fix(tui): responsive /compress with live progress + CLI-parity feedback (#17661)

* fix(tui): offload manual compaction RPC

Route TUI session compression through the existing long-handler pool so slow compaction does not block other gateway RPCs.

* fix(tui): show compaction progress immediately

Print a local status line before the compress RPC starts so slow manual compaction does not look like a no-op.

* feat(tui): rich /compress feedback parity with CLI

Show pre-compaction message count and rough token estimate immediately, emit a status update so the bottom bar reflects ongoing compaction, and report a multi-line summary (headline + token delta + optional note) using the shared summarize_manual_compression helper.

* fix(tui): show live compaction estimate in transcript

Mirror compression progress status into the transcript so users see the backend message count and token estimate while /compress is still running.

* fix(tui): single live compaction line with spinner glyph

Drop the redundant local "compressing context..." placeholder and prefix the live backend status line with a braille spinner glyph so /compress reads as a single in-progress row.

* fix(tui): address review nits on /compress feedback

Reuse the precomputed token estimate inside _compress_session_history so the gateway does not redo the O(n) work while holding history_lock, keep the status bar pinned during long manual compactions instead of auto-restoring after 4s, and drop the redundant noop bullet that doubled with the system role glyph.

* fix(tui): release history_lock during compaction LLM call

Move the snapshot/commit pattern into _compress_session_history so the lock is held only across the in-memory bookkeeping, not during agent._compress_context. Also emit a final neutral status update from session.compress so the pinned compressing indicator clears even on errors.

* fix(tui): rebuild prompt cleanly + sync session_key after compress

Pass system_message=None so AIAgent._compress_context rebuilds the system prompt without nesting the cached identity block. Reuse the handler's pre-snapshotted history inside _compress_session_history to avoid a second O(n) copy under the lock. After compaction, when AIAgent._compress_context rotates session_id, sync the gateway session_key, migrate approval notify + yolo state, restart the slash worker, and clear the stale pending title. Mirrors HermesCLI._manual_compress.

* Avoid /compress lock re-entry in slash side effects.

Stop pre-locking history before _compress_session_history in slash command mirroring, keep session-key sync parity with manual compression, and add a regression test that asserts /compress is invoked without holding history_lock.

tests/test_tui_gateway_server.py

@@ -1566,7 +1566,7 @@ def test_session_compress_uses_compress_helper(monkeypatch):
     monkeypatch.setattr(
         server,
         "_compress_session_history",
-        lambda session, focus_topic=None: (2, {"total": 42}),
+        lambda session, focus_topic=None, **_kw: (2, {"total": 42}),
     )
     monkeypatch.setattr(server, "_session_info", lambda _agent: {"model": "x"})
 
@@ -1577,7 +1577,52 @@ def test_session_compress_uses_compress_helper(monkeypatch):
 
     assert resp["result"]["removed"] == 2
     assert resp["result"]["usage"]["total"] == 42
-    emit.assert_called_once_with("session.info", "sid", {"model": "x"})
+    emit.assert_any_call("session.info", "sid", {"model": "x"})
+    # Final status.update clears the pinned "compressing" indicator so the
+    # status bar can revert to the neutral state when compaction finishes.
+    emit.assert_any_call(
+        "status.update", "sid", {"kind": "status", "text": "ready"}
+    )
+
+
+def test_session_compress_syncs_session_key_after_rotation(monkeypatch):
+    """When AIAgent._compress_context rotates session_id (compression split),
+    the gateway session_key must follow so subsequent approval routing,
+    DB title/history lookups, and slash worker resume target the new
+    continuation session — mirrors HermesCLI._manual_compress's
+    session_id sync (cli.py).
+    """
+    agent = types.SimpleNamespace(session_id="rotated-id")
+    server._sessions["sid"] = _session(agent=agent)
+    server._sessions["sid"]["session_key"] = "old-key"
+    server._sessions["sid"]["pending_title"] = "stale title"
+
+    monkeypatch.setattr(
+        server,
+        "_compress_session_history",
+        lambda session, focus_topic=None, **_kw: (2, {"total": 42}),
+    )
+    monkeypatch.setattr(server, "_session_info", lambda _agent: {"model": "x"})
+    restart_calls = []
+    monkeypatch.setattr(
+        server, "_restart_slash_worker", lambda s: restart_calls.append(s)
+    )
+
+    try:
+        with patch("tui_gateway.server._emit"):
+            server.handle_request(
+                {
+                    "id": "1",
+                    "method": "session.compress",
+                    "params": {"session_id": "sid"},
+                }
+            )
+
+        assert server._sessions["sid"]["session_key"] == "rotated-id"
+        assert server._sessions["sid"]["pending_title"] is None
+        assert len(restart_calls) == 1
+    finally:
+        server._sessions.pop("sid", None)
 
 
 def test_prompt_submit_sets_approval_session_key(monkeypatch):
@@ -2423,6 +2468,39 @@ def test_mirror_slash_side_effects_allowed_when_idle(monkeypatch):
     assert applied["model"]
 
 
+def test_mirror_slash_compress_does_not_prelock_history(monkeypatch):
+    """Regression guard: /compress side effect must not hold history_lock
+    when calling _compress_session_history (the helper snapshots under
+    the same non-reentrant lock internally)."""
+    import types
+
+    seen = {"compress": False, "sync": False}
+    emitted = []
+
+    def _fake_compress(session, focus_topic=None, **_kw):
+        seen["compress"] = True
+        assert not session["history_lock"].locked()
+        return (0, {"total": 0})
+
+    def _fake_sync(_sid, _session):
+        seen["sync"] = True
+
+    monkeypatch.setattr(server, "_compress_session_history", _fake_compress)
+    monkeypatch.setattr(server, "_sync_session_key_after_compress", _fake_sync)
+    monkeypatch.setattr(server, "_session_info", lambda _agent: {"model": "x"})
+    monkeypatch.setattr(server, "_emit", lambda *args: emitted.append(args))
+
+    session = _session(running=False)
+    session["agent"] = types.SimpleNamespace(model="x")
+
+    warning = server._mirror_slash_side_effects("sid", session, "/compress")
+
+    assert warning == ""
+    assert seen["compress"]
+    assert seen["sync"]
+    assert ("session.info", "sid", {"model": "x"}) in emitted
+
+
 # ---------------------------------------------------------------------------
 # session.create / session.close race: fast /new churn must not orphan the
 # slash_worker subprocess or the global approval-notify registration.

tests/tui_gateway/test_protocol.py

@@ -298,7 +298,7 @@ def test_session_resume_returns_hydrated_messages(server, monkeypatch):
         def reopen_session(self, _sid):
             return None
 
-        def get_messages_as_conversation(self, _sid):
+        def get_messages_as_conversation(self, _sid, include_ancestors=False):
             return [
                 {"role": "user", "content": "hello"},
                 {"role": "assistant", "content": "yo"},
@@ -641,6 +641,29 @@ def test_dispatch_long_handler_does_not_block_fast_handler(server):
     released.set()
 
 
+def test_dispatch_session_compress_does_not_block_fast_handler(server):
+    """Manual TUI compaction can take minutes, so it must not block the RPC loop."""
+    released = threading.Event()
+
+    def slow_compress(rid, params):
+        released.wait(timeout=5)
+        return server._ok(rid, {"done": True})
+
+    server._methods["session.compress"] = slow_compress
+    server._methods["fast.ping"] = lambda rid, params: server._ok(rid, {"pong": True})
+
+    t0 = time.monotonic()
+    assert server.dispatch({"id": "slow", "method": "session.compress", "params": {}}) is None
+
+    fast_resp = server.dispatch({"id": "fast", "method": "fast.ping", "params": {}})
+    fast_elapsed = time.monotonic() - t0
+
+    assert fast_resp["result"] == {"pong": True}
+    assert fast_elapsed < 0.5, f"fast handler blocked for {fast_elapsed:.2f}s behind session.compress"
+
+    released.set()
+
+
 def test_dispatch_long_handler_exception_produces_error_response(capture):
     """An exception inside a pool-dispatched handler still yields a JSON-RPC error."""
     server, buf = capture

tui_gateway/server.py

@@ -134,7 +134,7 @@ _DETAIL_MODES = frozenset({"hidden", "collapsed", "expanded"})
 # ── Async RPC dispatch (#12546) ──────────────────────────────────────
 # A handful of handlers block the dispatcher loop in entry.py for seconds
 # to minutes (slash.exec, cli.exec, shell.exec, session.resume,
-# session.branch, skills.manage).  While they're running, inbound RPCs —
+# session.branch, session.compress, skills.manage).  While they're running, inbound RPCs —
 # notably approval.respond and session.interrupt — sit unread in the
 # stdin pipe.  We route only those slow handlers onto a small thread pool;
 # everything else stays on the main thread so ordering stays sane for the
@@ -145,6 +145,7 @@ _LONG_HANDLERS = frozenset(
         "browser.manage",
         "cli.exec",
         "session.branch",
+        "session.compress",
         "session.resume",
         "shell.exec",
         "skills.manage",
@@ -1101,24 +1102,111 @@ def _apply_model_switch(sid: str, session: dict, raw_input: str) -> dict:
 
 
 def _compress_session_history(
-    session: dict, focus_topic: str | None = None
+    session: dict,
+    focus_topic: str | None = None,
+    approx_tokens: int | None = None,
+    before_messages: list | None = None,
+    history_version: int | None = None,
 ) -> tuple[int, dict]:
     from agent.model_metadata import estimate_messages_tokens_rough
 
     agent = session["agent"]
-    history = list(session.get("history", []))
+    # Snapshot history under the lock so the LLM-bound compression call
+    # below does NOT hold history_lock for the duration of the request —
+    # otherwise other handlers acquiring the lock (prompt.submit etc.)
+    # block on the dispatcher loop while compaction runs.
+    if before_messages is None or history_version is None:
+        with session["history_lock"]:
+            before_messages = list(session.get("history", []))
+            history_version = int(session.get("history_version", 0))
+    history = before_messages
     if len(history) < 4:
-        return 0, _get_usage(agent)
+        usage = _get_usage(agent)
+        return 0, usage
+    if approx_tokens is None:
         approx_tokens = estimate_messages_tokens_rough(history)
+    # Pass system_message=None so AIAgent._compress_context rebuilds the
+    # system prompt cleanly via _build_system_prompt(None). Passing the
+    # cached prompt (which already contains the agent identity block)
+    # makes the rebuild append the identity a second time. Mirrors the
+    # CLI's _manual_compress fix for issue #15281.
     compressed, _ = agent._compress_context(
         history,
-        getattr(agent, "_cached_system_prompt", "") or "",
+        None,
         approx_tokens=approx_tokens,
         focus_topic=focus_topic or None,
     )
+    with session["history_lock"]:
+        if int(session.get("history_version", 0)) != history_version:
+            # External mutation during compaction — drop the compressed
+            # result so we don't clobber concurrent edits.
+            usage = _get_usage(agent)
+            return 0, usage
         session["history"] = compressed
-    session["history_version"] = int(session.get("history_version", 0)) + 1
+        session["history_version"] = history_version + 1
-    return len(history) - len(compressed), _get_usage(agent)
+    usage = _get_usage(agent)
+    return len(history) - len(compressed), usage
+
+
+def _sync_session_key_after_compress(sid: str, session: dict) -> None:
+    """Re-anchor session_key when AIAgent._compress_context rotates session_id.
+
+    AIAgent._compress_context ends the current SessionDB session and creates
+    a new continuation session, rotating ``agent.session_id``.  The TUI
+    gateway keeps the gateway-side ``session_key`` separate (used for
+    approval routing, slash worker init, DB title/history lookups, yolo
+    state).  Without this sync, those operations would target the ended
+    parent session while the agent writes to the new continuation session.
+    Mirrors HermesCLI._manual_compress's session_id sync.
+    """
+    agent = session.get("agent")
+    new_session_id = getattr(agent, "session_id", None) or ""
+    old_key = session.get("session_key", "") or ""
+    if not new_session_id or new_session_id == old_key:
+        return
+
+    try:
+        from tools.approval import (
+            disable_session_yolo,
+            enable_session_yolo,
+            is_session_yolo_enabled,
+            register_gateway_notify,
+            unregister_gateway_notify,
+        )
+
+        try:
+            unregister_gateway_notify(old_key)
+        except Exception:
+            pass
+        session["session_key"] = new_session_id
+        try:
+            yolo_was_on = is_session_yolo_enabled(old_key)
+        except Exception:
+            yolo_was_on = False
+        if yolo_was_on:
+            try:
+                enable_session_yolo(new_session_id)
+                disable_session_yolo(old_key)
+            except Exception:
+                pass
+        try:
+            register_gateway_notify(
+                new_session_id,
+                lambda data: _emit("approval.request", sid, data),
+            )
+        except Exception:
+            pass
+    except Exception:
+        # Even if the approval module fails to import, still anchor the
+        # session_key on the new continuation id so downstream lookups
+        # don't keep targeting the ended row.
+        session["session_key"] = new_session_id
+
+    session["pending_title"] = None
+    try:
+        _restart_slash_worker(session)
+    except Exception:
+        pass
 
 
 def _get_usage(agent) -> dict:
@@ -2137,24 +2225,70 @@ def _(rid, params: dict) -> dict:
         return _err(
             rid, 4009, "session busy — /interrupt the current turn before /compress"
         )
+    sid = params.get("session_id", "")
+    focus_topic = str(params.get("focus_topic", "") or "").strip()
     try:
+        from agent.manual_compression_feedback import summarize_manual_compression
+        from agent.model_metadata import estimate_messages_tokens_rough
+
         with session["history_lock"]:
-            removed, usage = _compress_session_history(
+            before_messages = list(session.get("history", []))
-                session, str(params.get("focus_topic", "") or "").strip()
+            history_version = int(session.get("history_version", 0))
+        before_count = len(before_messages)
+        before_tokens = (
+            estimate_messages_tokens_rough(before_messages) if before_count else 0
         )
+
+        if before_count >= 4:
+            focus_suffix = f', focus: "{focus_topic}"' if focus_topic else ""
+            _status_update(
+                sid,
+                "compressing",
+                f"⠋ compressing {before_count} messages "
+                f"(~{before_tokens:,} tok){focus_suffix}…",
+            )
+
+        try:
+            removed, usage = _compress_session_history(
+                session,
+                focus_topic,
+                approx_tokens=before_tokens,
+                before_messages=before_messages,
+                history_version=history_version,
+            )
+            with session["history_lock"]:
                 messages = list(session.get("history", []))
-        info = _session_info(session["agent"])
+            after_count = len(messages)
-        _emit("session.info", params.get("session_id", ""), info)
+            after_tokens = (
+                estimate_messages_tokens_rough(messages) if after_count else 0
+            )
+            agent = session["agent"]
+            _sync_session_key_after_compress(sid, session)
+            summary = summarize_manual_compression(
+                before_messages, messages, before_tokens, after_tokens
+            )
+            info = _session_info(agent)
+            _emit("session.info", sid, info)
             return _ok(
                 rid,
                 {
                     "status": "compressed",
                     "removed": removed,
+                    "before_messages": before_count,
+                    "after_messages": after_count,
+                    "before_tokens": before_tokens,
+                    "after_tokens": after_tokens,
+                    "summary": summary,
                     "usage": usage,
                     "info": info,
                     "messages": messages,
                 },
             )
+        finally:
+            # Always clear the pinned compressing status so the bar
+            # reverts to neutral whether compaction succeeded, was a
+            # no-op, or raised.
+            _status_update(sid, "ready")
     except Exception as e:
         return _err(rid, 5005, str(e))
 
@@ -4508,8 +4642,8 @@ def _mirror_slash_side_effects(sid: str, session: dict, command: str) -> str:
             agent.ephemeral_system_prompt = new_prompt or None
             agent._cached_system_prompt = None
         elif name == "compress" and agent:
-            with session["history_lock"]:
             _compress_session_history(session, arg)
+            _sync_session_key_after_compress(sid, session)
             _emit("session.info", sid, _session_info(agent))
         elif name == "fast" and agent:
             mode = arg.lower()

ui-tui/src/__tests__/createGatewayEventHandler.test.ts

@@ -119,6 +119,19 @@ describe('createGatewayEventHandler', () => {
     expect(getTurnState().todos).toEqual(todos)
   })
 
+  it('prints compaction progress status into the transcript', () => {
+    const appended: Msg[] = []
+    const ctx = buildCtx(appended)
+    const onEvent = createGatewayEventHandler(ctx)
+
+    onEvent({
+      payload: { kind: 'compressing', text: 'compressing 968 messages (~123,400 tok)…' },
+      type: 'status.update'
+    } as any)
+
+    expect(ctx.system.sys).toHaveBeenCalledWith('compressing 968 messages (~123,400 tok)…')
+  })
+
   it('clears the visible todo list when the todo tool returns an empty list', () => {
     const appended: Msg[] = []
     const todos = [{ content: 'Boil water', id: 'boil', status: 'in_progress' }]

ui-tui/src/app/createGatewayEventHandler.ts

@@ -282,6 +282,11 @@ export function createGatewayEventHandler(ctx: GatewayEventHandlerContext): (ev:
 
         setStatus(p.text)
 
+        if (p.kind === 'compressing') {
+          sys(p.text)
+          return
+        }
+
         if (!p.kind || p.kind === 'status') {
           return
         }

ui-tui/src/app/slash/commands/session.ts

@@ -154,6 +154,22 @@ export const sessionCommands: SlashCommand[] = [
               patchUiState(state => ({ ...state, usage: { ...state.usage, ...r.usage } }))
             }
 
+            if (r.summary?.headline) {
+              const prefix = r.summary.noop ? '' : '✓ '
+
+              ctx.transcript.sys(`${prefix}${r.summary.headline}`)
+
+              if (r.summary.token_line) {
+                ctx.transcript.sys(`  ${r.summary.token_line}`)
+              }
+
+              if (r.summary.note) {
+                ctx.transcript.sys(`  ${r.summary.note}`)
+              }
+
+              return
+            }
+
             if ((r.removed ?? 0) <= 0) {
               return ctx.transcript.sys('nothing to compress')
             }
@@ -163,6 +179,7 @@ export const sessionCommands: SlashCommand[] = [
             )
           })
         )
+        .catch(ctx.guardedErr)
     }
   },
 

ui-tui/src/gatewayTypes.ts

@@ -167,9 +167,19 @@ export interface SessionUsageResponse {
 }
 
 export interface SessionCompressResponse {
+  after_messages?: number
+  after_tokens?: number
+  before_messages?: number
+  before_tokens?: number
   info?: SessionInfo
   messages?: GatewayTranscriptMessage[]
   removed?: number
+  summary?: {
+    headline?: string
+    noop?: boolean
+    note?: null | string
+    token_line?: string
+  }
   usage?: Usage
 }