Flashloans

Flashloans let you borrow tokens from a lending protocol without upfront collateral, execute a series of DeFi actions, and repay the debt — all within a single atomic transaction. If any step fails, the entire transaction reverts and no tokens are moved.

Flashloans are only available through the Bundle API. They are not available via the /route endpoint.

How Flashloans Work

You submit a /bundle request containing a flashloan action with callback actions
The API compiles the bundle into a single transaction
When executed, the FlashloanAdapter requests a flash borrow from the lending protocol
The lending protocol transfers the borrowed tokens to the wallet
The callback actions execute sequentially (swaps, deposits, borrows, etc.)
The borrowed amount plus any protocol fee is repaid to the lending protocol
The transaction completes — or reverts entirely if repayment cannot be satisfied

Flashloans are atomic: if any callback action fails or the repayment cannot be satisfied, the entire transaction reverts and no tokens are moved.

Parameters

Parameter	Type	Description	Required
`flashloanToken`	`string`	Address of the token to flash borrow	Yes
`flashloanAmount`	`string`	Amount to flash borrow in wei (with full decimals)	Yes
`tokenIn`	`string[]`	Addresses of additional tokens provided by the user as input	No
`amountIn`	`string`	Amount of `tokenIn` provided by the user in wei	No
`tokenOut`	`string[]`	Addresses of tokens expected as output after callback execution	No
`callback`	`Action[]`	Array of actions to execute after receiving the flash-borrowed tokens	Yes
`receiver`	`string`	Address to receive output tokens if not the caller	No

The callback actions must produce enough tokens to repay the flash-borrowed amount plus any protocol fee. If repayment cannot be satisfied, the entire transaction will revert.

Supported Protocols

Enso automatically selects the optimal flashloan source based on chain, token, and fee. The following lending protocols are supported:

Protocol	Slug	Fee
Morpho	`morpho`	0%
Bend (Morpho fork)	`bend`	0%
Dolomite	`dolomite`	0%
Aave V3	`aave-v3`	Dynamic (pool-specific, basis points from `FLASHLOAN_PREMIUM_TOTAL`)
Hyperlend (Aave V3 fork)	`hyperlend`	Dynamic (pool-specific)
Balancer V3	`balancer-v3`	Pool-specific fee
Uniswap V3	`uniswap-v3`	Pool-specific fee (0.05%, 0.3%, or 1% depending on pool tier)
Kodiak (Uniswap V3 fork)	`kodiak`	Pool-specific fee

Chain Availability

Not all flashloan protocols are deployed on every chain. The table below shows which protocols are available on each supported chain.

Chain	Aave V3	Morpho	Balancer V3	Dolomite	Uniswap V3
Ethereum	✅	✅	✅	✅	✅
Arbitrum	✅	✅	✅	✅	✅
Base	✅	✅	✅	✅	✅
HyperEVM	✅ (Hyperlend)	✅	✅	❌	❌
Optimism	✅	✅	❌	❌	✅
Polygon	✅	✅	❌	❌	✅
Berachain	❌	✅ (Bend)	❌	✅	✅ (Kodiak)
Sonic	✅	✅	❌	❌	❌
Binance	✅	❌	❌	❌	✅
Avalanche	✅	❌	❌	❌	❌
Plasma	✅	❌	❌	❌	❌
Ink	❌	❌	❌	✅	❌
Unichain	❌	✅	❌	❌	❌
World	❌	✅	❌	❌	✅
Soneium	❌	✅	❌	❌	❌
Plume	❌	✅	❌	❌	❌
Katana	❌	✅	❌	❌	❌
Monad	❌	✅	❌	❌	❌

Where a variant is noted (e.g. Hyperlend, Bend, Kodiak), the flashloan uses a fork or alternative deployment of the underlying protocol on that chain.

Routing Strategies

Flashloans are supported across three routing strategies. Each strategy uses a dedicated adapter contract:

Strategy	Description	Adapter Contract
`ensowallet-v2`	Smart contract wallet — tokens stay in the user’s wallet	EnsoWalletFlashloanAdapter
`router`	EOA via EnsoRouter — intermediate tokens held by the router	EnsoRouterFlashloanAdapter
`safe`	Gnosis Safe multisig wallet	EnsoSafeFlashloanAdapter

See the Routing Strategies reference for details on choosing a strategy.

Example: Leveraged Position on Bend

This example flash borrows HONEY on Berachain, swaps it to iBGT, deposits iBGT as collateral on Bend, and borrows HONEY against it to repay the flashloan — creating a leveraged iBGT position in a single transaction.

const fromAddress = "0x0125fAd1eBaF67Fb529BdEd12a7e68213994A2b8";

const bundle = await client.getBundleData(
  {
    chainId: 80094,
    fromAddress: fromAddress,
    routingStrategy: "ensowallet-v2",
    receiver: fromAddress,
    spender: fromAddress,
  },
  [
    {
      protocol: "bend",
      action: "flashloan",
      args: {
        flashloanToken: "0xFCBD14DC51f0A4d49d5E53C2E0950e0bC26d0Dce", // HONEY
        flashloanAmount: "26939472318660971",
        tokenIn: ["0x2f6f07cdcf3588944bf4c42ac74ff24bf56e7590"], // iBGT
        amountIn: "104715952583368",
        tokenOut: ["0xfcbd14dc51f0a4d49d5e53c2e0950e0bc26d0dce"], // HONEY
        callback: [
          {
            protocol: "enso",
            action: "route",
            args: {
              tokenIn: ["0xfcbd14dc51f0a4d49d5e53c2e0950e0bc26d0dce"], // HONEY
              tokenOut: ["0x2f6f07cdcf3588944bf4c42ac74ff24bf56e7590"], // iBGT
              amountIn: "26939472318660971",
              slippage: 50,
            },
          },
          {
            protocol: "enso",
            action: "balance",
            args: {
              token: "0x2F6F07CDcf3588944Bf4C42aC74ff24bF56e7590", // iBGT
            },
          },
          {
            protocol: "bend",
            action: "deposit",
            args: {
              primaryAddress: "0x24147243f9c08d835C218Cda1e135f8dFD0517D0",
              positionId:
                "0x1f05d324f604bd1654ec040311d2ac4f5820ecfd1801a3d19d2c6f09d4f7a614",
              tokenIn: ["0x2f6f07cdcf3588944bf4c42ac74ff24bf56e7590"], // iBGT
              amountIn: { useOutputOfCallAt: 1 }, // iBGT balance from step 2
              onBehalfOf: "0x0125fAd1eBaF67Fb529BdEd12a7e68213994A2b8",
            },
          },
          {
            protocol: "bend",
            action: "borrow",
            args: {
              primaryAddress: "0x24147243f9c08d835C218Cda1e135f8dFD0517D0",
              positionId:
                "0x1f05d324f604bd1654ec040311d2ac4f5820ecfd1801a3d19d2c6f09d4f7a614",
              collateral: "0x2F6F07CDcf3588944Bf4C42aC74ff24bF56e7590", // iBGT
              tokenOut: ["0xfcbd14dc51f0a4d49d5e53c2e0950e0bc26d0dce"], // HONEY
              amountOut: "26939472318660971", // Repay flashloan amount
              onBehalfOf: "0x0125fAd1eBaF67Fb529BdEd12a7e68213994A2b8",
            },
          },
        ],
      },
    },
  ]
);

What’s happening step by step:

Flash borrow — Borrow HONEY from Bend with zero fee (Morpho-based protocol)
Route — Swap the borrowed HONEY to iBGT via Enso’s optimal routing with 0.5% slippage
Balance — Check the iBGT balance in the wallet (needed for dynamic amount referencing)
Deposit — Deposit all iBGT as collateral into Bend’s lending pool, using useOutputOfCallAt: 1 to reference the balance from step 3
Borrow — Borrow HONEY against the deposited iBGT collateral to repay the flashloan

Use useOutputOfCallAt within callbacks to dynamically chain action outputs. This is essential when exact amounts are unknown at request time (e.g., swap output amounts). See Chaining Actions for details.

More Examples

Additional flashloan examples are coming soon:

Collateral swap — Replace one collateral type with another without closing the position
Debt refinancing — Move a lending position from one protocol to another

Updated

Get Started

Examples

Reference

How Flashloans Work

Parameters

Supported Protocols

Chain Availability

Routing Strategies

Example: Leveraged Position on Bend

More Examples

Get Started

Examples

Reference

​How Flashloans Work

​Parameters

​Supported Protocols

​Chain Availability

​Routing Strategies

​Example: Leveraged Position on Bend

​More Examples

How Flashloans Work

Parameters

Supported Protocols

Chain Availability

Routing Strategies

Example: Leveraged Position on Bend

More Examples