# Question about current serialization flow (FitIns / RecordDict)

**URL:** https://discuss.flower.ai/t/question-about-current-serialization-flow-fitins-recorddict/1179
**Category:** Flower Help - Intermediate
**Created:** [December 31, 2025, 9:55am UTC](https://discuss.flower.ai/t/question-about-current-serialization-flow-fitins-recorddict/1179 "2025-12-31T09:55:57Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![sarahfalco](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@sarahfalco](https://discuss.flower.ai/u/sarahfalco)
#### Post date: [December 31, 2025, 9:55am UTC](https://discuss.flower.ai/t/question-about-current-serialization-flow-fitins-recorddict/1179/1 "2025-12-31T09:55:57Z")

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Hi Flower team,

I’m trying to understand the **current serialization/deserialization flow** for `FitIns` / `FitRes`.

Previously, I understood the flow to be roughly:  
`FitIns → fitins_to_recorddict → transport → recorddict_to_fitins` (and similarly for `FitRes`).

However, when inspecting the runtime behavior and adding logs, it seems that some conversion functions (e.g. `fitins_to_recorddict`, `parameters_to_arrayrecord`) are **no longer always called** , and the flow doesn’t pass through `RecordDict` in the way I expected.

So I wanted to ask:

1. What is the **current canonical flow** for serializing/deserializing `FitIns` / `FitRes`?

2. Is the `RecordDict` path still always used, or only in specific cases?

3. Has this flow been recently updated or refactored?

Any clarification or pointer to updated docs/diagrams would be greatly appreciated.

Thanks a lot!

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### Author: ![mohammad](https://dub1.discourse-cdn.com/flex013/user_avatar/discuss.flower.ai/mohammad/32/35_2.png) [@mohammad](https://discuss.flower.ai/u/mohammad)
#### Post date: [December 31, 2025, 10:30am UTC](https://discuss.flower.ai/t/question-about-current-serialization-flow-fitins-recorddict/1179/2 "2025-12-31T10:30:52Z")

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Hey, yes, the logic has changed. Those helpers were part of a transitional bridge between `RecordDict` and the legacy `FitIns`/`FitRes` API, but they’re no longer on the main path. The current flow is message-first and parameters and metadata live directly in a `RecordDict` carried by a `Message`. You can find the details here: [https://flower.ai/docs/framework/ref-api/flwr.common.Message.html?utm\_source=chatgpt.com](https://flower.ai/docs/framework/ref-api/flwr.common.Message.html?utm_source=chatgpt.com)