# Tool

Displays a tool call the agent makes, from input to output.

## When to use

* Show a tool call from input to output, such as a search or a file read.
* Show the state of the call: running, done or failed.

## How it works

Tool is built with the [Trace](/components/trace) and [Code Block](/components/code-block) components. The demo streams a predefined conversation through `useChat` from `@ai-sdk/react`, with `createChat` from [`@shadcn/helpers/ai-sdk`](/helpers/ai-sdk), so it needs no model or API key. There is no package to install: copy the code into your project.

## Example

### Base UI

```tsx
'use client'

import { useChat } from "@ai-sdk/react"
import type { UIDataTypes, UIMessage } from "ai"
import { TerminalIcon } from "lucide-react"

import { createChat, getMessageText } from "@/lib/ai"
import { Bubble, BubbleContent } from "@/shadcn/base/ui/bubble"
import { Button } from "@/shadcn/base/ui/button"
import { CodeBlock, CodeBlockContent } from "@/shadcn/base/ui/code-block"
import { Message, MessageContent } from "@/shadcn/base/ui/message"
import {
  Trace,
  TraceCollapsible,
  TraceCollapsibleContent,
  TraceCollapsibleTrigger,
  TraceIcon,
  TraceLine,
  TraceTitle,
} from "@/shadcn/base/ui/trace"

type ChatMessage = UIMessage<
  unknown,
  UIDataTypes,
  {
    runCommand: {
      input: { command: string }
      output: { stdout: string }
    }
  }
>

type ToolPart = Extract<
  ChatMessage["parts"][number],
  { type: "tool-runCommand" }
>

const chat = createChat<ChatMessage>()
  .user("Which package managers are installed?")
  .assistant(({ writer }) => {
    writer
      .tool("runCommand", { input: { command: "node --version" } })
      .sleep(900)
      .output({ stdout: "v24.18.0" })
    writer
      .tool("runCommand", { input: { command: "npm --version" } })
      .sleep(900)
      .output({ stdout: "11.6.2" })
    writer
      .tool("runCommand", { input: { command: "pnpm --version" } })
      .sleep(900)
      .error("command not found: pnpm")
    writer.text("Node 24 and npm 11 are installed. pnpm is not.")
  })

const transcript = chat.get()
const [question] = chat.get(1)
const transport = chat.transport({ delayMs: 20 })

function ToolRow({
  part,
  streaming,
  defaultOpen,
}: {
  part: ToolPart
  streaming: boolean
  defaultOpen?: boolean
}) {
  const command = part.input?.command

  if (part.state === "output-available" || part.state === "output-error") {
    const failed = part.state === "output-error"

    return (
      <TraceCollapsible defaultOpen={defaultOpen}>
        <TraceCollapsibleTrigger>
          <TraceLine status={failed ? "error" : undefined}>
            <TraceIcon>
              <TerminalIcon />
            </TraceIcon>
            <TraceTitle>
              {failed ? "Failed to run" : "Ran"} {command}
            </TraceTitle>
          </TraceLine>
        </TraceCollapsibleTrigger>
        <TraceCollapsibleContent>
          <CodeBlock size="sm">
            <CodeBlockContent wrap className="max-h-64">
              {failed ? part.errorText : part.output.stdout}
            </CodeBlockContent>
          </CodeBlock>
        </TraceCollapsibleContent>
      </TraceCollapsible>
    )
  }

  return (
    <TraceLine status={streaming ? "running" : "error"}>
      <TraceIcon>
        <TerminalIcon />
      </TraceIcon>
      <TraceTitle>
        {streaming ? "Running" : "Failed to run"} {command}
      </TraceTitle>
    </TraceLine>
  )
}

export default function ToolDemo() {
  const { messages, sendMessage, setMessages, status } = useChat({
    messages: transcript,
    transport,
  })
  const busy = status === "submitted" || status === "streaming"

  return (
    <div className="flex min-h-72 w-full max-w-sm flex-col gap-4 py-6 text-sm">
      {messages.map((message) => {
        if (message.role === "user") {
          return (
            <Message key={message.id} align="end">
              <MessageContent>
                <Bubble align="end" variant="muted">
                  <BubbleContent>{getMessageText(message)}</BubbleContent>
                </Bubble>
              </MessageContent>
            </Message>
          )
        }

        const streaming = busy && message === messages.at(-1)
        const tools = message.parts.filter(
          (part) => part.type === "tool-runCommand"
        )
        const text = getMessageText(message)

        return (
          <Message key={message.id}>
            <MessageContent className="gap-4">
              {tools.length > 0 && (
                <Trace>
                  {tools.map((part) => (
                    <ToolRow
                      key={part.toolCallId}
                      part={part}
                      streaming={streaming}
                      defaultOpen={
                        busy ? undefined : part.state === "output-error"
                      }
                    />
                  ))}
                </Trace>
              )}
              {text && <p>{text}</p>}
            </MessageContent>
          </Message>
        )
      })}
      {!busy && (
        <Button
          variant="outline"
          size="sm"
          className="mt-auto self-start"
          onClick={() => {
            setMessages([])
            sendMessage(question)
          }}
        >
          Replay
        </Button>
      )}
    </div>
  )
}
```

### Radix

```tsx
'use client'

import { useChat } from "@ai-sdk/react"
import type { UIDataTypes, UIMessage } from "ai"
import { TerminalIcon } from "lucide-react"

import { createChat, getMessageText } from "@/lib/ai"
import { Bubble, BubbleContent } from "@/shadcn/radix/ui/bubble"
import { Button } from "@/shadcn/radix/ui/button"
import { CodeBlock, CodeBlockContent } from "@/shadcn/radix/ui/code-block"
import { Message, MessageContent } from "@/shadcn/radix/ui/message"
import {
  Trace,
  TraceCollapsible,
  TraceCollapsibleContent,
  TraceCollapsibleTrigger,
  TraceIcon,
  TraceLine,
  TraceTitle,
} from "@/shadcn/radix/ui/trace"

type ChatMessage = UIMessage<
  unknown,
  UIDataTypes,
  {
    runCommand: {
      input: { command: string }
      output: { stdout: string }
    }
  }
>

type ToolPart = Extract<
  ChatMessage["parts"][number],
  { type: "tool-runCommand" }
>

const chat = createChat<ChatMessage>()
  .user("Which package managers are installed?")
  .assistant(({ writer }) => {
    writer
      .tool("runCommand", { input: { command: "node --version" } })
      .sleep(900)
      .output({ stdout: "v24.18.0" })
    writer
      .tool("runCommand", { input: { command: "npm --version" } })
      .sleep(900)
      .output({ stdout: "11.6.2" })
    writer
      .tool("runCommand", { input: { command: "pnpm --version" } })
      .sleep(900)
      .error("command not found: pnpm")
    writer.text("Node 24 and npm 11 are installed. pnpm is not.")
  })

const transcript = chat.get()
const [question] = chat.get(1)
const transport = chat.transport({ delayMs: 20 })

function ToolRow({
  part,
  streaming,
  defaultOpen,
}: {
  part: ToolPart
  streaming: boolean
  defaultOpen?: boolean
}) {
  const command = part.input?.command

  if (part.state === "output-available" || part.state === "output-error") {
    const failed = part.state === "output-error"

    return (
      <TraceCollapsible defaultOpen={defaultOpen}>
        <TraceCollapsibleTrigger>
          <TraceLine status={failed ? "error" : undefined}>
            <TraceIcon>
              <TerminalIcon />
            </TraceIcon>
            <TraceTitle>
              {failed ? "Failed to run" : "Ran"} {command}
            </TraceTitle>
          </TraceLine>
        </TraceCollapsibleTrigger>
        <TraceCollapsibleContent>
          <CodeBlock size="sm">
            <CodeBlockContent wrap className="max-h-64">
              {failed ? part.errorText : part.output.stdout}
            </CodeBlockContent>
          </CodeBlock>
        </TraceCollapsibleContent>
      </TraceCollapsible>
    )
  }

  return (
    <TraceLine status={streaming ? "running" : "error"}>
      <TraceIcon>
        <TerminalIcon />
      </TraceIcon>
      <TraceTitle>
        {streaming ? "Running" : "Failed to run"} {command}
      </TraceTitle>
    </TraceLine>
  )
}

export default function ToolDemo() {
  const { messages, sendMessage, setMessages, status } = useChat({
    messages: transcript,
    transport,
  })
  const busy = status === "submitted" || status === "streaming"

  return (
    <div className="flex min-h-72 w-full max-w-sm flex-col gap-4 py-6 text-sm">
      {messages.map((message) => {
        if (message.role === "user") {
          return (
            <Message key={message.id} align="end">
              <MessageContent>
                <Bubble align="end" variant="muted">
                  <BubbleContent>{getMessageText(message)}</BubbleContent>
                </Bubble>
              </MessageContent>
            </Message>
          )
        }

        const streaming = busy && message === messages.at(-1)
        const tools = message.parts.filter(
          (part) => part.type === "tool-runCommand"
        )
        const text = getMessageText(message)

        return (
          <Message key={message.id}>
            <MessageContent className="gap-4">
              {tools.length > 0 && (
                <Trace>
                  {tools.map((part) => (
                    <ToolRow
                      key={part.toolCallId}
                      part={part}
                      streaming={streaming}
                      defaultOpen={
                        busy ? undefined : part.state === "output-error"
                      }
                    />
                  ))}
                </Trace>
              )}
              {text && <p>{text}</p>}
            </MessageContent>
          </Message>
        )
      })}
      {!busy && (
        <Button
          variant="outline"
          size="sm"
          className="mt-auto self-start"
          onClick={() => {
            setMessages([])
            sendMessage(question)
          }}
        >
          Replay
        </Button>
      )}
    </div>
  )
}
```

## Installation

```bash
npx shadcn@latest add trace code-block
```

## Reference

Official page: https://ui.shadcn.com/docs/ai-elements/base/tool