Transcript ExecOutput

ExecOutput

Tool output: a mono block clamped to 12 lines with a fade, and a footer with the size, the exit status, "Show all N lines" and "Open full output".

import 'package:agent_kit/agent_kit.dart';

Demo

Short output with exit code 0: the standalone specimen ExecOutput(output: ToolOutput(text: ...), exitCode: 0). Nothing is clamped, and the footer is empty: there is no totalBytes, the exit is not failed, and no callbacks are set.

Parameters

Parameter	Type	Notes
output	ToolOutput	Required. text is split into lines (a trailing empty line is dropped). totalLines sets the "Show all N lines" count (the counted lines when null). totalBytes, when set, shows the size in the footer.
exitCode	int?	A non-zero value shows "exited N" in the footer, in danger.
clampLines	int	Default 12. Lines shown before the fade.
onShowAll	VoidCallback?	Called when the output is expanded. The block also expands in place either way.
onOpenFull	VoidCallback?	"Open full output". Not drawn when null.

Behaviour from the code:

• Lines matching \bFAILED\b, a line starting with error, or panicked at are drawn in danger ink.
• When the output is longer than clampLines and not expanded, the last 36 px fade out.
• "Show all N lines" becomes "Show fewer lines" when expanded. It appears only when there are lines and the block is clamped or expanded.
• Line height is 18 px, mono 12 px.

Theme roles

muted (output text), dangerInk (failed lines and the exit text), faint (footer size and separator), surface2 (well fill), radii.sm (corners), typeScale.uiSmall (footer text). The fade uses the bb_ui constants kMaskOpaque and kTransparent, which are not theme roles.

Size classes

Does not read the size class. The block does not wrap: it scrolls sideways inside its well (softWrap: false), and the footer wraps (Wrap) when there is no room beside it.

Accessibility

• Semantics(container: true, label: 'Output, N lines'), with , exited X added when the exit code is non-zero.
• "Show all" and "Open full output" are KitTextButtons, each with its own button semantics and label.
• No keyboard handling in this file.

Gallery and tests

• Gallery scene: Components. Specimen "Exec output, short" in TranscriptSpecimens (apps/gallery/lib/components/transcript.dart).
• Golden: apps/gallery/test/component_shots_test.dart writes exec_output, which takes the second ExecOutput in the scene (index 1), light and dark. Index 0 is the clamped output inside the open activity group.
• Other tests, in packages/agent_kit/test/transcript/transcript_test.dart: "clamps, shows all, opens the full output" (line 310) and "short output has no clamp button" (338).
• Transcript goldens in packages/agent_kit/test/goldens/transcript_turn_*.png and transcript_states_*.png.

---

Generated from docs/components/transcript/ExecOutput.md. Edit the file there; changes made on the wiki are overwritten.