All requests sent to the Google Photos Library API are counted toward a quota. We put these limits in place to protect the system and its users.
Access to the API requires OAuth client credentials from a Google developers project. This project must have the Library API enabled as described in Get started.
To learn more about appropriate use of this API, see the Acceptable use policy.
General quota limit
During the developer preview, the quota for requests to the Library API is 2,500 requests per project per day. In the production launch of the Library API, the quota for requests will be increased to 10,000 requests per project per day. Requests to access media bytes (like loading a photo or video) are not counted against the limit.
Exceeding quota limits
If the quota of requests to the Library API is exceeded, the API returns an error code 429 and a message that the project has exceeded the quota. For more information, see the Terms of Service.
Requesting additional quota
Because the Library API is in developer preview, a higher quota can't be requested during this time. Once the API enters general availability, you may request additional quota via the Google Photos partner program.
Photo storage and quality
All media items uploaded to Google Photos using the API are stored in full resolution at original quality. They count toward the user’s storage.