Errors

The SDK never answers “no” with a null. When a quote, a transaction or a route cannot be used, you get an error whose class and message say why. Check errors with instanceof, not by matching messages.

From @anywalletkit/core

Error	When	Extra fields
InsufficientFundsError	The account cannot cover amount + fee	required, available (base units)
NetworkError	An RPC or API call failed	provider (the endpoint)
UserRejectedError	An external signer or your confirm policy declined
SignerError	The signer cannot sign: disposed, wrong curve, unsupported scheme
ReadOnlyAccountError	A write method was called on a read-only account
NotImplementedError	A protocol module does not implement an optional method

From @anywalletkit/kit

Error	When	Extra fields
PolicyViolationError	A policy refused the write	policy: 'maxFee', 'allowlist' or 'blocklist'

From chain and protocol packages

Each package adds errors for its own refusals: a simulation that would revert, a fee above the configured cap, an unsafe transaction shape, a swap quote that expired or whose route changed. They are listed in each package’s API reference.

import { InsufficientFundsError, UserRejectedError } from '@anywalletkit/core'
import { PolicyViolationError } from '@anywalletkit/kit'

try {
  await account.transfer({ recipient, amount })
} catch (e) {
  if (e instanceof UserRejectedError) return // the user cancelled: say nothing
  if (e instanceof InsufficientFundsError) return showTopUp(e.required - e.available)
  if (e instanceof PolicyViolationError) return showBlocked(e.policy)
  throw e
}