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Overview

If you run a wallet or super app, Sprinter Credit lets your users borrow USDC against their existing holdings — ETH, stETH, wstETH — without selling. Users lock collateral, get a credit line, and spend or transfer USDC while their assets stay productive. Your wallet already has the signer. Sprinter provides the credit engine — you just execute the calldata it returns.
Without SprinterWith Sprinter
User sells ETH to get USDCUser locks ETH, draws USDC — keeps ETH exposure
stETH sits in wallet earning yield but illiquidstETH earns yield and backs a spendable credit line
User bridges to get stablecoins on another chainCross-chain collateral — one credit line, any chain
No spending power without sellingInstant USDC credit against existing portfolio
Every Sprinter endpoint returns { calls: ContractCall[] } — unsigned transaction calldata. Your wallet signs and submits. No custody handoff.

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What You Need from Sprinter

Your wallet handlesSprinter handles
Wallet UX, account managementCollateral locking & credit line activation
Transaction signing & submissionUSDC credit draws to any receiver address
Portfolio display, balance trackingHealth factor monitoring, LTV enforcement
Network switching, gas estimationEarn vaults (collateral earns yield while locked)
User authenticationRepayment & collateral unlock

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Supported Collateral

Users can lock assets they already hold. Each asset has its own LTV based on its risk profile:
AssetLTVCollateral TierNotes
ETH80%Raw volatileNative ETH — highest liquidity
stETH75%Volatile DEX-swapLido staked ETH — earns staking yield while locked
wstETH75%Volatile DEX-swapWrapped stETH — same yield, no rebase
USDC90%Raw stablecoinStablecoin — highest LTV
Use GET /credit/protocol to fetch the latest supported assets and LTVs. See Supported Assets for the full list and collateral tier framework.

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Integration

1

User Locks Collateral

When a user wants to borrow, they lock collateral from their wallet. The API returns calldata — your wallet signs and submits.
# Lock 1 ETH as collateral on Base
curl -X GET 'https://api.sprinter.tech/credit/accounts/0xUSER/lock?amount=1000000000000000000&asset=0xETH_ADDRESS'
Returns { calls: ContractCall[] } — present to the user for signing. Once confirmed, the credit line is active.
2

Show Credit Position

After locking, display the user’s credit position in your wallet UI.
curl -X GET https://api.sprinter.tech/credit/accounts/0xUSER/info

{
  "data": {
    "USDC": {
      "totalCreditCapacity": "2400.00",
      "remainingCreditCapacity": "2400.00",
      "totalCollateralValue": "3000.00",
      "principal": "0",
      "interest": "0",
      "healthFactor": "Infinity",
      "dueDate": null
    }
  }
}
Key fields to surface in your UI:
FieldWhat to show
remainingCreditCapacityAvailable to borrow
totalCollateralValueTotal locked collateral value
principal + interestOutstanding debt
healthFactorPosition health (warn below 1.5, danger below 1.2)
dueDateRepayment deadline
3

User Draws USDC

When the user wants to borrow, draw USDC to any address — their own wallet, a merchant, a DEX, another wallet.
curl -X GET 'https://api.sprinter.tech/credit/accounts/0xUSER/draw?amount=500000000&receiver=0xRECEIVER'
ParameterDescription
accountUser’s wallet address (borrower)
amountUSDC amount (6 decimals — $500 = 500000000)
receiverAny address — user’s wallet, merchant, protocol
Returns { calls: ContractCall[] } — user signs, USDC is delivered.
A 0.50% origination fee is deducted from each draw. See Fees.
4

Repay & Unlock

Users repay debt to free their collateral. Anyone can repay on behalf of any account.
# Check outstanding debt
curl -X GET https://api.sprinter.tech/credit/accounts/0xUSER/info

# Repay
curl -X GET 'https://api.sprinter.tech/credit/accounts/0xUSER/repay?amount=500000000'

# Unlock collateral
curl -X GET 'https://api.sprinter.tech/credit/accounts/0xUSER/unlock?amount=1000000000000000000&asset=0xCOLLATERAL'
Credit runs on a 30-day billing cycle with a 7-day grace period. See Fees.

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UX Patterns

If your wallet supports in-app payments, Sprinter Credit lets users pay with USDC drawn against their ETH/stETH — no selling required.Flow:
  1. User initiates a payment within your wallet
  2. Your app checks if the user has a Sprinter credit line with sufficient capacity
  3. If yes — draw USDC to the merchant/recipient via /draw
  4. User signs one transaction (the draw), payment is settled
  5. User repays later from any source
This turns every ETH/stETH holder into a USDC spender without any sell pressure.

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Integration Notes

Poll healthFactor from the info endpoint and surface alerts in your wallet UI. A health factor approaching 1.0 means the position is close to liquidation — prompt the user to add collateral or repay. See Risk Management.
Use the earn parameter when locking to wrap collateral into a yield-bearing vault. For stETH users, this means earning staking yield and vault yield simultaneously. Use GET /credit/protocol to discover available strategies.
Sprinter returns unsigned calldata — the user’s wallet signs everything. Sprinter never has access to user funds. This means your wallet integration doesn’t change your custody model.
ETH and stETH prices fluctuate. If collateral value drops, the health factor decreases and the user may face liquidation. Build alerts into your wallet UI — warn at health factor 1.5, strongly warn at 1.2.
Users can lock collateral on any supported chain. Sprinter handles cross-chain accounting — one credit line across all chains. This means users don’t need to bridge assets before borrowing.

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API Reference

Every step maps to a single Sprinter endpoint:
Wallet FlowSprinter API
User locks collateralGET /credit/accounts/{account}/lock
Lock + earn vaultGET /credit/accounts/{account}/lock?earn=STRATEGY_ID
Show credit positionGET /credit/accounts/{account}/info
Draw USDCGET /credit/accounts/{account}/draw?receiver={addr}
Repay debtGET /credit/accounts/{account}/repay
Unlock collateralGET /credit/accounts/{account}/unlock
Get protocol configGET /credit/protocol

Credit Draw

Core credit draw lifecycle — lock, draw, repay, unlock.

Supported Assets

Full collateral list, LTVs, and earn strategies.

Credit API Reference

Full API reference with interactive playground.