How to hit /api/files directly? (Programmatic uploads via MCP server)

[asnijders-dc]

Hey everyone,

I'm trying to bypass the web UI and programmatically push files directly to LibreChat from an external backend (specifically, an MCP server handling local docs).

I've tested the /api/files endpoint and can successfully auth if I grab and reuse my active session cookies/tokens from the browser. However, I haven't been able to successfully auth with the endpoint directly using either the Librechat OpenID ID token, Access token, etc.

Since there's no public documentation on direct backend ingestion for files yet, I'm looking for some clarity on the intended workflow:

• Auth: Is there a way to hit this endpoint using a standard API key, or is it strictly locked to frontend session JWTs/cookies for now?
• Payload: Standard multipart/form-data, I assume? Are there any hidden required fields besides the file binary (like purpose or conversationId)?
• Return Object: What metadata (e.g., file_id) comes back that I need to map into a subsequent message payload so the LLM actually sees the file?

If anyone has a quick curl snippet or node script of a direct backend file upload to LibreChat without relying on a hijacked session token, that would be amazing.

Cheers!