`[Performance] TransactionHistory fetches Stellar payments on every render with no cache or request deduplication`

[cybermax4200]

Why this matters now

TransactionHistory is rendered inside WalletScreen, which itself remounts on every tab switch. Each mount issues a getPayments() call to the Horizon API with no check for a cached result. On a slow 3G connection (the target environment) this produces visible layout flicker, unnecessary data usage, and redundant Horizon load. With multiple Horizon requests in-flight from other wallet balance calls, this compounds the existing sequential fetch problem.

Problem / What

src/components/TransactionHistory.tsx fetches on every render:

useEffect(() => {
  void load();
}, [publicKey]);   // fires on every WalletScreen mount

There is no local cache, no staleness check, and no deduplication. getPayments is a pure Horizon API call with no memoization. The component holds payments purely in useState, so nothing survives a remount.

The fix should cache payments in walletStore (which is already MMKV-persisted) alongside a paymentsLastFetchedAt timestamp, and skip the Horizon call when the cache is fresh (< 60 s).

Key Challenges

• walletStore must gain payments, paymentsLastFetchedAt, and setter actions without breaking existing partialize behavior (once Issue 7 is resolved, or in coordination with it).
• The 60-second TTL should be a named constant and tested.
• The cache must be invalidated after a sendTokens success (so a freshly sent payment appears immediately).
• TransactionHistory.tsx should expose a refresh affordance so the user can manually bust the cache.

Acceptance Criteria

• TransactionHistory reads from walletStore instead of fetching on every mount.
• A Horizon fetch is only issued when the cache is absent or older than PAYMENTS_CACHE_TTL_MS (default 60 s).
• SendTokensScreen calls a refreshPayments action after a successful submission.
• Tests: (a) no second Horizon call within TTL, (b) cache busted after sendTokens, (c) manual refresh triggers a fresh call.

Relevant files / functions

• src/components/TransactionHistory.tsx
• src/store/walletStore.ts — add payments, paymentsLastFetchedAt, setPayments
• src/screens/SendTokensScreen.tsx — call refreshPayments on success
• src/services/stellar.ts — getPayments

Out of scope

• Pagination of the payments list (the current limit=10 default is acceptable for now).
• Real-time streaming via Horizon SSE.

[Jerry-Tekh]

Hello manager. i will implement the required fix. Plasee get me assigned to this issue and i will get it done correctly. thank you .

[grantfox-oss]

🦊 GrantFox — @Jerry-Tekh has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #126)
2. Your PR will be reviewed by the ecotask-network maintainers

Good luck! Track your progress on GrantFox.