Module client 

Client — the calling side of a negotiated session.

What it is

A client holds the revisions it will speak, in preference order, and the features it wants. It does not open a connection: a transport does that, and until T13 supplies one, a test can hand the client a closure directly.

The gate, and where it lives

Every typed method consults the resolved FeatureProfile before it does anything, exactly as the server’s RequestContext does. The asymmetry is deliberate: the server’s gate protects the peer from a feature the server did not negotiate, and the client’s gate protects the caller from a round trip that cannot work.

Both produce the same ClientError, because from the caller’s side “this session cannot do that” is one fact with one fix — configure a version that can, or drop the call.

Modules

bearer

How a client authenticates to an HTTP server.

handler

Answering the requests a server sends the client.

inputs

Answering a server’s request for input (SEP-2322, 2026-07-28).

Structs

Client

A client bound to a negotiated session.

ClientConfig

What a client offers a server, before anything is negotiated.

Enums

ClientError

Why a client call did not happen.

ConnectError

Why a session could not be opened.

HandshakeError

Why a session could not be established.

StdioConnectError

What failed when Client::connect_stdio could not open a session.

TransportError

Why a request did not complete.

Constants

DISCOVER

The method that opens a 2026-07-28 session.

INITIALIZE

The method that opens every other session this crate speaks.

INITIALIZED

The notification that ends a handshake, on the revisions that have one.

Traits

ClientTransport

Sends one request to the peer and returns its answer.

Functions

default_versions

The revisions a client offers when the caller expresses no preference.

discover_session

Reads a server/discover answer into a session.

handshake

Establishes a session over transport.

initialize_params

The initialize params: the offer, what this client can do, and who it is.

initialize_session

Reads an initialize answer into a session.

offer

The revision this client prefers, and the set it can speak.

open

Opens spec, negotiates, and binds the result.