Anthropic Messages Images and PDFs with AI Gateway

import Anthropic from '@anthropic-ai/sdk';
import fs from 'node:fs';
 
const apiKey = process.env.AI_GATEWAY_API_KEY || process.env.VERCEL_OIDC_TOKEN;
 
const anthropic = new Anthropic({
  apiKey,
  baseURL: 'https://ai-gateway.vercel.sh',
});
 
// Read files as base64
const pdfData = fs.readFileSync('./document.pdf');
const imageData = fs.readFileSync('./image.png');
 
const pdfBase64 = pdfData.toString('base64');
const imageBase64 = imageData.toString('base64');
 
const message = await anthropic.messages.create({
  model: 'anthropic/claude-opus-5',
  max_tokens: 1024,
  messages: [
    {
      role: 'user',
      content: [
        {
          type: 'document',
          source: {
            type: 'base64',
            media_type: 'application/pdf',
            data: pdfBase64,
          },
        },
        {
          type: 'image',
          source: {
            type: 'base64',
            media_type: 'image/png',
            data: imageBase64,
          },
        },
        {
          type: 'text',
          text: 'Please summarize the PDF and describe the image.',
        },
      ],
    },
  ],
});
 
for (const block of message.content) {
  if (block.type === 'text') console.log('Response:', block.text);
}

import os
import base64
import anthropic
 
api_key = os.getenv('AI_GATEWAY_API_KEY') or os.getenv('VERCEL_OIDC_TOKEN')
 
client = anthropic.Anthropic(
    api_key=api_key,
    base_url='https://ai-gateway.vercel.sh'
)
 
# Read files as base64
with open('./document.pdf', 'rb') as f:
    pdf_base64 = base64.b64encode(f.read()).decode('utf-8')
 
with open('./image.png', 'rb') as f:
    image_base64 = base64.b64encode(f.read()).decode('utf-8')
 
message = client.messages.create(
    model='anthropic/claude-opus-5',
    max_tokens=1024,
    messages=[
        {
            'role': 'user',
            'content': [
                {
                    'type': 'document',
                    'source': {
                        'type': 'base64',
                        'media_type': 'application/pdf',
                        'data': pdf_base64,
                    },
                },
                {
                    'type': 'image',
                    'source': {
                        'type': 'base64',
                        'media_type': 'image/png',
                        'data': image_base64,
                    },
                },
                {
                    'type': 'text',
                    'text': 'Please summarize the PDF and describe the image.',
                },
            ],
        }
    ],
)
 
for block in message.content:
    if block.type == "text":
        print('Response:', block.text)

PDF_B64=$(base64 -i document.pdf)
IMAGE_B64=$(base64 -i image.png)
 
curl -X POST "https://ai-gateway.vercel.sh/v1/messages" \
  -H "Authorization: Bearer $AI_GATEWAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-opus-5",
    "max_tokens": 1024,
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "document",
            "source": {
              "type": "base64",
              "media_type": "application/pdf",
              "data": "'"$PDF_B64"'"
            }
          },
          {
            "type": "image",
            "source": {
              "type": "base64",
              "media_type": "image/png",
              "data": "'"$IMAGE_B64"'"
            }
          },
          {
            "type": "text",
            "text": "What do this document and image show?"
          }
        ]
      }
    ]
  }'