A cross-chain tip and donation widget lets anyone pay you in any token on any chain and settles the value to USDC in your wallet, with every swap tagged to your LI.FI integrator id. You build it by embedding the LI.FI Widget in a small web app, locking the destination token to USDC, passing your integrator string, and optionally taking a small fee on volume. It is one of the cleanest beginner builds in DeFi because it ships a real, useful product in a weekend and produces on-chain proof that you can wire up cross-chain infrastructure.
What you are building and who it is for
The product is a single-page tip jar. A supporter lands on your page, connects a wallet, picks whatever token they already hold (ETH on Base, USDT on Arbitrum, a memecoin on Solana if you enable it), and sends you a tip. Under the hood, LI.FI routes that token through the best bridge and DEX combination and delivers USDC to your receiving address on the chain you choose. The sender never has to bridge manually or hold the "right" token first.
This is for creators, open-source maintainers, streamers, DAO contributors, and small nonprofits who want donations without forcing donors into a specific chain or asset. It is also for you, the developer, as a portfolio piece. LI.FI reports support for a large and growing set of chains (its widget material cites 60+ chains), so the same 200 lines of code work across ecosystems.
Why this positions you as an onchain developer
Airdrop teams and grant reviewers look for developers who have actually integrated real infrastructure, not just clicked through a testnet faucet. A working LI.FI integration shows three concrete skills at once: cross-chain routing, DEX aggregation, and wallet UX. Because every route you send carries your integrator id, you also generate a verifiable on-chain trail of volume attributed to your build. That is exactly the kind of measurable, attributable activity that separates a real builder from a farmer.
LI.FI is multichain by design, so this single project demonstrates competence across Ethereum L2s and other ecosystems rather than tying you to one chain's narrative. If you later want to specialize, you already have a live cross-chain app to point to.
The build path and stack
Keep the stack boring and shippable.
Core stack
- Next.js or Vite plus React for the frontend
- The official LI.FI Widget npm package for the swap and bridge UI
- A wallet connector the widget is tested against (RainbowKit, Reown AppKit, Privy, Dynamic, or ConnectKit)
- Your own receiving wallet address for USDC
Step by step
- Sign up in the LI.FI partner portal, create an integration, and get a free API key plus your integrator string. This is where fees, if any, are configured and collected.
- Install the LI.FI Widget package and drop the component into a page. No backend is required for the core flow, since the widget requests quotes and executes routes client-side.
- Configure the destination. Use the widget's allow and deny options plus default token and chain settings to preselect USDC as the destination token and your preferred settlement chain. This is what turns a generic swap box into a tip jar that always lands in USDC.
- Pre-fill your receiving address so tips settle to you, not to the connected sender.
- Pass your integrator id so every route is attributed to your build. LI.FI's fee model lets you optionally take a percentage of volume by passing a fee parameter (a float, where 0.02 means 2%). Collected fees are tracked per integrator and withdrawn through LI.FI's integrator endpoints. For a donation tool you may want zero fee, and that is a legitimate choice.
- Theme it to match your brand, add a short "why I am raising" blurb, and deploy.
Later you can add a thank-you message on success, a running total pulled from an indexer, or an allowlist of tokens to keep the UI clean.
Common pitfalls
- Fee percentage confusion. The fee parameter is a decimal fraction, not a whole percent. 0.02 is 2%, not 0.02%. Double check before you go live.
- Destination not locked. If you leave the destination token open, a distracted donor can accidentally send you a volatile token instead of USDC. Lock the to-token.
- Wrong receiving address or chain. Confirm your USDC address on the exact settlement chain. USDC exists on many chains and they are not interchangeable.
- Slippage and small tips. Cross-chain routes have gas and bridge costs. A $2 tip through several hops can be uneconomical. Surface a sensible minimum.
- Assuming fees auto-appear. Fees accrue to your integrator account and must be withdrawn through the documented endpoints. They do not stream into your wallet automatically.
- Wallet connector mismatch. Use a connector the widget is tested against to avoid subtle signing bugs.
- Treating uncertain facts as fixed. LI.FI updates chain counts, supported bridges, and portal flows regularly. Verify current specifics in the official docs before you ship, rather than trusting a number you read months ago.
How DEPLOYR builds and ships this with you
DEPLOYR exists to make you the real onchain developer that teams look for, and this widget is a perfect first shipped project. We help you scope the build, wire the LI.FI Widget with your own integrator id and USDC settlement, connect a wallet layer, and get it live on a storefront you own. The code is yours, the integrator id is yours, and the on-chain trail points to you.
Start at /build to plan the project, browse /hackathons if you want to ship it against a deadline, and read /insights for more cross-chain build ideas. When you are ready to launch and show it off, the DEPLOYR store at / turns the finished widget into a public proof of work.
Ship the tip jar, and you have a live, attributable cross-chain app to your name. One honest note: airdrops are never guaranteed, and no build, however clean, entitles you to a payout. Build it because it makes you a better, more visible developer, and let any upside be a bonus.