feat(anthropic): Add URL-based PDF support

[anishsrinivasan]

Add URL-based PDF support for Anthropic provider

This PR adds support for URL-based PDF documents in the Anthropic provider, complementing the existing base64-encoded PDF support. This aligns with Anthropic's official documentation which supports both methods.

https://docs.anthropic.com/en/docs/build-with-claude/pdf-support#option-1-url-based-pdf-document

Changes

• Added support for URL-based PDF documents in the Anthropic provider
• Updated documentation with examples for both URL and base64-encoded PDF usage
• Added implementation and tests for URL-based PDF handling

Example Usage

const result = await generateText({
  model: anthropic('claude-3-5-sonnet-20241022'),
  messages: [
    {
      role: 'user',
      content: [
        {
          type: 'text',
          text: 'What is an embedding model according to this document?',
        },
        {
          type: 'file',
          data: new URL('https://example.com/document.pdf'),
          mimeType: 'application/pdf',
        },
      ],
    },
  ],
});

Documentation

Documentation has been updated to show both methods of PDF handling:

1. URL-based PDF documents (new)
2. Base64-encoded PDF documents (existing)

Changeset

---
"@ai-sdk/anthropic": patch
---

Add support for URL-based PDF documents in the Anthropic provider

Testing

• Added tests for URL-based PDF handling
• Verified existing base64 PDF functionality remains unchanged
• Tested with various PDF URLs and sizes