## Recoil → Jotai progressive migration: infrastructure +
ChipFieldDisplay
### Benchmark
In the beginning, there was no hope:
<img width="1180" height="948" alt="image"
src="https://github.com/user-attachments/assets/f8635991-52e6-4958-8240-6ba7214132b2"
/>
Then the hope was reborn
<img width="2070" height="948" alt="image"
src="https://github.com/user-attachments/assets/be1182b9-1c8d-4fdc-ab4c-1484ad74449d"
/>
### Approach
We introduce a **V2 state management layer** backed by Jotai that
mirrors the existing Recoil API, enabling component-by-component
migration without a big-bang rewrite.
#### V2 API (Jotai-backed, Recoil-ergonomic)
- `createStateV2` / `createFamilyStateV2` — drop-in replacements for
`createState` / `createFamilyState`, returning wrapper types over Jotai
atoms
- `useRecoilValueV2`, `useRecoilStateV2`, `useFamilyRecoilValueV2`, etc.
— thin wrappers around Jotai's `useAtomValue` / `useAtom` / `useSetAtom`
- A shared `jotaiStore` (via `createStore()`) passed to a
`<JotaiProvider>` wrapping `<RecoilRoot>`, also accessible imperatively
for dual-writes
#### Dual-write bridge for progressive migration
For state shared between migrated and non-migrated components, we use
**dual-write**: writers update both the Recoil atom and the Jotai V2
atom (via `jotaiStore.set()`). This avoids sync components or extra
subscriptions.
Write sites updated: `useUpsertRecordsInStore`, `useSetRecordTableData`,
`ListenRecordUpdatesEffect`, `RecordShowEffect`,
`useLoadRecordIndexStates`, `useUpdateObjectViewOptions`.
#### First migration: ChipFieldDisplay render path
- `useChipFieldDisplay` → reads `recordStoreFamilyStateV2` via
`useFamilyRecoilValueV2` (was `useRecoilValue(recordStoreFamilyState)`)
- `RecordChip` → reads `recordIndexOpenRecordInStateV2` via
`useRecoilValueV2` (was `useRecoilValue(recordIndexOpenRecordInState)`)
- `Avatar` (twenty-ui) and event handlers (`useOpenRecordInCommandMenu`)
left on Recoil — not on the render path / in a different package
#### Pattern for migrating additional state
1. Create V2 atom: `createStateV2` or `createFamilyStateV2`
2. Add `jotaiStore.set(v2Atom, value)` at each write site
3. Switch readers to `useRecoilValueV2(v2Atom)`
4. Once all readers are migrated, remove the Recoil atom and dual-writes
#### Why not jotai-recoil-adapter?
Evaluated
[jotai-recoil-adapter](https://github.com/clockelliptic/jotai-recoil-adapter)
— not production-ready (21 open issues, no React 19, forces providerless
mode, missing types). We built a purpose-built thin layer instead.
Charles Bochet
d2f8352cb8