File attachment is broken due to file path

[LorenzaIacobuzioHybrid]

Description

When attaching a file, OpenCode passes the full file path as the document name to the Bedrock API. The / characters in the path cause the API to reject the request with "The document file name can only contain alphanumeric characters...". OpenCode should pass only the filename (basename), not the full path.

Plugins

No response

OpenCode version

1.18.4

Steps to reproduce

Just try to attach any file from your local machine and see what happens

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• File Upload: Full path is being passed as the document name to the AP #36113: File Upload: Full path is being passed as the document name to the API (same root cause)
• Bug: MCP tool binary attachment triggers Bedrock document name ValidationException (variant of #36113) #37191: MCP tool binary attachment triggers Bedrock document name ValidationException (related variant)