Transaction Sponsorship
Transaction sponsorship is a service that lets you pay blockchain network fees on behalf of your users. By covering gas costs from a developer-controlled wallet, you remove the biggest barrier to Web3 adoption: requiring users to own cryptocurrency before they can interact.
Why do transaction fees block adoption?
Network fees create significant friction for new users:
- A user wants to mint an NFT on your platform
- At checkout, they discover an unfamiliar fee payable only in a cryptocurrency they do not own
- They must find an exchange, pass KYC, purchase tokens, and transfer them to their wallet
- Most users abandon at this point
This is like asking someone to pay for shipping in a currency they have never heard of, with no instructions on how to get it.
How does sponsorship work?
With transaction sponsorship, you cover network fees from a developer-controlled wallet. Your users sign transactions without holding any native tokens. The result: a checkout experience as smooth as any traditional Web2 application.
Sponsorship works with both UTXOS user-controlled wallets and external CIP-30 browser wallets.
Key Benefits
| Benefit | Description |
|---|---|
| Zero-friction onboarding | Users transact immediately without acquiring tokens first |
| Higher conversion rates | Remove the drop-off point where users abandon due to fee complexity |
| Predictable costs | Control and budget your sponsorship spend through the dashboard |
| Automated UTXO management | The SDK handles UTXO creation, selection, and consolidation automatically |
Supported Chains
| Chain | Status | Native Token |
|---|---|---|
| Cardano | Available | ADA |
| Bitcoin | Coming Soon | BTC |
| Spark | Coming Soon | SPARK |
How It Works
- Create a sponsorship in the UTXOS dashboard
- Fund the sponsorship wallet with native tokens
- Build transactions using static placeholder inputs from the SDK
- Submit for sponsorship and the SDK swaps in real UTXOs and signs
- User signs and submits the final transaction
The SDK handles all UTXO management, including automatic pool maintenance and contention avoidance.
Quick Start
import { Web3Sdk } from "@utxos/sdk";
const sdk = new Web3Sdk({
projectId: process.env.NEXT_PUBLIC_UTXOS_PROJECT_ID,
apiKey: process.env.UTXOS_API_KEY,
network: "testnet",
privateKey: process.env.UTXOS_PRIVATE_KEY,
fetcher: provider,
submitter: provider,
});
// Get placeholder inputs for transaction building
const staticInfo = sdk.sponsorship.getStaticInfo();
// Build your transaction with staticInfo.changeAddress and staticInfo.utxo
// Then sponsor and submit
const result = await sdk.sponsorship.sponsorTx({
sponsorshipId: "your_sponsorship_id",
tx: unsignedTransaction,
});Next Steps
Frequently asked questions
Does sponsorship work with external wallets?
Yes. Sponsorship works with both UTXOS user-controlled wallets and external CIP-30 browser wallets like Nami, Eternl, or Lace.
How much does sponsorship cost?
You fund the sponsorship wallet with your own ADA. UTXOS does not charge a fee on top of network fees. Your only cost is the actual blockchain transaction fee (typically under 0.5 ADA).
Can I limit how much I sponsor per user?
Yes. Implement per-user limits, daily caps, and transaction-type restrictions in your application logic. The SDK gives you full control over sponsorship rules.