# Step 7 — Wallet API

1. **wallet-api repo** — If Ethereum family already supports multiple chainIds, add **138** to validation and routing. Otherwise use:
   - **validation.ethereum-chain138.ts** — Zod schema allowing chainId 138.
   - **types.ethereum-chain138.ts** — Transaction types.
   - **serializer.ethereum-chain138.ts** — Serialize/deserialize for JSON-RPC.
   - In `packages/core/src/families/common.ts` ensure `FAMILIES` includes the family; in `validation.ts` and `serializer.ts` add the new type to the union.
2. **ledger-live repo** — Bump `@ledgerhq/wallet-api-core`, `-server`, `-client`. Add or extend **walletApiAdapter.chain138.ts** in `libs/ledger-live-common/src/families/ethereum/walletApiAdapter.ts` so WalletAPI transactions with chainId 138 map to LL transactions. Do not edit the generated `generated/walletApiAdapter.ts` by hand; add the source adapter and run the sync-families-dispatch script.
3. **Changelog** — `pnpm changelog`, create changeset for `@ledgerhq/wallet-api-core` (minor), open PR.