From 419ec5078b6e97811171d011405b69657b8509e8 Mon Sep 17 00:00:00 2001
From: banteg <4562643+banteg@users.noreply.github.com>
Date: Sat, 17 Jan 2026 01:17:50 +0400
Subject: [PATCH] feat(telegram): make /ctx work everywhere (#159)

---
 docs/how-to/topics.md                     |   2 +
 docs/reference/commands-and-directives.md |  12 ++-
 docs/reference/context-resolution.md      |   3 +
 docs/reference/transports/telegram.md     |   4 +-
 docs/tutorials/conversation-modes.md      |   9 +-
 src/takopi/telegram/chat_prefs.py         |  40 +++++++
 src/takopi/telegram/commands/executor.py  |   4 +-
 src/takopi/telegram/commands/handlers.py  |   2 +
 src/takopi/telegram/commands/menu.py      |   6 +-
 src/takopi/telegram/commands/topics.py    | 102 ++++++++++++++++++
 src/takopi/telegram/loop.py               |  40 +++++--
 tests/test_telegram_bridge.py             | 126 +++++++++++++++++++++-
 tests/test_telegram_topics_command.py     |  60 ++++++++++-
 13 files changed, 390 insertions(+), 20 deletions(-)

diff --git a/docs/how-to/topics.md b/docs/how-to/topics.md
index 6a230ab..85ee424 100644
--- a/docs/how-to/topics.md
+++ b/docs/how-to/topics.md
@@ -70,6 +70,8 @@ Takopi will bind the topic and rename it to match the context.
 - `/ctx set <project> @branch` updates it
 - `/ctx clear` removes it
 
+Note: Outside topics (private chats or main group chats), `/ctx` binds the chat context instead of a topic.
+
 ## Reset a topic session
 
 Use `/new` inside the topic to clear stored sessions for that thread.
diff --git a/docs/reference/commands-and-directives.md b/docs/reference/commands-and-directives.md
index e96da66..99a7b76 100644
--- a/docs/reference/commands-and-directives.md
+++ b/docs/reference/commands-and-directives.md
@@ -42,11 +42,17 @@ This line is parsed from replies and takes precedence over new directives.
 | `/file put <path>` | Upload a document into the repo/worktree (requires file transfer enabled). |
 | `/file get <path>` | Fetch a file or directory back into Telegram. |
 | `/topic <project> @branch` | Create/bind a topic (topics enabled). |
-| `/ctx` | Show topic context binding (topics enabled). |
-| `/ctx set <project> @branch` | Update topic context binding. |
-| `/ctx clear` | Remove topic context binding. |
+| `/ctx` | Show context binding (chat or topic). |
+| `/ctx set <project> @branch` | Update context binding. |
+| `/ctx clear` | Remove context binding. |
 | `/new` | Clear stored sessions for the current scope (topic/chat). |
 
+Notes:
+
+- Outside topics, `/ctx` binds the chat context.
+- In topics, `/ctx` binds the topic context.
+- `/new` clears sessions but does **not** clear a bound context.
+
 ## CLI
 
 Takopi’s CLI is an auto-router by default; engine subcommands override the default engine.
diff --git a/docs/reference/context-resolution.md b/docs/reference/context-resolution.md
index ddbec6d..a43002a 100644
--- a/docs/reference/context-resolution.md
+++ b/docs/reference/context-resolution.md
@@ -119,6 +119,9 @@ When a message arrives in a chat whose `chat_id` matches `projects.<alias>.chat_
 Takopi defaults the project context to that alias unless a reply `ctx:` or explicit
 `/project` directive is present.
 
+In non-topic chats, `/ctx` can bind a chat context. That bound context is treated as
+ambient and takes precedence over the default project mapping until cleared.
+
 ## Worktree resolution
 
 When `@branch` is present:
diff --git a/docs/reference/transports/telegram.md b/docs/reference/transports/telegram.md
index 9178e7b..eb99d66 100644
--- a/docs/reference/transports/telegram.md
+++ b/docs/reference/transports/telegram.md
@@ -204,8 +204,8 @@ Commands:
 - `projects`: `/topic @branch` creates a topic in the project chat and binds it.
 - `all`: use `/topic <project> @branch` in the main chat, or `/topic @branch` in
   project chats.
-- `/ctx` inside a topic shows the bound context and stored session engines.
-  `/ctx set ...` and `/ctx clear` update the binding.
+- `/ctx` shows the bound context and stored session engines inside topics.
+  Outside topics, `/ctx set ...` and `/ctx clear` bind the chat context.
 - `/new` inside a topic clears stored resume tokens for that topic.
 
 State is stored in `telegram_topics_state.json` alongside the config file.
diff --git a/docs/tutorials/conversation-modes.md b/docs/tutorials/conversation-modes.md
index ce3c53c..3cd3f84 100644
--- a/docs/tutorials/conversation-modes.md
+++ b/docs/tutorials/conversation-modes.md
@@ -31,6 +31,13 @@ Takopi treats the second message as a continuation. If you want a clean slate, u
 !!! user "You"
     /new
 
+To pin a project or branch for the chat, use:
+
+!!! user "You"
+    /ctx set <project> [@branch]
+
+`/new` clears the session but keeps the bound context.
+
 Tip: set a default agent for this chat with `/agent set claude`.
 
 ## Stateless (reply-to-continue)
@@ -81,7 +88,7 @@ takopi --onboard
 ## Resume lines in chat mode
 
 If you enable chat mode (or topics), Takopi can auto-resume, so you can hide resume lines for a cleaner chat.
-Resume lines are still shown when no project context is set, so replies can branch there.
+Disable them if you want a fully clean footer, or enable `show_resume_line` to keep reply-branching visible.
 
 If you prefer always-visible resume lines, set:
 
diff --git a/src/takopi/telegram/chat_prefs.py b/src/takopi/telegram/chat_prefs.py
index 63d688b..b140866 100644
--- a/src/takopi/telegram/chat_prefs.py
+++ b/src/takopi/telegram/chat_prefs.py
@@ -4,6 +4,7 @@ from pathlib import Path
 
 import msgspec
 
+from ..context import RunContext
 from ..logging import get_logger
 from .engine_overrides import EngineOverrides, normalize_overrides
 from .state_store import JsonStateStore
@@ -17,6 +18,8 @@ STATE_FILENAME = "telegram_chat_prefs_state.json"
 class _ChatPrefs(msgspec.Struct, forbid_unknown_fields=False):
     default_engine: str | None = None
     trigger_mode: str | None = None
+    context_project: str | None = None
+    context_branch: str | None = None
     engine_overrides: dict[str, EngineOverrides] = msgspec.field(default_factory=dict)
 
 
@@ -129,6 +132,41 @@ class ChatPrefsStore(JsonStateStore[_ChatPrefsState]):
     async def clear_trigger_mode(self, chat_id: int) -> None:
         await self.set_trigger_mode(chat_id, None)
 
+    async def get_context(self, chat_id: int) -> RunContext | None:
+        async with self._lock:
+            self._reload_locked_if_needed()
+            chat = self._get_chat_locked(chat_id)
+            if chat is None:
+                return None
+            project = _normalize_text(chat.context_project)
+            if project is None:
+                return None
+            branch = _normalize_text(chat.context_branch)
+            return RunContext(project=project, branch=branch)
+
+    async def set_context(self, chat_id: int, context: RunContext | None) -> None:
+        project = _normalize_text(context.project) if context is not None else None
+        branch = _normalize_text(context.branch) if context is not None else None
+        async with self._lock:
+            self._reload_locked_if_needed()
+            chat = self._get_chat_locked(chat_id)
+            if project is None:
+                if chat is None:
+                    return
+                chat.context_project = None
+                chat.context_branch = None
+                if self._chat_is_empty(chat):
+                    self._remove_chat_locked(chat_id)
+                self._save_locked()
+                return
+            chat = self._ensure_chat_locked(chat_id)
+            chat.context_project = project
+            chat.context_branch = branch
+            self._save_locked()
+
+    async def clear_context(self, chat_id: int) -> None:
+        await self.set_context(chat_id, None)
+
     async def get_engine_override(
         self, chat_id: int, engine: str
     ) -> EngineOverrides | None:
@@ -184,6 +222,8 @@ class ChatPrefsStore(JsonStateStore[_ChatPrefsState]):
         return (
             _normalize_text(chat.default_engine) is None
             and _normalize_trigger_mode(chat.trigger_mode) is None
+            and _normalize_text(chat.context_project) is None
+            and _normalize_text(chat.context_branch) is None
             and not self._has_engine_overrides(chat.engine_overrides)
         )
 
diff --git a/src/takopi/telegram/commands/executor.py b/src/takopi/telegram/commands/executor.py
index 65a6ab0..8212cb2 100644
--- a/src/takopi/telegram/commands/executor.py
+++ b/src/takopi/telegram/commands/executor.py
@@ -109,9 +109,9 @@ def _should_show_resume_line(
     stateful_mode: bool,
     context: RunContext | None,
 ) -> bool:
-    if show_resume_line or not stateful_mode:
+    if show_resume_line:
         return True
-    return context is None or context.project is None
+    return not stateful_mode
 
 
 async def _send_runner_unavailable(
diff --git a/src/takopi/telegram/commands/handlers.py b/src/takopi/telegram/commands/handlers.py
index d03be2a..7530650 100644
--- a/src/takopi/telegram/commands/handlers.py
+++ b/src/takopi/telegram/commands/handlers.py
@@ -16,6 +16,7 @@ from .model import _handle_model_command as handle_model_command
 from .parse import _parse_slash_command as parse_slash_command
 from .reasoning import _handle_reasoning_command as handle_reasoning_command
 from .topics import _handle_chat_new_command as handle_chat_new_command
+from .topics import _handle_chat_ctx_command as handle_chat_ctx_command
 from .topics import _handle_ctx_command as handle_ctx_command
 from .topics import _handle_new_command as handle_new_command
 from .topics import _handle_topic_command as handle_topic_command
@@ -25,6 +26,7 @@ __all__ = [
     "dispatch_command",
     "get_reserved_commands",
     "handle_agent_command",
+    "handle_chat_ctx_command",
     "handle_chat_new_command",
     "handle_ctx_command",
     "handle_file_command",
diff --git a/src/takopi/telegram/commands/menu.py b/src/takopi/telegram/commands/menu.py
index ea39c7f..1341b47 100644
--- a/src/takopi/telegram/commands/menu.py
+++ b/src/takopi/telegram/commands/menu.py
@@ -72,6 +72,7 @@ def build_bot_commands(
         seen.add(cmd)
     for cmd, description in [
         ("new", "start a new thread"),
+        ("ctx", "show or update context"),
         ("agent", "set default agent"),
         ("model", "set model override"),
         ("reasoning", "set reasoning override"),
@@ -82,10 +83,7 @@ def build_bot_commands(
         commands.append({"command": cmd, "description": description})
         seen.add(cmd)
     if include_topics:
-        for cmd, description in [
-            ("topic", "create or bind a topic"),
-            ("ctx", "show or update topic context"),
-        ]:
+        for cmd, description in [("topic", "create or bind a topic")]:
             if cmd in seen:
                 continue
             commands.append({"command": cmd, "description": description})
diff --git a/src/takopi/telegram/commands/topics.py b/src/takopi/telegram/commands/topics.py
index 7249a47..817da09 100644
--- a/src/takopi/telegram/commands/topics.py
+++ b/src/takopi/telegram/commands/topics.py
@@ -2,8 +2,11 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
+from ...context import RunContext
 from ...markdown import MarkdownParts
+from ...transport_runtime import TransportRuntime
 from ...transport import RenderedMessage, SendOptions
+from ..chat_prefs import ChatPrefsStore
 from ..chat_sessions import ChatSessionStore
 from ..context import (
     _format_context,
@@ -116,6 +119,105 @@ async def _handle_ctx_command(
     )
 
 
+def _parse_chat_ctx_args(
+    args_text: str,
+    *,
+    runtime: TransportRuntime,
+    default_project: str | None,
+) -> tuple[RunContext | None, str | None]:
+    tokens = split_command_args(args_text)
+    if not tokens:
+        return None, _usage_ctx_set(chat_project=None)
+    if len(tokens) > 2:
+        return None, "too many arguments"
+    project_token: str | None = None
+    branch: str | None = None
+    first = tokens[0]
+    if first.startswith("@"):
+        branch = first[1:] or None
+    else:
+        project_token = first
+        if len(tokens) == 2:
+            second = tokens[1]
+            if not second.startswith("@"):
+                return None, "branch must be prefixed with @"
+            branch = second[1:] or None
+    project_key: str | None = None
+    if project_token is None:
+        if default_project is None:
+            return None, "project is required"
+        project_key = default_project
+    else:
+        project_key = runtime.normalize_project_key(project_token)
+        if project_key is None:
+            return None, f"unknown project {project_token!r}"
+    return RunContext(project=project_key, branch=branch), None
+
+
+async def _handle_chat_ctx_command(
+    cfg: TelegramBridgeConfig,
+    msg: TelegramIncomingMessage,
+    args_text: str,
+    chat_prefs: ChatPrefsStore | None,
+) -> None:
+    reply = make_reply(cfg, msg)
+    if chat_prefs is None:
+        await reply(text="chat context unavailable; config path is not set.")
+        return
+
+    tokens = split_command_args(args_text)
+    action = tokens[0].lower() if tokens else "show"
+    if action in {"show", ""}:
+        bound = await chat_prefs.get_context(msg.chat_id)
+        resolved = cfg.runtime.resolve_message(
+            text="",
+            reply_text=msg.reply_to_text,
+            chat_id=msg.chat_id,
+            ambient_context=bound,
+        )
+        source = resolved.context_source
+        if bound is not None and resolved.context_source == "ambient":
+            source = "bound"
+        lines = [
+            f"bound ctx: {_format_context(cfg.runtime, bound)}",
+            f"resolved ctx: {_format_context(cfg.runtime, resolved.context)} (source: {source})",
+        ]
+        if bound is None:
+            ctx_usage = (
+                _usage_ctx_set(chat_project=None).removeprefix("usage: ").strip()
+            )
+            lines.append(f"note: no bound context — bind with {ctx_usage}")
+        await reply(text="\n".join(lines))
+        return
+    if action == "set":
+        rest = " ".join(tokens[1:])
+        context, error = _parse_chat_ctx_args(
+            rest,
+            runtime=cfg.runtime,
+            default_project=cfg.runtime.default_project,
+        )
+        if error is not None:
+            await reply(
+                text=f"error:\n{error}\n{_usage_ctx_set(chat_project=None)}",
+            )
+            return
+        if context is None:
+            await reply(text=f"error:\n{_usage_ctx_set(chat_project=None)}")
+            return
+        await chat_prefs.set_context(msg.chat_id, context)
+        await reply(
+            text=f"chat bound to `{_format_context(cfg.runtime, context)}`",
+        )
+        return
+    if action == "clear":
+        await chat_prefs.clear_context(msg.chat_id)
+        await reply(text="chat context cleared.")
+        return
+    await reply(
+        text="unknown `/ctx` command. use `/ctx`, `/ctx set`, or `/ctx clear`.",
+    )
+
+
 async def _handle_new_command(
     cfg: TelegramBridgeConfig,
     msg: TelegramIncomingMessage,
diff --git a/src/takopi/telegram/loop.py b/src/takopi/telegram/loop.py
index 46dc7d4..cb6458f 100644
--- a/src/takopi/telegram/loop.py
+++ b/src/takopi/telegram/loop.py
@@ -28,6 +28,7 @@ from .commands.file_transfer import FILE_PUT_USAGE
 from .commands.handlers import (
     dispatch_command,
     handle_agent_command,
+    handle_chat_ctx_command,
     handle_chat_new_command,
     handle_ctx_command,
     handle_file_command,
@@ -169,8 +170,13 @@ def _dispatch_builtin_command(
         task_group.start_soon(handler)
         return True
 
-    if cfg.topics.enabled and topic_store is not None:
-        if command_id == "ctx":
+    if command_id == "ctx":
+        topic_key = (
+            _topic_key(msg, cfg, scope_chat_ids=scope_chat_ids)
+            if cfg.topics.enabled and topic_store is not None
+            else None
+        )
+        if topic_key is not None:
             handler = partial(
                 handle_ctx_command,
                 cfg,
@@ -180,7 +186,19 @@ def _dispatch_builtin_command(
                 resolved_scope=resolved_scope,
                 scope_chat_ids=scope_chat_ids,
             )
-        elif command_id == "new":
+        else:
+            handler = partial(
+                handle_chat_ctx_command,
+                cfg,
+                msg,
+                args_text,
+                chat_prefs,
+            )
+        task_group.start_soon(handler)
+        return True
+
+    if cfg.topics.enabled and topic_store is not None:
+        if command_id == "new":
             handler = partial(
                 handle_new_command,
                 cfg,
@@ -1507,9 +1525,19 @@ async def run_main_loop(
                     if state.topic_store is not None and topic_key is not None
                     else None
                 )
-                ambient_context = _merge_topic_context(
-                    chat_project=chat_project, bound=bound_context
-                )
+                chat_bound_context = None
+                if state.chat_prefs is not None:
+                    chat_bound_context = await state.chat_prefs.get_context(chat_id)
+                if bound_context is not None:
+                    ambient_context = _merge_topic_context(
+                        chat_project=chat_project, bound=bound_context
+                    )
+                elif chat_bound_context is not None:
+                    ambient_context = chat_bound_context
+                else:
+                    ambient_context = _merge_topic_context(
+                        chat_project=chat_project, bound=None
+                    )
                 return TelegramMsgContext(
                     chat_id=chat_id,
                     thread_id=msg.thread_id,
diff --git a/tests/test_telegram_bridge.py b/tests/test_telegram_bridge.py
index 81a30e7..e83c358 100644
--- a/tests/test_telegram_bridge.py
+++ b/tests/test_telegram_bridge.py
@@ -135,6 +135,7 @@ def test_build_bot_commands_includes_cancel_and_engine() -> None:
     assert {"command": "cancel", "description": "cancel run"} in commands
     assert {"command": "file", "description": "upload or fetch files"} in commands
     assert {"command": "new", "description": "start a new thread"} in commands
+    assert {"command": "ctx", "description": "show or update context"} in commands
     assert {"command": "agent", "description": "set default agent"} in commands
     assert any(cmd["command"] == "codex" for cmd in commands)
 
@@ -179,7 +180,7 @@ def test_build_bot_commands_includes_topics_when_enabled() -> None:
     commands = build_bot_commands(runtime, include_topics=True)
 
     assert {"command": "topic", "description": "create or bind a topic"} in commands
-    assert {"command": "ctx", "description": "show or update topic context"} in commands
+    assert {"command": "ctx", "description": "show or update context"} in commands
 
 
 def test_build_bot_commands_includes_command_plugins(monkeypatch) -> None:
@@ -2515,6 +2516,129 @@ async def test_run_main_loop_hides_resume_line_when_disabled(
     assert resume_value not in final_text
 
 
+@pytest.mark.anyio
+async def test_run_main_loop_hides_resume_line_without_context(
+    tmp_path: Path,
+) -> None:
+    resume_value = "resume-ctxless"
+    state_path = tmp_path / "takopi.toml"
+
+    transport = FakeTransport()
+    bot = FakeBot()
+    runner = ScriptRunner(
+        [Return(answer="ok")],
+        engine=CODEX_ENGINE,
+        resume_value=resume_value,
+    )
+    exec_cfg = ExecBridgeConfig(
+        transport=transport,
+        presenter=MarkdownPresenter(),
+        final_notify=True,
+    )
+    runtime = TransportRuntime(
+        router=_make_router(runner),
+        projects=_empty_projects(),
+        config_path=state_path,
+    )
+    cfg = TelegramBridgeConfig(
+        bot=bot,
+        runtime=runtime,
+        chat_id=123,
+        startup_msg="",
+        exec_cfg=exec_cfg,
+        forward_coalesce_s=FAST_FORWARD_COALESCE_S,
+        media_group_debounce_s=FAST_MEDIA_GROUP_DEBOUNCE_S,
+        session_mode="chat",
+        show_resume_line=False,
+    )
+
+    async def poller(_cfg: TelegramBridgeConfig):
+        yield TelegramIncomingMessage(
+            transport="telegram",
+            chat_id=123,
+            message_id=1,
+            text="hello",
+            reply_to_message_id=None,
+            reply_to_text=None,
+            sender_id=123,
+            chat_type="private",
+        )
+
+    await run_main_loop(cfg, poller)
+
+    assert transport.send_calls
+    final_text = transport.send_calls[-1]["message"].text
+    assert resume_value not in final_text
+
+
+@pytest.mark.anyio
+async def test_run_main_loop_applies_chat_bound_context(
+    tmp_path: Path,
+) -> None:
+    state_path = tmp_path / "takopi.toml"
+
+    transport = FakeTransport()
+    bot = FakeBot()
+    runner = ScriptRunner([Return(answer="ok")], engine=CODEX_ENGINE)
+    exec_cfg = ExecBridgeConfig(
+        transport=transport,
+        presenter=MarkdownPresenter(),
+        final_notify=True,
+    )
+    projects = ProjectsConfig(
+        projects={
+            "alpha": ProjectConfig(
+                alias="Alpha",
+                path=tmp_path,
+                worktrees_dir=Path(".worktrees"),
+            ),
+            "beta": ProjectConfig(
+                alias="Beta",
+                path=tmp_path / "beta",
+                worktrees_dir=Path(".worktrees"),
+            ),
+        },
+        default_project="alpha",
+    )
+    (tmp_path / "beta").mkdir()
+    runtime = TransportRuntime(
+        router=_make_router(runner),
+        projects=projects,
+        config_path=state_path,
+    )
+    prefs = ChatPrefsStore(resolve_prefs_path(state_path))
+    await prefs.set_context(123, RunContext(project="beta"))
+    cfg = TelegramBridgeConfig(
+        bot=bot,
+        runtime=runtime,
+        chat_id=123,
+        startup_msg="",
+        exec_cfg=exec_cfg,
+        forward_coalesce_s=FAST_FORWARD_COALESCE_S,
+        media_group_debounce_s=FAST_MEDIA_GROUP_DEBOUNCE_S,
+        session_mode="chat",
+        show_resume_line=False,
+    )
+
+    async def poller(_cfg: TelegramBridgeConfig):
+        yield TelegramIncomingMessage(
+            transport="telegram",
+            chat_id=123,
+            message_id=1,
+            text="hello",
+            reply_to_message_id=None,
+            reply_to_text=None,
+            sender_id=123,
+            chat_type="private",
+        )
+
+    await run_main_loop(cfg, poller)
+
+    assert transport.send_calls
+    final_text = transport.send_calls[-1]["message"].text
+    assert "`ctx: Beta`" in final_text
+
+
 @pytest.mark.anyio
 async def test_run_main_loop_chat_sessions_isolate_group_senders(
     tmp_path: Path,
diff --git a/tests/test_telegram_topics_command.py b/tests/test_telegram_topics_command.py
index 2c67bbf..6d18038 100644
--- a/tests/test_telegram_topics_command.py
+++ b/tests/test_telegram_topics_command.py
@@ -4,8 +4,12 @@ from pathlib import Path
 import pytest
 
 from takopi.settings import TelegramTopicsSettings
+from takopi.config import ProjectConfig, ProjectsConfig
+from takopi.runners.mock import Return, ScriptRunner
 from takopi.telegram.chat_sessions import ChatSessionStore
+from takopi.telegram.chat_prefs import ChatPrefsStore, resolve_prefs_path
 from takopi.telegram.commands.topics import (
+    _handle_chat_ctx_command,
     _handle_chat_new_command,
     _handle_ctx_command,
     _handle_new_command,
@@ -13,7 +17,13 @@ from takopi.telegram.commands.topics import (
 )
 from takopi.telegram.topic_state import TopicStateStore
 from takopi.telegram.types import TelegramIncomingMessage
-from tests.telegram_fakes import FakeTransport, make_cfg
+from tests.telegram_fakes import (
+    DEFAULT_ENGINE_ID,
+    FakeTransport,
+    _make_router,
+    make_cfg,
+)
+from takopi.transport_runtime import TransportRuntime
 
 
 def _msg(
@@ -37,6 +47,27 @@ def _msg(
     )
 
 
+def _runtime(tmp_path: Path) -> tuple[TransportRuntime, Path]:
+    runner = ScriptRunner([Return(answer="ok")], engine=DEFAULT_ENGINE_ID)
+    projects = ProjectsConfig(
+        projects={
+            "alpha": ProjectConfig(
+                alias="Alpha",
+                path=tmp_path,
+                worktrees_dir=Path(".worktrees"),
+            )
+        },
+        default_project="alpha",
+    )
+    state_path = tmp_path / "takopi.toml"
+    runtime = TransportRuntime(
+        router=_make_router(runner),
+        projects=projects,
+        config_path=state_path,
+    )
+    return runtime, state_path
+
+
 @pytest.mark.anyio
 async def test_ctx_command_requires_topic(tmp_path: Path) -> None:
     transport = FakeTransport()
@@ -60,6 +91,33 @@ async def test_ctx_command_requires_topic(tmp_path: Path) -> None:
     assert "only works inside a topic" in text
 
 
+@pytest.mark.anyio
+async def test_chat_ctx_command_sets_binding(tmp_path: Path) -> None:
+    transport = FakeTransport()
+    runtime, state_path = _runtime(tmp_path)
+    cfg = replace(make_cfg(transport), runtime=runtime, session_mode="chat")
+    store = ChatPrefsStore(resolve_prefs_path(state_path))
+
+    msg = _msg("/ctx set alpha @dev", chat_type="private")
+    await _handle_chat_ctx_command(
+        cfg,
+        msg,
+        args_text="set alpha @dev",
+        chat_prefs=store,
+    )
+
+    msg_show = _msg("/ctx", chat_type="private")
+    await _handle_chat_ctx_command(
+        cfg,
+        msg_show,
+        args_text="",
+        chat_prefs=store,
+    )
+
+    text = transport.send_calls[-1]["message"].text
+    assert "bound ctx: Alpha @dev" in text
+
+
 @pytest.mark.anyio
 async def test_new_command_requires_topic(tmp_path: Path) -> None:
     transport = FakeTransport()