title: Google Cloud Storage OAuth cross project access
body: <p>Are OAuth user credentials in Google Cloud limited to the project in which the OAuth client ID exists or is it across the whole Google Cloud?</p>
  <p>For example:</p>
  <p>If there are two projects <strong>P1</strong> and <strong>P2</strong>.</p>
  <p><strong>P1</strong> has a bucket <strong>B1</strong> and <strong>P2</strong> has a bucket <strong>B2</strong>.</p>
  <p><strong>P1</strong> defines an OAuth client ID for user credentials. The scope of this client ID is read-write to buckets.</p>
  <p>A client uses this client ID in <strong>P1</strong> and authenticates some user called Alice and gets an access token.</p>
  <p>Assuming Alice has access to both buckets <strong>B1</strong> and <strong>B2</strong>. Will this token also have access to both the buckets <strong>B1</strong> and <strong>B2</strong>?</p>