vercel/ai · error · UnsupportedFunctionalityError

file part media type

Error message

file part media type ${fullMediaType}

What it means

Perplexity file support is effectively limited to PDFs. When a file part's resolved full media type is anything other than application/pdf, convertToPerplexityMessages throws UnsupportedFunctionalityError naming the offending media type, because Perplexity cannot ingest it (images must be sent as image parts, not file parts).

Solutions

1. Convert the document to PDF before sending it to Perplexity
2. Send images as image parts ({ type: 'image', ... }) rather than file parts
3. Filter or reject non-PDF attachments in your app before invoking the model

Example fix

// before
{ type: 'file', data: new URL('https://example.com/shot.png'), mediaType: 'image/png' }
// after
{ type: 'image', image: new URL('https://example.com/shot.png') }

for (const part of msg.content) {
  if (part.type === 'file') {
    const mediaType = part.mediaType ?? '';
    if (mediaType !== 'application/pdf') {
      throw new Error(`Perplexity only supports PDF file parts, got ${mediaType}`);
    }
  }
}

function isPdfFilePart(part: { type: string; mediaType?: string }): part is { type: 'file'; mediaType: 'application/pdf' } {
  return part.type === 'file' && part.mediaType === 'application/pdf';
}

try {
  await generateText({ model: perplexity('sonar-pro'), messages });
} catch (e) {
  if (UnsupportedFunctionalityError.isInstance(e) && e.message.includes('file part media type')) {
    // convert to PDF, route as image part, or drop the attachment
  } else throw e;
}

When it happens

Trigger: Sending a file part with a media type such as image/png, application/msword, text/csv, or audio/* (anything non-PDF) to a Perplexity chat model, including via URL or data parts.

Common situations: Uploading images as file parts instead of image parts; passing Office/CSV documents that only some providers accept; dynamically chosen attachments where media type is not filtered before dispatch.

Related errors

• file parts with provider references
• text file parts
• AI_UnsupportedFunctionalityError
• 'file part media type
• 'file part media type

AI-assisted analysis of vercel/ai@69428b1f8b (2026-08-30). Data as JSON: /api/errors/2ff275f707242147. Report an issue: GitHub.

Appendix: source

Thrown at packages/perplexity/src/convert-to-perplexity-messages.ts:68

                      functionality: 'file parts with provider references',
                    });
                  }
                  case 'text': {
                    throw new UnsupportedFunctionalityError({
                      functionality: 'text file parts',
                    });
                  }
                  case 'url':
                  case 'data': {
                    const topLevelMediaType = getTopLevelMediaType(
                      part.mediaType,
                    );

                    if (topLevelMediaType === 'application') {
                      const fullMediaType = resolveFullMediaType({ part });

                      if (fullMediaType !== 'application/pdf') {
                        throw new UnsupportedFunctionalityError({
                          functionality: `file part media type ${fullMediaType}`,
                        });
                      }

                      return part.data.type === 'url'
                        ? {
                            type: 'file_url',
                            file_url: {
                              url: part.data.url.toString(),
                            },
                            file_name: part.filename,
                          }
                        : {
                            type: 'file_url',
                            file_url: {
                              url:
                                typeof part.data.data === 'string'
                                  ? part.data.data

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