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Fuse turns multi-step DeFi flows — approve → swap → bridge → deposit — into one user-facing signature. You describe the outcome you want; a solver picks the route and settles it.
In code, Fuse features are still named Zap* — getZapQuote, signGaslessDzapUserIntent, /v1/bundle. Public docs use Fuse.

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What it solves

Without Fuse, putting USDC on Arbitrum into a USDC/ETH LP on Base looks like this:
  1. User signs approval for USDC
  2. User signs swap (USDC → bridged USDC)
  3. User signs bridge (Arbitrum → Base)
  4. …waits for bridge settlement…
  5. User signs swap (USDC → 50/50 USDC/WETH)
  6. User signs LP deposit
Six signatures. With Fuse: one. The solver handles the choreography.

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When to use Fuse

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How it works

1

Quote the intent

getZapQuote() → bundle of steps + estimated output.
2

Build the bundle

buildZapTxn() → transaction calldata for the entire bundle.
3

Sign once

Either: standard transaction (user pays gas) — zap(). Or: gasless EIP-712 intent — signGaslessDzapUserIntent().
4

Solver settles

Steps execute atomically where possible, with cross-chain hops settled by the relayer.
5

Track

getZapTxnStatus() returns step-level status.

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Next steps

Intents

Intent format, EIP-712 types, lifecycle.

Execution flow

User → solver → settlement.

Bundle

Composing multi-step intents.

Gasless

signGaslessDzapUserIntent flow.
Last modified on May 4, 2026