Yes, OPAL Client can read from data sources with a configurable timeout. This is controlled by the

OPAL_DATA_UPDATER_CONN_RETRY

configuration (1) . The configuration accepts a JSON object that specifies retry options when connecting to data sources :

{
  "wait_strategy": "random_exponential",
  "max_wait": 10,
  "attempts": 5,
  "wait_time": 1
}

This configuration controls retry behavior when the OPAL Client connects to base data sources (such as external API servers that return data snapshots) . Additionally, when using the HTTPX client provider (

OPAL_HTTP_FETCHER_PROVIDER_CLIENT=httpx

) , there's now support for specifying HTTP timeouts via environment variables, which was added in OPAL v0.8.2 (2) . Previously, the default timeout of 5 seconds was always used .

To learn more, see the sources I considered: [[1] OPAL Configuration Guide | OPAL](https://docs.opal.ac/getting-started/configuration) [[2] Add option to OPAL Client for specifying HTTPX client timeout](https://github.com/permitio/opal/issues/756)

Yes, timeouts work with custom fetchers as well. When you write a custom fetch provider, you have full control over the timeout behavior since you implement the fetching logic yourself (1) . In your custom fetch provider, you handle timeouts in the

__aenter__

method where you initialize connections . For example, when using asyncio-ready libraries like

asyncpg

for database connections, you can specify connection parameters including timeouts :

async def __aenter__(self) :
    # initializing parameters from the event/config
    self._event: PostgresFetchEvent
    dsn: str = self._event.url
    connection_params: dict = {} if self._event.config.connection_params is None else self._event.config.connection_params.dict(exclude_none=True)
    
    # connect to the postgres database
    self._connection: asyncpg.Connection = await asyncpg.connect(dsn, **connection_params)
    
    # start a readonly transaction (we don't want OPAL client writing data due to security!)
    self._transaction: Transaction = self._connection.transaction(readonly=True)
    await self._transaction.__aenter__()
    
    return self

Since custom fetch providers should use asyncio-ready libraries instead of blocking libraries , you can configure timeouts directly in whatever async library you're using for your specific data source.

To learn more, see the sources I considered: [[1] How to extend OPAL with custom Fetch Providers](https://docs.opal.ac/tutorials/write_your_own_fetch_provider)

Thanks for the feedback, glad I was helpful.