nebius.aio.token.token.Receiver

class documentation

class Receiver(ABC): (source)

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Abstract asynchronous token receiver interface.

Implementations get bearer tokens from an external source, such as an OAuth endpoint or local cache. The request layer uses this interface for per-request authentication.

A receiver gets and refreshes a token for one request. A Bearer supports multiple requests and supplies a receiver for each request.

The built-in channel calls receivers on its internal SDK event loop. A custom receiver must be thread-safe and loop-neutral. It must not retain asyncio state that belongs to an application loop.

Method	`can_retry`	Decide whether a failed authentication attempt should be retried.
Async Method	`fetch`	Fetch a token and record it as the latest value.
Property	`latest`	Return the latest fetched token or `None`.
Async Method	`_fetch`	Low-level asynchronous fetch implementation.
Instance Variable	`_latest`	The most recently fetched token, or `None` if no token has been fetched yet. Implementations may update this to support inspection or caching by callers.

@abstractmethod
def can_retry(self, err: Exception, options: dict[str, str] | None = None) -> bool: (source) ¶

overridden in nebius.aio.token.exchangeable.Receiver, nebius.aio.token.federation_bearer.Receiver, nebius.aio.token.file.Receiver, nebius.aio.token.file_cache.async_renewable_bearer.AsynchronousRenewableFileCacheReceiver, nebius.aio.token.file_cache.file_bearer.PureFileCacheReceiver, nebius.aio.token.file_cache.renewable_bearer.RenewableFileCacheReceiver, nebius.aio.token.impersonated.Receiver, nebius.aio.token.renewable.Receiver, nebius.aio.token.static.Receiver, nebius.aio.metrics._InstrumentedReceiver

Decide whether a failed authentication attempt should be retried.

Inspect err and optional options. Return whether a new fetch call is likely to succeed, for example after credential refresh.

Default implementations should return False.

Parameters
err:`Exception`	The exception that triggered the retry decision.
options:`dict[str, str]` or `None`	Optional implementation-specific options.
Returns
`bool`	`True` when a retry is advisable, otherwise `False`.

async def fetch(self, timeout: float | None = None, options: dict[str, str] | None = None) -> Token: (source) ¶

overridden in nebius.aio.metrics._InstrumentedReceiver

Fetch a token and record it as the latest value.

This method calls the concrete _fetch implementation and stores the result on _latest before returning it.

Parameters
timeout:optional `float`	Optional timeout in seconds forwarded to the fetch.
options:optional `dict[str, str]`	Optional implementation-specific options.
Returns
`Token`	The fetched `Token`.

@property
latest: Token or None = (source) ¶

overridden in nebius.aio.metrics._InstrumentedReceiver

Return the latest fetched token or None.

@abstractmethod
async def _fetch(self, timeout: float | None = None, options: dict[str, str] | None = None) -> Token: (source) ¶

Low-level asynchronous fetch implementation.

Subclasses must implement this token-retrieval method. Call fetch instead of this internal method. fetch records the result in _latest.

Parameters
timeout:optional `float`	Optional timeout in seconds for the fetch operation.
options:optional `dict[str, str]`	Optional implementation-specific options forwarded by the request layer.
Returns
`Token`	A freshly fetched `Token`.

_latest: Token | None = (source) ¶

overridden in nebius.aio.token.static.Receiver

The most recently fetched token, or None if no token has been fetched yet. Implementations may update this to support inspection or caching by callers.