makeAssistantTool

Create React components that provide reusable tools to the assistant.

For most apps, the Tools() API is an easier starting point: tool definitions live in a toolkit object rather than the component tree. makeAssistantTool is fully supported and remains a good fit when a tool's availability is tied to a component being mounted, for example a product-specific tool that should only be exposed while that product's UI is on screen (the intelligent components pattern).

makeAssistantTool creates a React component that provides a tool to the assistant. This is useful for defining reusable tools that can be composed into your application.

Usage

import { makeAssistantTool, tool } from "@assistant-ui/react";
import { z } from "zod";

// Define the tool using the tool() helper
const submitForm = tool({
  parameters: z.object({
    email: z.string().email(),
    name: z.string(),
  }),
  execute: async ({ email, name }) => {
    // Implementation
    return { success: true };
  },
});

// Create a tool component
const SubmitFormTool = makeAssistantTool({
  ...submitForm,
  toolName: "submitForm",
});

// Use in your component
function Form() {
  return (
    <div>
      <form>{/* form fields */}</form>
      <SubmitFormTool />
    </div>
  );
}

API Reference

Parameters

AssistantToolProps<TArgs, TResult>

toolName : string

The unique identifier for the tool

parameters : StandardSchemaV1<TArgs> | JSONSchema7

Schema defining the tool's parameters (typically a Zod schema)

execute : (args: TArgs, context: ToolExecutionContext) => TResult | Promise<TResult>

Function that implements the tool's behavior (required for frontend tools)

description ?: string

Optional description of the tool's purpose

render ?: ComponentType<ToolCallMessagePartProps<TArgs, TResult>>

Optional custom UI component for rendering the tool execution. Receives the following props:

type ?: "tool-call": The message part type
toolCallId ?: string: Unique identifier for this tool call
toolName ?: string: The name of the tool being called
args ?: TArgs: The arguments passed to the tool
argsText ?: string: String representation of the arguments
result ?: TResult | undefined: The result of the tool execution (if complete)
isError ?: boolean | undefined: Whether the result is an error
status ?: ToolCallMessagePartStatus: The execution status object with a type property: "running", "complete", "incomplete", or "requires-action"
addResult ?: (result: TResult | ToolResponse<TResult>) => void: Function to add a result (useful for human-in-the-loop tools)
artifact ?: unknown: Optional artifact data associated with the tool call

Returns

Returns a React component that:

Provides the tool to the assistant when mounted
Automatically removes the tool when unmounted
Renders nothing in the DOM (returns null)

Example with Multiple Tools

import { makeAssistantTool, tool } from "@assistant-ui/react";
import { z } from "zod";

// Define tools
const validateEmail = tool({
  parameters: z.object({
    email: z.string(),
  }),
  execute: ({ email }) => {
    const isValid = email.includes("@");
    return { isValid, reason: isValid ? "Valid email" : "Missing @" };
  },
});

const sendEmail = tool({
  parameters: z.object({
    to: z.string().email(),
    subject: z.string(),
    body: z.string(),
  }),
  execute: async (params) => {
    // Tool logic
    return { sent: true };
  },
});

// Create tool components
const EmailValidator = makeAssistantTool({
  ...validateEmail,
  toolName: "validateEmail",
});
const EmailSender = makeAssistantTool({
  ...sendEmail,
  toolName: "sendEmail",
});

// Use together
function EmailForm() {
  return (
    <div>
      <form>{/* form fields */}</form>
      <EmailValidator />
      <EmailSender />
    </div>
  );
}

Best Practices

Parameter Validation
- Always use Zod schemas to define parameters
- Be specific about parameter types and constraints
- Add helpful error messages to schema validations
Error Handling
- Return meaningful error messages
- Consider returning partial results when possible
- Handle async errors appropriately
Composition
- Break complex tools into smaller, focused ones
- Consider tool dependencies and interactions
- Use multiple tools together for complex functionality