The unit tests are failing after the recent refactor. Can you fix them?
Chat - Agentic code assistant
Streaming tool calls (Bash, Read, Edit, Write, Glob), reasoning, step boundaries, and an interactive approval flow — driven entirely by the adapter API.
How it works
The demo has three pre-populated conversations, each showcasing a different aspect of the agentic loop:
- Fix test failures — a complete multi-step task:
globfinds the files,read_fileinspects the broken import,edit_filepatches it, andbashconfirms the tests pass. - Add dark mode toggle —
read_fileinspects the existing component,write_filecreates a new one, thenbashverifies the build. - Clean build artifacts — a
bashcommand in theapproval-requestedstate. Click Approve or Deny to see the state transition live.
Send any new message in any conversation to watch the scripted agentic stream play out from scratch: reasoning → text → tool input streaming → tool output → next tool → final summary.
Streaming tool calls
The adapter's sendMessage method returns a ReadableStream of typed chunks. Tool calls
flow through a state machine driven by those chunks:
// 1. Tool starts — input streams in as JSON deltas
{ type: 'tool-input-start', toolCallId, toolName: 'glob', dynamic: true }
{ type: 'tool-input-delta', toolCallId, inputTextDelta: '{"pattern":' }
{ type: 'tool-input-delta', toolCallId, inputTextDelta: '"src/**/*.ts"}' }
{ type: 'tool-input-available', toolCallId, toolName: 'glob', input: { pattern: 'src/**/*.ts' } }
// 2. Tool finishes — output arrives as a single chunk
{ type: 'tool-output-available', toolCallId, output: { files: ['src/api.ts', ...] } }
The component renders each state automatically: a spinner during input-streaming,
the formatted input once input-available, and the output once output-available.
Tool approval flow
When the adapter emits a tool-approval-request chunk (or a message is pre-populated with
state: 'approval-requested'), the built-in ToolPart renders Approve and Deny
buttons. Clicking either calls adapter.addToolApprovalResponse({ id, approved }).
The adapter then updates the tool's state to output-available or output-denied,
which the component reflects immediately:
const adapter: ChatAdapter = {
async addToolApprovalResponse({ id, approved }) {
// Update the tool invocation state in your message store
},
};
Reasoning parts
Before the first tool call the model emits a reasoning chunk sequence:
{ type: 'reasoning-start', id }
{ type: 'reasoning-delta', id, delta: 'Let me explore...' }
{ type: 'reasoning-end', id }
This produces a collapsible ReasoningPart in the message — collapsed by default so it
doesn't dominate the conversation but still inspectable.
Step boundaries
{ type: 'start-step' } marks the beginning of a new agentic iteration. The corresponding
step-start part in the rendered message visually separates reasoning loops, making it
clear where one planning cycle ends and the next begins.
Tool slot overrides
Both slots and slotProps on the built-in ToolPart renderer are fully
customizable. Pass them through slotProps.messageContent.partProps['dynamic-tool']
on ChatBox.
Icon styles
Five variations of the icon slot — from the default first-letter monogram to
emoji, coloured circles, terminal squares, and Unicode symbols. Each icon
receives ownerState.toolName so a single component can branch on the tool type.
Block themes
Five color themes, all built on toolSlotProps — per-tool overrides that style
the header, icon, title, state chip, and root border without touching the global
slots. This keeps collapse/expand and all other built-in behaviors intact while
giving each tool its own distinct accent: Colorful (gradient + circular icon),
Pastel (light fills), Vivid (solid saturated header, white text),
Outlined (transparent fill, colored border), and Dark (dark background
with glowing accents).
Custom renderer
Replace the tool block entirely by providing a custom root slot component via
toolSlots. The component receives ownerState.toolName and ownerState.state
from the slot system — no default markup, no expand/collapse. Here each call
renders as a single-line process trace: tool name, a dotted rule, and a state badge.
See also
- Multi-conversation — two-pane inbox layout
- Split layout — place message list and composer in separate DOM zones