Configuration

Build the configuration at the application boundary with defineSeamsConfig, or seamsTestnetConfig for the NEAR and Tempo testnets. Both take the values a wallet cannot start without and default everything else, and both make those values required at the type level:

import { seamsTestnetConfig } from '@seams/wallet/react';

const config = seamsTestnetConfig({
  walletOrigin: import.meta.env.VITE_WALLET_ORIGIN,
  relayerUrl: import.meta.env.VITE_RELAYER_URL,
  publishableKey: import.meta.env.VITE_SEAMS_PUBLISHABLE_KEY,
});

SeamsConfigsInput remains available for a hand-built object; every field on it is optional, so prefer the helpers unless you are constructing a partial config for a custom runtime.

Hosted wallet branch

Use iframeWallet for the isolated wallet origin. Set the HTTPS walletOrigin; keep walletServicePath and sdkBasePath aligned with the assets deployed at that origin. rpIdOverride changes credential scope and needs an explicit security review.

Registration branch

Managed registration requires the publishableKey issued for the current origin. The key identifies the environment on its own — its record carries the environment it belongs to, and the Router API builds the runtime policy scope from the authenticated key.

projectEnvironmentId is an optional cross-check. Supply it when one build can be pointed at staging or production by configuration: a key belonging to a different environment is then rejected instead of silently working.

Keep environment identities public and keep server or custody secrets outside browser configuration.

Network branch

Each chain record selects one supported network; rpcUrl and explorerUrl are optional and fall back to the SDK defaults, which carry working testnet endpoints and RPC failover for NEAR. EVM-family chains also need their numeric chain identity.

Signing names a chain from this configuration by network slug. The RPC endpoint used at execution time is resolved from the configured chain, never from the signing call.

Relayer branch

Configure the relayer only when the chosen registration or relay flow uses it. The app URL identifies the service; request authentication and custody secrets stay at the server boundary.

Leave relayerAccount unset. It is the NEAR parent under which the Router API creates named subaccounts (alice becomes alice.<relayerAccount>) and the postfix the account-name input displays — not a delegated-signing credential. Unset, the SDK discovers it from the relayer's /healthz response, so it always matches the server. Setting it pins a value and skips that discovery, in which case it must match.

Appearance branch

Initial appearance belongs in configuration. Use setAppearance for runtime theme changes. Keep the app-owned React theme and wallet-owned iframe appearance on the same semantic palette.

See environment variables for the browser and server ownership split.