fix(channel): record who stopped a run, show it in the timeline, and tell the next run

.lane/memory/apps/app/src/transcript.ts/01M4YQRMMB6JT09W33MJMPKSMF-a-re-watch-keeps-showing-the.md

@@ -4,9 +4,9 @@ anchor: function useTranscript
 created: 2026-10-15T02:55:20Z
 norm: '1'
 sig: 3961cde46070e655
-body_hash: 715b52c056e02eac
-raw_hash: 0c5f8df4fea08fca
-vouched: 2026-10-22T20:30:45Z
+body_hash: 835435c05643b8c8
+raw_hash: 4c294bc99f24c95b
+vouched: 2026-10-22T21:41:25Z
 lines: 174-275
 ---
 

.lane/memory/apps/app/src/transcript.ts/01M4YYQEXJX6JQ04TBRZ4DW1X8-a-watch-rejected-with-discon.md

@@ -4,9 +4,9 @@ anchor: function useTranscript
 created: 2026-10-15T04:57:01Z
 norm: '1'
 sig: 3961cde46070e655
-body_hash: 715b52c056e02eac
-raw_hash: 0c5f8df4fea08fca
-vouched: 2026-10-22T20:30:45Z
+body_hash: 835435c05643b8c8
+raw_hash: 4c294bc99f24c95b
+vouched: 2026-10-22T21:41:26Z
 lines: 197-314
 ---
 

.lane/memory/packages/channel/src/channel.ts/01M4XQKND0900E94CG3BXBEJP7-a-run-s-end-is-read-from-the.md

@@ -4,9 +4,9 @@ anchor: class Channel
 created: 2026-10-14T17:33:22Z
 norm: '1'
 sig: c905677fa4be33c1
-body_hash: c6d2a615cf4deee2
-raw_hash: e9f2af52a8b6629d
-vouched: 2026-10-22T21:13:56Z
+body_hash: edc1045f02d80405
+raw_hash: 95969dbe14ea6781
+vouched: 2026-10-22T21:41:26Z
 lines: 114-792
 ---
 

.lane/memory/packages/channel/src/channel.ts/01M4YFFTK7TWGKENJAD1W10HJJ-the-desktop-default-changes.md

@@ -4,9 +4,9 @@ anchor: class Channel
 created: 2026-10-15T00:30:42Z
 norm: '1'
 sig: c905677fa4be33c1
-body_hash: c6d2a615cf4deee2
-raw_hash: e9f2af52a8b6629d
-vouched: 2026-10-22T21:13:56Z
+body_hash: edc1045f02d80405
+raw_hash: 95969dbe14ea6781
+vouched: 2026-10-22T21:41:26Z
 lines: 114-792
 ---
 

.lane/memory/packages/channel/src/channel.ts/01M4YPJQB6KKEW1YTRD08YCYJY-only-gateways-admit-clients.md

@@ -4,9 +4,9 @@ anchor: class Channel
 created: 2026-10-15T02:34:37Z
 norm: '1'
 sig: c905677fa4be33c1
-body_hash: c6d2a615cf4deee2
-raw_hash: e9f2af52a8b6629d
-vouched: 2026-10-22T21:13:56Z
+body_hash: edc1045f02d80405
+raw_hash: 95969dbe14ea6781
+vouched: 2026-10-22T21:41:26Z
 lines: 114-794
 ---
 

.lane/memory/packages/channel/src/channel.ts/01M4ZH31DXZK0Y57C97DP84ZKX-handoffs-learns-queued-hando.md

@@ -4,9 +4,9 @@ anchor: class Channel
 created: 2026-10-15T10:17:55Z
 norm: '1'
 sig: c905677fa4be33c1
-body_hash: c6d2a615cf4deee2
-raw_hash: e9f2af52a8b6629d
-vouched: 2026-10-22T21:13:56Z
+body_hash: edc1045f02d80405
+raw_hash: 95969dbe14ea6781
+vouched: 2026-10-22T21:41:26Z
 lines: 121-817
 ---
 

.lane/memory/packages/channel/src/channel.ts/01M53CAGW2RVRKCYF5BCJRTZX2-a-fork-s-starting-lane-is-re.md

@@ -4,9 +4,9 @@ anchor: class Channel
 created: 2026-10-16T22:11:35Z
 norm: '1'
 sig: c905677fa4be33c1
-body_hash: c6d2a615cf4deee2
-raw_hash: e9f2af52a8b6629d
-vouched: 2026-10-22T21:13:56Z
+body_hash: edc1045f02d80405
+raw_hash: 95969dbe14ea6781
+vouched: 2026-10-22T21:41:26Z
 lines: 127-873
 ---
 

.lane/memory/packages/channel/src/room.ts/01M5JRZAPC72D0EX9F0DSEYGDY-a-person-s-stop-is-a-durable.md

@@ -0,0 +1,12 @@
+---
+id: 01M5JRZAPC72D0EX9F0DSEYGDY
+anchor: const StopEntry
+created: 2026-10-22T21:41:16Z
+norm: '1'
+sig: ff54ace4b8f574ba
+body_hash: e3b0c44298fc1c14
+raw_hash: 69408999a208ec7e
+lines: 27-27
+---
+
+a person's Stop is a durable ace.stopped entry whose user message reaches the next run; stopped events go only to watchers that ask with stops, since older clients' reducers can't take an unknown event kind

apps/app/src/timeline.ts

@@ -225,7 +225,15 @@ export function toEvents(
 			}
 		}
 		if (item.error) content.push(text(`Run failed: ${item.error}`));
-		if (item.stopped) content.push(text("Stopped."));
+		if (item.stopped) {
+			content.push(
+				text(
+					item.stopper
+						? `Stopped by ${authorName(item.stopper, people, channels)}.`
+						: "Stopped.",
+				),
+			);
+		}
 		if (item.withdrawn) content.push(text(withdrawal(item.withdrawn, people, channels)));
 		return {
 			...base,

apps/app/src/transcript.ts

@@ -47,6 +47,8 @@ export type Item =
 		tools: Tool[];
 		error?: string;
 		stopped?: boolean;
+		/** Who stopped the run, once the channel records it. */
+		stopper?: string;
 		/** Queued messages withdrawn when the run was stopped. */
 		withdrawn?: QueuedMessage[];
 	};
@@ -232,6 +234,24 @@ export function apply(state: Transcript, event: Event): Transcript {
 			const items = withdraw(state.items, state.withdrawn);
 			return { ...state, busy, draft: "", items, withdrawn: [] };
 		}
+		case "stopped": {
+			const last = state.items.at(-1);
+			if (last?.kind === "reply") {
+				const item: Item = { ...last, stopped: true, stopper: event.author };
+				return { ...state, items: [...state.items.slice(0, -1), item] };
+			}
+			const item: Item = {
+				kind: "reply",
+				key: `s${event.at}`,
+				at: event.at,
+				model: "",
+				text: "",
+				tools: [],
+				stopped: true,
+				stopper: event.author,
+			};
+			return { ...state, items: [...state.items, item] };
+		}
 		case "live":
 			return { ...state, live: true };
 		case "agent":
@@ -377,6 +397,7 @@ export function useTranscript(
 				actions: true,
 				typing: true,
 				agent: true,
+				stops: true,
 				...(chat === undefined ? {} : { chat }),
 			}, {
 				event(event) {

apps/host/src/cli.ts

@@ -173,6 +173,8 @@ function render(event: Event, info: ChannelInfo) {
 	switch (event.kind) {
 		case "message":
 			return console.log(`${tag}${bold(event.author)}: ${event.text}`);
+		case "stopped":
+			return console.log(dim(`${tag}Stopped by ${event.author}.`));
 		case "reply": {
 			const ending = event.error
 				? `\x1b[31m${event.text ? "\n" : ""}Run failed: ${event.error}\x1b[0m`
@@ -212,7 +214,7 @@ async function watch(session: Session, replay = true): Promise<{ ended: Promise<
 	const info = await session.request<ChannelInfo>({ op: "info" });
 	let live = false;
 	const ended = Promise.withResolvers<void>();
-	await session.request({ op: "watch", chat: chat() }, {
+	await session.request({ op: "watch", chat: chat(), stops: true }, {
 		event(event) {
 			if (event.kind === "live") return void (live = true);
 			if (live || replay) render(event, info);

packages/channel/src/channel.ts

@@ -419,7 +419,15 @@ export class Channel {
 				this.#author(request.author);
 				// Whoever can't start a run here can't end the owner's either.
 				await this.#mayInvoke(request.author);
-				return (await this.#conversation(request.chat)).abort(context);
+				const conversation = await this.#conversation(request.chat);
+				const running = this.#runs.has(conversation.id);
+				await conversation.abort(context);
+				if (!running) return;
+				await conversation.submit(
+					{ type: "write", entry: room.stop(request.author, Date.now()) },
+					context,
+				);
+				return;
 			}
 			case "kill":
 				this.#author(request.author);
@@ -1034,6 +1042,7 @@ export class Channel {
 		// a deleted message's content and shows an edited one's newest text.
 		const forward = (event: Event) => {
 			if ((event.kind === "deleted" || event.kind === "edited") && !actions) return;
+			if (event.kind === "stopped" && !request.stops) return;
 			if (event.kind !== "message" || !deleted[event.entry]) return send(event);
 			const { images: _, files: __, edited: ___, ...rest } = event;
 			send({ ...rest, text: "", deleted: true });
@@ -1190,6 +1199,10 @@ function events(entry: EntryRecord): Event[] {
 		const { target, text, at } = entry.data;
 		return [{ kind: "edited", chat, entry: target, text, at }];
 	}
+	if (room.StopEntry.is(entry)) {
+		const at = entry.model![0]!.timestamp;
+		return [{ kind: "stopped", chat, at, author: entry.data.author }];
+	}
 	const human = room.human(entry);
 	if (human) return [{ kind: "message", chat, entry: entry.id, ...human }];
 	const message = entry.model?.[0];

packages/channel/src/protocol.ts

@@ -297,6 +297,8 @@ export type Request =
 		typing?: boolean;
 		/** Include agent events; older clients do not understand them. */
 		agent?: boolean;
+		/** Include stopped events; older clients do not understand them. */
+		stops?: boolean;
 	};
 
 export type Event =
@@ -385,6 +387,8 @@ export type Event =
 	 */
 	| { kind: "recap"; chat: ChatId; calls: string[]; text: string }
 	| { kind: "run"; chat: ChatId; state: "start" | "end" }
+	/** `author` stopped the run, whose aborted reply came before this. */
+	| { kind: "stopped"; chat: ChatId; at: number; author: string }
 	/** The chat's model or effort changed, so the next run uses these. */
 	| { kind: "agent"; chat: ChatId; model: ModelRef; effort: Effort }
 	/**

packages/channel/src/room.ts

@@ -20,6 +20,27 @@ import { type Image, MAX_IMAGES, type TextFile } from "./protocol";
 /** A human message that did not invoke an agent. */
 export const MessageEntry = defineEntry<{ author: string; text: string }>("ace.message");
 
+/**
+ * A person stopped the run before this entry. Its user message tells the chat's next run, which
+ * otherwise sees only an aborted reply and can't tell a person's Stop from a failure.
+ */
+export const StopEntry = defineEntry<{ author: string }>("ace.stopped");
+
+export function stop(author: string, timestamp: number) {
+	return {
+		kind: StopEntry.kind,
+		data: { author } satisfies JsonObject,
+		model: [
+			{
+				role: "user",
+				content:
+					`[${author} stopped your previous run before it finished. Anything it was doing when stopped may not have completed.]`,
+				timestamp,
+			} satisfies UserMessage,
+		],
+	};
+}
+
 const AUTHOR = /^[A-Za-z0-9][A-Za-z0-9._@-]*$/;
 
 export function isAuthor(value: string): boolean {