User onboarding shouldn't start with "go buy some ADA first." With Transaction Sponsorship on utxos.dev, your users can interact with your dApp without worrying about transaction fees, creating a seamless, Web2-like experience while you retain the benefits of Cardano's UTxO model. Sponorship feature gives addition to our seemless non-custodian wallet experience with social logins useful for marketplaces, gaming platforms, social apps, or enterprise solutions, sponsored transactions can dramatically reduce onboarding friction and improve user conversion. Available as a premium feature starting at $199/month, giving your project access to managed transaction sponsorship infrastructure so you can focus on building, not fee management. Remove barriers. Increase adoption. Deliver the experience users expect. Ready to offer gasless interactions on Cardano? start building the next generation of user-friendly blockchain applications.

Your brand. Our infrastructure. UTXOS white-label features: - Custom wallet UI - Your auth providers - Your domain - Your branding Users never see "UTXOS." They see you. Enterprise-grade Web3 without building from scratch.

Meet Spark: Bitcoin's Layer 2 that actually scales. UTXOS supports Spark natively: - Fast, low-cost BTC transactions - Token transfers - Same social login UX - Inherits Bitcoin security Bitcoin speed without sacrificing decentralization.

Bitcoin wallet integration in UTXOS: ✓ Native SegWit (P2WPKH) ✓ Taproot (P2TR) ✓ PSBT signing ✓ Message signing All through social login. Non-custodial. This is what Bitcoin adoption looks like.

Cardano's superpower: Native assets without smart contracts. UTXOS makes it accessible: - Manage NFTs and tokens - CIP-30 compliant - Stake delegation support - Multi-asset UTXOs Full Cardano, zero complexity.

The hidden complexity of transaction sponsorship: UTXO contention. UTXOS handles it automatically: - Consolidates dust UTXOs - Fragments large UTXOs - Chains prepare transactions - Excludes pending UTXOs You just call sponsorTx(). We do the math.

Passwords are dead. Long live passkeys. UTXOS supports WebAuthn with PRF extension: - Touch ID / Face ID as signing auth - Hardware-backed security - Phishing resistant - Better UX than passwords The future of Web3 auth is already here.

Where does signing actually happen in UTXOS? In an isolated iframe: 1. Tx sent to iframe 2. Key reconstructed in memory 3. Signature created 4. Key destroyed 5. Only signature returned Your key never touches your app's main thread.

How UTXOS keeps your keys safe: Your private key → split into 3 shards - Device Share (encrypted on your device) - Auth Share (requires valid login) - Recovery Share (for new devices) 2-of-3 needed to reconstruct. UTXOS only ever holds 1. You control 2.

"Why would I pay users' transaction fees?" Because conversion cost. Sponsorship models: - Free tier (first 10 tx/user) - Tiered (premium users unlimited) - Subsidized (partial sponsorship) Your CAC is probably higher than sponsoring 1000 transactions.

Sometimes you need to manage wallets server-side. UTXOS Developer-Controlled Wallets: - Create wallets programmatically - Sign with your Entity Secret - Keys encrypted at rest - Full API control Perfect for exchanges, custodians, and treasury management.

How does UTXOS transaction sponsorship actually work? 1. You build tx with static placeholder UTXO 2. SDK rewrites with real UTXO from your pool 3. Your wallet signs the fee input 4. User signs their inputs 5. Combined tx submitted Automatic UTXO pool management included.

Adding wallets to your app shouldn't take weeks. UTXOS integration: ``` npm install @utxos/sdk ``` That's it. Social login. Multi-chain. Non-custodial. Your users are signing transactions in 5 minutes.

Integrating 3 blockchains used to mean: - 3 different SDKs - 3 different auth flows - 3x the complexity UTXOS: One SDK for Bitcoin, Cardano, and Spark. ``` const wallet = await Web3Wallet.enable() wallet.bitcoin.signTx(...) wallet.cardano.signTx(...) wallet.spark.signTx(...) ```

"But what if UTXOS disappears?" Export your private key anytime. Standard formats. Works with any wallet. We're infrastructure, not a prison. True self-custody means you can leave whenever you want.

Lost your phone? No problem. UTXOS wallet recovery: 1. Sign in with your social account 2. Verify with passkey OR recovery answer 3. Done. Same wallet. Same keys. New device. No hunting for seed phrases. No cold sweats.

"I can't send this NFT because I don't have crypto for fees" This is why Web3 onboarding sucks. UTXOS Transaction Sponsorship: Developers pay fees on your behalf. Users transact. Devs sponsor. Friction eliminated.

With UTXOS: ✓ Sign in with Google/Discord/Apple ✓ Your keys are split using Shamir's Secret Sharing ✓ 2-of-3 shards needed to sign ✓ UTXOS never has access to your full key Non-custodial good UX. Finally.

What if your grandma could use Bitcoin without knowing what a seed phrase is? That's UTXOS. We're building the infrastructure layer that makes Web3 as simple as Web2, without sacrificing self-custody.

Why is it called UTXOS? UTXO = Unspent Transaction Output Bitcoin & Cardano use this model: your "balance" is actually a collection of unspent outputs. We built infrastructure specifically for UTXO chains. Not an afterthought. Native.