Show and tell: OMIKAMI WALLET — a strictly read-only viem app; feedback on transports, getLogs & untrusted-data decoding welcome

[Reprisal369]

Hi wevm community

I built OMIKAMI WALLET, a non-custodial, read-only Ethereum dashboard on the
Sepolia testnet with viem 2.55.10 (+ wagmi 3.7.4, Next.js static export). It reads
balances, tokens, recent activity, and allowances and shows a transfer preview
no signing, no transactions, no first-party contracts yet.

viem-specific things I'd love a sanity check on:

• Pinned transports: I set explicit http(...) transports (Sepolia default +
  mainnet-for-ENS only) rather than relying on viem's default, so a default change
  can't silently move egress. A build-time allowlist + CSP connect-src enforce the
  same two hosts. Is this the idiomatic way to lock egress?
• getLogs paging: recent ERC-20 activity + allowances are read via getLogs
  in small sequential block ranges (free RPCs cap ranges / rate-limit), fault-
  tolerant per range. Any pitfalls in how I page / dedupe / handle partial failures?
• Untrusted on-chain data: token symbol/name strings are sanitized (bidi/zero-
  width stripped) before render; unknown token contracts are quarantined and never
  called; addresses are EIP-55 checksummed with an address-poisoning heuristic.
  Anything I'm missing in decoding/rendering log args safely?

The read-only invariant is enforced by a build gate that fails on any write/sign
action (writeContract, sendTransaction, signMessage/​TypedData, switchChain,
prepareTransactionRequest, …); transactionsEnabled is false everywhere.

Full scope, threat model, test evidence and one-page reproduction:

• Repo: https://github.com/Reprisal369/OMIKAMI-WALLET
• Tag to review: v0.5.5 (commit 1b1bbc2)
• Start here: docs/reviews/AUDIT_PACKAGE_v0.5.4.md

Small typed pnpm monorepo, pure unit-tested logic (unit 94 / e2e 38), full CI,
A+ headers, CodeQL 0 open, pnpm audit 0. Any pointers welcome - thanks for viem!

Reprisal