Fuel Any Chain

Fuel Any Chain.
With Any Token.

NexaFuel lets wallets and dApps top up user gas balances instantly using cross-chain liquidity.

SwapGas Top-Up

BASEBase→

SOLPay with SOL0.052 SOL

Built for wallet teams

Wire NexaFuel into your existing UI. Detect low balances, surface a single CTA, and hand off the swap, bridge, and funding steps to us.

Drop-in gas top-ups

Surface a single CTA when a wallet lacks native funds. We handle swaps, bridging, and settlement behind the scenes.

SDK or REST

Use the TypeScript helper for EIP-1193 wallets or hit the /gas endpoints directly from any backend.

Risk controls

Route limits, webhook callbacks, and detailed status polling help you keep users informed at every step.

< 3 min

SOL → ETH settlement

4 steps

Quote · Execute · Confirm · Fund

5+ chains

Base, Arbitrum, Polygon, BSC, more

How the API works

The core flow mirrors what you saw in Backpack. Quote the SOL cost, execute when the user accepts, confirm their Solana signature, then poll or listen for the funding webhook.

QuotePOST /gas/quote with the user’s Solana pubkey and target chain. We respond with SOL cost, ETA, and routeId.

ExecutePOST /gas/execute when the user accepts. We return a base64 Solana transaction for your signer to broadcast.

ConfirmSend the signature via /gas/confirm-solana and poll /gas/status/{opId} or subscribe to webhooks.

Docs & Sandbox

Ship faster with the OpenAPI spec, TypeScript SDK, and local test harnesses. The demo gateway mirrors production endpoints so you can test without live liquidity.

Start with the API

REST-first design means any wallet can integrate. Use your own signer, custodial backend, or the provided helpers for Backpack and EIP-1193 providers.

curl

curl -X POST https://api.nexafuel.dev/gas/quote   -H "Content-Type: application/json"   -H "X-API-Key: YOUR_KEY"   -d '{
    "src": {"chain": "solana", "token": "SOL"},
    "dst": {"chain": "base", "native": "ETH", "targetAmountNative": "0.003"},
    "user": {"solanaPubkey": "...", "evmAddress": "0x..."},
    "mode": "fast"
  }'

Testing stack

Spin up Redis, MongoDB, and the worker streams with make up. Webhooks replay automatically so you can see every state change.

Explore documentation

Early access for wallet teams

Join the private beta to get a dedicated Slack channel, mock credentials, and guided integration support. We prioritise teams enabling gasless onboarding and cross-chain swaps.

Fuel Any Chain. With Any Token.