
 					channel={channel}
 					chat={id}

apps/app/src/message-queue.tsx

@@ -1,9 +1,14 @@
 import type { QueuedMessage } from "@ace/channel/protocol";
+import type { Listing } from "@ace/host/protocol";
 
-/** Authors are Tailscale logins, named as the timeline names them. */
-export function MessageQueue(
-	{ messages, people }: { messages: QueuedMessage[]; people: Record<string, string> },
-) {
+import { authorName } from "./timeline";
+
+/** Authors are named as the timeline names them. */
+export function MessageQueue({ messages, people, channels }: {
+	messages: QueuedMessage[];
+	people: Record<string, string>;
+	channels: Map<string, Listing>;
+}) {
 	if (!messages.length) return null;
 	return (
 		<section
@@ -21,7 +26,7 @@ export function MessageQueue(
 					<li key={message.submission} className="px-3 py-2">
 						<div className="mb-1 flex min-w-0 items-center gap-2 text-muted-foreground">
 							<span className="truncate font-medium">
-								{people[message.author] || message.author.split("@")[0]}
+								{authorName(message.author, people, channels)}
 							</span>
 							<span className="shrink-0">{message.invoked ? "@ace" : "Chat"}</span>
 						</div>

apps/app/src/timeline.ts

@@ -1,11 +1,38 @@
-import type { People } from "@ace/host/protocol";
+import type { Listing, People } from "@ace/host/protocol";
 import type { Event } from "@ace/ui";
 
 import type { Item, Tool } from "./transcript";
 
 const AGENT = "ace:agent";
 const MENTION = /(?<=^|\s)@([a-zA-Z0-9_-]+)/g;
 
+/**
+ * Channels on the viewed channel's host keyed by the author their agent's messages carry. The prefix
+ * outlives renames, so messages sent before one still find their channel.
+ */
+export function sources(channels: Listing[], host: string): Map<string, Listing> {
+	return new Map(
+		channels.flatMap((channel) =>
+			channel.host === host && channel.prefix ? [[`agent@${channel.prefix}`, channel]] : []
+		),
+	);
+}
+
+/**
+ * Human authors are Tailscale logins; without a known GitHub login, the name before the domain
+ * reads as a handle. Agent authors name the chat or channel after the `@`, so they stay whole.
+ */
+export function authorName(
+	author: string,
+	people: People,
+	channels: Map<string, Listing>,
+): string {
+	const source = channels.get(author);
+	if (source) return `#${source.name}`;
+	if (author.startsWith("agent@")) return author;
+	return people[author] || author.split("@")[0]!;
+}
+
 function text(value: string): Event.Message.Content.Text {
 	const parts = [...value.matchAll(MENTION)].map((match) => ({
 		type: "mention" as const,
@@ -57,6 +84,7 @@ export function toEvents(
 	busy: boolean,
 	draft: { text: string; model?: string },
 	people: People,
+	channels: Map<string, Listing>,
 	captions: Record<string, string>,
 	recaps: Record<string, string>,
 ): Event[] {
@@ -71,12 +99,10 @@ export function toEvents(
 		if (item.kind === "message") {
 			return {
 				...base,
-				// Authors are Tailscale logins; without a known GitHub login, the name before the domain
-				// reads as a handle.
 				sender: {
 					kind: "user",
 					value: item.author,
-					display: people[item.author] || item.author.split("@")[0]!,
+					display: authorName(item.author, people, channels),
 				},
 				content: [
 					text(item.invoked && !/(^|\s)@ace\b/i.test(item.text) ? `@ace ${item.text}` : item.text),

apps/host/src/gateway.ts

@@ -71,6 +71,7 @@ function local(): Listing[] {
 		const {
 			id,
 			name: channel,
+			prefix,
 			summary,
 			revision,
 			owner,
@@ -85,6 +86,7 @@ function local(): Listing[] {
 			id,
 			host: name,
 			name: channel,
+			prefix,
 			summary,
 			revision,
 			owner,

apps/host/src/protocol.ts

@@ -44,6 +44,11 @@ export type Listing = {
 	/** The machine running the channel, by its tailnet name. */
 	host: string;
 	name: string;
+	/**
+	 * The channel's original name, which stays unique on its host across renames. Messages its agent
+	 * sends other channels are authored `agent@<prefix>`. Older hosts omit it.
+	 */
+	prefix?: string;
 	summary?: string;
 	/** Revision of the channel's projected name and summary. */
 	revision?: number;

packages/ui/src/components/timeline/timeline.tsx

@@ -612,6 +612,7 @@ type GroupProps = {
 	onRowLeave?: () => void;
 	onReact?: (uid: string, emoji: string) => void;
 	onLink?: (href: string) => void;
+	openSender?: TimelineProps["openSender"];
 	onFileOpen?: (file: string) => void;
 	onDiffFileOpen?: (file: string) => void;
 	onReviewChanges?: () => void;
@@ -621,8 +622,18 @@ type GroupProps = {
 };
 
 function frame(
-	{ group, turn, width, currentUser, alignment, avatars, hover, openWorking, settlingWorking }:
-		GroupProps,
+	{
+		group,
+		turn,
+		width,
+		currentUser,
+		alignment,
+		avatars,
+		hover,
+		openWorking,
+		settlingWorking,
+		openSender,
+	}: GroupProps,
 ) {
 	let content = width - PAD * 2 - AVATAR - AVATAR_GAP;
 	let text = content - BUBBLE_PAD_X * 2;
@@ -633,6 +644,9 @@ function frame(
 		? group.display || String(group.sender || "User")
 		: group.display || (group.run ? "Ace" : "ace");
 	let name = label;
+	let open = group.role === "user" && group.sender != null
+		? openSender?.(String(group.sender))
+		: undefined;
 	let hasByline = group.rows.length > 0;
 	let own = !!currentUser && group.role === "user"
 		&& (currentUser.own
@@ -667,6 +681,7 @@ function frame(
 		workingSettling,
 		label,
 		name,
+		open,
 		hasByline,
 		own,
 		mine,
@@ -784,7 +799,7 @@ function GroupAvatar({ props, state }: GroupRender) {
 }
 
 function GroupByline({ state }: { state: GroupState }) {
-	let { hasByline, mine, name, agent, tone, title, date, edit, editTitle } = state;
+	let { hasByline, mine, name, open, agent, tone, title, date, edit, editTitle } = state;
 	return (
 		<>
 			{hasByline && (
@@ -800,9 +815,22 @@ function GroupByline({ state }: { state: GroupState }) {
 						paddingInlineEnd: mine ? 4 : 0,
 					}}
 				>
-					<span className="min-w-0 truncate font-medium text-foreground" title={name}>
-						{name}
-					</span>
+					{open
+						? (
+							<button
+								type="button"
+								className="min-w-0 truncate font-medium text-foreground hover:underline"
+								title={name}
+								onClick={open}
+							>
+								{name}
+							</button>
+						)
+						: (
+							<span className="min-w-0 truncate font-medium text-foreground" title={name}>
+								{name}
+							</span>
+						)}
 					{agent && (
 						<span
 							className="min-w-0 truncate text-[0.625rem] font-medium"
@@ -1067,6 +1095,8 @@ type TimelineProps =
 		target?: string;
 		/** Called when the user clicks a rendered message link. */
 		onLink?: (href: string) => void;
+		/** How to open a sender whose name links somewhere, such as the channel that sent it. */
+		openSender?: (sender: string) => (() => void) | undefined;
 		/** Called when the user clicks a resolved document reference. */
 		onDocumentOpen?: (uid: DocumentCandidate["uid"]) => void;
 		/** Called when the user clicks the reserved Plan reference. */
@@ -1117,6 +1147,7 @@ function useTimeline(
 		onReact,
 		target,
 		onLink,
+		openSender,
 		onDocumentOpen,
 		onPlanOpen,
 		onFileOpen,
@@ -1482,6 +1513,7 @@ function useTimeline(
 		onRowLeave,
 		onReact,
 		onLink,
+		openSender,
 		onFileOpen,
 		onDiffFileOpen,
 		onReviewChanges,
@@ -1530,6 +1562,7 @@ function Timeline(input: TimelineProps) {
 		onRowLeave,
 		onReact,
 		onLink,
+		openSender,
 		onFileOpen,
 		onDiffFileOpen,
 		onReviewChanges,
@@ -1631,6 +1664,7 @@ function Timeline(input: TimelineProps) {
 									onRowLeave={onRowLeave}
 									onReact={onReact}
 									onLink={onLink}
+									openSender={openSender}
 									onFileOpen={onFileOpen}
 									onDiffFileOpen={onDiffFileOpen}
 									onReviewChanges={onReviewChanges}