feat: Add async functionality to providers

README.md

@@ -390,6 +390,57 @@ class MyProvider(AbstractProvider):
         ...
 ```
 
+Providers can also be extended to support async functionality.
+To support add asynchronous calls to a provider:
+* Implement the `AbstractProvider` as shown above.
+* Define asynchronous calls for each data type.
+
+```python
+class MyProvider(AbstractProvider):
+    ...
+    async def resolve_boolean_details_async(
+        self,
+        flag_key: str,
+        default_value: bool,
+        evaluation_context: Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[bool]:
+        ...
+
+    async def resolve_string_details_async(
+        self,
+        flag_key: str,
+        default_value: str,
+        evaluation_context: Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[str]:
+        ...
+
+    async def resolve_integer_details_async(
+        self,
+        flag_key: str,
+        default_value: int,
+        evaluation_context: Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[int]:
+        ...
+
+    async def resolve_float_details_async(
+        self,
+        flag_key: str,
+        default_value: float,
+        evaluation_context: Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[float]:
+        ...
+
+    async def resolve_object_details_async(
+        self,
+        flag_key: str,
+        default_value: Union[dict, list],
+        evaluation_context: Optional[EvaluationContext] = None,
+    ) -> FlagResolutionDetails[Union[dict, list]]:
+        ...
+
+```
+
+
 > Built a new provider? [Let us know](https://github.com/open-feature/openfeature.dev/issues/new?assignees=&labels=provider&projects=&template=document-provider.yaml&title=%5BProvider%5D%3A+) so we can add it to the docs!
 
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