Base Sepolia bridge

Swap between Base Sepolia (chain id 84532) and NEAR testnet through Tidepool's testnet relayer, with 1Click-style deposit addresses, status and refunds.

Trusted relayer, testnet only. This route is run by Tidepool as its own testnet service. It is not a NEAR, Omni Bridge or 1Click bridge, and the tokens have no value. Read Test bridges for what you are trusting.

Contracts

What	Address
Chain	Base Sepolia, chain id `84532`, `blockchain: "base"`
Vault	`0x2e6AD9E6D59bB4585ea0E6762c3b637dde29DAD2`
Test USDC (6 decimals)	`0x38d81431B9f76d9699AF7517040D5221D9dEA252`
Test USDT (6 decimals)	`0xC15Cf5600225302675604310094f134e88705E62`
Relayer	`0x55F2c8044D790e1b8369508c31c756c0c2Ca0E93`

Asset id	NEP-141 on NEAR testnet
`nep141:base-0x38d81431b9f76d9699af7517040d5221d9dea252.tp-omft.testnet`	USDC on Base Sepolia
`nep141:base-0xc15cf5600225302675604310094f134e88705e62.tp-omft.testnet`	USDT on Base Sepolia

Both appear in GET /v0/tokens with blockchain: "base" and contractAddress set to the ERC-20.

1. Get tokens and gas

curl -X POST https://www.usetidepool.tech/v0/faucet -H 'content-type: application/json' \
  -d '{"chain":"base","address":"0xYourAddress"}'

This mints 100 test USDC and 100 test USDT on Base Sepolia. It is also in the dropdown on the Faucet page. To get the bridged USDC and USDT into your NEAR intents balance instead, use {"accountId":"alice.testnet","mode":"intents","assets":["base"]}. You can also call faucet() on either token contract yourself (once per hour per address). Gas is not included: get Base Sepolia ETH from a public faucet.

2. Base Sepolia → NEAR

const quote = await OneClickService.getQuote({
  dry: false, swapType: 'EXACT_INPUT', slippageTolerance: 100,
  originAsset: 'nep141:base-0x38d81431b9f76d9699af7517040d5221d9dea252.tp-omft.testnet',
  destinationAsset: 'nep141:wnear.tidepool-sandbox.testnet',
  amount: '10000000',                       // 10 USDC
  depositType: 'ORIGIN_CHAIN', refundTo: '0xYourAddress', refundType: 'ORIGIN_CHAIN',
  recipient: 'you.testnet', recipientType: 'DESTINATION_CHAIN',
  deadline: new Date(Date.now() + 30 * 60_000).toISOString(),
});
// quote.quote.depositAddress is a 0x address on Base Sepolia. Send the ERC-20 there:
// usdc.transfer(quote.quote.depositAddress, 10_000000n)
await OneClickService.submitDepositTx({ txHash: '0x…', depositAddress: quote.quote.depositAddress });

The relayer sweeps the deposit into the vault, mints the bridged NEP-141 and credits it to the verifier with a normal ft_transfer_call. The swap then settles exactly like a NEAR-only swap. Status goes PENDING_DEPOSIT → KNOWN_DEPOSIT_TX → PROCESSING → SUCCESS, usually within a minute.

Full quote request and response

The request below sets every required field (plus depositMode: "MEMO" where this route needs it). It is a dry quote, so nothing is created. The response is the real, complete body from the live deployment on 2026-10-30; prices move, so your amounts will differ. Optional fields such as appFees or referral are in Swap types.

curl -X POST https://www.usetidepool.tech/v0/quote -H 'content-type: application/json' -d '{
  "dry": true,
  "swapType": "EXACT_INPUT",
  "slippageTolerance": 100,
  "originAsset": "nep141:base-0x38d81431b9f76d9699af7517040d5221d9dea252.tp-omft.testnet",
  "depositType": "ORIGIN_CHAIN",
  "destinationAsset": "nep141:wnear.tidepool-sandbox.testnet",
  "amount": "10000000",
  "refundTo": "0x2527D02599Ba641c19FEa793cD0F167589a0f10D",
  "refundType": "ORIGIN_CHAIN",
  "recipient": "user.testnet",
  "recipientType": "DESTINATION_CHAIN",
  "deadline": "2030-01-01T00:00:00.000Z"
}'

{
  "correlationId": "eaa724f3-9b14-4133-90d5-99ff492d5211",
  "timestamp": "2026-10-30T16:28:47.606Z",
  "quoteRequest": {
    "dry": true,
    "swapType": "EXACT_INPUT",
    "slippageTolerance": 100,
    "originAsset": "nep141:base-0x38d81431b9f76d9699af7517040d5221d9dea252.tp-omft.testnet",
    "depositType": "ORIGIN_CHAIN",
    "destinationAsset": "nep141:wnear.tidepool-sandbox.testnet",
    "amount": "10000000",
    "refundTo": "0x2527D02599Ba641c19FEa793cD0F167589a0f10D",
    "refundType": "ORIGIN_CHAIN",
    "recipient": "user.testnet",
    "recipientType": "DESTINATION_CHAIN",
    "deadline": "2030-01-01T00:00:00.000Z"
  },
  "quote": {
    "amountIn": "10000000",
    "amountInFormatted": "10",
    "amountInUsd": "9.9976",
    "minAmountIn": "10000000",
    "amountOut": "2298519836027713650880000",
    "amountOutFormatted": "2.29851983602771365088",
    "amountOutUsd": "9.9526",
    "minAmountOut": "2275534637667436514371200",
    "timeEstimate": 60
  },
  "signature": "ed25519:2irGpWS1TXwTM5SVPqtV1hsX8WtmxEWM929KK7TkZi9HzJ1qcJY1P6LBXaAeTvLtMZoZZnp9gqneKdFhfaFEbSsM"
}

With "dry": false and a deadline between a minute and a day ahead, the quote also carries depositAddress, deadline and timeWhenInactive. See Quotes and pricing and the status response for what comes back after the deposit.

3. NEAR → Base Sepolia

Quote with destinationAsset: 'nep141:base-0x38d81431b9f76d9699af7517040d5221d9dea252.tp-omft.testnet', recipient: '0xYourAddress' and recipientType: 'DESTINATION_CHAIN', then deposit on NEAR as usual. The verifier ft_withdraws the bridged token to the relayer, which calls release on the vault. Status stays PROCESSING until the Base Sepolia payout confirms, then turns SUCCESS with the payout in destinationChainTxHashes.

Runnable: EVM_PRIVATE_KEY=0x… EVM_CHAIN=base RECIPIENT=you.testnet WITHDRAW=1 npm run evm-deposit in tidepool-examples. It deposits USDC on the EVM chain, receives wNEAR on NEAR, and with WITHDRAW=1 sends it back. Use a testnet-only key with a little gas ETH.

Refunds

Refunds follow the same rules as NEAR-only swaps (DEADLINE_PASSED, PARTIAL_DEPOSIT, overpay). A refund of an EVM deposit with refundType: "ORIGIN_CHAIN" is paid back from the vault to refundTo on Base Sepolia.

Tested round trips

Route	Transaction
Base Sepolia USDC → NEAR USDC	0x00f00aef…
NEAR USDC → Base Sepolia USDC	0xcc677ee4…
Late Base Sepolia deposit, refunded (DEADLINE_PASSED)	0xf44e7709…

Community-built · not affiliated with NEAR. Tidepool is community-built and not affiliated with NEAR, Defuse or 1Click. Testnet only; test tokens have no value. Built by @realchriswilder.