TokenHandler

QuantConnect.Brokerages.Authentication.TokenHandler

TokenHandler(
    create_auth_header: Callable[
        [TokenType, str], AuthenticationHeaderValue
    ] = None,
    retry_interval: Optional[timedelta] = None,
)

Bases: DelegatingHandler

Provides base functionality for token-based HTTP request handling, including automatic retries and token refresh on unauthorized responses.

Initializes a new instance of the TokenHandler class.

This codeEntityType is protected.

Parameters:

Name	Type	Description	Default
create_auth_header	Callable[[TokenType, str], AuthenticationHeaderValue]	An optional delegate for creating an AuthenticationHeaderValue from the token type and access token. If not provided, a default implementation is used.	None
retry_interval	Optional[timedelta]	An optional time interval to wait between retry attempts when fetching the token or retrying a failed request. If null, the default interval of 5 seconds is used.	None

get_access_token

get_access_token(
    cancellation_token: CancellationToken,
) -> TokenCredentials

Retrieves a valid access token for authenticating HTTP requests. Must be implemented by derived classes to provide token type and value, with optional support for caching and refresh logic.

Parameters:

Name	Type	Description	Default
cancellation_token	CancellationToken	A cancellation token that can be used to cancel the token retrieval operation.	required

Returns:

Type	Description
TokenCredentials	A TokenCredentials instance containing the token type and access token string.

send

send(
    request: Any, cancellation_token: CancellationToken
) -> Any

Sends an HTTP request synchronously with retry support. This override includes token-based authentication and refresh logic on 401 Unauthorized responses.

This codeEntityType is protected.

Parameters:

Name	Type	Description	Default
request	Any	The HTTP request message to send.	required
cancellation_token	CancellationToken	A cancellation token to cancel operation.	required

Returns:

Type	Description
Any	The HTTP response message.

send_async

send_async(
    request: Any, cancellation_token: CancellationToken
) -> Task[HttpResponseMessage]

Sends an HTTP request asynchronously by internally invoking the synchronous send(HttpRequestMessage, CancellationToken) method. This is useful for compatibility with components that require an asynchronous pipeline, even though the core logic is synchronous.

This codeEntityType is protected.

Parameters:

Name	Type	Description	Default
request	Any	The HTTP request message to send.	required
cancellation_token	CancellationToken	A cancellation token to cancel the operation.	required

Returns:

Type	Description
Task[HttpResponseMessage]	A task representing the asynchronous operation, containing the HTTP response message.