Polymarket Relayer API (2026): Gasless Transactions Explained
The Short Answer
The Polymarket Relayer at https://relayer-v2.polymarket.com submits wallet transactions on a user's behalf so the account never needs POL for gas. It covers wallet deployment, token approvals and conditional token operations: the user signs the transaction, the relayer broadcasts it, and Polymarket covers the gas. Submitting requires Builder API keys or Relayer API keys, and your daily allowance depends on your Builder Program tier: 100 relayer transactions a day unverified, 10,000 verified, unlimited for partners. Predictefy follows the same rule across 15+ venues: it returns unsigned transactions and orders, and the signing stays with you.
Key Takeaways
- Polymarket runs on Polygon, where every transaction costs POL in gas. The relayer pays it so users only ever hold pUSD.
- Three read endpoints are public:
/deployed,/nonceand/relay-payload. Submitting and listing transactions need a key. - Builder API keys use four
POLY_BUILDER_headers; Relayer API keys use two headers and are capped at 100 per address. - Daily relayer limits are 100 transactions unverified, 10,000 verified and unlimited for partners.
- Builders can add their own fee to orders they route, up to 1% on taker orders and 0.5% on maker orders.
- Predictefy applies the same you-sign model across 15+ venues, returning unsigned transactions and orders for your own wallet to sign.
What is the Polymarket relayer?
Polymarket settles on Polygon, and anything that touches a wallet onchain, deploying it, approving tokens, splitting, merging or redeeming positions, is a transaction that normally needs POL for gas. The relayer removes that requirement. The user signs the transaction, the relayer submits it, and Polymarket covers the gas, so an account funded only with pUSD, Polymarket's collateral token, can still deploy its wallet, approve tokens and manage its positions.
Polymarket describes the relayer's API as an HTTP service for submitting and tracking gasless transactions. It is a separate surface from the order book: placing orders goes through the Polymarket CLOB API, while the relayer handles the wallet operations around them.
Which endpoints does the relayer have?
| Endpoint | What it does | Key needed |
|---|---|---|
POST /submit | Submit a signed transaction | Yes |
GET /transaction?id= | Look up one submitted transaction | Yes |
GET /transactions | Recent transactions for a user | Yes |
GET /nonce?address=&type= | The current Safe or Proxy nonce for an address | No |
GET /relay-payload?address=&type= | The relayer address and nonce to sign against | No |
GET /deployed?address= | Whether a wallet is already deployed | No |
GET /relayer/api/keys | Your Relayer API keys | Yes |
curl -s "https://relayer-v2.polymarket.com/deployed?address=0xYOUR_WALLET&type=SAFE"
# {"deployed":false}
curl -s "https://relayer-v2.polymarket.com/nonce?address=0xYOUR_WALLET&type=SAFE"
# {"nonce":"510"}The public reads are what you call before building a transaction: whether the wallet exists yet, and which nonce the next signed transaction must carry. type is SAFE or PROXY, matching the wallet the account uses. Which of your addresses is the wallet and which is the signer is explained in the Polymarket proxy wallet guide.
How does relayer authentication work?
Submitting and reading your own transactions takes one of two kinds of key.
Builder API keys belong to a Builder Program profile and are created at polymarket.com under Settings, Builders, with "+ Create New". Requests carry four headers: POLY_BUILDER_API_KEY, POLY_BUILDER_TIMESTAMP, POLY_BUILDER_PASSPHRASE and POLY_BUILDER_SIGNATURE. This is the route for apps that operate wallets on behalf of their users.
Relayer API keys let a user call the relayer without Polymarket's Gamma sign-in on every request, although creating one requires that sign-in. Requests carry two headers, RELAYER_API_KEY and RELAYER_API_KEY_ADDRESS, and the address must match the one that owns the key. Each address can hold up to 100 keys.
Both are separate from the CLOB API credentials used to trade, which are covered in Polymarket API keys explained.
How do you submit a gasless transaction?
Read the nonce, sign the transaction, then submit it with your key headers. The body names the signer, the target contract, the user's wallet, the encoded call and its signature:
POST https://relayer-v2.polymarket.com/submit
{
"from": "0xSIGNER_ADDRESS",
"to": "0xTARGET_CONTRACT",
"proxyWallet": "0xUSER_WALLET",
"data": "0xENCODED_CALL",
"nonce": "510",
"signature": "0xSIGNATURE",
"signatureParams": { },
"type": "SAFE"
}The response returns a transactionID and the transaction's state. Poll GET /transaction?id= with the same key until it is mined. signatureParams depends on the wallet type, which is the main reason to let a client library assemble the payload rather than building it by hand.
In practice most apps never touch raw payloads. Polymarket's unified SDK exposes the common wallet operations as methods, including setupTradingApprovals, splitPosition, mergePositions and redeemPositions. Choosing and installing it is covered in the Polymarket SDK guide.
How many relayer transactions can you send?
It depends on your Builder Program tier:
| Unverified | Verified | Partner | |
|---|---|---|---|
| Daily relayer transactions | 100 | 10,000 | Unlimited |
| API rate limits | Standard | Standard | Highest |
| Gasless trading and order attribution | Yes | Yes | Yes |
| Builder Leaderboard visibility | No | Yes | Yes |
| Private Telegram and engineering support | No | Yes | Yes, elevated |
Every new builder starts Unverified with no approval needed, with gas subsidized on relayer transactions up to the daily limit, for new deposit wallets and existing Safe and Proxy wallets alike. Moving to Verified is a manual review: email builder@polymarket.com with your Builder API key, your use case and your expected volume.
What are builder codes and builder fees?
A builder is anyone routing users' orders to Polymarket through their own app. Your profile gets a bytes32 builder code, and attaching it to every order you submit does two things. The code is serialized into the signed order, so matched volume is credited to your profile and appears on the Builder Leaderboard at builders.polymarket.com within 24 hours. And the code lets you charge a builder fee on the orders you route.
| Fee setting | Default | Maximum |
|---|---|---|
| Taker fee rate | 0% | 1% (100 basis points) |
| Maker fee rate | 0% | 0.5% (50 basis points) |
Builder fees are flat percentages of trade notional and always stack on top of Polymarket's platform fees rather than replacing them. Rates can change at most once every seven days, and a change takes effect three days after it is scheduled, so users can see it coming. Polymarket's own fees are explained in Polymarket fees explained.
Where does Predictefy fit?
The relayer's design principle, that the user signs and the infrastructure never holds keys, is the same one Predictefy is built on. Predictefy holds no funds and no keys: its funding routes return unsigned transactions, such as Polymarket's approve and wrap steps, for your own wallet to sign, and its trading routes build orders server side for you to sign in your own process. The difference is scope: one integration covers Polymarket alongside 15+ prediction market venues, with every order book and every order in the same shape.
Frequently Asked Questions
What is the Polymarket relayer?
It is Polymarket's service for gasless transactions at https://relayer-v2.polymarket.com. Users sign wallet operations such as deployment, token approvals and splitting, merging or redeeming positions, and the relayer submits them with Polymarket covering the gas, so accounts never need to hold POL on Polygon.
Do you need POL to trade on Polymarket?
No. Trading collateral is pUSD, and the wallet operations that would normally need POL for Polygon gas go through Polymarket's relayer, which covers the fee. Builders get gas subsidized up to their tier's daily relayer limit, which starts at 100 transactions a day and rises to 10,000 for verified builders.
What is the difference between Builder API keys and Relayer API keys?
Builder API keys belong to a Builder Program profile, authenticate with four POLY_BUILDER headers, and suit apps operating wallets for their users. Relayer API keys let an individual address call the relayer with two headers, RELAYER_API_KEY and RELAYER_API_KEY_ADDRESS, and each address can hold up to 100 of them.
How many relayer transactions can a builder send per day?
Unverified builders get 100 relayer transactions a day, Verified builders 10,000, and Partners have no daily limit. Every new builder starts Unverified without approval. Upgrading to Verified is a manual review requested by email with your Builder API key, your use case and your expected volume.
How do builder fees work on Polymarket?
Builders attach a bytes32 builder code to orders they route and can set a taker fee of up to 1% and a maker fee of up to 0.5% of trade notional. Builder fees stack on top of Polymarket's platform fees, can change at most weekly, and take effect three days after scheduling.
Can you sign Polymarket transactions without handing over your keys?
Yes. With the relayer, you sign each transaction yourself and Polymarket only submits it and pays the gas. Predictefy applies the same model across 15+ venues: its funding routes return unsigned transactions such as Polymarket's approve and wrap steps, and its trading routes build orders for you to sign, so keys stay with you.