Description

I consistently get the following error when using the bedrock provider when a message contains a "file" part. Note I have confirmed the file name contains valid characters despite the error. I'm using model id global.anthropic.claude-sonnet-4-5-20250929-v1:0 if it helps.

APICallError [AI_APICallError]: undefined: The document file name can only contain alphanumeric characters, whitespace characters, hyphens, parentheses, and square brackets. The
 name can't contain more than one consecutive whitespace character. Check that the file name conforms to these restrictions and retry your request.

When using an LLM to debug this it gives me the following root cause?:

The error occurs because of a property name mismatch in file attachments:

• File parts have: filename and mediaType properties
• Bedrock expects: name and mimeType properties
• Result: Bedrock can't find the name property, resulting in "undefined:" error

AI SDK Version

ai 6.0.6
@ai-sdk/amazon-bedrock 4.0.4

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