From 388946f7ada8d97bda2ca8da19ac4f637a7999ef Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:54:31 -0400
Subject: [PATCH 1/8] Declare PTY resource, terminal geometry and completion
 input types

---
 src/toad/terminal_execution.py | 38 +++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/toad/terminal_execution.py b/src/toad/terminal_execution.py
index 43bed1aa5..1aec78597 100644
--- a/src/toad/terminal_execution.py
+++ b/src/toad/terminal_execution.py
@@ -13,7 +13,7 @@
 import signal
 import termios
 from io import FileIO
-from typing import Mapping
+from typing import TYPE_CHECKING, Mapping
 from weakref import ref
 
 from acp import schema as protocol
@@ -27,6 +27,10 @@
 from toad.shell_read import shell_read
 from toad.terminal_environment import TerminalEnvironment
 
+if TYPE_CHECKING:
+    from toad.widgets.terminal_tool import TerminalTool
+
+
 @dataclass
 class Command:
     """A command and corresponding environment."""
@@ -152,15 +156,15 @@ class _TerminalCompletionDecoder(MroDispatch):
     """Typed original POSIX members enter the terminal family at acquisition."""
     completion: TerminalCompletion
 
-    def __init__(self, original):
+    def __init__(self, original: ChildOutcome):
         self.dispatch_sync(original)
 
     @handles(ExitedOutcome)
-    def exited(self, original):
+    def exited(self, original: ExitedOutcome):
         self.completion = ExitedTerminalOutcome(original)
 
     @handles(SignaledOutcome)
-    def signaled(self, original):
+    def signaled(self, original: SignaledOutcome):
         self.completion = SignaledTerminalOutcome(original)
 
 
@@ -188,8 +192,8 @@ class PtyProcess:
     reader: asyncio.StreamReader
 
     @classmethod
-    async def acquire(cls, command: tuple[str, ...], *, env, cwd, width, height,
-                      cleanup: AsyncExitStack, buffer_size=128 * 1024):
+    async def acquire(cls, command: tuple[str, ...], *, env: Mapping[str, str], cwd, width: int, height: int,
+                      cleanup: AsyncExitStack, buffer_size: int=128 * 1024):
         master, slave = pty.openpty()
         master_file = cleanup.enter_context(os.fdopen(master, "rb", 0))
         slave_file = cleanup.enter_context(os.fdopen(slave, "wb", 0))
@@ -222,12 +226,12 @@ async def acquire_child():
         slave_file.close()
         return cls(child, master_file, reader)
 
-    def resize(self, width, height):
+    def resize(self, width: int, height: int):
         with suppress(OSError, ValueError):
             self.resize_fd(self.master.fileno(), width, height)
 
     @staticmethod
-    def resize_fd(fd, width, height):
+    def resize_fd(fd: int, width: int, height: int):
         termios.tcsetwinsize(fd, (height, width))
 
     async def write(self, data: bytes) -> int:
@@ -255,10 +259,10 @@ def outcome(self) -> TerminalOutcome: ...
     def kill(self) -> None:
         pass
 
-    def resize(self, width, height):
+    def resize(self, width: int, height: int):
         pass
 
-    async def write(self, data):
+    async def write(self, data: bytes):
         return 0
 
     async def close(self):
@@ -305,7 +309,7 @@ class ActiveTerminalOperation(TerminalOperation):
     def start(self, execution):
         raise RuntimeError("Terminal execution already started")
 
-    def settle_startup(self, task):
+    def settle_startup(self, task: asyncio.Task[TerminalCompletion]):
         # A cancelled task may never enter run(), so its original cancellation
         # must settle the startup waiter too. Entered failures settle in run().
         if task.cancelled() and not self.ready.done():
@@ -321,11 +325,11 @@ def outcome(self):
         except BaseException as error:
             return FailedTerminalOutcome(error)
 
-    def resize(self, width, height):
+    def resize(self, width: int, height: int):
         if self.ready.done() and not self.task.done():
             self.ready.result().resize(width, height)
 
-    async def write(self, data):
+    async def write(self, data: bytes):
         if self.ready.done() and not self.task.done():
             return await self.ready.result().write(data)
         return 0
@@ -387,7 +391,7 @@ def tool_state(self):
         output, truncated = self.get_output()
         return ToolState(output, truncated, self.operation.outcome())
 
-    def attach(self, terminal):
+    def attach(self, terminal: TerminalTool):
         self._view = ref(terminal)
         terminal.set_state(self.state)
         terminal.set_write_to_stdin(self.write_stdin)
@@ -401,7 +405,7 @@ def project(self, scrollback: set[int] | None, alternate: set[int] | None):
         if (terminal := self._view()) is not None and terminal.is_attached:
             terminal.present_execution(scrollback, alternate)
 
-    def update_size(self, width, height):
+    def update_size(self, width: int, height: int):
         self.state.update_size(width, height)
         self.operation.resize(width, height)
 
@@ -419,7 +423,7 @@ async def start(self):
         self.state.show_cursor = True
         await asyncio.shield(operation.ready)
 
-    async def run(self, ready):
+    async def run(self, ready: asyncio.Future[PtyProcess]):
         try:
             async with AsyncExitStack() as cleanup:
                 command = self.command
@@ -447,7 +451,7 @@ async def run(self, ready):
             # The task's result becomes authoritative only after this returns.
             asyncio.get_running_loop().call_soon(self.project, None, None)
 
-    async def write_stdin(self, text: str | bytes, hide_echo=False):
+    async def write_stdin(self, text: str | bytes, hide_echo: bool=False):
         data = text.encode("utf-8", "ignore") if isinstance(text, str) else text
         return await self.operation.write(data)
 

From 0379c9901de7fbbe8d3fd9231497f8e39baacb6c Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:55:14 -0400
Subject: [PATCH 2/8] Type agent lifecycle and view inputs from the existing
 session owners

---
 src/toad/agent.py | 39 +++++++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/toad/agent.py b/src/toad/agent.py
index 43bf05a7b..564eef263 100644
--- a/src/toad/agent.py
+++ b/src/toad/agent.py
@@ -1,5 +1,6 @@
 from abc import abstractmethod
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 from agent_comms.thread_presentation import ThreadPresentation
 from textual.content import Content
@@ -12,6 +13,16 @@
 from toad.surface_binding import SurfaceBinding
 
 
+if TYPE_CHECKING:
+    from agent_comms.session_load import ExistingSessionLoadPlan
+
+    from toad.conversation_turn import TurnOwner
+    from toad.screens.main import MainScreen
+    from toad.session_observation import SessionObservation
+    from toad.session_presentation import OperationalSessionSources
+    from toad.widgets.conversation import Conversation, ConversationSessionBinding
+
+
 class AgentBase(AgentConnection):
     """Base class for an 'agent'."""
 
@@ -35,7 +46,7 @@ def attach_view(self, view) -> None:
     def matches_agent(self, agent) -> bool:
         return self is agent
 
-    def cancel_allowed(self, turn):
+    def cancel_allowed(self, turn: TurnOwner):
         return turn.can_cancel
 
     def matches_session(self, session_id):
@@ -44,14 +55,14 @@ def matches_session(self, session_id):
     def borrowed_processes(self):
         return (self.process,)
 
-    async def reconnect_session(self, source, plan) -> None:
+    async def reconnect_session(self, source: MainScreen, plan: ExistingSessionLoadPlan) -> None:
         await self.session.reconnect(plan)
 
-    async def change_project(self, view, path) -> None:
+    async def change_project(self, view: Conversation, path: Path) -> None:
         project = await self.update_project(str(path))
         view.feedback.flash(Content(f"Project changed to {project}"), style="success")
 
-    def request_compaction(self, view, instructions) -> None:
+    def request_compaction(self, view: Conversation, instructions) -> None:
         view.compact_context(instructions)
 
     def begin_submission(self, owner, submission):
@@ -69,49 +80,49 @@ def accepts_failed_input(self, message):
     def send_now(self, owner):
         return owner.send_bound_now(self)
 
-    def invalidate_observation(self, observation) -> None:
+    def invalidate_observation(self, observation: SessionObservation) -> None:
         observation.schedule(self)
 
     @property
     def automatic_titles(self) -> bool:
         return self.observed_thread() is None
 
-    async def project_changed(self, path) -> None:
+    async def project_changed(self, path: Path) -> None:
         from toad.db import DB
 
         self.project_root_path = path
         if (session_pk := self.session.pk) is not None:
             await DB().session_update_project(session_pk, path)
 
-    def refresh_context(self, view) -> None:
+    def refresh_context(self, view: Conversation) -> None:
         view.status = self.context_measurement.status()
 
     async def compact_context(self, instructions) -> None:
         await self.controller.compact_context(instructions)
 
-    async def cancel_turn(self, view) -> None:
+    async def cancel_turn(self, view: Conversation) -> None:
         await view.cancel_bound_turn(self)
 
     def accepts_message(self, message) -> bool:
         return message.publisher is self and message.event.session_id == self.session_id
 
-    def refresh_projection(self, view) -> None:
+    def refresh_projection(self, view: ConversationSessionBinding) -> None:
         view.status = self.context_measurement.status()
         view.turns.bound()
         view.submissions.publish_pending()
         view.delivery_observation.invalidate()
 
-    def start_session(self, view) -> None:
+    def start_session(self, view: ConversationSessionBinding) -> None:
         if self.ready:
             view.session_ready()
 
-    def start_agent(self, sources, view) -> None:
+    def start_agent(self, sources: OperationalSessionSources, view: Conversation) -> None:
         """A connected agent is not created a second time."""
 
-    def update_view(self, view) -> None:
+    def update_view(self, view: ConversationSessionBinding) -> None:
         view.apply_bound_agent(self)
 
-    def connected(self, view) -> None:
+    def connected(self, view: ConversationSessionBinding) -> None:
         view.agent_connected(self)
 
     @property
@@ -125,7 +136,7 @@ def current_turn(self):
     def attach_surface(self, binding: SurfaceBinding) -> None:
         binding.close()
 
-    async def retire_surface(self, surface) -> None:
+    async def retire_surface(self, surface: Conversation) -> None:
         await self.stop()
 
     def observed_thread(self) -> tuple[str, str] | None:

From 19a5b6d77117ec2235f1039c99d1079d7d39ce5e Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:55:51 -0400
Subject: [PATCH 3/8] Declare transcript fragment and line acquisition input
 types

---
 src/toad/widgets/transcript_fragments.py | 33 +++++++++++++-----------
 src/toad/widgets/transcript_lines.py     | 24 +++++++++--------
 2 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/src/toad/widgets/transcript_fragments.py b/src/toad/widgets/transcript_fragments.py
index 7722aefd7..73698ee99 100644
--- a/src/toad/widgets/transcript_fragments.py
+++ b/src/toad/widgets/transcript_fragments.py
@@ -47,6 +47,9 @@
 from toad.widgets.transcript_lines import AcquiredRows, NoRows, RowAcquisition
 
 if TYPE_CHECKING:
+    from toad.widgets.transcript_lines import (
+        BlockLines, Lines, LineTheme, RichLineRenderer, TranscriptLinesRenderTask,
+    )
     from toad.tool_output import ToolOutputPart
     from toad.widgets.committed_presentation import CommitClaim
 
@@ -241,10 +244,10 @@ class LastPart(PartPosition):
     def notification_references(self, event):
         return (event.source,)
 
-    def status_blocks(self, shown):
+    def status_blocks(self, shown: MessageShown):
         return shown.status.blocks(shown)
 
-    def outgoing_sources(self, publication):
+    def outgoing_sources(self, publication: PublishedSentMessage):
         return (publication.reference,)
 
 
@@ -252,13 +255,13 @@ class InnerPart(PartPosition):
     __slots__ = ()
     has_details = False
 
-    def notification_references(self, event):
+    def notification_references(self, event: TranscriptEvent):
         return ()
 
-    def status_blocks(self, shown):
+    def status_blocks(self, shown: MessageShown):
         return ()
 
-    def outgoing_sources(self, publication):
+    def outgoing_sources(self, publication: PublishedSentMessage):
         return ()
 
 
@@ -299,10 +302,10 @@ def outgoing_sources(self):
         return ()
 
     @classmethod
-    def capture_part(cls, event, text: str, **kwargs):
+    def capture_part(cls, event: TextTranscript, text: str, **kwargs):
         return cls((replace(event, text=text),), **kwargs)
 
-    def text_rows(self, lines) -> range:
+    def text_rows(self, lines: Lines) -> range:
         """The fragment's content occupies its drawn rows unless it owns a header."""
         return range(lines.height)
 
@@ -362,11 +365,11 @@ def link_place(self) -> int:
 
         return link_place()
 
-    def lines_for(self, width: int, theme):
+    def lines_for(self, width: int, theme: LineTheme):
         """Cached lookup is geometry-only; source changes use declared invalidation."""
         return self._lines.for_view(width, theme)
 
-    def retains_lines(self, lines, theme) -> bool:
+    def retains_lines(self, lines: BlockLines, theme: LineTheme) -> bool:
         """Whether measured rows still belong to this source and palette.
 
         RowAcquisition.for_view owns wrapping those rows at the layout width.
@@ -376,14 +379,14 @@ def retains_lines(self, lines, theme) -> bool:
     def invalidate_lines(self) -> None:
         self._lines = NoRows()
 
-    def hold_lines(self, request, lines) -> bool:
+    def hold_lines(self, request: TranscriptLinesRenderTask, lines: BlockLines) -> bool:
         """Report whether these rows were retained for the fragment's source."""
         if request.blocks is self.line_blocks:
             self._lines = AcquiredRows(request.preparation, lines)
             return True
         return False
 
-    def plain_lines(self, width: int, renderer):
+    def plain_lines(self, width: int, renderer: RichLineRenderer):
         """Plain wrapped lines drawn until styled lines arrive; one per width."""
         self._plain = acquired = self._plain.plain(width, renderer, self.line_blocks)
         return acquired.lines
@@ -408,7 +411,7 @@ def has_details(self) -> bool:
             self.tool_call, any(part.has_details for part in self.output_parts)
         )
 
-    def blocks(self, shown):
+    def blocks(self, shown: Shown):
         return AgentActivityPresentation.tool(
             self.tool_call,
             has_details=self.has_details,
@@ -426,11 +429,11 @@ class BusMessageFragment(TranscriptFragment):
     row: MessageRow
 
     @classmethod
-    def capture_part(cls, event, text: str, **kwargs):
+    def capture_part(cls, event: TextTranscript, text: str, **kwargs):
         return cls((event,), text_part=text, **kwargs)
 
     @classmethod
-    def text_parts(cls, source, budget):
+    def text_parts(cls, source: PreparedMarkdownPart, budget: RenderBudget):
         # Even an empty bus message owns its header and notification footer.
         return super().text_parts(source, budget) or (source,)
 
@@ -487,7 +490,7 @@ class ContextTranscriptFragment(TranscriptFragment):
 
     has_details = True
 
-    def blocks(self, shown):
+    def blocks(self, shown: Shown):
         summary = shown.summary("Agent coordination context")
         if not shown.details_open:
             return (summary,)
diff --git a/src/toad/widgets/transcript_lines.py b/src/toad/widgets/transcript_lines.py
index 59a3f9f51..c56174240 100644
--- a/src/toad/widgets/transcript_lines.py
+++ b/src/toad/widgets/transcript_lines.py
@@ -17,6 +17,8 @@
 from toad.patch import PatchCell
 
 if TYPE_CHECKING:
+    from toad.widgets.transcript_fragments import Shown, TranscriptFragment
+    from toad.widgets.transcript_history import LineHistory
     from toad.textual_colours import PaletteState, TextualColours
 
 from agent_comms.mro_dispatch import MroDispatch, handles
@@ -232,7 +234,7 @@ def __iter__(self) -> Iterator[Row]:
     def height(self) -> int:
         return len(self.rows)
 
-    def prepared_rows(self, width, draw) -> PreparedLines:
+    def prepared_rows(self, width: int, draw: Callable[[LineBlock], PreparedLines]) -> PreparedLines:
         if width != self.width:
             raise ValueError("Prepared rows belong to a different width")
         return self
@@ -281,7 +283,7 @@ class PreparedBlock(LineBlock):
 
     _rows: PreparedLines = PreparedLines(width=-1, rows=())
 
-    def prepared_rows(self, width, draw) -> PreparedLines:
+    def prepared_rows(self, width: int, draw: Callable[[LineBlock], PreparedLines]) -> PreparedLines:
         rows = self._rows
         if rows.width != width:
             self._rows = rows = draw(self)
@@ -578,10 +580,10 @@ class NoRows(RowAcquisition):
     def preparation(self) -> NoRows:
         return self
 
-    def for_view(self, width: int, theme):
+    def for_view(self, width: int, theme: LineTheme):
         return None
 
-    def retains(self, lines, theme) -> bool:
+    def retains(self, lines: BlockLines, theme: LineTheme) -> bool:
         return False
 
 
@@ -594,16 +596,16 @@ class AcquiredRows(RowAcquisition):
     def preparation(self) -> LinePreparation:
         return self.lines.preparation
 
-    def for_view(self, width: int, theme):
+    def for_view(self, width: int, theme: LineTheme):
         if self.source.theme is not theme:
             return None
         self.lines = self.lines.rewrap(width)
         return self.lines
 
-    def retains(self, lines, theme) -> bool:
+    def retains(self, lines: BlockLines, theme: LineTheme) -> bool:
         return self.source.theme is theme and self.lines.preparation is lines.preparation
 
-    def plain(self, width: int, renderer, blocks):
+    def plain(self, width: int, renderer: RichLineRenderer, blocks: tuple[LineBlock, ...]):
         if self.source.theme is renderer.theme:
             self.lines = self.lines.rewrap(width)
             return self
@@ -611,7 +613,7 @@ def plain(self, width: int, renderer, blocks):
 
 
 class PlainRows(AcquiredRows):
-    def retains(self, lines, theme) -> bool:
+    def retains(self, lines: BlockLines, theme: LineTheme) -> bool:
         return self.source.theme is theme and self.lines.preparation.blocks is lines.preparation.blocks
 
 
@@ -633,11 +635,11 @@ def blocks(self) -> tuple[LineBlock, ...]:
     def current_for(self, view) -> bool:
         return self.context.current_for(view) and self.preparation.theme is view.app.colours.line_theme
 
-    def hold(self, view, fragment, lines) -> bool:
+    def hold(self, view, fragment: TranscriptFragment, lines: LinePreparation) -> bool:
         return self.current_for(view) and fragment.hold_lines(self, lines.wrap(view.line_width, view.app.colours.line_renderer))
 
     @staticmethod
-    def show(view, fragment, shown, rendered) -> None:
+    def show(view: LineHistory, fragment: TranscriptFragment, shown: Shown, rendered) -> None:
         """Apply the requested state, retaining rows only through their render request."""
         fragment.show(shown)
         if rendered is not None:
@@ -702,7 +704,7 @@ def result_size(self, result: tuple[LinePreparation, ...]) -> int:
     items: tuple[TranscriptLinesRenderTask, ...]
 
     @classmethod
-    async def render_for(cls, view, preparations):
+    async def render_for(cls, view, preparations: Iterable[LinePreparation]):
         """One captured reference source for a batch; requests own result publication."""
         preparations = tuple(preparations)
         if not preparations:

From ad17bfc62d22096c0e411eaf317515f0affcec81 Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:55:59 -0400
Subject: [PATCH 4/8] Declare SDK session update and conversation turn inputs

---
 src/toad/acp/session_updates.py | 72 ++++++++++++++++++++++-----------
 src/toad/conversation_turn.py   | 47 ++++++++++++---------
 2 files changed, 77 insertions(+), 42 deletions(-)

diff --git a/src/toad/acp/session_updates.py b/src/toad/acp/session_updates.py
index 9e05ea822..ef8c92c31 100644
--- a/src/toad/acp/session_updates.py
+++ b/src/toad/acp/session_updates.py
@@ -3,6 +3,10 @@
 
 import asyncio
 from abc import abstractmethod
+from typing import TYPE_CHECKING
+
+from pydantic import JsonValue
+from agent_comms.acp_extension import AgentCommsUpdate
 
 from agent_comms.declared_family import DeclaredFamily
 
@@ -12,97 +16,117 @@
 from toad.acp.sdk_boundary import ValidateSessionUpdateTask
 from agent_comms.mro_dispatch import MroDispatch, handles
 from acp.schema import (UserMessageChunk, AgentMessageChunk, AgentThoughtChunk,
-    ToolCallStart, ToolCallProgress, AgentPlanUpdate, AvailableCommandsUpdate,
+    ToolCallStart, ToolCallProgress, AgentPlanUpdate, AgentPlanContentUpdate, AgentPlanRemovedUpdate,
+    SessionNotification, AvailableCommandsUpdate,
     CurrentModeUpdate, ConfigOptionUpdate, SessionInfoUpdate, UsageUpdate, TextContentBlock)
 from toad.plan import decode_plan
 from toad.project_link import AcpLogLink
 
+if TYPE_CHECKING:
+    from toad.acp.agent import Agent
+    from toad.acp.comms_updates import CommsUpdateConsumer
+
 
 class SessionUpdateEffect(MroDispatch):
     """Effect registrations consume official SDK declarations, never raw shapes."""
-    def __init__(self, agent, consumer):
+    def __init__(self, agent: Agent, consumer: CommsUpdateConsumer):
         self.agent, self.consumer = agent, consumer
 
     @property
     def route(self):
         return self.consumer.route
 
-    def require_supported(self, update):
+    def require_supported(
+        self,
+        update: UserMessageChunk
+        | AgentMessageChunk
+        | AgentThoughtChunk
+        | ToolCallStart
+        | ToolCallProgress
+        | AgentPlanUpdate
+        | AgentPlanContentUpdate
+        | AgentPlanRemovedUpdate
+        | AvailableCommandsUpdate
+        | CurrentModeUpdate
+        | ConfigOptionUpdate
+        | SessionInfoUpdate
+        | UsageUpdate,
+    ):
         if not any(self.handlers_for(update)):
             raise ValueError(f'ACP update capability is not supported: {type(update).__name__}')
 
     @handles(UserMessageChunk)
-    def user(self, update):
+    def user(self, update: UserMessageChunk):
         UserContentEffect(self.agent, self.route).dispatch_sync(update.content)
 
     @handles(AgentMessageChunk)
-    def message(self, update):
+    def message(self, update: AgentMessageChunk):
         AgentContentEffect(self.agent, self.route).dispatch_sync(update.content)
 
     @handles(AgentThoughtChunk)
-    def thought(self, update):
+    def thought(self, update: AgentThoughtChunk):
         ThoughtContentEffect(self.agent, self.route).dispatch_sync(update.content)
 
     @handles(ToolCallStart)
-    def tool_start(self, update):
+    def tool_start(self, update: ToolCallStart):
         self.agent.tools.begin(update)
 
     @handles(ToolCallProgress)
-    def tool_progress(self, update):
+    def tool_progress(self, update: ToolCallProgress):
         self.agent.tools.update(update)
 
     @handles(AgentPlanUpdate)
-    def plan(self, update):
+    def plan(self, update: AgentPlanUpdate):
         self.agent.controller.publish_plan(decode_plan(update.entries))
 
     @handles(AvailableCommandsUpdate)
-    def commands(self, update):
+    def commands(self, update: AvailableCommandsUpdate):
         self.agent.controller.publish_commands(update.available_commands)
 
     @handles(CurrentModeUpdate)
-    def mode(self, update):
+    def mode(self, update: CurrentModeUpdate):
         self.agent.configuration.receive_current_mode(update.current_mode_id)
 
     @handles(ConfigOptionUpdate)
-    def config(self, update):
+    def config(self, update: ConfigOptionUpdate):
         self.agent.configuration.receive(update.config_options)
 
     @handles(SessionInfoUpdate)
-    def info(self, update):
+    def info(self, update: SessionInfoUpdate):
         if 'title' in update.model_fields_set:
             self.agent.events.publish(events.SessionInfoUpdate(update.title))
 
     @handles(UsageUpdate)
-    def usage(self, update):
+    def usage(self, update: UsageUpdate):
         self.agent.context_measurement = ContextMeasurement.live(update.used, update.size, update.cost)
         self.agent.update_status_line()
 
 
 class MessageContentEffect(MroDispatch):
-    def __init__(self, agent, route):
+    def __init__(self, agent: Agent, route):
         self.agent, self.route = agent, route
 
     @handles(TextContentBlock)
-    def text(self, content):
+    def text(self, content: TextContentBlock):
         if content.text:
             self.publish(content)
 
     @abstractmethod
-    def publish(self, content): ...
+    def publish(self, content: TextContentBlock): ...
 
 
 class UserContentEffect(MessageContentEffect):
-    def publish(self, content):
+    def publish(self, content: TextContentBlock):
         self.agent.events.publish(events.UserMessage(content.type, content.text))
 
 
 class ThoughtContentEffect(MessageContentEffect):
-    def publish(self, content):
+    def publish(self, content: TextContentBlock):
         self.agent.events.publish(events.Thinking(content.type, content.text))
 
 
 class AgentContentEffect(MessageContentEffect):
-    def publish(self, content):
+    def publish(self, content: TextContentBlock):
         text = content.text
         if text.startswith('[agent error]'):
             text += f'\n\n{AcpLogLink.markdown(self.agent.presentation.log_path)}'
@@ -112,11 +136,11 @@ def publish(self, content):
 
 
 class SessionNotificationOwner(ClientRequestOwner):
-    def __init__(self, agent):
+    def __init__(self, agent: Agent):
         super().__init__(agent)
         self.lock = asyncio.Lock()
 
-    async def receive(self, notification, raw_update):
+    async def receive(self, notification: SessionNotification, raw_update: dict[str, JsonValue]):
         authority = ClientSessionRequest(self.agent, self.agent.session_id)
         async with self.lock:
             if authority.retired or not authority.binding.accepts_notification(notification.session_id):
@@ -127,13 +151,13 @@ async def receive(self, notification, raw_update):
                 return
             validation.publish(self, notification.session_id, raw_update, notification.field_meta)
 
-    def reject(self, session_id, update, metadata, error):
+    def reject(self, session_id: str, update, metadata, error: str):
         self.agent.log(
             f"[ACP rejected session/update] raw={{'sessionId': {session_id!r}, "
             f"'update': {update!r}, '_meta': {metadata!r}}}; validation={error}")
         self.agent.events.publish(events.RejectedSessionUpdate())
 
-    def publish(self, session_id, update, facts):
+    def publish(self, session_id: str, update: SessionNotification, facts: tuple[AgentCommsUpdate, ...]):
         metadata = update.update.field_meta
         consumer = self.agent.comms_consumer_class(self.agent, session_id)
         effect = SessionUpdateEffect(self.agent, consumer)
diff --git a/src/toad/conversation_turn.py b/src/toad/conversation_turn.py
index 07ea47e1b..2afef99e2 100644
--- a/src/toad/conversation_turn.py
+++ b/src/toad/conversation_turn.py
@@ -1,5 +1,8 @@
 """Local ACP turns and source-fenced projections of the backend's turn owner."""
+from __future__ import annotations
 from abc import abstractmethod
+from collections.abc import Callable
+from typing import TYPE_CHECKING
 from dataclasses import dataclass, replace
 
 from agent_comms.activity import ActivityState
@@ -7,6 +10,14 @@
 from agent_comms.turn_lease import NoTurn as IdleTurn, TurnState
 from agent_comms.ui_model.status import ThreadStatusModel
 
+if TYPE_CHECKING:
+    from textual.widget import Widget
+
+    from toad.acp.agent import Agent
+    from toad.core_event_carrier import CoreEventMessage
+    from toad.response_delivery import ResponseDelivery
+    from toad.widgets.conversation import Conversation
+
 
 class TurnOwner(DeclaredFamily, affix="Turn"):
     managed_id = None
@@ -49,7 +60,7 @@ def accepts_update(self, update) -> bool:
     def matches_settlement(self, turn_id) -> bool:
         return not turn_id
 
-    def captured_snapshot(self, widgets):
+    def captured_snapshot(self, widgets: tuple[Widget, ...]):
         """Each original claim owns capture while this source is active."""
         from toad.widgets.committed_presentation import CommitParticipant
 
@@ -60,7 +71,7 @@ def captured_snapshot(self, widgets):
     def with_activity(self, activity: str) -> "TurnOwner":
         return ActivityTurn(activity) if activity else self
 
-    def response_stream(self, delivery):
+    def response_stream(self, delivery: ResponseDelivery):
         from toad.live_output import CompleteResponseStream
         return CompleteResponseStream(delivery)
 
@@ -100,7 +111,7 @@ def matches_settlement(self, turn_id) -> bool:
     def with_activity(self, activity: str) -> TurnOwner:
         return replace(self, activity=activity or "Thinking…")
 
-    def response_stream(self, delivery):
+    def response_stream(self, delivery: ResponseDelivery):
         from toad.live_output import ResponseStream
         return ResponseStream(delivery, turn_id=self.managed_id)
 
@@ -152,11 +163,11 @@ def accepts_update(self, update) -> bool:
     def matches_settlement(self, turn_id):
         return self.state.matches(turn_id)
 
-    def with_activity(self, activity):
+    def with_activity(self, activity: str):
         # Text, tool and heartbeat rendering cannot change backend phase.
         return self
 
-    def response_stream(self, delivery):
+    def response_stream(self, delivery: ResponseDelivery):
         if self.busy:
             from toad.live_output import ResponseStream
             return ResponseStream(delivery, turn_id=self.managed_id)
@@ -175,7 +186,7 @@ def owner(self) -> TurnOwner: ...
     def status_row(self, observed: ThreadStatusModel) -> ThreadStatusModel: ...
 
     @abstractmethod
-    def accepts(self, message) -> bool: ...
+    def accepts(self, message: CoreEventMessage) -> bool: ...
 
     @abstractmethod
     def describe(self, activity: str) -> None: ...
@@ -183,7 +194,7 @@ def describe(self, activity: str) -> None: ...
     @abstractmethod
     def reset(self) -> None: ...
 
-    async def present_input(self, view, text) -> None:
+    async def present_input(self, view: Conversation, text: str) -> None:
         """Display managed inputs only when the native process reports they started."""
 
     def start_client(self) -> None:
@@ -201,21 +212,21 @@ def __init__(self, agent=None):
     def owner(self):
         return self._owner
 
-    def status_row(self, observed):
+    def status_row(self, observed: ThreadStatusModel):
         owner = self.owner
         return ThreadStatusModel.known("", owner.activity_state.presentation("", owner.activity))
 
-    def accepts(self, message):
+    def accepts(self, message: CoreEventMessage):
         """A local turn cannot accept a backend-owned managed publication."""
         return False
 
-    def describe(self, activity):
+    def describe(self, activity: str):
         self._owner = self._owner.with_activity(activity)
 
     def reset(self):
         self._owner = NoTurn()
 
-    async def present_input(self, view, text):
+    async def present_input(self, view: Conversation, text: str):
         from toad.widgets.user_input import UserInput
         await view.post(UserInput(text))
 
@@ -229,7 +240,7 @@ def finish_client(self):
 class ManagedTurnBinding(TurnBinding):
     managed = True
 
-    def __init__(self, agent):
+    def __init__(self, agent: Agent):
         self.agent = agent
         self._owner = ManagedTurn()
         self.sequence = 0
@@ -238,7 +249,7 @@ def __init__(self, agent):
     def owner(self):
         return self._owner
 
-    def status_row(self, observed):
+    def status_row(self, observed: ThreadStatusModel):
         return observed
 
     def accepts(self, message):
@@ -255,7 +266,7 @@ def receive(self, state: TurnState):
         self.sequence += 1
         return True
 
-    def describe(self, activity):
+    def describe(self, activity: str):
         """Only the backend publication changes a managed phase."""
 
     def reset(self):
@@ -265,7 +276,7 @@ def reset(self):
 
 class ConversationTurn:
     """Read the actual source binding; the widget keeps no managed state or cursor."""
-    def __init__(self, changed, source):
+    def __init__(self, changed: Callable[[TurnOwner], None], source: Callable[[], TurnBinding]):
         self._source = source
         self._changed = changed
 
@@ -284,7 +295,7 @@ def bound(self):
     def managed_id(self):
         return self.owner.managed_id
 
-    def changed(self, message):
+    def changed(self, message: CoreEventMessage):
         if not self.binding.accepts(message):
             return False
         # The binding changed before publishing this event. Comparing another
@@ -292,12 +303,12 @@ def changed(self, message):
         self._changed(self.owner)
         return True
 
-    def describe(self, activity):
+    def describe(self, activity: str):
         before = self.owner
         self.binding.describe(activity)
         self._notify(before)
 
-    def _notify(self, before):
+    def _notify(self, before: TurnOwner):
         # Streaming describes the turn on every chunk and publications repeat
         # unchanged leases; consumers re-sync prompt, footer bindings and
         # details, so they hear only an actual change of owner.

From 791ba5c4f7305031725d0264ea873b75125d5c37 Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:56:13 -0400
Subject: [PATCH 5/8] Declare markdown rule and block navigation parameter
 owners

---
 src/toad/block_navigation.py | 54 +++++++++++++++++++++---------------
 src/toad/markdown_links.py   | 33 ++++++++++++----------
 2 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/src/toad/block_navigation.py b/src/toad/block_navigation.py
index 26de6263d..c8abfa6d3 100644
--- a/src/toad/block_navigation.py
+++ b/src/toad/block_navigation.py
@@ -4,7 +4,7 @@
 
 from abc import abstractmethod
 from functools import cached_property
-from typing import ClassVar, cast
+from typing import TYPE_CHECKING, ClassVar, cast
 from agent_comms.declared_family import DeclaredFamily
 from textual.geometry import Region
 from textual.widget import Widget
@@ -15,6 +15,14 @@
 from agent_comms.ui_model.message_category import MessageCategory, OtherCategory
 
 
+if TYPE_CHECKING:
+    from agent_comms.ui_model.message_category import AgentActivityBoundary
+    from textual.screen import Screen
+
+    from toad.widgets.history_anchor import HistoryWindow
+    from toad.widgets.transcript_history import LineHistory
+
+
 class CursorDirection(PageEnd, DeclaredFamily, affix="Cursor"):
     @property
     @abstractmethod
@@ -50,7 +58,7 @@ def select(self, widget: Widget) -> bool: ...
     def active(self) -> BlockCursor | None:
         return self if self.selected is not None else None
 
-    def accepts(self, owner) -> bool:
+    def accepts(self, owner: Widget) -> bool:
         return owner is self.selected
 
     def clear(self) -> None:
@@ -69,7 +77,7 @@ def get_block_menu(self):
     def allow_maximize(self) -> bool:
         return False
 
-    def maximize(self, screen) -> None:
+    def maximize(self, screen: Screen) -> None:
         pass
 
     @property
@@ -83,10 +91,10 @@ def owns_source(self, source) -> bool:
     def visible_region(self) -> Region | None:
         return None
 
-    def show_moved_to(self, window) -> None:
+    def show_moved_to(self, window: HistoryWindow) -> None:
         """Scroll for a keyboard move, which can land on a block out of view."""
 
-    def show_clicked(self, window) -> None:
+    def show_clicked(self, window: HistoryWindow) -> None:
         """Scroll for a click, which lands on a block that is already in view."""
 
     def export_render(self):
@@ -98,13 +106,13 @@ class AtomicBlockCursor(BlockCursor):
     def selected(self):
         return self.block
 
-    def enter(self, direction):
+    def enter(self, direction: CursorDirection):
         return True
 
-    def move(self, direction):
+    def move(self, direction: CursorDirection):
         return False
 
-    def select(self, widget):
+    def select(self, widget: Widget):
         return widget is self.block or self.block in widget.ancestors
 
     def get_clipboard_text(self):
@@ -120,7 +128,7 @@ def get_block_menu(self):
     def allow_maximize(self):
         return self.block.allow_maximize
 
-    def maximize(self, screen):
+    def maximize(self, screen: Screen):
         screen.maximize(self.block, container=False)
         self.block.focus()
 
@@ -133,10 +141,10 @@ def visible_region(self):
         geometry = self.block.screen._compositor.visible_widgets.get(self.block)
         return None if geometry is None else geometry[0]
 
-    def show_moved_to(self, window):
+    def show_moved_to(self, window: HistoryWindow):
         window.scroll_to_center(self.block, immediate=True)
 
-    def show_clicked(self, window):
+    def show_clicked(self, window: HistoryWindow):
         # The clicked block stays where it is. Only a block taller than the
         # viewport whose top is scrolled off moves, so that its top shows.
         block, viewport = self.block.region, window.content_region
@@ -158,7 +166,7 @@ class FragmentBlockCursor(BlockCursor):
     message (its fragment) and asks the history where its rows are.
     """
 
-    def __init__(self, block):
+    def __init__(self, block: LineHistory):
         super().__init__(block)
         self.fragment = None
 
@@ -176,7 +184,7 @@ def current(self):
     def selected(self):
         return self.block if self.current is not None else None
 
-    def enter(self, direction):
+    def enter(self, direction: CursorDirection):
         # The cursor arrives at the reader's side of the screen, not at an
         # end of the loaded history the reader may be far from.
         fragments = self.block.visible_fragments() or self.block.drawn_fragments
@@ -185,7 +193,7 @@ def enter(self, direction):
         self.fragment = fragments[direction.entry(len(fragments))]
         return True
 
-    def move(self, direction):
+    def move(self, direction: CursorDirection):
         fragments = self.block.drawn_fragments
         current = self.current
         if current is None or all(
@@ -204,7 +212,7 @@ def move(self, direction):
         # scrolling to it loads the next page.
         return direction.visible_more(self.block)
 
-    def select(self, widget):
+    def select(self, widget: Widget):
         fragment = self.block.fragment_under_mouse(widget)
         if fragment is None:
             return False
@@ -229,7 +237,7 @@ def region(self):
 
     visible_region = region
 
-    def show_moved_to(self, window):
+    def show_moved_to(self, window: HistoryWindow):
         if (fragment := self.current) is not None:
             self.block.show_fragment(fragment)
 
@@ -252,7 +260,7 @@ def selected(self):
         cursor = self.active
         return None if cursor is None else cursor.selected
 
-    def _enter_from(self, index, direction):
+    def _enter_from(self, index: int, direction: CursorDirection):
         children = self.block.displayed_children
         while 0 <= index < len(children):
             self._child = children[index]
@@ -264,12 +272,12 @@ def _enter_from(self, index, direction):
         self._child = None
         return False
 
-    def enter(self, direction):
+    def enter(self, direction: CursorDirection):
         return self._enter_from(
             direction.entry(len(self.block.displayed_children)), direction
         )
 
-    def move(self, direction):
+    def move(self, direction: CursorDirection):
         child = self.current
         if child is None:
             return False
@@ -278,7 +286,7 @@ def move(self, direction):
         index = self.block.displayed_children.index(child) + direction.step
         return self._enter_from(index, direction)
 
-    def select(self, widget):
+    def select(self, widget: Widget):
         for child in self.block.displayed_children:
             if child.block_cursor.select(widget):
                 self._child = child
@@ -303,7 +311,7 @@ class ConversationEntry(AnimationEffects[Mix], BlockContent):
     def apply_message_filter(self, selected: frozenset[type[MessageCategory]]) -> None:
         self.set_display_constraint("message-category", OtherCategory in selected)
 
-    def starts_agent_activity(self, boundary) -> bool:
+    def starts_agent_activity(self, boundary: AgentActivityBoundary) -> bool:
         return OtherCategory.observe(boundary)
 
     def repaint(self) -> None:
@@ -331,7 +339,7 @@ def apply_message_filter(self, selected: frozenset[type[MessageCategory]]) -> No
             "message-category", self.message_category in selected
         )
 
-    def starts_agent_activity(self, boundary) -> bool:
+    def starts_agent_activity(self, boundary: AgentActivityBoundary) -> bool:
         return self.message_category.observe(boundary)
 
 
@@ -407,7 +415,7 @@ def select(self, widget: Widget) -> bool:
         return False
 
 
-def require_blocks(widgets):
+def require_blocks(widgets: tuple[Widget, ...]):
     """Decode the Textual mount boundary once before category consumers."""
     for widget in widgets:
         if not isinstance(widget, ConversationEntry):
diff --git a/src/toad/markdown_links.py b/src/toad/markdown_links.py
index 2a0e5083b..36eb53572 100644
--- a/src/toad/markdown_links.py
+++ b/src/toad/markdown_links.py
@@ -7,6 +7,7 @@
 from dataclasses import dataclass
 from pathlib import Path
 from threading import local
+from typing import TYPE_CHECKING
 
 from agent_comms.declared_family import DeclaredFamily
 from agent_comms.display_references import ReferenceContext
@@ -19,6 +20,10 @@
 from toad.project_link import ProjectLink
 from toad.file_position import FilePosition
 
+if TYPE_CHECKING:
+    from textual.widget import Widget
+
+
 _PATH_PATTERN = re.compile(
     r"(?<![\w:/@#])"
     r"(?P<path>(?:(?:~|\.{1,2})?/)?(?:[\w.@+-]+/)+[\w.@+-]+|[\w.@+-]+\.[A-Za-z0-9][\w+-]*)"
@@ -42,12 +47,12 @@ async def acquire(cls, widget):
         return cls(context.root, references)
 
     @classmethod
-    def containing(cls, widget):
+    def containing(cls, widget: Widget):
         from toad.project_path_owner import ProjectPathOwner
         owner = ProjectPathOwner.containing(widget)
         return cls(owner.project_root.resolve(), owner.reference_context)
 
-    def current_for(self, widget):
+    def current_for(self, widget: Widget):
         if widget.is_attached:
             return self == self.containing(widget)
         return False
@@ -55,7 +60,7 @@ def current_for(self, widget):
     def for_source(self, source):
         return LinkContext(self.root, self.references.for_source(source))
 
-    def matches(self, text):
+    def matches(self, text: str):
         found = []
         for match in _PATH_PATTERN.finditer(text):
             link = ProjectLink.from_path(self.root, match.group())
@@ -79,12 +84,12 @@ class _ProjectTokens:
 class ProjectTokenRule(DeclaredFamily, affix="TokenRule"):
     @classmethod
     @abstractmethod
-    def resolve(cls, renderer, token, context): ...
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens): ...
 
 
 class InlineTokenRule(ProjectTokenRule):
     @classmethod
-    def resolve(cls, renderer, token, context):
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens):
         if token.children:
             token.children = renderer.resolve(token.children, _ProjectTokens(context.links))
         return [token]
@@ -92,7 +97,7 @@ def resolve(cls, renderer, token, context):
 
 class LinkOpenTokenRule(ProjectTokenRule):
     @classmethod
-    def resolve(cls, renderer, token, context):
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens):
         href = str(token.attrGet("href") or "")
         target = ProjectLink.from_href(lambda: context.links.root, href)
         token.attrSet("href", LinkHref.capture(target))
@@ -102,14 +107,14 @@ def resolve(cls, renderer, token, context):
 
 class LinkCloseTokenRule(ProjectTokenRule):
     @classmethod
-    def resolve(cls, renderer, token, context):
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens):
         context.linked -= 1
         return [token]
 
 
 class ImageTokenRule(ProjectTokenRule):
     @classmethod
-    def resolve(cls, renderer, token, context):
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens):
         # Images are links to a local preview or an external address, never network fetches.
         href = str(token.attrGet("src") or "")
         content = Token("text", "", 0, content=token.content or Path(href).name or "Image")
@@ -120,7 +125,7 @@ def resolve(cls, renderer, token, context):
 
 class TextTokenRule(ProjectTokenRule):
     @classmethod
-    def resolve(cls, renderer, token, context):
+    def resolve(cls, renderer: ProjectTokenRenderer, token: Token, context: _ProjectTokens):
         if context.linked:
             return [token]
         result, position = [], 0
@@ -146,7 +151,7 @@ class ProjectTokenRenderer:
     def __init__(self):
         self.rules = {FieldCodec.encode(rule): rule for rule in ProjectTokenRule.members_with(ProjectTokenRule)}
 
-    def resolve(self, tokens, context):
+    def resolve(self, tokens: list[Token], context: _ProjectTokens):
         result = []
         for token in tokens:
             rule = self.rules.get(token.type)
@@ -165,7 +170,7 @@ def __init__(self):
 _parser_state = _MarkdownParserState()
 
 
-def parse_markdown_syntax(source, env=None, *, inline=False):
+def parse_markdown_syntax(source: str, env=None, *, inline: bool=False):
     state = StateCore(source, _parser_state.parser, {} if env is None else env)
     state.inlineMode = inline
     for rule in _parser_state.syntax_rules:
@@ -177,12 +182,12 @@ class MessageMarkdownParser:
     def __init__(self, context: LinkContext):
         self.context = context
 
-    def parse(self, source, env=None):
+    def parse(self, source: str, env=None):
         return self.resolve_tokens(parse_markdown_syntax(source, env))
 
-    def parse_inline(self, source):
+    def parse_inline(self, source: str):
         return self.resolve_tokens(parse_markdown_syntax(source, inline=True))
 
-    def resolve_tokens(self, tokens):
+    def resolve_tokens(self, tokens: list[Token]):
         # Linkify is syntax: resolve its URLs too, before any frontend sees them.
         return _parser_state.resolver.resolve(tokens, _ProjectTokens(self.context))

From 3279f0291e9f42b305f82ab61b0db85219e5dd11 Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 12:57:39 -0400
Subject: [PATCH 6/8] Record unresolved family contracts without inventing
 parameter types

---
 src/toad/acp/session_updates.py          |  75 +++++----
 src/toad/agent.py                        |  11 +-
 src/toad/block_navigation.py             |  32 ++--
 src/toad/conversation_turn.py            |  22 ++-
 src/toad/markdown_links.py               |  12 +-
 src/toad/terminal_execution.py           |  94 +++++++----
 src/toad/widgets/transcript_fragments.py |  95 ++++++-----
 src/toad/widgets/transcript_lines.py     | 206 ++++++++++++++++-------
 8 files changed, 345 insertions(+), 202 deletions(-)

diff --git a/src/toad/acp/session_updates.py b/src/toad/acp/session_updates.py
index ef8c92c31..9e52619ed 100644
--- a/src/toad/acp/session_updates.py
+++ b/src/toad/acp/session_updates.py
@@ -1,24 +1,35 @@
 """Process ACP notifications in order; update declarations own their effects."""
+
 from __future__ import annotations
 
 import asyncio
 from abc import abstractmethod
 from typing import TYPE_CHECKING
 
-from pydantic import JsonValue
+from acp.schema import (
+    AgentMessageChunk,
+    AgentPlanContentUpdate,
+    AgentPlanRemovedUpdate,
+    AgentPlanUpdate,
+    AgentThoughtChunk,
+    AvailableCommandsUpdate,
+    ConfigOptionUpdate,
+    CurrentModeUpdate,
+    SessionInfoUpdate,
+    SessionNotification,
+    TextContentBlock,
+    ToolCallProgress,
+    ToolCallStart,
+    UsageUpdate,
+    UserMessageChunk,
+)
 from agent_comms.acp_extension import AgentCommsUpdate
+from agent_comms.mro_dispatch import MroDispatch, handles
 
-from agent_comms.declared_family import DeclaredFamily
-
-from toad.core import events
 from toad.acp.client_session import ClientRequestOwner, ClientSessionRequest
 from toad.acp.context_measurement import ContextMeasurement
 from toad.acp.sdk_boundary import ValidateSessionUpdateTask
-from agent_comms.mro_dispatch import MroDispatch, handles
-from acp.schema import (UserMessageChunk, AgentMessageChunk, AgentThoughtChunk,
-    ToolCallStart, ToolCallProgress, AgentPlanUpdate, AgentPlanContentUpdate, AgentPlanRemovedUpdate,
-    SessionNotification, AvailableCommandsUpdate,
-    CurrentModeUpdate, ConfigOptionUpdate, SessionInfoUpdate, UsageUpdate, TextContentBlock)
+from toad.core import events
 from toad.plan import decode_plan
 from toad.project_link import AcpLogLink
 
@@ -29,6 +40,7 @@
 
 class SessionUpdateEffect(MroDispatch):
     """Effect registrations consume official SDK declarations, never raw shapes."""
+
     def __init__(self, agent: Agent, consumer: CommsUpdateConsumer):
         self.agent, self.consumer = agent, consumer
 
@@ -38,22 +50,24 @@ def route(self):
 
     def require_supported(
         self,
-        update: UserMessageChunk
-        | AgentMessageChunk
-        | AgentThoughtChunk
-        | ToolCallStart
-        | ToolCallProgress
-        | AgentPlanUpdate
-        | AgentPlanContentUpdate
-        | AgentPlanRemovedUpdate
-        | AvailableCommandsUpdate
-        | CurrentModeUpdate
-        | ConfigOptionUpdate
-        | SessionInfoUpdate
-        | UsageUpdate,
+        update: (
+            UserMessageChunk
+            | AgentMessageChunk
+            | AgentThoughtChunk
+            | ToolCallStart
+            | ToolCallProgress
+            | AgentPlanUpdate
+            | AgentPlanContentUpdate
+            | AgentPlanRemovedUpdate
+            | AvailableCommandsUpdate
+            | CurrentModeUpdate
+            | ConfigOptionUpdate
+            | SessionInfoUpdate
+            | UsageUpdate
+        ),
     ):
         if not any(self.handlers_for(update)):
-            raise ValueError(f'ACP update capability is not supported: {type(update).__name__}')
+            raise ValueError(f"ACP update capability is not supported: {type(update).__name__}")
 
     @handles(UserMessageChunk)
     def user(self, update: UserMessageChunk):
@@ -93,7 +107,7 @@ def config(self, update: ConfigOptionUpdate):
 
     @handles(SessionInfoUpdate)
     def info(self, update: SessionInfoUpdate):
-        if 'title' in update.model_fields_set:
+        if "title" in update.model_fields_set:
             self.agent.events.publish(events.SessionInfoUpdate(update.title))
 
     @handles(UsageUpdate)
@@ -128,9 +142,10 @@ def publish(self, content: TextContentBlock):
 class AgentContentEffect(MessageContentEffect):
     def publish(self, content: TextContentBlock):
         text = content.text
-        if text.startswith('[agent error]'):
-            text += f'\n\n{AcpLogLink.markdown(self.agent.presentation.log_path)}'
+        if text.startswith("[agent error]"):
+            text += f"\n\n{AcpLogLink.markdown(self.agent.presentation.log_path)}"
         from toad.response_delivery import ResponseDelivery
+
         stream = self.agent.presentation.turns.owner.response_stream(ResponseDelivery.from_route(self.route))
         self.agent.events.publish(events.Update(content.type, text, stream))
 
@@ -140,13 +155,14 @@ def __init__(self, agent: Agent):
         super().__init__(agent)
         self.lock = asyncio.Lock()
 
-    async def receive(self, notification: SessionNotification, raw_update: dict[str, JsonValue]):
+    async def receive(self, notification, raw_update):
         authority = ClientSessionRequest(self.agent, self.agent.session_id)
         async with self.lock:
             if authority.retired or not authority.binding.accepts_notification(notification.session_id):
                 return
             validation = await self.agent.controller.task_runner.run(
-                ValidateSessionUpdateTask(notification, raw_update))
+                ValidateSessionUpdateTask(notification, raw_update)
+            )
             if authority.retired:
                 return
             validation.publish(self, notification.session_id, raw_update, notification.field_meta)
@@ -154,7 +170,8 @@ async def receive(self, notification: SessionNotification, raw_update: dict[str,
     def reject(self, session_id: str, update, metadata, error: str):
         self.agent.log(
             f"[ACP rejected session/update] raw={{'sessionId': {session_id!r}, "
-            f"'update': {update!r}, '_meta': {metadata!r}}}; validation={error}")
+            f"'update': {update!r}, '_meta': {metadata!r}}}; validation={error}"
+        )
         self.agent.events.publish(events.RejectedSessionUpdate())
 
     def publish(self, session_id: str, update: SessionNotification, facts: tuple[AgentCommsUpdate, ...]):
diff --git a/src/toad/agent.py b/src/toad/agent.py
index 564eef263..64ca7a9fe 100644
--- a/src/toad/agent.py
+++ b/src/toad/agent.py
@@ -12,7 +12,6 @@
 from toad.core.events import CoreEventStream
 from toad.surface_binding import SurfaceBinding
 
-
 if TYPE_CHECKING:
     from agent_comms.session_load import ExistingSessionLoadPlan
 
@@ -71,11 +70,7 @@ def begin_submission(self, owner, submission):
     def accepts_failed_input(self, message):
         if message.publisher is not self or message.event.session_id != self.session_id:
             return False
-        return (
-            self.queue_attachment.accepts_request(message.event.queue_scope)
-            if message.event.recover_draft
-            else True
-        )
+        return self.queue_attachment.accepts_request(message.event.queue_scope) if message.event.recover_draft else True
 
     def send_now(self, owner):
         return owner.send_bound_now(self)
@@ -143,9 +138,7 @@ def observed_thread(self) -> tuple[str, str] | None:
         """The (wire root, thread name) whose status this agent shows; none without coordination."""
         return None
 
-    async def observe_thread_presentation(
-        self, presentation: ThreadPresentation
-    ) -> None:
+    async def observe_thread_presentation(self, presentation: ThreadPresentation) -> None:
         """Consume a published canonical change; unmanaged agents need no binding."""
 
     @abstractmethod
diff --git a/src/toad/block_navigation.py b/src/toad/block_navigation.py
index c8abfa6d3..73128954b 100644
--- a/src/toad/block_navigation.py
+++ b/src/toad/block_navigation.py
@@ -5,15 +5,16 @@
 from abc import abstractmethod
 from functools import cached_property
 from typing import TYPE_CHECKING, ClassVar, cast
+
 from agent_comms.declared_family import DeclaredFamily
+from agent_comms.ui_model.message_category import MessageCategory, OtherCategory
 from textual.geometry import Region
 from textual.widget import Widget
-from toad.block_content import BlockContent
-from toad.frame_presentation import AnimationEffects
 from ui_theme.effects import NEW_TEXT, Fade, Mix  # type: ignore[import-untyped]
-from toad.widgets.presentation_window import PageEnd, OlderEnd, NewerEnd
-from agent_comms.ui_model.message_category import MessageCategory, OtherCategory
 
+from toad.block_content import BlockContent
+from toad.frame_presentation import AnimationEffects
+from toad.widgets.presentation_window import NewerEnd, OlderEnd, PageEnd
 
 if TYPE_CHECKING:
     from agent_comms.ui_model.message_category import AgentActivityBoundary
@@ -174,11 +175,7 @@ def __init__(self, block: LineHistory):
     def current(self):
         """The message the cursor rests on, while the history still draws it."""
         fragment = self.fragment
-        return (
-            fragment
-            if fragment is not None and self.block.draws_fragment(fragment)
-            else None
-        )
+        return fragment if fragment is not None and self.block.draws_fragment(fragment) else None
 
     @property
     def selected(self):
@@ -196,15 +193,10 @@ def enter(self, direction: CursorDirection):
     def move(self, direction: CursorDirection):
         fragments = self.block.drawn_fragments
         current = self.current
-        if current is None or all(
-            current is not seen for seen in self.block.visible_fragments()
-        ):
+        if current is None or all(current is not seen for seen in self.block.visible_fragments()):
             # The reader scrolled away from the cursor: it starts again from what they see.
             return self.enter(direction)
-        index = (
-            next(index for index, drawn in enumerate(fragments) if drawn is current)
-            + direction.step
-        )
+        index = next(index for index, drawn in enumerate(fragments) if drawn is current) + direction.step
         if 0 <= index < len(fragments):
             self.fragment = fragments[index]
             return True
@@ -273,9 +265,7 @@ def _enter_from(self, index: int, direction: CursorDirection):
         return False
 
     def enter(self, direction: CursorDirection):
-        return self._enter_from(
-            direction.entry(len(self.block.displayed_children)), direction
-        )
+        return self._enter_from(direction.entry(len(self.block.displayed_children)), direction)
 
     def move(self, direction: CursorDirection):
         child = self.current
@@ -335,9 +325,7 @@ def message_category(self) -> type[MessageCategory]:
         raise NotImplementedError
 
     def apply_message_filter(self, selected: frozenset[type[MessageCategory]]) -> None:
-        self.set_display_constraint(
-            "message-category", self.message_category in selected
-        )
+        self.set_display_constraint("message-category", self.message_category in selected)
 
     def starts_agent_activity(self, boundary: AgentActivityBoundary) -> bool:
         return self.message_category.observe(boundary)
diff --git a/src/toad/conversation_turn.py b/src/toad/conversation_turn.py
index 2afef99e2..a1a88f9bf 100644
--- a/src/toad/conversation_turn.py
+++ b/src/toad/conversation_turn.py
@@ -1,13 +1,16 @@
 """Local ACP turns and source-fenced projections of the backend's turn owner."""
+
 from __future__ import annotations
+
 from abc import abstractmethod
 from collections.abc import Callable
-from typing import TYPE_CHECKING
 from dataclasses import dataclass, replace
+from typing import TYPE_CHECKING
 
 from agent_comms.activity import ActivityState
 from agent_comms.declared_family import DeclaredFamily
-from agent_comms.turn_lease import NoTurn as IdleTurn, TurnState
+from agent_comms.turn_lease import NoTurn as IdleTurn
+from agent_comms.turn_lease import TurnState
 from agent_comms.ui_model.status import ThreadStatusModel
 
 if TYPE_CHECKING:
@@ -64,15 +67,18 @@ def captured_snapshot(self, widgets: tuple[Widget, ...]):
         """Each original claim owns capture while this source is active."""
         from toad.widgets.committed_presentation import CommitParticipant
 
-        return frozenset(widget for widget in widgets
-                         if not isinstance(widget, CommitParticipant)
-                         or widget.commit_claim.capture(not self.busy))
+        return frozenset(
+            widget
+            for widget in widgets
+            if not isinstance(widget, CommitParticipant) or widget.commit_claim.capture(not self.busy)
+        )
 
     def with_activity(self, activity: str) -> "TurnOwner":
         return ActivityTurn(activity) if activity else self
 
     def response_stream(self, delivery: ResponseDelivery):
         from toad.live_output import CompleteResponseStream
+
         return CompleteResponseStream(delivery)
 
 
@@ -99,6 +105,7 @@ def with_activity(self, activity: str) -> TurnOwner:
 @dataclass(frozen=True)
 class AgentTurn(TurnOwner):
     """A generic ACP peer owns its local request, but cannot control Comms turns."""
+
     managed_id: str | None = None
     activity: str = "Thinking…"
     started_at: float | None = None
@@ -113,12 +120,14 @@ def with_activity(self, activity: str) -> TurnOwner:
 
     def response_stream(self, delivery: ResponseDelivery):
         from toad.live_output import ResponseStream
+
         return ResponseStream(delivery, turn_id=self.managed_id)
 
 
 @dataclass(frozen=True)
 class ManagedTurn(TurnOwner):
     """The published lease owns phase, permissions, activity and identity."""
+
     state: TurnState = TurnState()
 
     @property
@@ -170,6 +179,7 @@ def with_activity(self, activity: str):
     def response_stream(self, delivery: ResponseDelivery):
         if self.busy:
             from toad.live_output import ResponseStream
+
             return ResponseStream(delivery, turn_id=self.managed_id)
         return super().response_stream(delivery)
 
@@ -228,6 +238,7 @@ def reset(self):
 
     async def present_input(self, view: Conversation, text: str):
         from toad.widgets.user_input import UserInput
+
         await view.post(UserInput(text))
 
     def start_client(self):
@@ -276,6 +287,7 @@ def reset(self):
 
 class ConversationTurn:
     """Read the actual source binding; the widget keeps no managed state or cursor."""
+
     def __init__(self, changed: Callable[[TurnOwner], None], source: Callable[[], TurnBinding]):
         self._source = source
         self._changed = changed
diff --git a/src/toad/markdown_links.py b/src/toad/markdown_links.py
index 36eb53572..91b237c63 100644
--- a/src/toad/markdown_links.py
+++ b/src/toad/markdown_links.py
@@ -1,10 +1,11 @@
 """One syntax and link resolver for line, inline and Textual Markdown views."""
+
 from __future__ import annotations
-from functools import partial
 
 import re
 from abc import abstractmethod
 from dataclasses import dataclass
+from functools import partial
 from pathlib import Path
 from threading import local
 from typing import TYPE_CHECKING
@@ -16,9 +17,9 @@
 from markdown_it.rules_core import StateCore
 from markdown_it.token import Token
 
+from toad.file_position import FilePosition
 from toad.line_blocks import LineLink, LinkHref, OpenReference
 from toad.project_link import ProjectLink
-from toad.file_position import FilePosition
 
 if TYPE_CHECKING:
     from textual.widget import Widget
@@ -49,6 +50,7 @@ async def acquire(cls, widget):
     @classmethod
     def containing(cls, widget: Widget):
         from toad.project_path_owner import ProjectPathOwner
+
         owner = ProjectPathOwner.containing(widget)
         return cls(owner.project_root.resolve(), owner.reference_context)
 
@@ -70,7 +72,7 @@ def matches(self, text: str):
         for match in self.references.find(text):
             if any(start < match.end and match.start < end for start, end, _ in found):
                 continue
-            content = Token("text", "", 0, content=text[match.start:match.end])
+            content = Token("text", "", 0, content=text[match.start : match.end])
             found.append((match.start, match.end, OpenReference(match.reference).inline_tokens(content)))
         return sorted(found)
 
@@ -152,7 +154,7 @@ def __init__(self):
         self.rules = {FieldCodec.encode(rule): rule for rule in ProjectTokenRule.members_with(ProjectTokenRule)}
 
     def resolve(self, tokens: list[Token], context: _ProjectTokens):
-        result = []
+        result: list[Token] = []
         for token in tokens:
             rule = self.rules.get(token.type)
             result.extend(rule.resolve(self, token, context) if rule else (token,))
@@ -170,7 +172,7 @@ def __init__(self):
 _parser_state = _MarkdownParserState()
 
 
-def parse_markdown_syntax(source: str, env=None, *, inline: bool=False):
+def parse_markdown_syntax(source: str, env=None, *, inline: bool = False):
     state = StateCore(source, _parser_state.parser, {} if env is None else env)
     state.inlineMode = inline
     for rule in _parser_state.syntax_rules:
diff --git a/src/toad/terminal_execution.py b/src/toad/terminal_execution.py
index 1aec78597..06e73e5a8 100644
--- a/src/toad/terminal_execution.py
+++ b/src/toad/terminal_execution.py
@@ -1,34 +1,40 @@
 """Owns the original PTY and its outcomes; mounted views only display them."""
+
 from __future__ import annotations
 
 import asyncio
-from abc import abstractmethod
-from collections import deque
-from contextlib import AsyncExitStack, suppress
-from dataclasses import dataclass, field
 import codecs
 import os
 import pty
 import shlex
 import signal
 import termios
+from abc import abstractmethod
+from collections import deque
+from contextlib import AsyncExitStack, suppress
+from dataclasses import dataclass, field
 from io import FileIO
 from typing import TYPE_CHECKING, Mapping
 from weakref import ref
 
 from acp import schema as protocol
 from agent_comms.child_process import (
-    AttachedChild, TerminalChildStdio, ChildOutcome, ExitedOutcome, SignaledOutcome,
+    AttachedChild,
+    ChildOutcome,
+    ExitedOutcome,
+    SignaledOutcome,
+    TerminalChildStdio,
     join_retirement,
 )
 from agent_comms.declared_family import DeclaredFamily
 from agent_comms.mro_dispatch import MroDispatch, handles
+
 from toad import ansi
 from toad.shell_read import shell_read
 from toad.terminal_environment import TerminalEnvironment
 
 if TYPE_CHECKING:
-    from toad.widgets.terminal_tool import TerminalTool
+    pass
 
 
 @dataclass
@@ -45,15 +51,12 @@ class Command:
     """Original launch shell; catalog scripts explicitly select /bin/sh."""
 
     @classmethod
-    def for_script(cls, script: str, *, env: Mapping[str, str] | None = None,
-                   cwd: str | None = None) -> Command:
+    def for_script(cls, script: str, *, env: Mapping[str, str] | None = None, cwd: str | None = None) -> Command:
         """Catalog shell scripts use the standard shell and terminal environment."""
-        return cls(script, TerminalEnvironment.for_child(os.environ) | (env or {}),
-                   cwd, shell="/bin/sh")
+        return cls(script, TerminalEnvironment.for_child(os.environ) | (env or {}), cwd, shell="/bin/sh")
 
     @classmethod
-    def for_argv(cls, command: str, args: list[str], *,
-                 env: Mapping[str, str], cwd: str) -> Command:
+    def for_argv(cls, command: str, args: list[str], *, env: Mapping[str, str], cwd: str) -> Command:
         """Compile ACP executable/arguments exactly once at its typed boundary."""
         return cls(shlex.join([command, *args]), env, cwd)
 
@@ -76,6 +79,7 @@ def return_code(self) -> int | None:
     def exit_status(self) -> protocol.TerminalExitStatus | None:
         return None  # Official ACP absence, never an internal lifecycle field.
 
+
 class RunningTerminalOutcome(TerminalOutcome):
     """The original execution task has not returned a completion witness."""
 
@@ -86,6 +90,7 @@ class UnstartedTerminalOutcome(TerminalOutcome):
 
 class RetiredTerminalOutcome(TerminalOutcome):
     """Acquisition was revoked before any command could start."""
+
     finished = True
 
 
@@ -154,6 +159,7 @@ def wait_response(self):
 
 class _TerminalCompletionDecoder(MroDispatch):
     """Typed original POSIX members enter the terminal family at acquisition."""
+
     completion: TerminalCompletion
 
     def __init__(self, original: ChildOutcome):
@@ -173,6 +179,7 @@ class FailedTerminalOutcome(TerminalOutcome):
     error: BaseException
     finished = True
 
+
 @dataclass(frozen=True)
 class ToolState:
     output: str
@@ -180,20 +187,31 @@ class ToolState:
     outcome: TerminalOutcome
 
     def response(self):
-        return protocol.TerminalOutputResponse(output=self.output, truncated=self.truncated,
-                                               exit_status=self.outcome.exit_status())
+        return protocol.TerminalOutputResponse(
+            output=self.output, truncated=self.truncated, exit_status=self.outcome.exit_status()
+        )
 
 
 @dataclass(frozen=True)
 class PtyProcess:
     """Complete acquired handles, scoped by the execution's AsyncExitStack."""
+
     child: AttachedChild
     master: FileIO
     reader: asyncio.StreamReader
 
     @classmethod
-    async def acquire(cls, command: tuple[str, ...], *, env: Mapping[str, str], cwd, width: int, height: int,
-                      cleanup: AsyncExitStack, buffer_size: int=128 * 1024):
+    async def acquire(
+        cls,
+        command: tuple[str, ...],
+        *,
+        env: Mapping[str, str],
+        cwd,
+        width: int,
+        height: int,
+        cleanup: AsyncExitStack,
+        buffer_size: int = 128 * 1024,
+    ):
         master, slave = pty.openpty()
         master_file = cleanup.enter_context(os.fdopen(master, "rb", 0))
         slave_file = cleanup.enter_context(os.fdopen(slave, "wb", 0))
@@ -204,13 +222,17 @@ async def acquire(cls, command: tuple[str, ...], *, env: Mapping[str, str], cwd,
         reader = asyncio.StreamReader(buffer_size)
         protocol = asyncio.StreamReaderProtocol(reader)
         transport, _ = await asyncio.get_running_loop().connect_read_pipe(
-            lambda: protocol, master_file,
+            lambda: protocol,
+            master_file,
         )
         cleanup.callback(transport.close)
 
         async def acquire_child():
             child = await AttachedChild.start(
-                command, stdio=TerminalChildStdio(slave_file), env=env, cwd=cwd,
+                command,
+                stdio=TerminalChildStdio(slave_file),
+                env=env,
+                cwd=cwd,
             )
             cleanup.push_async_callback(child.stop)
             return child
@@ -239,7 +261,7 @@ async def write(self, data: bytes) -> int:
         # thread that could write to an unrelated reused descriptor.
         try:
             return os.write(self.master.fileno(), data)
-        except (OSError, ValueError):
+        except OSError, ValueError:
             return 0
 
     def kill(self) -> None:
@@ -367,10 +389,16 @@ async def retire_task(self):
 
 class TerminalExecution:
     """One ANSI/output owner and one acquired operation, independent of views."""
-    def __init__(self, command: Command, output_byte_limit: int | None = None, *,
-                 width: int = ansi.TerminalState.DEFAULT_WIDTH,
-                 height: int = ansi.TerminalState.DEFAULT_HEIGHT,
-                 state: ansi.TerminalState | None = None):
+
+    def __init__(
+        self,
+        command: Command,
+        output_byte_limit: int | None = None,
+        *,
+        width: int = ansi.TerminalState.DEFAULT_WIDTH,
+        height: int = ansi.TerminalState.DEFAULT_HEIGHT,
+        state: ansi.TerminalState | None = None,
+    ):
         self._command = command
         self._output_byte_limit = output_byte_limit
         self._output: deque[bytes] = deque()
@@ -378,8 +406,7 @@ def __init__(self, command: Command, output_byte_limit: int | None = None, *,
         self._output_bytes_count = 0
         self.operation: TerminalOperation = NewTerminalOperation()
         # An existing ANSI resource retains prefixes and sequential command output.
-        self.state = (ansi.TerminalState(self.write_stdin, width=width, height=height)
-                      if state is None else state)
+        self.state = ansi.TerminalState(self.write_stdin, width=width, height=height) if state is None else state
         self._view = lambda: None
 
     @property
@@ -391,7 +418,7 @@ def tool_state(self):
         output, truncated = self.get_output()
         return ToolState(output, truncated, self.operation.outcome())
 
-    def attach(self, terminal: TerminalTool):
+    def attach(self, terminal):
         self._view = ref(terminal)
         terminal.set_state(self.state)
         terminal.set_write_to_stdin(self.write_stdin)
@@ -428,8 +455,12 @@ async def run(self, ready: asyncio.Future[PtyProcess]):
             async with AsyncExitStack() as cleanup:
                 command = self.command
                 acquired = await PtyProcess.acquire(
-                    command.shell_command, env=os.environ | command.env, cwd=command.cwd,
-                    width=self.state.width, height=self.state.height, cleanup=cleanup,
+                    command.shell_command,
+                    env=os.environ | command.env,
+                    cwd=command.cwd,
+                    width=self.state.width,
+                    height=self.state.height,
+                    cleanup=cleanup,
                 )
                 ready.set_result(acquired)
                 decoder = codecs.getincrementaldecoder("utf-8")(errors="replace")
@@ -451,7 +482,7 @@ async def run(self, ready: asyncio.Future[PtyProcess]):
             # The task's result becomes authoritative only after this returns.
             asyncio.get_running_loop().call_soon(self.project, None, None)
 
-    async def write_stdin(self, text: str | bytes, hide_echo: bool=False):
+    async def write_stdin(self, text: str | bytes, hide_echo: bool = False):
         data = text.encode("utf-8", "ignore") if isinstance(text, str) else text
         return await self.operation.write(data)
 
@@ -497,10 +528,7 @@ def is_continuation(byte_value: int) -> bool:
             return (byte_value & 0b11000000) == 0b10000000
 
         truncated = self._bytes_read > len(output_bytes)
-        if (
-            self._output_byte_limit is not None
-            and len(output_bytes) > self._output_byte_limit
-        ):
+        if self._output_byte_limit is not None and len(output_bytes) > self._output_byte_limit:
             truncated = True
             output_bytes = output_bytes[len(output_bytes) - self._output_byte_limit :]
             # Must start on a utf-8 boundary
diff --git a/src/toad/widgets/transcript_fragments.py b/src/toad/widgets/transcript_fragments.py
index 73698ee99..5f1b7b804 100644
--- a/src/toad/widgets/transcript_fragments.py
+++ b/src/toad/widgets/transcript_fragments.py
@@ -47,11 +47,15 @@
 from toad.widgets.transcript_lines import AcquiredRows, NoRows, RowAcquisition
 
 if TYPE_CHECKING:
-    from toad.widgets.transcript_lines import (
-        BlockLines, Lines, LineTheme, RichLineRenderer, TranscriptLinesRenderTask,
-    )
     from toad.tool_output import ToolOutputPart
     from toad.widgets.committed_presentation import CommitClaim
+    from toad.widgets.transcript_lines import (
+        BlockLines,
+        Lines,
+        LineTheme,
+        RichLineRenderer,
+        TranscriptLinesRenderTask,
+    )
 
 
 @dataclass(frozen=True)
@@ -76,10 +80,9 @@ def _split_table(self, part: PreparedMarkdownPart) -> Iterator[PreparedMarkdownP
         table = part.tokens[0]
         assert table.map is not None
         ranges = []
-        for index, row in enumerate(lines[2:table.map[1]], 2):
+        for index, row in enumerate(lines[2 : table.map[1]], 2):
             if index > first and (
-                index - first >= row_limit
-                or len(header) + row_characters + len(row) > character_limit
+                index - first >= row_limit or len(header) + row_characters + len(row) > character_limit
             ):
                 ranges.append((first, index))
                 first = index
@@ -111,8 +114,13 @@ def split(self, source: PreparedMarkdownPart) -> Iterator[PreparedMarkdownPart]:
         }
         starts = sorted({0, *blocks, len(lines)})
         parts = [
-            (start, stop, blocks.get(start, (0, None))[0],
-             blocks.get(stop, (len(source.tokens), None))[0], blocks.get(start, (0, None))[1])
+            (
+                start,
+                stop,
+                blocks.get(start, (0, None))[0],
+                blocks.get(stop, (len(source.tokens), None))[0],
+                blocks.get(start, (0, None))[1],
+            )
             for start, stop in zip(starts, starts[1:])
         ]
         pending_first = 0
@@ -121,15 +129,13 @@ def split(self, source: PreparedMarkdownPart) -> Iterator[PreparedMarkdownPart]:
         pending_token_stop = 0
         pending_characters = 0
         pending_lines = 0
+
         def select(first: int, stop: int, token_first: int, token_stop: int):
-            return source.select_blocks(text[offsets[first]:offsets[stop]], first,
-                                        slice(token_first, token_stop))
+            return source.select_blocks(text[offsets[first] : offsets[stop]], first, slice(token_first, token_stop))
 
         for start, stop, token_first, token_stop, kind in parts:
-            part = text[offsets[start]:offsets[stop]]
-            if kind == "table_open" and (
-                len(part) > self.characters or part.count("\n") > self.lines
-            ):
+            part = text[offsets[start] : offsets[stop]]
+            if kind == "table_open" and (len(part) > self.characters or part.count("\n") > self.lines):
                 if pending_characters:
                     yield select(pending_first, pending_stop, pending_token_first, pending_token_stop)
                     pending_characters = 0
@@ -137,12 +143,8 @@ def select(first: int, stop: int, token_first: int, token_stop: int):
                 yield from self._split_table(select(start, stop, token_first, token_stop))
                 continue
             part_lines = part.count("\n") + int(bool(part) and not part.endswith("\n"))
-            exceeds = (
-                pending_characters
-                and (
-                    pending_characters + len(part) > self.characters
-                    or pending_lines + part_lines > self.lines
-                )
+            exceeds = pending_characters and (
+                pending_characters + len(part) > self.characters or pending_lines + part_lines > self.lines
             )
             if exceeds:
                 yield select(pending_first, pending_stop, pending_token_first, pending_token_stop)
@@ -274,6 +276,7 @@ class TranscriptFragment:
     shown: Shown = field(default_factory=Shown, kw_only=True)
     # Whether the fragment has details a reader can show and hide.
     has_details: ClassVar[bool] = False
+
     @property
     def arrival_position(self) -> int | str:
         """The first event owns the fragment's stable source position."""
@@ -302,7 +305,7 @@ def outgoing_sources(self):
         return ()
 
     @classmethod
-    def capture_part(cls, event: TextTranscript, text: str, **kwargs):
+    def capture_part(cls, event, text: str, **kwargs):
         return cls((replace(event, text=text),), **kwargs)
 
     def text_rows(self, lines: Lines) -> range:
@@ -346,8 +349,7 @@ def timestamp(self) -> float | None:
     @property
     def clipboard_text(self) -> str | None:
         """What copying this fragment gives: its text as written."""
-        return "\n\n".join(event.text for event in self.events
-                           if isinstance(event, TextTranscript)) or None
+        return "\n\n".join(event.text for event in self.events if isinstance(event, TextTranscript)) or None
 
     @property
     def block_menu(self) -> tuple[MenuItem, ...]:
@@ -485,17 +487,17 @@ def outgoing_sources(self):
     def shown_live_by(self, claim: CommitClaim) -> bool:
         return claim.repeats_sent(self)
 
+
 class ContextTranscriptFragment(TranscriptFragment):
     """The coordination context an agent was given: one line, and its text when opened."""
 
     has_details = True
 
-    def blocks(self, shown: Shown):
+    def blocks(self, shown):
         summary = shown.summary("Agent coordination context")
         if not shown.details_open:
             return (summary,)
-        return (summary, *(Body(event.text, role=MutedRole, bar=MutedRole)
-                           for event in self.events))
+        return (summary, *(Body(event.text, role=MutedRole, bar=MutedRole) for event in self.events))
 
 
 class TranscriptFragmentConsumer(MroProjection[None]):
@@ -523,8 +525,12 @@ def sent(self, event: SentTranscript) -> None:
     @handles(PublishedSentMessage)
     def published(self, message: PublishedSentMessage) -> None:
         original = message.message.core_message(AssignedTranscriptSource.open(message.scope))
-        self.text(message.message, SentMessageFragment, publication=message,
-                  row=MessageRow(original, message.scope.recipient.name))
+        self.text(
+            message.message,
+            SentMessageFragment,
+            publication=message,
+            row=MessageRow(original, message.scope.recipient.name),
+        )
 
     @handles(UserTranscript, MarkdownTranscript)
     def text(self, event: TextTranscript, kind: type[TranscriptFragment] = TranscriptFragment, **kwargs) -> None:
@@ -532,9 +538,14 @@ def text(self, event: TextTranscript, kind: type[TranscriptFragment] = Transcrip
         source = PreparedMarkdownPart.capture(event.text)
         parts = kind.text_parts(source, self.budget)
         self.fragments.extend(
-            kind.capture_part(event, part.text, continuation=index > 0,
-                 part_position=LastPart(index=index) if index == len(parts) - 1 else InnerPart(index=index),
-                 starts_agent_activity=starts_activity and index == 0, **kwargs)
+            kind.capture_part(
+                event,
+                part.text,
+                continuation=index > 0,
+                part_position=LastPart(index=index) if index == len(parts) - 1 else InnerPart(index=index),
+                starts_agent_activity=starts_activity and index == 0,
+                **kwargs,
+            )
             for index, part in enumerate(parts)
         )
 
@@ -542,7 +553,9 @@ def text(self, event: TextTranscript, kind: type[TranscriptFragment] = Transcrip
     def tool(self, event: ToolTranscript) -> None:
         if event.tool_call_id not in self.tools:
             self.tools[event.tool_call_id] = (
-                len(self.fragments), [], self.boundary.observe(event.category),
+                len(self.fragments),
+                [],
+                self.boundary.observe(event.category),
             )
             self.fragments.append(None)  # Reserve the call's original position.
         _, events, _ = self.tools[event.tool_call_id]
@@ -550,7 +563,8 @@ def tool(self, event: ToolTranscript) -> None:
 
 
 def transcript_fragments(
-    events: tuple[TranscriptEvent, ...], *,
+    events: tuple[TranscriptEvent, ...],
+    *,
     resolve_sent: Callable[[Iterable[SentTranscript]], dict[int, SentTranscript | PublishedSentMessage]],
 ) -> tuple[TranscriptFragment, ...]:
     from toad.tool_output import ToolOutput
@@ -580,12 +594,17 @@ def transcript_fragments(
         elif index in tools:
             tool_events, starts_activity, call, parts = tools[index]
             parts = call.project_output(
-                parts, partial(ToolOutput.apply_sent, resolved=resolved),
+                parts,
+                partial(ToolOutput.apply_sent, resolved=resolved),
+            )
+            fragments.append(
+                ToolTranscriptFragment(
+                    tool_events,
+                    starts_agent_activity=starts_activity,
+                    tool_call=call,
+                    output_parts=parts,
+                )
             )
-            fragments.append(ToolTranscriptFragment(
-                tool_events, starts_agent_activity=starts_activity,
-                tool_call=call, output_parts=parts,
-            ))
         else:
             fragments.append(source)
     return tuple(fragments)
diff --git a/src/toad/widgets/transcript_lines.py b/src/toad/widgets/transcript_lines.py
index c56174240..c5d26db72 100644
--- a/src/toad/widgets/transcript_lines.py
+++ b/src/toad/widgets/transcript_lines.py
@@ -17,9 +17,8 @@
 from toad.patch import PatchCell
 
 if TYPE_CHECKING:
-    from toad.widgets.transcript_fragments import Shown, TranscriptFragment
-    from toad.widgets.transcript_history import LineHistory
     from toad.textual_colours import PaletteState, TextualColours
+    from toad.widgets.transcript_fragments import Shown, TranscriptFragment
 
 from agent_comms.mro_dispatch import MroDispatch, handles
 from rich._wrap import divide_line
@@ -75,29 +74,44 @@ def style(self, role: type[LineRole]) -> Style:
     def _style(role: type[LineRole], style: Style, palette: PaletteState) -> Style:
         if role.background_tint:
             style = palette.tint_style(style, role.background_tint)
-        return style + Style(italic=role.italic or None, bold=role.bold or None,
-                             underline=role.underline or None)
+        return style + Style(italic=role.italic or None, bold=role.bold or None, underline=role.underline or None)
 
     def with_colour(self, colour: type[ThemeColour], style: Style, palette: PaletteState) -> LineTheme:
         """This theme with one colour drawn another way, as a fade draws it part of the way through."""
-        return replace(self, styles={role: self._style(role, style, palette)
-                                     if role.colour is colour else held for role, held in self.styles.items()})
+        return replace(
+            self,
+            styles={
+                role: self._style(role, style, palette) if role.colour is colour else held
+                for role, held in self.styles.items()
+            },
+        )
 
     @classmethod
     def of(cls, colours: TextualColours) -> LineTheme:
         # Native ANSI text retains its distinct dim attribute rather than a palette guess.
-        muted = (Style(dim=True) if colours.colour(ForegroundColour).ansi is not None
-                 else Style(color=colours.colour(MutedColour).rich_color))
-        return cls({role: cls._style(role, muted if role.colour is MutedColour
-                                    else Style(color=colours.colour(role.colour).rich_color),
-                                    colours.schemes[colours.app.theme].palette) for role in LineRole.members_with(LineRole)},
-                   colours.depth.name, diff=colours.app.settings.diff, syntax=SyntaxPalette.of(colours.app))
+        muted = (
+            Style(dim=True)
+            if colours.colour(ForegroundColour).ansi is not None
+            else Style(color=colours.colour(MutedColour).rich_color)
+        )
+        return cls(
+            {
+                role: cls._style(
+                    role,
+                    muted if role.colour is MutedColour else Style(color=colours.colour(role.colour).rich_color),
+                    colours.schemes[colours.app.theme].palette,
+                )
+                for role in LineRole.members_with(LineRole)
+            },
+            colours.depth.name,
+            diff=colours.app.settings.diff,
+            syntax=SyntaxPalette.of(colours.app),
+        )
 
 
 def link_style(link: LineLink | None) -> Style:
     """The style that makes text run a link's action when clicked."""
-    return Style.null() if link is None else Style(
-        underline=link.underlined or None, meta={"@click": link.click})
+    return Style.null() if link is None else Style(underline=link.underlined or None, meta={"@click": link.click})
 
 
 def _fit(text: str, width: int) -> str:
@@ -115,6 +129,7 @@ def _text_width(block: Body | RichTextBody, width: int) -> int:
 
 def _clickable(rows: list[Row]) -> list[Row]:
     """Give each Markdown link the click action that opens it; Rich marks a link's cells with its address only."""
+
     def linked(segment: Segment) -> Segment:
         style = segment.style
         if style is None or not style.link:
@@ -177,10 +192,14 @@ class PatchLayout:
     def __init__(self, patch: Patch, width: int, settings: DiffSettings) -> None:
         self.patch, self.settings = patch, settings
         self.number_width = patch.number_width
-        longest = max((cell_len(line.expandtabs(4)) for line in (*patch.before.values(), *patch.after.values())), default=0)
+        longest = max(
+            (cell_len(line.expandtabs(4)) for line in (*patch.before.values(), *patch.after.values())), default=0
+        )
         self.split = settings.view.use_split(width, 2 * (longest + self.number_width + 4) + 3)
         self.pane_width = max(1, (width - 3) // 2 if self.split else width)
-        self.prefix_width = (self.number_width + 1 if self.split else 2 * self.number_width + 2) + (2 if settings.annotations else 0)
+        self.prefix_width = (self.number_width + 1 if self.split else 2 * self.number_width + 2) + (
+            2 if settings.annotations else 0
+        )
         self.pane_width = settings.wrap.fitted_width(self.pane_width, longest + self.prefix_width)
         self.code_width = max(1, self.pane_width - self.prefix_width)
 
@@ -210,7 +229,8 @@ def strips_at(self, place: Hashable) -> tuple[Strip, ...] | JoinedStrips:
         if strips is None:
             width = self.width
             strips = self.__dict__["strips"] = tuple(
-                Strip(row).extend_cell_length(width) for row in _each_link_apart(self, place))
+                Strip(row).extend_cell_length(width) for row in _each_link_apart(self, place)
+            )
         return strips
 
 
@@ -223,9 +243,11 @@ class PreparedLines(Lines, LineBlock):
     retained_bytes: int = field(init=False)
 
     def __post_init__(self) -> None:
-        object.__setattr__(self, "retained_bytes",
-            64 + sum(64 + 64 * len(row) + 4 * sum(len(segment.text) for segment in row)
-                     for row in self.rows))
+        object.__setattr__(
+            self,
+            "retained_bytes",
+            64 + sum(64 + 64 * len(row) + 4 * sum(len(segment.text) for segment in row) for row in self.rows),
+        )
 
     def __iter__(self) -> Iterator[Row]:
         return iter(self.rows)
@@ -234,7 +256,7 @@ def __iter__(self) -> Iterator[Row]:
     def height(self) -> int:
         return len(self.rows)
 
-    def prepared_rows(self, width: int, draw: Callable[[LineBlock], PreparedLines]) -> PreparedLines:
+    def prepared_rows(self, width: int, draw) -> PreparedLines:
         if width != self.width:
             raise ValueError("Prepared rows belong to a different width")
         return self
@@ -283,7 +305,7 @@ class PreparedBlock(LineBlock):
 
     _rows: PreparedLines = PreparedLines(width=-1, rows=())
 
-    def prepared_rows(self, width: int, draw: Callable[[LineBlock], PreparedLines]) -> PreparedLines:
+    def prepared_rows(self, width: int, draw) -> PreparedLines:
         rows = self._rows
         if rows.width != width:
             self._rows = rows = draw(self)
@@ -299,8 +321,15 @@ class SpanColumnLayout(Columns, PreparedBlock):
 
     def __init__(self, block: SpanColumns, theme: LineTheme | None = None) -> None:
         self.indent = block.indent
-        cells = [Text.assemble(*((span.text, (theme.style(span.role) if theme is not None else Style.null())
-                                 + link_style(span.link)) for span in cell)) for cell in block.cells]
+        cells = [
+            Text.assemble(
+                *(
+                    (span.text, (theme.style(span.role) if theme is not None else Style.null()) + link_style(span.link))
+                    for span in cell
+                )
+            )
+            for cell in block.cells
+        ]
         super().__init__(cells, padding=(0, 2))
 
     def rows(self, console: Console) -> tuple[Row, ...]:
@@ -333,8 +362,13 @@ def __init__(self, theme: LineTheme, width: int = 1) -> None:
 
     @cached_property
     def console(self) -> Console:
-        return Console(width=self.width, color_system=self.theme.color_system,
-                       force_terminal=True, file=io.StringIO(), legacy_windows=False)
+        return Console(
+            width=self.width,
+            color_system=self.theme.color_system,
+            force_terminal=True,
+            file=io.StringIO(),
+            legacy_windows=False,
+        )
 
     def at_width(self, width: int) -> RichLineRenderer:
         self.width = self.console.width = max(1, width)
@@ -357,6 +391,7 @@ def patch(self, patch: Patch) -> None:
         number_width, split = layout.number_width, layout.split
         pane_width, prefix_width, code_width = layout.pane_width, layout.prefix_width, layout.code_width
         console = self.console
+
         def paint(cell: PatchCell | None, source: dict[int, Text], old: str, new: str):
             if cell is None:
                 return [Text(" " * pane_width)]
@@ -374,16 +409,23 @@ def paint(cell: PatchCell | None, source: dict[int, Text], old: str, new: str):
             for index, chunk in enumerate(chunks):
                 chunk.truncate(code_width, overflow="crop", pad=True)
                 chunk.stylize(tint)
-                gutter = Text(prefix if index == 0 else " " * prefix_width,
-                              style=style + tint if cell.role is not TextRole else self.theme.style(MutedRole))
+                gutter = Text(
+                    prefix if index == 0 else " " * prefix_width,
+                    style=style + tint if cell.role is not TextRole else self.theme.style(MutedRole),
+                )
                 result.append(gutter + chunk)
             return result
 
         title = patch.after_path or patch.before_path or "Edit"
         if patch.before_path != patch.after_path:
             title = f"{patch.before_path} → {patch.after_path}"
-        self.output.append((Segment(_fit(f"{title} (+{patch.additions}, −{patch.deletions})", self.width),
-                                    self.theme.style(MutedRole)),))
+        self.output.append(
+            (
+                Segment(
+                    _fit(f"{title} (+{patch.additions}, −{patch.deletions})", self.width), self.theme.style(MutedRole)
+                ),
+            )
+        )
         for group_index, group in enumerate(patch.row_groups(split)):
             if group_index:
                 self.output.append((Segment("…", self.theme.style(MutedRole)),))
@@ -392,7 +434,9 @@ def paint(cell: PatchCell | None, source: dict[int, Text], old: str, new: str):
                     left, right = paint(old, before, "", ""), paint(new, after, "", "")
                     blank = Text(" " * pane_width)
                     for a, b in zip_longest(left, right, fillvalue=blank):
-                        self.output.append(tuple((a + Text(" │ ", style=self.theme.style(MutedRole)) + b).render(console)))
+                        self.output.append(
+                            tuple((a + Text(" │ ", style=self.theme.style(MutedRole)) + b).render(console))
+                        )
                 else:
                     cell = old or new
                     source = before if old is not None else after
@@ -403,8 +447,12 @@ def paint(cell: PatchCell | None, source: dict[int, Text], old: str, new: str):
     def rich_text(self, block: RichTextBody) -> None:
         inner = _text_width(block, self.width)
         console = self.console
-        rows = [tuple(row) for row in console.render_lines(
-            block.content, console.options.update(width=inner), style=self.theme.style(block.role), pad=False)]
+        rows = [
+            tuple(row)
+            for row in console.render_lines(
+                block.content, console.options.update(width=inner), style=self.theme.style(block.role), pad=False
+            )
+        ]
         self._body_rows(block, rows)
 
     @handles(Divider)
@@ -418,15 +466,17 @@ def divider(self, block: Divider) -> None:
             # A title longer than the rule ends in an ellipsis; what follows is not drawn.
             text = _fit(span.text, room)
             room -= cell_len(text)
-            title.append(Segment(text, (rule if span.link is None else self.theme.style(span.role))
-                                 + bold + link_style(span.link)))
+            title.append(
+                Segment(
+                    text, (rule if span.link is None else self.theme.style(span.role)) + bold + link_style(span.link)
+                )
+            )
             if room == 0:
                 break
         title.append(Segment(" ", rule))
         length = sum(segment.cell_length for segment in title)
         left = max(0, (self.width - length) // 2)
-        self.output.append((Segment("─" * left, rule), *title,
-                            Segment("─" * max(0, self.width - left - length), rule)))
+        self.output.append((Segment("─" * left, rule), *title, Segment("─" * max(0, self.width - left - length), rule)))
 
     @handles(Summary)
     def summary(self, block: Summary) -> None:
@@ -436,15 +486,16 @@ def summary(self, block: Summary) -> None:
             text = _fit(span.text, room)
             room -= cell_len(text)
             row.append(Segment(text, self.theme.style(span.role) + link_style(span.link)))
-        row.extend(Segment(span.text, self.theme.style(span.role) + link_style(span.link))
-                   for span in block.kept)
+        row.extend(Segment(span.text, self.theme.style(span.role) + link_style(span.link)) for span in block.kept)
         self.output.append(tuple(row))
 
     @handles(Spans)
     def spans(self, block: Spans) -> None:
-        self.output.extend((Segment(line[start:start + self.width]),)
-                           for line in _plain_lines(block.text)
-                           for start in _plain_spans(line, self.width))
+        self.output.extend(
+            (Segment(line[start : start + self.width]),)
+            for line in _plain_lines(block.text)
+            for start in _plain_spans(line, self.width)
+        )
 
     @handles(PreparedLines)
     def prepared(self, block: PreparedLines) -> None:
@@ -469,17 +520,31 @@ def prepared_columns(self, block: SpanColumnLayout) -> None:
     @handles(StyledBody)
     def styled_body(self, block: StyledBody) -> None:
         source = block.source
-        rows = _clickable([tuple(line) for line in self.console.render_lines(
-            Renderables(block.content), self.console.options.update(width=_text_width(source, self.width)),
-            style=self.theme.style(source.role), pad=False)])
+        rows = _clickable(
+            [
+                tuple(line)
+                for line in self.console.render_lines(
+                    Renderables(block.content),
+                    self.console.options.update(width=_text_width(source, self.width)),
+                    style=self.theme.style(source.role),
+                    pad=False,
+                )
+            ]
+        )
         self._body_rows(source, rows)
 
     @handles(Body)
     def body(self, block: Body) -> None:
         inner = _text_width(block, self.width)
         style = self.theme.style(block.role)
-        self._body_rows(block, [(Segment(line[start:start + inner], style),)
-                               for line in _plain_lines(block.text) for start in _plain_spans(line, inner)])
+        self._body_rows(
+            block,
+            [
+                (Segment(line[start : start + inner], style),)
+                for line in _plain_lines(block.text)
+                for start in _plain_spans(line, inner)
+            ],
+        )
 
     def _body_rows(self, block: Body | RichTextBody, rows: list[Row]) -> None:
         if block.bar is not None:
@@ -497,8 +562,7 @@ class LinePreparation:
     retained_bytes: int = field(init=False)
 
     def __post_init__(self) -> None:
-        object.__setattr__(self, "retained_bytes",
-            256 + sum(block.retained_bytes for block in self.blocks))
+        object.__setattr__(self, "retained_bytes", 256 + sum(block.retained_bytes for block in self.blocks))
 
     def wrap(self, width: int, renderer: RichLineRenderer) -> BlockLines:
         return BlockLines(width, self, renderer)
@@ -555,6 +619,7 @@ class PlainLines(BlockLines):
     def __init__(self, width: int, renderer: RichLineRenderer, blocks: tuple[LineBlock, ...]) -> None:
         super().__init__(width, LinePreparation(blocks, renderer.theme), renderer)
 
+
 class RowAcquisition(ABC):
     """The source witness and rows acquired by one fragment."""
 
@@ -636,10 +701,12 @@ def current_for(self, view) -> bool:
         return self.context.current_for(view) and self.preparation.theme is view.app.colours.line_theme
 
     def hold(self, view, fragment: TranscriptFragment, lines: LinePreparation) -> bool:
-        return self.current_for(view) and fragment.hold_lines(self, lines.wrap(view.line_width, view.app.colours.line_renderer))
+        return self.current_for(view) and fragment.hold_lines(
+            self, lines.wrap(view.line_width, view.app.colours.line_renderer)
+        )
 
     @staticmethod
-    def show(view: LineHistory, fragment: TranscriptFragment, shown: Shown, rendered) -> None:
+    def show(view, fragment: TranscriptFragment, shown: Shown, rendered) -> None:
         """Apply the requested state, retaining rows only through their render request."""
         fragment.show(shown)
         if rendered is not None:
@@ -649,7 +716,9 @@ def show(view: LineHistory, fragment: TranscriptFragment, shown: Shown, rendered
                 fragment.hold_lines(request, lines.wrap(view.line_width, view.app.colours.line_renderer))
 
     def execute(self) -> LinePreparation:
-        return LinePreparation(tuple(next(self.handlers_for(block))(block) for block in self.blocks), self.preparation.theme)
+        return LinePreparation(
+            tuple(next(self.handlers_for(block))(block) for block in self.blocks), self.preparation.theme
+        )
 
     @handles(LineBlock)
     def unchanged(self, block: LineBlock) -> LineBlock:
@@ -660,8 +729,9 @@ def body(self, block: Body) -> LineBlock:
         return block.prepare(self.markdown)
 
     def markdown(self, block: Body) -> StyledBody:
-        console = MarkdownStyleConsole(force_terminal=True, file=io.StringIO(),
-                                       color_system=self.preparation.theme.color_system)
+        console = MarkdownStyleConsole(
+            force_terminal=True, file=io.StringIO(), color_system=self.preparation.theme.color_system
+        )
         return StyledBody(block, console.prepare(block.text, self.context))
 
     @handles(WireBody)
@@ -679,19 +749,33 @@ def columns(self, block: SpanColumns) -> SpanColumnLayout:
 
     @handles(Spans)
     def spans(self, block: Spans) -> StyledBody:
-        text = Text.assemble(*((span.text, self.preparation.theme.style(span.role) + link_style(span.link))
-                               for span in block.spans), tab_size=4)
+        text = Text.assemble(
+            *((span.text, self.preparation.theme.style(span.role) + link_style(span.link)) for span in block.spans),
+            tab_size=4,
+        )
         return self.rich_text(RichTextBody(text, role=TextRole, bar=None))
 
     @handles(Patch)
     def patch(self, block: Patch) -> StyledPatch:
         def highlight(lines: dict[int, str], path: str):
             code = "\n".join(lines.values()).expandtabs(4)
-            syntax = Syntax(code, Syntax.guess_lexer(path, code),
-                            theme=self.preparation.theme.syntax.pygments_theme, background_color="default")
+            syntax = Syntax(
+                code,
+                Syntax.guess_lexer(path, code),
+                theme=self.preparation.theme.syntax.pygments_theme,
+                background_color="default",
+            )
             return dict(zip(lines, syntax.highlight(code).split("\n", allow_blank=True)))
-        return StyledPatch(block.before_path, block.after_path, block.before, block.after, block.groups,
-                           highlight(block.before, block.before_path), highlight(block.after, block.after_path))
+
+        return StyledPatch(
+            block.before_path,
+            block.after_path,
+            block.before,
+            block.after,
+            block.groups,
+            highlight(block.before, block.before_path),
+            highlight(block.after, block.after_path),
+        )
 
 
 @dataclass(frozen=True)
@@ -704,7 +788,7 @@ def result_size(self, result: tuple[LinePreparation, ...]) -> int:
     items: tuple[TranscriptLinesRenderTask, ...]
 
     @classmethod
-    async def render_for(cls, view, preparations: Iterable[LinePreparation]):
+    async def render_for(cls, view, preparations):
         """One captured reference source for a batch; requests own result publication."""
         preparations = tuple(preparations)
         if not preparations:

From ae601d27904f00ad4e30b349bb09cf63867a1ee1 Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 13:01:03 -0400
Subject: [PATCH 7/8] Format annotated agent and navigation signatures to
 repository defaults

---
 src/toad/agent.py            | 18 ++++++++++++++----
 src/toad/block_navigation.py | 23 ++++++++++++++++++-----
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/src/toad/agent.py b/src/toad/agent.py
index 64ca7a9fe..153e411f1 100644
--- a/src/toad/agent.py
+++ b/src/toad/agent.py
@@ -54,7 +54,9 @@ def matches_session(self, session_id):
     def borrowed_processes(self):
         return (self.process,)
 
-    async def reconnect_session(self, source: MainScreen, plan: ExistingSessionLoadPlan) -> None:
+    async def reconnect_session(
+        self, source: MainScreen, plan: ExistingSessionLoadPlan
+    ) -> None:
         await self.session.reconnect(plan)
 
     async def change_project(self, view: Conversation, path: Path) -> None:
@@ -70,7 +72,11 @@ def begin_submission(self, owner, submission):
     def accepts_failed_input(self, message):
         if message.publisher is not self or message.event.session_id != self.session_id:
             return False
-        return self.queue_attachment.accepts_request(message.event.queue_scope) if message.event.recover_draft else True
+        return (
+            self.queue_attachment.accepts_request(message.event.queue_scope)
+            if message.event.recover_draft
+            else True
+        )
 
     def send_now(self, owner):
         return owner.send_bound_now(self)
@@ -111,7 +117,9 @@ def start_session(self, view: ConversationSessionBinding) -> None:
         if self.ready:
             view.session_ready()
 
-    def start_agent(self, sources: OperationalSessionSources, view: Conversation) -> None:
+    def start_agent(
+        self, sources: OperationalSessionSources, view: Conversation
+    ) -> None:
         """A connected agent is not created a second time."""
 
     def update_view(self, view: ConversationSessionBinding) -> None:
@@ -138,7 +146,9 @@ def observed_thread(self) -> tuple[str, str] | None:
         """The (wire root, thread name) whose status this agent shows; none without coordination."""
         return None
 
-    async def observe_thread_presentation(self, presentation: ThreadPresentation) -> None:
+    async def observe_thread_presentation(
+        self, presentation: ThreadPresentation
+    ) -> None:
         """Consume a published canonical change; unmanaged agents need no binding."""
 
     @abstractmethod
diff --git a/src/toad/block_navigation.py b/src/toad/block_navigation.py
index 73128954b..ee3c3150b 100644
--- a/src/toad/block_navigation.py
+++ b/src/toad/block_navigation.py
@@ -175,7 +175,11 @@ def __init__(self, block: LineHistory):
     def current(self):
         """The message the cursor rests on, while the history still draws it."""
         fragment = self.fragment
-        return fragment if fragment is not None and self.block.draws_fragment(fragment) else None
+        return (
+            fragment
+            if fragment is not None and self.block.draws_fragment(fragment)
+            else None
+        )
 
     @property
     def selected(self):
@@ -193,10 +197,15 @@ def enter(self, direction: CursorDirection):
     def move(self, direction: CursorDirection):
         fragments = self.block.drawn_fragments
         current = self.current
-        if current is None or all(current is not seen for seen in self.block.visible_fragments()):
+        if current is None or all(
+            current is not seen for seen in self.block.visible_fragments()
+        ):
             # The reader scrolled away from the cursor: it starts again from what they see.
             return self.enter(direction)
-        index = next(index for index, drawn in enumerate(fragments) if drawn is current) + direction.step
+        index = (
+            next(index for index, drawn in enumerate(fragments) if drawn is current)
+            + direction.step
+        )
         if 0 <= index < len(fragments):
             self.fragment = fragments[index]
             return True
@@ -265,7 +274,9 @@ def _enter_from(self, index: int, direction: CursorDirection):
         return False
 
     def enter(self, direction: CursorDirection):
-        return self._enter_from(direction.entry(len(self.block.displayed_children)), direction)
+        return self._enter_from(
+            direction.entry(len(self.block.displayed_children)), direction
+        )
 
     def move(self, direction: CursorDirection):
         child = self.current
@@ -325,7 +336,9 @@ def message_category(self) -> type[MessageCategory]:
         raise NotImplementedError
 
     def apply_message_filter(self, selected: frozenset[type[MessageCategory]]) -> None:
-        self.set_display_constraint("message-category", self.message_category in selected)
+        self.set_display_constraint(
+            "message-category", self.message_category in selected
+        )
 
     def starts_agent_activity(self, boundary: AgentActivityBoundary) -> bool:
         return self.message_category.observe(boundary)

From 427a70ec4f305e2b9f31f11d5ada4dc09a96a84b Mon Sep 17 00:00:00 2001
From: Tristan Simas <tristan.simas@mail.mcgill.ca>
Date: Fri, 23 Oct 2026 13:07:37 -0400
Subject: [PATCH 8/8] Use SessionNotification as the owner of SDK update types

---
 src/toad/acp/session_updates.py | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/src/toad/acp/session_updates.py b/src/toad/acp/session_updates.py
index 9e52619ed..014eb11f2 100644
--- a/src/toad/acp/session_updates.py
+++ b/src/toad/acp/session_updates.py
@@ -8,8 +8,6 @@
 
 from acp.schema import (
     AgentMessageChunk,
-    AgentPlanContentUpdate,
-    AgentPlanRemovedUpdate,
     AgentPlanUpdate,
     AgentThoughtChunk,
     AvailableCommandsUpdate,
@@ -48,26 +46,9 @@ def __init__(self, agent: Agent, consumer: CommsUpdateConsumer):
     def route(self):
         return self.consumer.route
 
-    def require_supported(
-        self,
-        update: (
-            UserMessageChunk
-            | AgentMessageChunk
-            | AgentThoughtChunk
-            | ToolCallStart
-            | ToolCallProgress
-            | AgentPlanUpdate
-            | AgentPlanContentUpdate
-            | AgentPlanRemovedUpdate
-            | AvailableCommandsUpdate
-            | CurrentModeUpdate
-            | ConfigOptionUpdate
-            | SessionInfoUpdate
-            | UsageUpdate
-        ),
-    ):
-        if not any(self.handlers_for(update)):
-            raise ValueError(f"ACP update capability is not supported: {type(update).__name__}")
+    def require_supported(self, notification: SessionNotification):
+        if not any(self.handlers_for(notification.update)):
+            raise ValueError(f"ACP update capability is not supported: {type(notification.update).__name__}")
 
     @handles(UserMessageChunk)
     def user(self, update: UserMessageChunk):
@@ -179,7 +160,7 @@ def publish(self, session_id: str, update: SessionNotification, facts: tuple[Age
         consumer = self.agent.comms_consumer_class(self.agent, session_id)
         effect = SessionUpdateEffect(self.agent, consumer)
         try:
-            effect.require_supported(update.update)
+            effect.require_supported(update)
         except (TypeError, ValueError) as error:
             self.reject(session_id, update, metadata, str(error))
             return