investigate: File Support in Gemini

[ekassos]

In November 2025, Google announced the new Files API, which allows storage of documents for up to 48 hours. This API makes the PingPong's assistant/thread model particularly hard to replicate, as all files would have to be constantly re-uploaded and embedded.

On Jan 12, 2026 Google announced "Increased file size limits and expanded inputs support in Gemini API".

Previously, using large files (video, long audio, massive documents) required uploading them to the Gemini Files API, where they persisted for only 48 hours. While sufficient for prototyping, this ephemeral storage became a bottleneck for production apps relying on persistent data in cloud storage platforms.

We are removing this friction with two new input methods.

1. External URLs (public / signed):

   We now support both files stored in public domains, as well as private storage (via signed URLs)

   • You can pass any publicly accessible URL (like a PDF or image on the web) directly in your generation request.
   • We support pre-signed URLs for accessing data from AWS S3, Azure Blob Storage or other cloud providers.

   The Gemini API securely fetches the content during processing, eliminating the need to download content to your backend just to forward it to the API.

2. Register GCS files: If your data is already in Google Cloud Storage (GCS), you no longer need to move bytes. You can now register your GCS files directly with the Files API.

Some things still need to be investigated:

• What's the processing timeline for File Search files uploaded to GCS? Does every new thread require new processing?