Documentation Index
Fetch the complete documentation index at: https://docs.usecrow.ai/llms.txt
Use this file to discover all available pages before exploring further.
Hook into the agent’s lifecycle to build custom experiences on top of Crow.
Available Callbacks
| Callback | Fires when |
|---|
onMessage | A new message (user or assistant) is added |
onMessageUpdate | A message is updated (e.g. during streaming) |
onToolCall | A tool starts, completes, or a client tool is invoked |
onWorkflow | A workflow starts, progresses, or ends |
onVerificationStatus | Identity verification status changes |
onError | An error occurs |
React SDK
Pass callbacks via the client.on() method:
import { CrowClient } from '@usecrow/client';
const client = new CrowClient({
productId: 'YOUR_PRODUCT_ID',
apiUrl: 'https://api.usecrow.org',
});
client.on({
onMessage: (message) => {
console.log(`[${message.role}] ${message.content}`);
},
onToolCall: (event) => {
if (event.type === 'tool_call_start') {
console.log(`Tool started: ${event.toolName}`);
}
if (event.type === 'tool_call_complete') {
console.log(`Tool done: ${event.toolName}`, event.success);
}
},
onError: (error) => {
myErrorTracker.capture(error);
},
});
Callback Reference
onMessage
onMessage?: (message: Message) => void
interface Message {
id: string;
content: string;
role: 'user' | 'assistant';
timestamp: Date;
citations?: Citation[];
thinking?: string;
}
onMessageUpdate
onMessageUpdate?: (messageId: string, updates: Partial<Message>) => void
onToolCall?: (event: ToolCallEvent) => void
event.type | Description |
|---|
tool_call_start | Server-side tool invocation began |
tool_call_complete | Server-side tool finished (event.success) |
client_tool_call | Client-side tool was invoked in the browser |
onWorkflow
onWorkflow?: (event: WorkflowEvent) => void
event.type | Description |
|---|
workflow_started | Workflow began (event.name, event.todos) |
workflow_todo_updated | A step completed (event.todoId, event.status) |
workflow_ended | Workflow finished |
workflow_complete_prompt | Workflow requests user confirmation |
onVerificationStatus
onVerificationStatus?: (isVerified: boolean) => void
onError
onError?: (error: Error) => void
Use Cases
Analytics — Track which tools are used and how often:
client.on({
onToolCall: (event) => {
if (event.type === 'tool_call_complete') {
analytics.track('crow_tool_used', {
tool: event.toolName,
success: event.success,
});
}
},
});
client.on({
onToolCall: (event) => {
if (event.type === 'tool_call_start') {
showToolSpinner(event.toolName);
}
if (event.type === 'tool_call_complete') {
hideToolSpinner();
}
},
});
client.on({
onError: (error) => {
Sentry.captureException(error);
},
});
Client Side Tools
Register browser-side tool handlers
Embed Widget
Install the widget
