Remove threads from Messages: every conversation is flat

All messages already render chronologically in the channel pane, so the thread affordance only duplicated them behind a second view. The reply chip, the in-place thread pane, and the thread composer are gone; ChatThreadView is deleted and the thread props are removed from the conversation, timeline, and message-row chain. Message writes are untouched.
2026-07-07 01:58:11 -04:00
1 parent d19573187c
commit 0ec13e3e3a
@@ -3,13 +3,11 @@ import { Field } from "../shared/ui";
 import { Dialog } from "../shared/Dialog";
 import { ChatSidebar } from "./chat/ChatSidebar";
 import { ChatConversation } from "./chat/ChatConversation";
-import { ChatThreadView } from "./chat/ChatThreadView";
 import {
  buildConversations,
  collectParticipants,
  filterApprovalsForSpace,
 } from "./chat/chat-helpers";
-import { ROLE_KEY } from "../../../shared/domain";
 import type { PageProps } from "./types";
 import { activeOrgId, requireActiveEmployee } from "./types";

@@ -28,7 +26,6 @@ export function ChatPage({ snapshot, actions }: PageProps) {
  const agents = useMemo(() => snapshot.agents.filter((item) => item.orgId === orgId), [snapshot.agents, orgId]);
  const files = useMemo(() => snapshot.files.filter((item) => item.orgId === orgId), [snapshot.files, orgId]);
  const messagesAll = useMemo(() => snapshot.chatMessages.filter((m) => m.orgId === orgId), [snapshot.chatMessages, orgId]);
-  const threadsAll = useMemo(() => snapshot.chatThreads.filter((t) => t.orgId === orgId), [snapshot.chatThreads, orgId]);
  const messageIds = useMemo(() => new Set(messagesAll.map((message) => message.id)), [messagesAll]);
  const mentionsAll = useMemo(
    () => snapshot.chatMentions.filter((mention) => messageIds.has(mention.messageId)),
@@ -38,10 +35,6 @@ export function ChatPage({ snapshot, actions }: PageProps) {
    () => snapshot.chatSlashInvocations.filter((invocation) => messageIds.has(invocation.messageId)),
    [snapshot.chatSlashInvocations, messageIds],
  );
-  const boardInterventionsAll = useMemo(
-    () => snapshot.boardInterventions.filter((item) => item.orgId === orgId),
-    [snapshot.boardInterventions, orgId],
-  );
  const approvalsAll = useMemo(
    () => snapshot.approvals.filter((a) => a.orgId === orgId && a.state === "pending"),
    [snapshot.approvals, orgId],
@@ -58,23 +51,9 @@ export function ChatPage({ snapshot, actions }: PageProps) {
    }),
    [spaces, snapshot.chatMemberships, messagesAll, snapshot.chatReadStates, employees, agents, employee.id],
  );
-  const canBoardIntervene = useMemo(
-    () =>
-      snapshot.roleGrants.some(
-        (grant) =>
-          grant.orgId === orgId &&
-          grant.principalType === "employee" &&
-          grant.principalId === employee.id &&
-          (grant.roleKey === ROLE_KEY.APPROVAL_DECIDER || grant.roleKey === ROLE_KEY.ORG_ADMIN),
-      ),
-    [snapshot.roleGrants, orgId, employee.id],
-  );
-
  const [selectedSpaceId, setSelectedSpaceId] = useState<string | null>(null);
-  const [openThreadId, setOpenThreadId] = useState<string | null>(null);
  const [createOpen, setCreateOpen] = useState(false);
  const [attachmentFileId, setAttachmentFileId] = useState<string>("");
-  const [threadAttachmentFileId, setThreadAttachmentFileId] = useState<string>("");
  const composerRef = useRef<HTMLTextAreaElement | null>(null);

  const firstAvailableSpaceId = conversations[0]?.space.id ?? null;
@@ -102,74 +81,12 @@ export function ChatPage({ snapshot, actions }: PageProps) {
    () => (activeSpace ? messagesAll.filter((m) => m.spaceId === activeSpace.id) : []),
    [messagesAll, activeSpace],
  );
-  const threadsInSpace = useMemo(
-    () => (activeSpace ? threadsAll.filter((t) => t.spaceId === activeSpace.id) : []),
-    [threadsAll, activeSpace],
-  );
-  const selectedThread = threadsInSpace.find((thread) => thread.id === openThreadId) ?? null;
-  const threadMessages = selectedThread
-    ? messagesInSpace.filter((m) => m.threadId === selectedThread.id && m.id !== selectedThread.rootMessageId)
-    : [];
-  const selectedBoardInterventions = useMemo(
-    () => (selectedThread ? boardInterventionsAll.filter((item) => item.threadId === selectedThread.id) : []),
-    [boardInterventionsAll, selectedThread],
-  );
  const participants = useMemo(
    () => collectParticipants(messagesInSpace, employees, agents),
    [messagesInSpace, employees, agents],
  );
  const pendingApprovalsInSpace = filterApprovalsForSpace(approvalsAll, activeSpace);

-  const openThread = (threadId: string) => {
-    setOpenThreadId(threadId);
-    setThreadAttachmentFileId("");
-  };
-
-  const closeThread = () => {
-    setOpenThreadId(null);
-    setThreadAttachmentFileId("");
-  };
-
-  const sendInThread = (event: FormEvent<HTMLFormElement>) => {
-    event.preventDefault();
-    if (!activeSpace || !selectedThread) return;
-    const form = new FormData(event.currentTarget);
-    const body = value(form, "message");
-    if (!body) return;
-    event.currentTarget.reset();
-    setThreadAttachmentFileId("");
-    void actions.run(() => window.agentCompany.sendMessage({
-      orgId,
-      spaceId: activeSpace.id,
-      threadId: selectedThread.id,
-      senderType: "employee",
-      senderId: employee.id,
-      bodyMd: body,
-      attachmentFileIds: threadAttachmentFileId ? [threadAttachmentFileId] : [],
-    }));
-  };
-
-  const sendBoardIntervention = (event: FormEvent<HTMLFormElement>) => {
-    event.preventDefault();
-    if (!activeSpace || !selectedThread) return;
-    const form = new FormData(event.currentTarget);
-    const action = value(form, "action");
-    const target = value(form, "target");
-    const details = value(form, "details");
-    if (!action || !details) return;
-    event.currentTarget.reset();
-    const targetMention = action === "takeover" && target && target !== "board" ? ` @${target}` : "";
-    void actions.run(() => window.agentCompany.sendMessage({
-      orgId,
-      spaceId: activeSpace.id,
-      threadId: selectedThread.id,
-      senderType: "board",
-      senderId: employee.id,
-      bodyMd: `/board ${action}${targetMention} ${details}`,
-      attachmentFileIds: [],
-    }));
-  };
-
  const sendInChannel = (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault();
    if (!activeSpace) return;
@@ -206,7 +123,6 @@ export function ChatPage({ snapshot, actions }: PageProps) {
      const created = result.chatSpaces.find((space) => space.orgId === orgId && !existingSpaceIds.has(space.id));
      if (!created) throw new Error("Created chat space is missing from snapshot.");
      setSelectedSpaceId(created.id);
-      closeThread();
      setCreateOpen(false);
    });
  };
@@ -259,59 +175,32 @@ export function ChatPage({ snapshot, actions }: PageProps) {
        conversations={conversations}
        presence={snapshot.chatPresence}
        activeSpaceId={activeSpaceId}
-        onSelect={(spaceId) => {
-          setSelectedSpaceId(spaceId);
-          closeThread();
-        }}
+        onSelect={setSelectedSpaceId}
        onCreateSpace={() => setCreateOpen(true)}
      />

-      {selectedThread ? (
-        <ChatThreadView
-          thread={selectedThread}
-          rootMessage={messagesAll.find((m) => m.id === selectedThread.rootMessageId) ?? null}
-          messages={threadMessages}
-          attachments={snapshot.chatAttachments}
-          mentions={mentionsAll}
-          slashInvocations={slashInvocationsAll}
-          boardInterventions={selectedBoardInterventions}
-          files={files}
-          context={{ employees, agents }}
-          canIntervene={canBoardIntervene}
-          attachmentFileId={threadAttachmentFileId}
-          onClose={closeThread}
-          onAttachmentChange={setThreadAttachmentFileId}
-          onAttach={() => importAttachment(setThreadAttachmentFileId)}
-          onSubmit={sendInThread}
-          onBoardSubmit={sendBoardIntervention}
-          onOpenFile={openFile}
-        />
-      ) : (
-        <ChatConversation
-          space={activeSpace}
-          participants={participants}
-          messagesInSpace={messagesInSpace}
-          threadsInSpace={threadsInSpace}
-          pendingApprovals={pendingApprovalsInSpace}
-          attachments={snapshot.chatAttachments}
-          mentions={mentionsAll}
-          slashInvocations={slashInvocationsAll}
-          files={files}
-          context={{ employees, agents }}
-          attachmentFileId={attachmentFileId}
-          currentEmployeeId={employee.id}
-          onAttachmentChange={setAttachmentFileId}
-          onAttach={attachFile}
-          onOpenThread={openThread}
-          onApprove={(approvalId) => decideApproval(approvalId, "approved")}
-          onDecline={(approvalId) => decideApproval(approvalId, "declined")}
-          onEditMessage={editChatMessage}
-          onDeleteMessage={deleteChatMessage}
-          onOpenFile={openFile}
-          onSubmit={sendInChannel}
-          composerRef={composerRef}
-        />
-      )}
+      <ChatConversation
+        space={activeSpace}
+        participants={participants}
+        messagesInSpace={messagesInSpace}
+        pendingApprovals={pendingApprovalsInSpace}
+        attachments={snapshot.chatAttachments}
+        mentions={mentionsAll}
+        slashInvocations={slashInvocationsAll}
+        files={files}
+        context={{ employees, agents }}
+        attachmentFileId={attachmentFileId}
+        currentEmployeeId={employee.id}
+        onAttachmentChange={setAttachmentFileId}
+        onAttach={attachFile}
+        onApprove={(approvalId) => decideApproval(approvalId, "approved")}
+        onDecline={(approvalId) => decideApproval(approvalId, "declined")}
+        onEditMessage={editChatMessage}
+        onDeleteMessage={deleteChatMessage}
+        onOpenFile={openFile}
+        onSubmit={sendInChannel}
+        composerRef={composerRef}
+      />

      <Dialog
        title="New space"
@@ -7,7 +7,6 @@ import type {
  ChatMessageRecord,
  ChatSpaceRecord,
  ChatSlashInvocationRecord,
-  ChatThreadRecord,
  FileObjectRecord,
 } from "../../../../shared/domain";
 import { ChatComposer } from "./ChatComposer";
@@ -18,7 +17,6 @@ export function ChatConversation({
  space,
  participants,
  messagesInSpace,
-  threadsInSpace,
  pendingApprovals,
  attachments,
  mentions,
@@ -29,7 +27,6 @@ export function ChatConversation({
  currentEmployeeId,
  onAttachmentChange,
  onAttach,
-  onOpenThread,
  onApprove,
  onDecline,
  onEditMessage,
@@ -41,7 +38,6 @@ export function ChatConversation({
  space: ChatSpaceRecord | null;
  participants: string[];
  messagesInSpace: ChatMessageRecord[];
-  threadsInSpace: ChatThreadRecord[];
  pendingApprovals: ApprovalRecord[];
  attachments: ChatAttachmentRecord[];
  mentions: ChatMentionRecord[];
@@ -52,7 +48,6 @@ export function ChatConversation({
  currentEmployeeId: string;
  onAttachmentChange: (next: string) => void;
  onAttach: () => void;
-  onOpenThread: (threadId: string) => void;
  onApprove: (approvalId: string) => void;
  onDecline: (approvalId: string) => void;
  onEditMessage: (messageId: string, bodyMd: string) => void;
@@ -74,7 +69,6 @@ export function ChatConversation({
          <ChatTimeline
            key={space.id}
            messagesInSpace={filtered}
-            threadsInSpace={threadsInSpace}
            pendingApprovals={pendingApprovals}
            attachments={attachments}
            mentions={mentions}
@@ -82,7 +76,6 @@ export function ChatConversation({
            files={files}
            context={context}
            currentEmployeeId={currentEmployeeId}
-            onOpenThread={onOpenThread}
            onApprove={onApprove}
            onDecline={onDecline}
            onEditMessage={onEditMessage}
@@ -16,10 +16,7 @@ export function ChatMessageRow({
  mentions,
  slashInvocations,
  files,
-  replyCount,
-  onOpenThread,
  context,
-  compact = false,
  canModify = false,
  onEdit,
  onDelete,
@@ -30,10 +27,7 @@ export function ChatMessageRow({
  mentions: ChatMentionRecord[];
  slashInvocations: ChatSlashInvocationRecord[];
  files: FileObjectRecord[];
-  replyCount: number;
-  onOpenThread: (() => void) | null;
  context: MessageContext;
-  compact?: boolean;
  canModify?: boolean;
  onEdit?: (bodyMd: string) => void;
  onDelete?: () => void;
@@ -54,8 +48,8 @@ export function ChatMessageRow({
    setEditing(false);
  };
  return (
-    <div style={{ display: "flex", gap: compact ? 10 : 12, marginBottom: compact ? 12 : 18 }}>
-      <Avatar name={name} size={compact ? "sm" : ""} bot={bot} />
+    <div style={{ display: "flex", gap: 12, marginBottom: 18 }}>
+      <Avatar name={name} bot={bot} />
      <div style={{ flex: 1, minWidth: 0 }}>
        <div className="row" style={{ alignItems: "baseline", gap: 8, marginBottom: 2 }}>
          <span style={{ fontSize: 14, fontWeight: 540 }}>{name}</span>
@@ -104,28 +98,6 @@ export function ChatMessageRow({
            })}
          </div>
        )}
-        {onOpenThread && (
-          <button
-            type="button"
-            aria-label="Open thread"
-            onClick={onOpenThread}
-            style={{
-              marginTop: 8,
-              display: "inline-flex",
-              alignItems: "center",
-              gap: 6,
-              fontSize: 11.5,
-              color: "var(--accent)",
-              cursor: "pointer",
-              padding: "3px 8px",
-              borderRadius: 6,
-              background: "var(--accent-soft)",
-              border: 0,
-            }}
-          >
-            <Icon name="chat" size={14} /> {replyCount > 0 ? `${replyCount} ${replyCount === 1 ? "reply" : "replies"}` : "Thread"} →
-          </button>
-        )}
      </div>
    </div>
  );
@@ -1,235 +0,0 @@
-import { useState, type FormEvent } from "react";
-import { Button, Icon, IconButton, Pill } from "../../shared/ui";
-import type {
-  BoardInterventionRecord,
-  ChatAttachmentRecord,
-  ChatMentionRecord,
-  ChatMessageRecord,
-  ChatSlashInvocationRecord,
-  ChatThreadRecord,
-  FileObjectRecord,
-} from "../../../../shared/domain";
-import { formatTime } from "../types";
-import { ChatMessageRow } from "./ChatMessageRow";
-import { MentionTextarea } from "./MentionTextarea";
-import type { MessageContext } from "./chat-helpers";
-
-/**
- * Thread focus, in place: the center pane narrows to one thread — root,
- * replies, board controls, and a reply composer — and the back control
- * returns to the conversation. No side panel duplicating the timeline.
- */
-export function ChatThreadView({
-  thread,
-  rootMessage,
-  messages,
-  attachments,
-  mentions,
-  slashInvocations,
-  boardInterventions,
-  files,
-  context,
-  canIntervene,
-  attachmentFileId,
-  onClose,
-  onAttachmentChange,
-  onAttach,
-  onSubmit,
-  onBoardSubmit,
-  onOpenFile,
-}: {
-  thread: ChatThreadRecord;
-  rootMessage: ChatMessageRecord | null;
-  messages: ChatMessageRecord[];
-  attachments: ChatAttachmentRecord[];
-  mentions: ChatMentionRecord[];
-  slashInvocations: ChatSlashInvocationRecord[];
-  boardInterventions: BoardInterventionRecord[];
-  files: FileObjectRecord[];
-  context: MessageContext;
-  canIntervene: boolean;
-  attachmentFileId: string;
-  onClose: () => void;
-  onAttachmentChange: (next: string) => void;
-  onAttach: () => void;
-  onSubmit: (event: FormEvent<HTMLFormElement>) => void;
-  onBoardSubmit: (event: FormEvent<HTMLFormElement>) => void;
-  onOpenFile: (fileId: string) => void;
-}) {
-  const attachment = files.find((file) => file.id === attachmentFileId) ?? null;
-  return (
-    <section style={{ flex: 1, minWidth: 0, display: "flex", flexDirection: "column", background: "var(--panel)" }}>
-      <header className="row" style={{ height: 52, padding: "0 16px", borderBottom: "1px solid var(--border-soft)", flexShrink: 0, gap: 10 }}>
-        <IconButton icon="chevronLeft" label="Close thread" onClick={onClose} />
-        <span style={{ fontSize: 14, fontWeight: 600 }}>Thread</span>
-        <Pill tone={boardStateTone(thread.boardState)}>{boardStateLabel(thread.boardState)}</Pill>
-      </header>
-      <div style={{ flex: 1, overflow: "auto", padding: "20px 24px 8px" }}>
-        <BoardControl
-          thread={thread}
-          interventions={boardInterventions}
-          context={context}
-          canIntervene={canIntervene}
-          onSubmit={onBoardSubmit}
-        />
-        {rootMessage && (
-          <ChatMessageRow
-            message={rootMessage}
-            attachments={attachments}
-            mentions={mentions}
-            slashInvocations={slashInvocations}
-            files={files}
-            replyCount={0}
-            onOpenThread={null}
-            context={context}
-            onOpenFile={onOpenFile}
-          />
-        )}
-        {messages.length > 0 && (
-          <div className="row" style={{ gap: 12, margin: "4px 0 16px" }}>
-            <div style={{ flex: 1, height: 1, background: "var(--border-soft)" }} />
-            <div style={{ fontSize: 12, color: "var(--text-3)", fontWeight: 540 }}>
-              {messages.length} {messages.length === 1 ? "reply" : "replies"}
-            </div>
-            <div style={{ flex: 1, height: 1, background: "var(--border-soft)" }} />
-          </div>
-        )}
-        {messages.map((message) => (
-          <ChatMessageRow
-            key={message.id}
-            message={message}
-            attachments={attachments}
-            mentions={mentions}
-            slashInvocations={slashInvocations}
-            files={files}
-            replyCount={0}
-            onOpenThread={null}
-            context={context}
-            onOpenFile={onOpenFile}
-          />
-        ))}
-      </div>
-      <form onSubmit={onSubmit} style={{ padding: "0 24px 16px", flexShrink: 0 }}>
-        <div style={{ border: "1px solid var(--border-strong)", borderRadius: 10, background: "var(--panel)", padding: "8px 10px" }}>
-          <MentionTextarea
-            name="message"
-            rows={2}
-            ariaLabel="Thread reply"
-            agents={context.agents}
-            employees={context.employees}
-            style={{ minHeight: 36 }}
-          />
-          <div className="row" style={{ paddingTop: 6, gap: 4 }}>
-            <IconButton icon="attach" label="Attach file" onClick={onAttach} />
-            {attachment && (
-              <span className="pill" style={{ maxWidth: 150 }}>
-                <Icon name="file" size={14} />
-                <span style={{ overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>{attachment.name}</span>
-                <button
-                  type="button"
-                  aria-label="Remove thread attachment"
-                  onClick={() => onAttachmentChange("")}
-                  style={{ display: "inline-flex", border: 0, background: "transparent", padding: 0, color: "var(--text-3)", cursor: "pointer" }}
-                >
-                  <Icon name="x" size={14} />
-                </button>
-              </span>
-            )}
-            <div style={{ marginLeft: "auto" }}>
-              <Button tone="primary" size="small" type="submit"><Icon name="send" size={12} /> Reply</Button>
-            </div>
-          </div>
-        </div>
-      </form>
-    </section>
-  );
-}
-
-function BoardControl({
-  thread,
-  interventions,
-  context,
-  canIntervene,
-  onSubmit,
-}: {
-  thread: ChatThreadRecord;
-  interventions: BoardInterventionRecord[];
-  context: MessageContext;
-  canIntervene: boolean;
-  onSubmit: (event: FormEvent<HTMLFormElement>) => void;
-}) {
-  const [action, setAction] = useState("decision");
-  if (!canIntervene && interventions.length === 0) return null;
-  return (
-    <section style={{ border: "1px solid var(--border)", borderRadius: 10, padding: 10, background: "var(--panel)", marginBottom: 16, maxWidth: 480 }}>
-      <div className="row" style={{ marginBottom: 8 }}>
-        <div className="section-label">Board</div>
-        <Pill tone={boardStateTone(thread.boardState)}>{boardStateLabel(thread.boardState)}</Pill>
-      </div>
-      {canIntervene && (
-      <form onSubmit={onSubmit} style={{ display: "grid", gridTemplateColumns: "1fr 1fr", gap: 8 }}>
-        <label className="field" style={{ margin: 0 }}>
-          <span>Action</span>
-          <select className="input" name="action" value={action} onChange={(event) => setAction(event.target.value)}>
-            <option value="decision">Decision</option>
-            <option value="freeze">Freeze</option>
-            <option value="takeover">Takeover</option>
-            <option value="rollback">Rollback</option>
-            <option value="force-approval">Force approval</option>
-          </select>
-        </label>
-        <label className="field" style={{ margin: 0 }}>
-          <span>Target</span>
-          <select className="input" name="target" defaultValue="board" disabled={action !== "takeover"}>
-            <option value="board">Board</option>
-            {context.employees.map((employee) => (
-              <option key={employee.id} value={employee.id}>Employee · {employee.displayName}</option>
-            ))}
-            {context.agents.map((agent) => (
-              <option key={agent.id} value={agent.id}>Agent · {agent.name}</option>
-            ))}
-          </select>
-        </label>
-        <label className="field" style={{ gridColumn: "1 / -1", margin: 0 }}>
-          <span>Details</span>
-          <input className="input" name="details" required aria-label="Board intervention details" />
-        </label>
-        <div className="row" style={{ gridColumn: "1 / -1", justifyContent: "flex-end" }}>
-          <Button tone="primary" size="small" type="submit"><Icon name="shield" size={12} /> Board</Button>
-        </div>
-      </form>
-      )}
-      {interventions.length > 0 && (
-        <div style={{ display: "flex", flexDirection: "column", gap: 7, marginTop: 10 }}>
-          {interventions.map((intervention) => (
-            <div key={intervention.id} style={{ borderTop: "1px solid var(--border-soft)", paddingTop: 7 }}>
-              <div className="row" style={{ gap: 6, marginBottom: 3 }}>
-                <span className="mono" style={{ fontSize: 12, color: "var(--text-3)" }}>{formatTime(intervention.createdAt)}</span>
-                <Pill tone={intervention.mode === "takeover" ? "violet" : intervention.action === "freeze" ? "red" : undefined}>
-                  {formatBoardAction(intervention.action)}
-                </Pill>
-              </div>
-              <div style={{ fontSize: 12, color: "var(--text-2)", lineHeight: 1.4, wordBreak: "break-word" }}>{intervention.details}</div>
-            </div>
-          ))}
-        </div>
-      )}
-    </section>
-  );
-}
-
-function boardStateTone(state: string): "red" | "violet" | undefined {
-  if (state === "frozen") return "red";
-  if (state === "takeover") return "violet";
-  return undefined;
-}
-
-function boardStateLabel(state: string): string {
-  if (state === "frozen") return "Frozen";
-  if (state === "takeover") return "Takeover";
-  return "Open";
-}
-
-function formatBoardAction(action: string): string {
-  return action.replace(/_/g, " ");
-}
@@ -6,7 +6,6 @@ import type {
  ChatMentionRecord,
  ChatMessageRecord,
  ChatSlashInvocationRecord,
-  ChatThreadRecord,
  FileObjectRecord,
 } from "../../../../shared/domain";
 import { ChatMessageRow } from "./ChatMessageRow";
@@ -30,7 +29,6 @@ function groupBy<T>(items: T[], keyOf: (item: T) => string): Map<string, T[]> {

 export function ChatTimeline({
  messagesInSpace,
-  threadsInSpace,
  pendingApprovals,
  attachments,
  mentions,
@@ -38,7 +36,6 @@ export function ChatTimeline({
  files,
  context,
  currentEmployeeId,
-  onOpenThread,
  onApprove,
  onDecline,
  onEditMessage,
@@ -46,7 +43,6 @@ export function ChatTimeline({
  onOpenFile,
 }: {
  messagesInSpace: ChatMessageRecord[];
-  threadsInSpace: ChatThreadRecord[];
  pendingApprovals: ApprovalRecord[];
  attachments: ChatAttachmentRecord[];
  mentions: ChatMentionRecord[];
@@ -54,7 +50,6 @@ export function ChatTimeline({
  files: FileObjectRecord[];
  context: MessageContext;
  currentEmployeeId: string;
-  onOpenThread: (threadId: string) => void;
  onApprove: (approvalId: string) => void;
  onDecline: (approvalId: string) => void;
  onEditMessage: (messageId: string, bodyMd: string) => void;
@@ -66,15 +61,6 @@ export function ChatTimeline({
  const attachmentsByMessage = groupBy(attachments, (item) => item.messageId);
  const mentionsByMessage = groupBy(mentions, (item) => item.messageId);
  const invocationsByMessage = groupBy(slashInvocations, (item) => item.messageId);
-  const threadByRoot = new Map<string, ChatThreadRecord>();
-  for (const thread of threadsInSpace) {
-    if (thread.rootMessageId) threadByRoot.set(thread.rootMessageId, thread);
-  }
-  const replyCountByThread = new Map<string, number>();
-  for (const message of messagesInSpace) {
-    if (!message.threadId) continue;
-    replyCountByThread.set(message.threadId, (replyCountByThread.get(message.threadId) ?? 0) + 1);
-  }

  const hiddenCount = Math.max(0, messagesInSpace.length - visibleCount);
  const visible = hiddenCount > 0 ? messagesInSpace.slice(hiddenCount) : messagesInSpace;
@@ -96,10 +82,6 @@ export function ChatTimeline({
      lastDay = day;
      elements.push(<DayDivider key={`day-${day}`} label={day} />);
    }
-    const thread = threadByRoot.get(message.id) ?? null;
-    const replyCount = thread
-      ? Math.max(0, (replyCountByThread.get(thread.id) ?? 0) - (thread.rootMessageId && message.threadId === thread.id ? 1 : 0))
-      : 0;
    elements.push(
      <ChatMessageRow
        key={message.id}
@@ -108,8 +90,6 @@ export function ChatTimeline({
        mentions={mentionsByMessage.get(message.id) ?? EMPTY_MENTIONS}
        slashInvocations={invocationsByMessage.get(message.id) ?? EMPTY_INVOCATIONS}
        files={files}
-        replyCount={replyCount}
-        onOpenThread={thread ? () => onOpenThread(thread.id) : null}
        context={context}
        canModify={message.senderType === "employee" && message.senderId === currentEmployeeId && !message.deletedAt}
        onEdit={(bodyMd) => onEditMessage(message.id, bodyMd)}
@@ -106,12 +106,9 @@ test("onboards, hires, and creates work in the Electron shell", async () => {
    await page.getByRole("button", { name: "Send" }).click();
    await expect(page.getByText("@Board").first()).toBeVisible();
    await expect(page.getByText("/escalate").first()).toBeVisible();
-    // Threads open in place: the center pane becomes the thread and the
-    // channel composer is gone until you go back.
-    await page.getByRole("button", { name: "Open thread" }).first().click();
-    await expect(page.getByRole("textbox", { name: "Thread reply" })).toBeVisible();
-    await expect(page.getByRole("textbox", { name: "Message" })).not.toBeVisible();
-    await page.getByRole("button", { name: "Close thread" }).click();
+    // Conversations are flat: every message lives in the channel pane and no
+    // thread affordance exists.
+    await expect(page.getByRole("button", { name: "Open thread" })).toHaveCount(0);
    await expect(page.getByRole("textbox", { name: "Message" })).toBeVisible();
    await page.getByRole("button", { name: "Approvals" }).click();
    await expect(page.getByText("Escalate release").first()).toBeVisible();