Thinking and Used tools are both auxiliary rows, but Thinking still carried
an internal mb-2 even when it was standalone. That made collapsed Thinking
rows visually taller than tool trace rows despite the shared thread spacing.
Only add the extra bottom margin when a Thinking bubble has answer content
below it in the same assistant message. Standalone Thinking rows now share
the same outer box model as Used tools. Tests lock both standalone and
answer-backed cases.
Co-authored-by: Cursor <cursoragent@cursor.com>
Tool trace groups are supporting details, so default them to collapsed.
Match the Thinking bubble's expanded body to the tool trace affordance by
using the same grouped header and animated fade/slide body treatment.
Update MessageBubble tests to assert tool traces start collapsed and expand
on click.
Co-authored-by: Cursor <cursoragent@cursor.com>
Reasoning now flows as its own stream — symmetric to the answer's
``delta`` / ``stream_end`` pair — instead of being shipped as one
oversized progress message. This lets WebUI render a live "Thinking…"
bubble that updates in place, then auto-collapses when the stream
closes. Other channels remain plugin no-ops by default.
## Protocol
New metadata: ``_reasoning_delta`` (chunk) and ``_reasoning_end``
(close marker). ChannelManager routes both to the dedicated plugin
hooks below; the legacy one-shot ``_reasoning`` is kept for back-compat
and BaseChannel expands it into a single delta + end pair so plugins
only ever implement the streaming primitives.
WebSocket emits two new events:
- ``reasoning_delta`` (event, chat_id, text, optional stream_id)
- ``reasoning_end`` (event, chat_id, optional stream_id)
## BaseChannel surface
- ``send_reasoning_delta(chat_id, delta, metadata)`` — no-op default
- ``send_reasoning_end(chat_id, metadata)`` — no-op default
- ``send_reasoning(msg)`` — back-compat wrapper, base impl forwards
to the streaming primitives
A channel adds reasoning support by overriding the two streaming
primitives. Telegram / Slack / Discord / Feishu / WeChat / Matrix keep
the base no-ops until their bubble UIs are adapted; reasoning silently
drops at dispatch, never as a stray text message.
## AgentHook
Adds ``emit_reasoning_end`` to the hook lifecycle. ``_LoopHook`` tracks
whether a reasoning segment is open and closes it on:
- the first answer delta arriving (so the UI locks the bubble before
the answer renders below),
- ``on_stream_end``,
- one-shot ``reasoning_content`` / ``thinking_blocks`` after a single
non-streaming response.
## WebUI
- ``UIMessage.reasoning`` is now a single accumulated string with a
companion ``reasoningStreaming`` flag.
- ``useNanobotStream`` consumes ``reasoning_delta`` / ``reasoning_end``;
legacy ``kind: "reasoning"`` is auto-translated to a delta + end.
- New ``ReasoningBubble``: shimmer header + auto-expanded while
streaming, collapses to a clickable "Thinking" pill once closed,
respects ``prefers-reduced-motion``.
- Answer deltas adopt the reasoning placeholder so the bubble and the
answer share one assistant row.
## Tests
- ``tests/channels/test_channel_manager_reasoning.py`` — manager routes
delta + end, drops on channel opt-out, expands one-shot back-compat.
- ``tests/channels/test_websocket_channel.py`` — new ``reasoning_delta``
/ ``reasoning_end`` frames, empty-chunk safety, no-subscriber safety,
back-compat expansion.
- ``tests/agent/test_runner_reasoning.py`` — runner closes the segment
on streaming answer start and after one-shot reasoning.
- WebUI ``useNanobotStream`` + ``message-bubble`` cover the new
protocol and the shimmer styling.
## Docs
``docs/configuration.md`` and ``docs/websocket.md`` document the new
events and the plugin contract.
Co-authored-by: Cursor <cursoragent@cursor.com>
Reasoning was being shipped to every channel as a generic progress
message with a `_reasoning: true` flag. Two problems with that:
1. Channels without a low-emphasis UI primitive (Telegram, Slack,
Discord, Feishu...) would dump raw model thoughts as ordinary
replies, polluting the conversation.
2. The agent loop double-gated by inspecting `channels_config`, which
coupled the loop to display policy.
Treat reasoning as its own plugin action — `BaseChannel.send_reasoning`
defaults to a documented no-op; channels that have a fitting affordance
override. ChannelManager routes `_reasoning` outbounds to that method
only when the channel opts in via `show_reasoning` (camelCase alias
`showReasoning` mirrors `sendProgress`). Plugins that don't override
silently drop reasoning — "no fit, no leak" is the contract.
Reference implementation lands for WebSocket / WebUI: a new
`kind: "reasoning"` frame, parked on the active assistant bubble as a
collapsible `Thinking` group above the answer. CLI keeps its existing
direct path (it doesn't go through the bus). `ChannelsConfig.show_reasoning`
flips to `true` by default — only adapted channels surface anything,
others stay quiet.
Loop net diff is -3 lines: the `channels_config.show_reasoning` check
moves out, leaving emit_reasoning a one-liner that publishes and trusts
the channel to decide.
Co-authored-by: Cursor <cursoragent@cursor.com>
Align the WebUI sidebar and chat chrome with the updated design, and generate WebUI session titles asynchronously without blocking turns.
Co-authored-by: Cursor <cursoragent@cursor.com>
Add signed media URLs to live WebSocket replies and teach the WebUI to classify and render video attachments, so bot-sent videos can play inline in both live chats and session history.
Made-with: Cursor
Xubin RenandCursor
