# Scopes

> A scope is one client request and everything that follows from it, numbered by the client and ended only by the server.

Canonical: https://provider.diverge.network/2.3.0/frames/scopes/
Specification revision: 2.3.0

A **scope** is one client request and everything that follows from it.

- **Opening.** A client opens a scope by sending a request (type
  `1`). The client chooses the scope number, and every subsequent
  frame belonging to the scope — in both directions — carries that
  number in its scope field.
- **Answering.** The server answers with zero or more responses (type
  `2`) and ends the scope with exactly one response finish (type `3`).
  The responses to a scope's request form one stream: their order is
  significant, and the finish is its end.
- **Only the server ends a scope.** The client has no frame that
  closes, cancels, or abandons one. A scope is open from its request
  until its finish.
- **A finish with no response before it is meaningful.** It states
  that the request was received and could not be served. It is not an
  error frame, and no reason accompanies it at this layer.
- **Numbering.** The scope number is the client's to choose. A scope
  number names one scope from that scope's request until that scope's
  response finish; after the finish the number is free to bear a new
  scope.
- **A request naming an open scope is disregarded.** The server
  disregards a request whose scope field names a scope that is open
  on the connection. The disregarded request is never answered, and
  the scope it named continues, unaffected.
- **The scope's exchange is not a channel.** The frames that carry it
  — types `1`, `2`, and `3` — involve no channel, and their channel
  fields are ignored. Every other exchange within the scope is a
  [channel](/2.3.0/frames/channels/).