Get started with the Anthropic Claude Messages API

The Anthropic Claude Messages API allows you to build an AI Agent with Anthropic's models.

Client-side setup

First, install the AI Agent extension.

npm install @tiptap-pro/extension-ai-agent

Then, import the extension and configure it with the AiAgentProvider class.

import { Editor } from '@tiptap/core'
import StarterKit from '@tiptap/starter-kit'
import AiAgent, { AiAgentProvider } from '@tiptap-pro/extension-ai-agent'

const provider = new AiAgentProvider()

const editor = new Editor({
  extensions: [
    StarterKit,
    AiAgent.configure({
      provider,
    }),
  ],
})

Inside the AI Agent provider, define a resolver function that calls your backend.

Also define an adapter function that converts the chat messages to the format expected by the Anthropic Claude Messages API.

import AiAgent, { AiAgentProvider, anthropicMessagesAdapter } from '@tiptap-pro/extension-ai-agent'

const provider = new AiAgentProvider({
  adapter: anthropicMessagesAdapter,
  // The llmMessages property contains the chat messages in the format expected by the Anthropic API
  resolver: async ({ llmMessages }) => {
    // Call the API endpoint of your backend
    const response = await fetch('/api-endpoint', {
      method: 'POST',
      body: JSON.stringify({ llmMessages }),
    })
    return await response.json()
  },
})

In the next section, we'll see how to implement the API endpoint that returns the response in the correct format.

Server-side setup

First, install the AI Agent and Anthropic server libraries.

npm install @tiptap-pro/extension-ai-agent @tiptap-pro/extension-ai-agent-server @anthropic-ai/sdk

Then, inside your API endpoint, create an AiAgentToolkit instance. It lets you configure the tools that will be available to the AI model.

import { AiAgentToolkit } from '@tiptap-pro/extension-ai-agent-server'

const toolkit = new AiAgentToolkit()

After creating the toolkit, send the request to the Anthropic Claude Messages API.

import { AiAgentToolkit } from '@tiptap-pro/extension-ai-agent-server'
import { anthropicMessagesAdapter } from '@tiptap-pro/extension-ai-agent'
import Anthropic from '@anthropic-ai/sdk'

const toolkit = new AiAgentToolkit()

// Initialize the Anthropic client
const anthropic = new Anthropic()

// Call the Anthropic Claude Messages API
const response = await anthropic.messages.create({
  model: 'claude-sonnet-4-0',
  system: `
<Your system prompt>
${toolkit.getSystemPrompt()}
`,
  messages: llmMessages,
  // Provide the tools that the AI model can call
  tools: toolkit.getTools(anthropicMessagesAdapter),
})

At the end of the system prompt, include the system prompt generated by the AiAgentToolkit instance, like this: toolkit.getSystemPrompt(). This contains instructions on how to use the tools.

To write the system prompt, see the system prompt guide. It includes an example system prompt that you can use as a starting point.

Finally, use anthropicMessagesAdapter to convert the response to the format expected by the AI Agent extension.

const result = anthropicMessagesAdapter.parseResponse(response)

The result should be the response of the API endpoint, and the return value of the resolver function.