Can't cache just the system prompt CachedContent must have at least one content

[DreamGenX]

When you try to create cache with just system prompt:

    await vertex.preview.cachedContents.create({
      displayName: key,
      model,
      contents: []; // either [] or undefined, does not change the result
      systemInstruction: systemInstructions,
      ttl: `${ttlSeconds}s`
    });

You will get:

[VertexAI.ClientError]: got status: 400 Bad Request. {"error":{"code":400,"message":"CachedContent must have at least one content.","status":"INVALID_ARGUMENT"}}

[cabljac]

Could be related?

#469

[DreamGenX]

@cabljac Don't think so, also happens with Python SDK.

[salopge]

Are there any further updates?

I'm experiencing the same issue.
I'm using a long system prompt, and I only want to set the system instructions when creating the cache, but it seems impossible with the current structure.

Thanks!