# Transcript and tool calls (/cloud/surfaces/transcript)
## Parts [#parts]
| Component | File | Pure? | Purpose |
| ----------------- | ---------------------------------- | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `TurnView` | `conversation/turn-view.tsx` | mostly | "One transcript item. User prompts are the only ordinary contained message region. Assistant prose stays flat, while reasoning, tools, and system history use compact rows." |
| `UserMessageView` | `turn-view.tsx` | yes | The prompt bubble with edit. |
| `ReasoningBlock` | `turn-view.tsx` | yes | Collapsible thinking; open while streaming, `aria-busy`. |
| `WorkGroupView` | `conversation/tool-group.tsx` | yes | "Intermediate narration, reasoning, and tool calls form one work episode." |
| `ToolCallView` | `conversation/tool-call.tsx` | yes | "One tool call: a quiet verb line that expands into its evidence." |
| `Prose` | `conversation/prose.tsx` | link clicks only | Streamdown Markdown with Nyte components. |
| `CodeBlock` | `conversation/code-block.tsx` | yes | Escaped text immediately, worker highlight when near the viewport. |
| `UserMessageText` | `conversation/message-content.tsx` | yes | Message text with inline reference chips. |
| `ImagePreview` | `conversation/image-preview.tsx` | yes | Thumbnail opening a Dialog at natural size. |
## `TurnView` [#turnview]
| Prop | Type | Description |
| --------------- | ------------------------------------------ | ------------------------------------------------------ |
| `turn` | `Turn` | `turn` / `checkpoint` / `summary` / `config` / `note`. |
| `liveTools` | `ReadonlyMap` | |
| `live` | `LiveSnapshot` | "Only the trailing group carries the run." |
| `cwd` | `string \| undefined` | Path shortening. |
| `onEditUser` | `(part, content, choice) => Promise` | Enables editing. |
| `branchModel` | `BranchModelPicker` | Catalog and model state for the edit footer picker. |
| `onOpenChanges` | `(target: TurnChangesTarget) => void` | Review / open file. |
| `running` | `boolean` | |
"Parts keep core's stable identity so settled and streaming content exchange in place." Two
constraints from the file: "A completion's continuation turn draws nothing until its response
lands; an empty completed turn must not leave a blank row behind." and "an earlier \[group] is
settled history, and the run's indicator belongs below the prose that follows it."
## User message editing [#user-message-editing]
`UserMessageView` is a button until edited. Click or **F2** begins an edit, unless a text
selection exists (so selecting to copy never opens the editor). In edit mode it mounts a
`ComposerEditor` and a `ModelPicker` in the footer:
| Key | Effect |
| ------------- | ------ |
| Escape | Cancel |
| Enter, ⌘Enter | Save |
The Send button is labelled "Send edited message". Sticky behavior is data-attribute driven
(`data-sticky-user-message`, `data-sticky-active`, `data-sticky-visible`) and mutated by
`syncStickyUserMessage` in the thread screen, which "avoids cloning the prompt or rerendering the
transcript on every scroll tick."
## Tool calls: the locked law [#tool-calls-the-locked-law]
From `tool-call.tsx`:
> Its locked law carries over: no status icons on tool calls. The running state is the shimmer,
> failure is the red line, and the chevron is a control, not a status. Neither shimmer nor red
> line survives a screen reader or a colour-blind eye, so the same two states also ship as
> visually hidden text.
| Prop | Type | Default |
| ---------- | --------------------------- | ----------- |
| `part` | `ToolTurnPart` | |
| `progress` | `ToolProgress \| undefined` | |
| `cwd` | `string \| undefined` | |
| `density` | `"compact" \| "detailed"` | `"compact"` |
Anatomy: `Collapsible.Root` with `render` callbacks ("Open state lives in Base UI, not here: a
controlled `open` would re-render this component (and re-parse the patch) on every toggle."),
`data-tool-status={state}`, `srOnly` "Running" / "Failed", a `Collapsible.Panel role="region" aria-label="{verb} output"` with `data-nyte-scrollport`, and for edits a `keepMounted` panel with
`DiffView variant="inline"`. Closed output shows an `OutputPreview` that is a second trigger
labelled "Show full command output".
## Work groups [#work-groups]
`WorkGroupView` props: `parts`, `live`, `liveTools`, `cwd`, `durationMs`, `running`, `density`.
Summary verbs: Edited / Ran / Read / Listed / Worked / "Work failed"; while running: Working /
Thinking / "Preparing next move" / "This is taking a bit longer" after 15s. Compact mode keeps
the episode in a clipped window that follows new output; scrolling away pauses following for 10s;
click opens. Uses `Spinner`, `AnimatedNumber`, `srOnly`, `focus.ring`.
## Prose and code [#prose-and-code]
`Prose({ markdown, streaming })` runs Streamdown with `animated={false}`, `controls={false}`,
`skipHtml`, link safety off, and maps `pre` → `CodeBlock`, `table` → a scrollable wrapper
(`data-nyte-scrollport`, `data-prose-table`), `img` → alt text, `a` → `preventDefault` +
`nyte.host.openExternal`.
`CodeBlock({ code, lang })`: "Fenced code paints as escaped plain text immediately. Known grammars
upgrade in a bundled worker, keeping grammars and syntax work off the UI thread." Highlight is
requested once within 300px of the viewport (`IntersectionObserver`); LRU of 64; worker replies
are validated with typebox at the boundary. Copy button labels flip "Copy code" → "Code copied".
## Images [#images]
`ImagePreview({ src, name, compact })`: a 80px (64px compact) thumbnail that is a
`Dialog.Trigger`; the popup shows the image at natural size "capped only by the window", on
`t.imageBg` so transparency does not pick up the workspace tint. Close is labelled "Close image
preview".