***
title: Get Started with Gasless API
description: Learn how to send your first Gasless API request.
--------------------------------------------------------------
## About Gasless API
[Gasless API](../introduction) allows developers to create the smoothest trading experience in DeFi by abstracting away the complexities related to approvals, allowances, and swaps for their users.
Enabling Gasless API in your app allows you to:
* build more intuitive user interfaces and user flows in your applications
* improve your conversion funnel drop-offs due to insufficient gas, and
* set yourself up to easily onboard the next wave of users into Web3.
Make sure to read [Understanding Gasless API](/docs/gasless-api/guides/understanding-gasless-api) for an in-depth understanding of how it works, key terms, and technical flow charts for how to implement in-app.
## Try It Out
### Example Code
Follow along locally with the example code: [https://github.com/0xProject/0x-examples/tree/main/gasless-v2-headless-example](https://github.com/0xProject/0x-examples/tree/main/gasless-v2-headless-example)
### Playground
Try this code example directly in your browser—no installation needed!
## Gasless Swaps in 4 Steps
0. Get a 0x API key
1. Get an indicative price using `/gasless/price`
2. Get a firm quote using `/gasless/quote`
3. Submit the transaction using `/gasless/submit`
a. Sign the gasless approval object (if applicable)
b. Sign the trade object
c. Split the signatures
d. Package signed objects into a format that can be POST to /submit
e. Compute trade hash
4. Check the trade status using `/gasless/status/{tradeHash}`
Checkout the [Gasless API Runnable Headless
Example](https://github.com/0xProject/0x-examples/tree/main/gasless-v2-headless-example)
to see these steps in action
## 0. Before You Begin
### Get a 0x API Key
Every call to a 0x API must include a 0x API key. Get one from the [0x Dashboard](https://go.0x.org/create-account-txrelay-z).
### Enable Gasless API from your dashboard
You will be able to enable Gasless API in your app from "App Settings" in your [0x dashboard](https://dashboard.0x.org/). You can enable it for any active apps you have (see screenshot).
## 1. Fetch Price
Use [`/gasless/price`](/api-reference/openapi-yaml/gasless/getprice) to get the indicative price. This is used when the user is just *browsing* for the price they could receive on the specified asset pair, but they are not ready to submit the quote yet.
This endpoint responds with pricing information, but the response does not contain a full 0x order, so it does not constitute a full transaction that can be submitted to the Ethereum network (you must use [`/gasless/quote`](/api-reference/openapi-yaml/gasless/getquote) for this). Think of `/price` as the the "read-only" version of `/quote`.
### Example Request
Here is an example indicative price request to sell 100 [USDC](https://basescan.org/address/0x833589fcd6edb6e08f4c7c32d4f71b54bda02913) for [WETH](https://basescan.org/token/0x4200000000000000000000000000000000000006) using `/price` on Base (8453):
```
https://api.0x.org/gasless/price // Request an indicative price
?sellToken=0x833589fcd6edb6e08f4c7c32d4f71b54bda02913 // Sell USDC
&sellAmount=100000000 // Sell amount 100 USDC (6 decimals)
&buyToken=0x4200000000000000000000000000000000000006 // Buy WETH
&takerAddress=$USER_TAKER_ADDRESS // Address that will make the trade
--header '0x-api-key: [API_KEY]' // Replace with your own API key
--header '0x-version: v2' // API version
```
### Sample cURL Request
```bash
curl --request GET \
--url 'https://api.0x.org/gasless/price?chainId=8453&sellToken=0x833589fcd6edb6e08f4c7c32d4f71b54bda02913&buyToken=0x4200000000000000000000000000000000000006&sellAmount=100000&taker=' \
--header '0x-api-key: '
--header '0x-version: v2'
```
### Example Response
```json
{
"blockNumber": "17225085",
"buyAmount": "24516376467802",
"buyToken": "0x4200000000000000000000000000000000000006",
"fees": {
"integratorFee": null,
"zeroExFee": {
"amount": "150",
"token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"type": "volume"
},
"gasFee": {
"amount": "16279",
"token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"type": "gas"
}
},
"issues": {
"allowance": {
"actual": "0",
"spender": "0x000000000022d473030f116ddee9f6b43ac78ba3"
},
"balance": null,
"simulationIncomplete": false,
"invalidSourcesPassed": []
},
"liquidityAvailable": true,
"minBuyAmount": "24442827338399",
"route": {
"fills": [
{
"from": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"to": "0x4200000000000000000000000000000000000006",
"source": "PancakeSwap_V2",
"proportionBps": "10000"
}
],
"tokens": [
{
"address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"symbol": "USDC"
},
{
"address": "0x4200000000000000000000000000000000000006",
"symbol": "WETH"
}
]
},
"sellAmount": "99850",
"sellToken": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"target": "0xca11bde05977b3631167028862be2a173976ca11",
"zid": "0x0428a9c5f42998e4e00237fe"
}
```
## 2. Fetch Quote
When the user has found a price they are happy with and are ready to fill a quote, they should request a firm quote from Gasless API using the [`/gasless/quote`](/api-reference/openapi-yaml/gasless/getquote) endpoint. At this point, the taker is making a soft commitment to fill the suggested orders, and understands they may be penalized by the [Market Maker](/docs/core-concepts/glossary#maker) if they do not.
Quotes expire in \~ 30s in order to ensure freshness. Make sure to take this
into account when building your app with a timer and/or automatic refresh.
### Example Request
Here is an example to fetch a firm quote to sell 100 USDC (supports Permit) for WETH (does not support Permit) using `/quote` on Polygon (137):
```
https://api.0x.org/gasless/quote // Request a fiirm quote
?sellToken=0x833589fcd6edb6e08f4c7c32d4f71b54bda02913 // Sell USDC
&sellAmount=100000000 // Sell amount 100 USDC (6 decimals)
&buyToken=0x4200000000000000000000000000000000000006 // Buy WETH
&takerAddress=$USER_TAKER_ADDRESS // Address that will make the trade
--header '0x-api-key: [API_KEY]' // Replace with your own API key
--header '0x-version: v2' // API version
```
### Sample Request
```bash
curl --request GET
https://api.0x.org/gasless/quote?chainId=137&buyToken=0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270&sellToken=0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174&sellAmount=10000000&taker=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045&swapFeeBps=10&swapFeeRecipient=0xa8aac589a67ecfade31efde49a062cc21d68a64e&swapFeeToken=0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174&tradeSurplusRecipient=0xa8aac589a67ecfade31efde49a062cc21d68a64e
--header '0x-api-key: YOUR_API_KEY'
--header '0x-version: v2'
```
### Example Response
```json
{
"approval": {
"type": "permit",
"hash": "0xbf16458c9666dea26c2c810a64a5e9525d3fe79790038cd86a50608ae2dcd764",
"eip712": {
"types": {
"EIP712Domain": [
{
"name": "name",
"type": "string"
},
{
"name": "version",
"type": "string"
},
{
"name": "verifyingContract",
"type": "address"
},
{
"name": "salt",
"type": "bytes32"
}
],
"Permit": [
{
"name": "owner",
"type": "address"
},
{
"name": "spender",
"type": "address"
},
{
"name": "value",
"type": "uint256"
},
{
"name": "nonce",
"type": "uint256"
},
{
"name": "deadline",
"type": "uint256"
}
]
},
"domain": {
"name": "USD Coin (PoS)",
"version": "1",
"verifyingContract": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"salt": "0x0000000000000000000000000000000000000000000000000000000000000089"
},
"message": {
"owner": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"spender": "0x000000000022d473030f116ddee9f6b43ac78ba3",
"value": "115792089237316195423570985008687907853269984665640564039457584007913129639935",
"nonce": 0,
"deadline": "1720478400"
},
"primaryType": "Permit"
}
},
"blockNumber": "59125336",
"buyAmount": "19821286934697663036",
"buyToken": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"fees": {
"integratorFee": {
"amount": "10000",
"token": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"type": "volume"
},
"zeroExFee": {
"amount": "15000",
"token": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"type": "volume"
},
"gasFee": {
"amount": "11585",
"token": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"type": "gas"
}
},
"issues": {
"allowance": {
"actual": "0",
"spender": "0x000000000022d473030f116ddee9f6b43ac78ba3"
},
"balance": null,
"simulationIncomplete": false,
"invalidSourcesPassed": []
},
"liquidityAvailable": true,
"minBuyAmount": "19761823073893570047",
"route": {
"fills": [
{
"from": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"to": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"source": "Dfyn",
"proportionBps": "250"
},
{
"from": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"to": "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359",
"source": "Uniswap_V3",
"proportionBps": "9750"
},
{
"from": "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359",
"to": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"source": "WOOFi_V2",
"proportionBps": "9306"
},
{
"from": "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359",
"to": "0x7ceb23fd6bc0add59e62ac25578270cff1b9f619",
"source": "Uniswap_V3",
"proportionBps": "444"
},
{
"from": "0x7ceb23fd6bc0add59e62ac25578270cff1b9f619",
"to": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"source": "Uniswap_V3",
"proportionBps": "444"
}
],
"tokens": [
{
"address": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"symbol": "USDC"
},
{
"address": "0x3c499c542cef5e3811e1192ce70d8cc03d5c3359",
"symbol": "USDC"
},
{
"address": "0x7ceb23fd6bc0add59e62ac25578270cff1b9f619",
"symbol": "WETH"
},
{
"address": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"symbol": "WMATIC"
}
]
},
"sellAmount": "9975000",
"sellToken": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"target": "0xca11bde05977b3631167028862be2a173976ca11",
"trade": {
"type": "settler_metatransaction",
"hash": "0x102c2f33fb20988e171393bc5d7a497705a69b57e6d3116337b0b254adf481a7",
"eip712": {
"types": {
"PermitWitnessTransferFrom": [
{
"name": "permitted",
"type": "TokenPermissions"
},
{
"name": "spender",
"type": "address"
},
{
"name": "nonce",
"type": "uint256"
},
{
"name": "deadline",
"type": "uint256"
},
{
"name": "slippageAndActions",
"type": "SlippageAndActions"
}
],
"TokenPermissions": [
{
"name": "token",
"type": "address"
},
{
"name": "amount",
"type": "uint256"
}
],
"SlippageAndActions": [
{
"name": "recipient",
"type": "address"
},
{
"name": "buyToken",
"type": "address"
},
{
"name": "minAmountOut",
"type": "uint256"
},
{
"name": "actions",
"type": "bytes[]"
}
],
"EIP712Domain": [
{
"name": "name",
"type": "string"
},
{
"name": "chainId",
"type": "uint256"
},
{
"name": "verifyingContract",
"type": "address"
}
]
},
"domain": {
"name": "Permit2",
"chainId": 137,
"verifyingContract": "0x000000000022d473030f116ddee9f6b43ac78ba3"
},
"message": {
"permitted": {
"token": "0x2791bca1f2de4661ed88a30c99a7a9449aa84174",
"amount": "10000000"
},
"spender": "0xf9332450385291b6dce301917af6905e28e8f35f",
"nonce": "2241959297937691820908574931991585",
"deadline": "1720478100",
"slippageAndActions": {
"recipient": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"buyToken": "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270",
"minAmountOut": "19761823073893570047",
"actions": [
"0x0dfeb419000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f0000000000000000000000002791bca1f2de4661ed88a30c99a7a9449aa8417400000000000000000000000000000000000000000000000000000000009896800000000000000000000000000000000000006e898131631616b1779bad70bc2100000000000000000000000000000000000000000000000000000000668c6994",
"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",
"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",
"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",
"0x103b48be000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f0000000000000000000000002791bca1f2de4661ed88a30c99a7a9449aa8417400000000000000000000000000000000000000000000000000000000000000fa000000000000000000000000d776c65b2a7a5832b4172742bf8c40cc062c678e0000000000000000000000000000000000000000000000000000000000001e000000000000000000000000000000000000000000000000000000000000000000",
"0x8d68a156000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f000000000000000000000000000000000000000000000000000000000000271000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002c2791bca1f2de4661ed88a30c99a7a9449aa84174000000643c499c542cef5e3811e1192ce70d8cc03d5c33590000000000000000000000000000000000000000",
"0x38c9c1470000000000000000000000003c499c542cef5e3811e1192ce70d8cc03d5c335900000000000000000000000000000000000000000000000000000000000025490000000000000000000000004c4af8dbc524681930a27b2f1af5bcc8062e6fb7000000000000000000000000000000000000000000000000000000000000004400000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000c47dc203820000000000000000000000003c499c542cef5e3811e1192ce70d8cc03d5c33590000000000000000000000000d500b1d8e8ef31e21c99d1db9a6444d3adf127000000000000000000000000000000000000000000000000000000000008da4f70000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f0000000000000000000000005e01d320e95133d80dd59a2191c95728fa69036d00000000000000000000000000000000000000000000000000000000",
"0x8d68a156000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f000000000000000000000000000000000000000000000000000000000000271000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002c3c499c542cef5e3811e1192ce70d8cc03d5c3359000000647ceb23fd6bc0add59e62ac25578270cff1b9f6190000000000000000000000000000000000000000",
"0x8d68a156000000000000000000000000f9332450385291b6dce301917af6905e28e8f35f000000000000000000000000000000000000000000000000000000000000271000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002c7ceb23fd6bc0add59e62ac25578270cff1b9f619000001f40d500b1d8e8ef31e21c99d1db9a6444d3adf12700000000000000000000000000000000000000000",
"0xc876d21d000000000000000000000000a8aac589a67ecfade31efde49a062cc21d68a64e0000000000000000000000000d500b1d8e8ef31e21c99d1db9a6444d3adf1270000000000000000000000000000000000000000000000001136817746ac32f00"
]
}
},
"primaryType": "PermitWitnessTransferFrom"
}
}
}
```
### Response Details
If liquidity is available, 2 objects may be returned:
* `approval`: This is the “approval” object which contains the necessary information to process a gasless approval. See the [quote response](/api-reference/openapi-yaml/gasless/getquote#option-1) for an example.
* If a gasless approval is possible, this object includes all the required information to process it.
* If a gasless approval is **not** possible, this object will be `null`, and you must use the [standard approval flow](/docs/gasless-api/guides/understanding-gasless-api#technical-flow-charts) to [set a token allowance](/docs/swap-api/additional-topics/how-to-set-token-allowances). NEVER SET AN ALLOWANCE ON THE SETTLER CONTRACT.
* You can also see all the token addresses that support gasless approvals with the [`/gasless-approval-tokens`](/api-reference/openapi-yaml/gasless/getgaslessapprovaltokens) endpoint.
* `trade`: This is the "trade" object which contains the necessary information to process a gasless trade. See the quote response [here](/api-reference#tag/Gasless/operation/gasless::getQuote).
## 3. Submit Transaction
When user accepts the quote and wants to submit the trade, use [`/gasless/submit`](/api-reference/openapi-yaml/gasless/submit) to send both signatures back along with the payload from `/gasless/quote`.
In order to submit the trade, we must complete the following:
* [Sign the gasless approval](./gasless-api-technical-appendix#sign-gasless-approval-object)
* [Sign the gasless trade object](./gasless-api-technical-appendix#sign-trade-object)
* [Split signatures for both signed objects](./gasless-api-technical-appendix#splitting-signatures)
* [Package both signed objects in a format that is acceptable to POST to /submit](./gasless-api-technical-appendix#post-the-split-signatures-to-)
### Example Request
```bash
curl -X POST '' --header '0x-api-key: ' --header '0x-version: v2' --data '{
"trade": {
"type": "settler_metatransaction", // this is trade.type from the /quote endpoint
"eip712": { /* this is trade.eip712 from the /quote endpoint */ },
"signature": {
"v": 28,
"r": "0xeaad7568c0d17ad9e1043a4dd41ce294ed51792a0fb8bed3a3318f7e1df3ff88",
"s": "0x09444d25869d91946d7c26f9e5448c7fea369ba9c90deac1d761261565c487d2",
"signatureType": 2
}
},
"approval":{
"type": "permit", // this is approval.type from the /quote endpoint
"eip712": {/* this is approval.eip712 from the /quote endpoint */},
"signature": {
"v": 27,
"r": "0xa1be4e6177d95f7e634d7cf8f93021b96e5e4f3d4d8605e85204b97d4a4060eb",
"s": "0x371e85adcfa9a5d0f53cc9f467a4230305899e4a18c0174466b8da784a4f9c81",
"signatureType": 2
}
}
}'
```
### Example Response
```json
{
"tradeHash": "0xcb3285b35c024fca76037bea9ea4cb68645fed3bdd84030956577de2f1592aa9",
"type": "settler_metatransaction",
"zid": "0x111111111111111111111111"
}
```
## 4. Check Trade Status
Once the user has signed, split, and submitted both signatures - gasless approval (if applicable) and gasless trade - and a `tradeHash` is returned from `/submit`, you can poll [`/gasless/status/{tradeHash}`](/api-reference/openapi-yaml/gasless/getstatus) to check the status of the trade.
### Example Request
```bash
curl '' \\
--header '0x-api-key: ' --header '0x-version: v2'
```
### Example Response
```jsx
// succeeded means it has been included in a block
checks: {
status: "succeeded",
transactions: [
{
hash: "0xc619aae86b1fbbb7418ab09cd849a21e4f0c07a316f87ec991ee6639fec67f5b",
timestamp: 1721085056563,
}
],
zid: "0xd480bf2cca5769626b4549c7",
}
// confirmed means it has at least 3 confirmations onchain
checks: {
status: "confirmed",
transactions: [
{
hash: "0xc619aae86b1fbbb7418ab09cd849a21e4f0c07a316f87ec991ee6639fec67f5b",
timestamp: 1721085056563,
}
],
zid: "0x67e11e02ba701a762e58ebe4",
}
```
If you receive an error response, see the [`/status` response in the Gasless API reference](/api-reference/openapi-yaml/gasless/getstatus)
Once the trade is successful, you can display the transaction confirmation to your user.
## Gasless Approval Tokens
Use [`/gasless/gasless-approval-tokens`](/api-reference/openapi-yaml/gasless/getgaslessapprovaltokens) to get token addresses that support gasless approvals on each chain.
## Gasless Chains
Use [`/gasless/chains`](/api-reference/openapi-yaml/gasless/getgaslessapprovaltokens) to get a list of supported chains for gasless.