Client API

aiosignalr.client

HubConnection

The client connection. See the client guide for usage.

Construction

HubConnection(
    *,
    protocol: str | IHubProtocol = "json",
    options: HubConnectionOptions | None = None,
    logger: logging.Logger | None = None,
)

Builder methods

Method	Description
with_retry_policy(policy) -> HubConnection	Enable automatic reconnect
with_stateful_reconnect(buffer_size=100_000) -> HubConnection	Enable stateful reconnect

Connection methods

Method	Description
async start(url, *, access_token_factory=None, headers=None, transports=None, skip_negotiation=False)	Negotiate, connect, handshake
async stop()	Gracefully close and clean up
async invoke(target, *args) -> Any	Call and await the result
async stream(target, *args) -> AsyncIterator	Call a streaming method
async send(target, *args)	Fire-and-forget call
async client_stream(target, *args) -> AsyncIterator[_UploadHandle]	Upload a client stream
on(target, handler) -> HubConnection	Register a server-call handler
remove(target, handler)	Remove a handler

Properties & events

Member	Type	Description
state	ConnectionState	Current lifecycle state
on_open	Callable[[], ...] | None	Fired on first connect
on_close	Callable[[BaseException | None], ...] | None	Fired on permanent close
on_reconnecting	Callable[[BaseException | None], ...] | None	Fired when a reconnect cycle starts
on_reconnected	Callable[[], ...] | None	Fired when a reconnect succeeds

_UploadHandle

Returned by client_stream():

• async send_item(item) — upload one item.
• async complete(error=None) — finish the upload.
• result — the server result after completion.

HubConnectionOptions

Field	Default	Description
handshake_timeout	15.0	Seconds to wait for the handshake
server_timeout	30.0	Seconds of silence before the client drops
keep_alive_interval	15.0	Seconds between client pings
stateful_reconnect_buffer_size	100_000	Outbound buffer byte limit

Retry policies

RetryContext(previous_retry_count, elapsed_time, retry_reason) — passed to RetryPolicy.next_retry_delay.

• RetryPolicy (ABC) — implement next_retry_delay(context) -> float | None.
• DefaultRetryPolicy — 0s, 2s, 10s, 30s, then None.

Negotiation helpers

negotiate(session, base_url, *, headers=None, negotiate_version=1, use_stateful_reconnect=False) -> NegotiateResult

NegotiateResult fields:

Field	Description
connection_id	Server connection id
connection_token	Token used in the ?id= query (negotiate v1+)
negotiate_version	Agreed negotiate version
available_transports	[AvailableTransport(name, transfer_formats)]
use_stateful_reconnect	Whether the ack protocol is agreed
url / access_token	Redirect response fields (if any)

Constants: WEB_SOCKETS, SERVER_SENT_EVENTS, LONG_POLLING, DEFAULT_TRANSPORTS, NEGOTIATE_VERSION.

aiosignalr.enums

Enum	Values
ConnectionState	DISCONNECTED, CONNECTING, CONNECTED, RECONNECTING
TransferFormat	TEXT, BINARY
MessageType	INVOCATION=1 … SEQUENCE=9