Gasless crypto tip links on Starknet. No wallet setup. No gas fees. Just a link.
starkzappypay lets anyone create a shareable payment link and receive STRK, USDC, or ETH from anyone — using only a social login (Email, Farcaster). Built on Starknet using the Starkzap SDK.
- Enter an optional username (e.g.
@alice) and your Starknet address - Add an optional message — "Buy me a coffee ☕"
- Optionally set a preferred receive token, a tip goal label, and target amount
- Hit Generate — your link is saved and ready:
/pay/@alice - Share it in your bio, Linktree, or anywhere
- Open the creator's link —
starkzappypay.vercel.app/pay/@alice - The username resolves to the creator's address automatically
- Sign in with Email or Farcaster — no seed phrase, no wallet extension
- Pick a token (STRK, USDC, ETH), enter an amount, hit Send
- If your token differs from the creator's preferred token, it's auto-swapped via AVNU
- Done — zero gas paid
| Feature | Details |
|---|---|
| Username links | /pay/@alice — clean, human-readable, globally resolvable |
| Persistent usernames | Username → address stored in Supabase, works on any device |
| Gasless transactions | AVNU Paymaster sponsors all fees — tippers never pay gas |
| Social login | Privy embedded wallet — email, Google, Apple, Twitter, Discord |
| No seed phrase | EVM embedded wallet derives a Starknet key via grindKey |
| Auto account deploy | Argent account deployed on first use, fee sponsored |
| Multi-token | STRK, USDC, ETH — tipper picks at send time |
| Token auto-swap | Tipper sends any token; creator receives their preferred token via AVNU swap |
| Wall of Tips | Live feed of supporters — name, message, amount, and Voyager link per tip |
| Top Supporters leaderboard | Tab on the tip page ranking tippers by cumulative count; drives repeat behaviour |
| Tipping streaks | Returning tippers see "You've supported @alice N times!" — gamification with no extra infra |
| QR code generation | One-click QR modal for any /pay/@username link — downloadable PNG, violet-themed |
| Auto-tweet after tipping | Post-success share prompt: pre-filled tweet with creator handle and tip link |
| Tip goals | Creator sets a goal label + target amount; progress bar fills live |
| Goal reached UX | Goal card goes green with "tips still welcome" — form stays open, no hard cap |
| On-chain proof | Every supporter entry links to Voyager for transaction verification |
| Mainnet | Deployed and running on Starknet Mainnet |
starkzappypay is built on three Starkzap modules:
Privy handles social login. After authentication, the EVM embedded wallet signs a fixed derivation message. We use ec.starkCurve.grindKey to produce a deterministic Starknet private key — no seed phrase ever exposed.
const signature = await evmProvider.request({
method: 'personal_sign',
params: ['starkzappypay: authorize my Starknet wallet', address],
})
const starkPrivKey = ec.starkCurve.grindKey(signature)
const signer = new StarkSigner(starkPrivKey)AVNU Paymaster is configured at SDK init. Every transaction is executed with feeMode: "sponsored" — users never need gas tokens.
const sdk = new StarkZap({
network: 'mainnet',
paymaster: {
nodeUrl: 'https://starknet.paymaster.avnu.fi',
headers: { 'x-paymaster-api-key': AVNU_API_KEY },
},
})
const wallet = await sdk.connectWallet({
account: { signer, accountClass: ArgentXV050Preset },
feeMode: 'sponsored',
})
await wallet.ensureReady({ deploy: 'if_needed', feeMode: 'sponsored' })Direct ERC-20 transfer executed gaslessly when no swap is needed.
const tx = await wallet.execute([{
contractAddress: token.address,
entrypoint: 'transfer',
calldata: CallData.compile({ recipient, amount: uint256.bnToUint256(amount) }),
}], { feeMode: 'sponsored' })When the tipper's selected token differs from the creator's preferred token, the flow runs as two sequential sponsored transactions to stay within AVNU paymaster simulation constraints.
Step 1 — Swap: fetch a fresh quote from AVNU v3, build calldata with includeApprove: true, execute approve + swap. USDC lands in the sender's wallet. Wait for confirmation.
Step 2 — Transfer: send the received USDC to the creator's address.
// Step 1: approve + swap (USDC → sender wallet)
const swapCalls = await buildSwapCalls(quote.quoteId, wallet.address)
const swapTx = await wallet.execute(swapCalls, { feeMode: 'sponsored' })
await provider.waitForTransaction(swapTx.hash)
// Step 2: transfer USDC to creator
const minReceived = (BigInt(quote.buyAmount) * BigInt(995)) / BigInt(1000)
await wallet.execute([{
contractAddress: USDC_ADDRESS,
entrypoint: 'transfer',
calldata: CallData.compile({ recipient: creatorAddress, amount: uint256.bnToUint256(minReceived) }),
}], { feeMode: 'sponsored' })| Token | Decimals | Mainnet Address |
|---|---|---|
| STRK | 18 | 0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d |
| USDC | 6 | 0x053c91253bc9682c04929ca02ed00b3e423f6710d2ee7e0d5ebb06f3ecf368a8 |
| ETH | 18 | 0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7 |
- The Starknet wallet address shown in the app is derived from your Privy EVM signature — it is a fresh address separate from your existing Argent or Braavos wallet
- Fund this address from your main Starknet wallet before tipping
- Usernames are stored in Supabase and resolve globally — any device, any browser
- The AVNU API key is included in the frontend bundle — for production, proxy paymaster requests through a backend endpoint
- Tip goal progress is calculated from the
tipstable using the creator's preferred token — tips logged after a swap correctly record the received token, not the sent token
- Starkzap SDK — wallet + paymaster + DeFi modules for Starknet
- Privy — embedded wallets and social auth
- AVNU — DEX aggregator (swap v3 API) and paymaster on Starknet
- Supabase — username → address storage and tips feed
- starknet.js — Starknet JavaScript library
- Voyager — Starknet block explorer (linked per tip)
- Wall of Tips — live supporter feed with names, messages, amounts
- Top Supporters leaderboard — tab ranking tippers by cumulative tip count
- Tipping streaks — returning tippers see personalised "N times" banner
- QR code generation — one-click modal with violet-themed PNG download
- Auto-tweet after tipping — pre-filled tweet prompting followers to tip the same creator
- Tip goals — creator-set targets with live progress bar
- Goal reached UX — green card, "tips still welcome" message, no hard cap
- Token auto-swap — AVNU v3 two-step sponsored swap flow
- On-chain proof — every supporter links to Voyager transaction
- Fixed USDC contract address to canonical Circle USDC on Starknet mainnet
- Fixed AVNU swap to use v3 API with correct
{ calls }response shape
- Username links (
/pay/@username) - Social login via Privy (Email, Google, Apple, Twitter, Farcaster)
- Gasless STRK / USDC / ETH transfers via AVNU Paymaster
- Auto Argent account deploy on first use
MIT — free to use, fork, and build on.
Built for the Starkzap Builder Program · Starknet Mainnet · March 2026