feat(anthropic): Add Anthropic PDF support (document type) in invoke

[adhambadr]

Since claude-3-5-sonnet-20240620 PDF Support has been added to Anthropic's message types.

You are able to send the PDF document to Anthropic and they do text extraction, Image conversion and supply the LLM with both (Text + Screenshot) of each page to do deep dive analysis, text extraction and more. Its pretty neat and handy especially in doing structured output and I added support for it in the Langchain Ecosystem as right now using document type throws an unsupported type error before passing it to the LLM.

I added the source type document support as well as simplifying the source object to just pass the base64 or the object exactly as in Anthropic's documentation.
I added a working example inside yarn example examples/src/prompts/pdf_document.ts

Here is an example usage:

import { ChatAnthropic } from "@langchain/anthropic";

const llm = new ChatAnthropic({
    model: "claude-3-5-sonnet-20240620",
 // Key 
});

// Local file
const file = fs.readFileSync("test.pdf");
const base64 = Buffer.from(file).toString("base64");
// Or Load remotely (web environment): 
const res = await fetch("https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf")
const buffer = await res.arrayBuffer();
const base64 = Buffer.from(buffer).toString("base64");

const prompt = "Summarize for me the contents of this document"; 
const {content} = await llm.invoke([ 
  {
     role : "user",
     content :  [
        {
          type: "text",
          text: prompt,
        },
        {
          type: "document",
          source: base64,
        }
      ]
   }
]);

console.log(content);

It's my first PR to this project so apologies if I missed something crucial, feedback or improvements are welcomed, as all as the shoutout to my twitter

Supported models as of Jan 2025:

1. claude-3-5-sonnet-20240620
2. claude-3-5-sonnet-20241022

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
langchainjs-docs	✅ Ready (Inspect)	Visit Preview		Jan 18, 2025 8:55am

1 Skipped Deployment

Name	Status	Preview	Comments	Updated (UTC)
langchainjs-api-refs	⬜️ Ignored (Inspect)			Jan 18, 2025 8:55am

[jacoblee93]

Ah nice!

[jacoblee93]

Thanks for flagging this - see comment!

[camwardy]

Thanks for adding this @adhambadr, hopefully this can get merged soon as it'd be really useful for us!

[jacoblee93]

Thank you!

[adhambadr]

Thank you!

thanks a lot for the clean up (removing console, unnecessary import etc)!