File attachments. Certain item types may allow file attachments.

A Comment is a text-only response to some other Item.

Metadata about a file attachment. All fields are REQUIRED.

Each FeoBlog user's "blog" is really a collection of "Items" of different types. It's important to keep in mind that different servers may cache different subsets of items.

A list of items available on a server. Exmaples: GET /u/{userID}/items[?before=timestamp_ms_utc] to list a single user's items. GET /u/{userID]/feed/items[?before=...] to list items in a user's feed.

The unique ID of an item is its (user_id,signature) This type encapsulates that, plus some additional metadata which

Servers should render posts at at least two URLs:

1. /u/{userID}/[?before={timestamp_ms_utc}] should render (some number of) the user's most recent posts before timestamp_ms_utc. These may be truncated.
2. /u/{userID}/i/{itemID}/ should render a single user post, in full.

A user profile, where a user can provide information about themselves.

Information about an Item that we're replying to.

Information about where a user's posts may be found. This lets content creators' clients know where to send posts when they're uploaded. This also lets consumers' clients know where they can find the creator's content.

This is redundant with the Item.item_type oneof. But it allows us to specify the type of an item in ItemLists.