The Output-Centric Model: Rethinking Onchain Transactions

In traditional web commerce, when you want to buy something, you know exactly what you need to pay. You see a product for $29.99, click buy, and your payment method handles the rest. You don't start by saying "I have $30, what can I get?" Yet in crypto, we've built an entire infrastructure around the opposite approach.

Most bridges and DEXs today follow an input-first model: you specify what you have and see what you can get. This creates friction at every step of the user journey, from complex calculations to unexpected slippage to the dreaded "insufficient funds" error that sends users on wild goose chases across different chains and bridges.

It's time to flip this model on its head.

The Problem with Input-First Thinking

The current state of onchain transactions mirrors a confusing shopping experience. Imagine walking into a store, pulling out your wallet, and asking "I have $47.83 in cash, $200 on this credit card, and some loose change, what can I buy?" Instead of simply knowing that the item you want costs a specific amount and paying for it.

This input-centric approach has become the norm because of how DeFi protocols evolved. AMMs and bridges were designed around the technical constraints of blockchain infrastructure, not user experience. The result? Users face:

• Complex mental math to figure out how much input yields their desired output
• Slippage that changes their expected results mid-transaction
• Constant context switching between apps to bridge tokens
• The anxiety of not knowing if they have "enough" in the right token on the right chain

For crypto to achieve mainstream adoption, we need transactions that feel as intuitive as traditional payments.

Commerce is Output-Centric by Nature

Think about every commercial transaction you make. Whether you're buying coffee, booking a flight, or subscribing to software, you always know the price upfront. The vendor tells you exactly what you need to pay, and your payment system figures out how to fulfill that requirement.

This output-centric model works because:

• Cognitive simplicity: Users don't need to calculate what they can afford
• Price transparency: The cost is clear before committing
• Payment abstraction: The underlying complexity is hidden
• Predictable outcomes: You know exactly what you're getting

Web2 payments solved this decades ago. When you buy something online, you don't care whether the money comes from your checking account, savings, or credit line. The payment processor handles routing behind the scenes.

Crypto should work the same way.

Ready to experience seamless onchain transactions? Try Universal Bridge and see the difference output-centric design makes.

Building for Outcomes, Not Inputs

At thirdweb, we've rebuilt our approach around what users actually need: knowing the exact cost of an action and having it "just work" regardless of which tokens they hold or which chains they're on.

Universal Bridge implements an output-centric model by default. When you need to pay 100 USDC for an NFT mint on Base, but only have ETH on mainnet, you shouldn't need to:

1. Calculate exchange rates
2. Navigate to a separate bridge interface
3. Estimate gas costs across chains
4. Hope you bridge the right amount
5. Return to the original app

Instead, the system should simply say "this costs 100 USDC" and handle the conversion automatically. Behind the scenes, Universal Bridge finds the optimal route across major bridges and DEXs, but users never see that complexity.

This isn't just about convenience, it's about removing the barriers that prevent crypto from fulfilling its promise of permissionless, instant payments.

Eliminating "Insufficient Funds" Forever

One of the most frustrating experiences in crypto is the "insufficient funds" error. You know you have money, just not in the exact token on the exact chain the app requires. This artificial scarcity creates unnecessary friction.

With an output-centric approach, "insufficient funds" should only occur if you genuinely don't have enough value across all your holdings. If you need 100 USDC but have 0.05 ETH on mainnet, the system should recognize that you have sufficient value and route the transaction automatically.

This transformation eliminates the wild goose chases users currently endure:

• No more hunting for the right bridge
• No more switching between apps mid-transaction
• No more anxiety about which chain to use
• No more failed transactions due to poor route planning

The Path to Mainstream Adoption

For crypto to become the native payment layer of the internet, transactions need to feel as seamless as traditional payments. This means:

Price Certainty: Users should always know exactly what they're paying Payment Flexibility: Any token on any chain should be valid payment Automatic Routing: The system handles optimal execution behind the scenes Instant Settlement: Transactions complete without manual intervention

The infrastructure to make this possible exists today. We have sophisticated bridges, efficient DEXs, and robust cross-chain messaging protocols. What's been missing is the abstraction layer that makes these tools accessible to everyday users.

Want to eliminate transaction friction in your app? Add Universal Bridge to your app with just a few lines of code.

Beyond DeFi: Output-Centric Everything

While DeFi pioneered many onchain innovations, its input-centric design patterns don't translate well to other use cases. Consider:

• Gaming: Players want to buy in-game items for a fixed price, not calculate token ratios
• NFTs: Collectors want to purchase specific pieces, not optimize yield farming
• Subscriptions: Users expect consistent pricing, not variable token amounts
• Commerce: Merchants need predictable revenue, not fluctuating inputs

Each of these use cases benefits from output-centric design. By starting with what users want to accomplish rather than what they currently hold, we can build experiences that feel familiar while delivering crypto's unique benefits.

The Future is Multi-Chain by Default

As the blockchain ecosystem continues expanding across L2s and alt-L1s, the need for seamless interoperability only grows. Users shouldn't need to become experts in bridge mechanics or gas optimization strategies.

Output-centric design makes multi-chain usage invisible. Whether you're paying for compute on a gaming chain, collecting NFTs on a creator platform, or staking on a DeFi protocol, the experience should be consistent: see the price, confirm the action, and trust that the underlying infrastructure handles the complexity.

This approach doesn't eliminate choice for users who want control. Power users can still specify exact routes, tokens, and chains. But for the majority who simply want to complete their intended action, the system should optimize automatically.

Building the Invisible Infrastructure

The best infrastructure disappears into the background. When you send a text message, you don't think about cellular towers, routing protocols, or network operators. When you make a credit card payment, you don't consider the bank networks, fraud detection systems, or settlement processes.

Crypto infrastructure should aspire to the same invisibility. Bridges, DEXs, and cross-chain protocols should power seamless experiences without forcing users to understand their technical details.

Universal Bridge represents a step toward this vision: powerful interoperability infrastructure that works behind the scenes, surfacing only the information users actually need to make decisions.

The future of onchain payments isn't just about better technology, it's about better abstraction. By embracing output-centric design, we can finally deliver on crypto's promise of instant, permissionless payments for everyone, everywhere.