useMintUnderlying
Mint standard (non-confidential) ERC-20 test tokens (TTT) to a recipient.
@tokenops/sdk/testnet-faucet/react{ mutate, mutateAsync, isPending, error, data }Description
Mint standard (non-confidential) ERC-20 test tokens (TTT) to a recipient.
Open and permissionless on testnet. Use this when you want plain TTT — e.g.
to then approve + wrap it into CTTT through the standard ERC-7984 flow.
Delegates 1:1 to TestnetFaucetClient.mintUnderlying.
Mutations do NOT auto-invalidate read queries. After a successful mint, invalidate every faucet query for fresh balances:
const queryClient = useQueryClient();
const mint = useMintUnderlying();
mint.mutate({ amount: 1_000_000_000_000_000_000_000n }, {
onSuccess: () => {
queryClient.invalidateQueries({ queryKey: ["tokenops-sdk", "testnet-faucet"] });
},
});Signature
function useMintUnderlying(options?: BaseHookOptions): UseMutationResult<MintUnderlyingResult, Error, UseMintUnderlyingArgs>;Parameters
Shape of the object you pass to .mutate(args) is the SDK type UseMintUnderlyingArgs. Inspect the type for the full shape (discriminated unions collapse to a tagged variant at call time).
Example
const mint = useMintUnderlying();
mint.mutate({ amount: 1_000_000_000_000_000_000_000n }); // 1,000 TTT (18-decimal units)
// mint.data → { hash, to, amount }Pulled directly from the hook's TSDoc block — the same snippet your IDE shows on hover.
Errors
This mutation can reject with SDK-level, product-level, or generic-fallback errors. Product classes carry the offending value as fields — render them inline instead of a generic "transaction failed." See Testnet Faucet › Errors for the per-class recovery table.
Invalidation recipe
After this mutation succeeds, invalidate the queries it affects so consumer UI re-fetches fresh state. The SDK never auto-invalidates — that's a consumer decision (different apps cache different shapes).
import { useQueryClient } from "@tanstack/react-query";
const queryClient = useQueryClient();
const mintUnderlying = useMintUnderlying(/* options */);
mintUnderlying.mutate(args, {
onSuccess() {
// Coarse invalidation: refresh every cached read on this product surface.
queryClient.invalidateQueries({
queryKey: ["tokenops-sdk", "testnet-faucet"],
});
},
});See also
Other Write hooks in testnet faucet: