# Implement Custom FL Strategy
**URL:** https://discuss.flower.ai/t/implement-custom-fl-strategy/202
**Category:** Flower Help - Beginners
**Created:** [April 17, 2024, 2:49pm UTC](https://discuss.flower.ai/t/implement-custom-fl-strategy/202 "2024-04-17T14:49:24Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@ruhul5347](https://discuss.flower.ai/u/ruhul5347)
#### Post date: [April 17, 2024, 2:49pm UTC](https://discuss.flower.ai/t/implement-custom-fl-strategy/202/1 "2024-04-17T14:49:24Z")
I want to implement an FL algorithm and run it like [flower-simulation-step-by-step-pytorch](https://github.com/adap/flower/tree/main/examples/flower-simulation-step-by-step-pytorch/Part-I). Therefore, I have to change the strategy from the line 55 to 78 in the **main.py** file. Suppose my strategy name is FedNew. What steps should I follow to do this type of strategy implementation? If there is any example code available please share.
Thank you
---
### Author:  [@yan-gao](https://discuss.flower.ai/u/yan-gao)
#### Post date: [April 29, 2024, 4:36am UTC](https://discuss.flower.ai/t/implement-custom-fl-strategy/202/2 "2024-04-29T04:36:38Z")
Hi @ruhul5347, you could customise a new strategy (e.g., inherited from FedAvg) as below:
```auto
class FedNew(flwr.server.strategy.FedAvg):
def __init__ (**kwargs: Any,)
# define any new arguments
super(). __init__ (**kwargs)
def aggregate_fit(
self,
server_round: int,
results: List[Tuple[ClientProxy, FitRes]],
failures: List[Union[Tuple[ClientProxy, FitRes], BaseException]],
) -> Tuple[Optional[Parameters], Dict[str, Scalar]]:
# define new aggregation methods here
def configure_fit(
self, rnd: int, parameters: Parameters, client_manager: ClientManager
) -> List[Tuple[ClientProxy, FitIns]]:
# override client sampling method if needed
```
Note that `aggregate_fit()` and `configure_fit()` are for training. If doing changes for evaluation, then override `aggregate_evaluate()` and `configure_evaluate()`.
Then, call this new `FedNew` strategy similar to line 68 in main.py.
`strategy = FedNew(...)`
---
### Author:  [@system](https://discuss.flower.ai/u/system)
#### Post date: [August 1, 2025, 3:32pm UTC](https://discuss.flower.ai/t/implement-custom-fl-strategy/202/3 "2025-08-01T15:32:47Z")
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