OpenMarkets

Connect Polymarket

Polymarket runs on USDC on Polygon and signs every trade with the wallet that holds the funds — so connecting it requires a wallet private key. Use a dedicated trading wallet, not your main wallet. About 10 minutes if you're setting up the wallet for the first time.

Polymarket

Set up a dedicated Polymarket trading wallet

Skip this group if you already have a dedicated wallet you only use for Polymarket trading.

3 steps
  1. Create a brand-new wallet specifically for Polymarket (e.g. a fresh MetaMask account or a new Coinbase Wallet profile). Do not reuse a wallet that holds anything else.
  2. Move only the USDC you want to trade into the new wallet on the Polygon network.
  3. Sign in to polymarket.com with this dedicated wallet so Polymarket recognises it.
OpenMarkets

Open the connect form in OpenMarkets

Get to the form with the two empty fields.

3 steps
  1. In OpenMarkets, tap the partner icon (top right of the Markets screen) to open the partners list.
    OpenMarkets partner icon top-right
  2. Find Polymarket in the partners list and tap it.
    Polymarket row in the partners list
    Polymarket reads "Add credentials to activate" until it's connected.
  3. Polymarket's connect form opens with two fields — Private Key (Ethereum Wallet) and Funder Address. Leave it on this screen.
    Polymarket connect form
Polymarket

Grab the Funder Address and Private Key

Funder Address from Polymarket's profile; Private Key from your dedicated trading wallet.

2 steps
  1. On polymarket.com, click your profile picture (top-right). Your Funder Address is shown under the avatar — copy it.
  2. Open your dedicated Polymarket wallet and export its private key.
OpenMarkets

Paste and test in OpenMarkets

Two fields, two buttons.

1 step
  1. Back in OpenMarkets: paste the Private Key and Funder Address, then tap Save credentials and Test connection.

How to know it worked

The Polymarket card flips to Connected with a green dot, your USDC balance shows, and Polymarket markets appear in your slate.

If something goes wrong

Test connection failed
Confirm the wallet has been used to sign in to Polymarket at least once (Polymarket needs to have seen this wallet). Also re-check the Funder Address — it's under the profile picture on polymarket.com, not your wallet's own address.
Balance shows $0 but I have USDC
Make sure USDC is on the Polygon network (not Ethereum mainnet) and held by the wallet whose private key you pasted. Cross-chain USDC won't appear.
I want to rotate the wallet
In OpenMarkets, tap Disconnect on the Polymarket card. Move funds to a new dedicated wallet, sign in to Polymarket with it, then reconnect with the new private key + funder address.
Should I really paste my private key?
Only if it's a wallet you set up specifically for Polymarket trading and holds only what you plan to trade. The page Before you start explains why — never paste the private key of a wallet that holds anything you'd hate to lose.

Disconnecting Polymarket

In OpenMarkets, open the Polymarket partner card and tap Disconnect partner. That removes the encrypted key from OpenMarkets. For full hygiene, also move the funds to a new dedicated wallet and use that going forward — once a private key has been pasted anywhere, treat it as exposed.

Your private key is encrypted at rest in OpenMarkets and used only to sign Polymarket transactions for the orders you tap. The key never leaves the OM backend except to sign transactions. Even with this protection, the right posture is to use a dedicated wallet so the key only ever controls funds you're actively trading.

Connect your other accounts

Kutt→4Casters→AlphaArcade→SX Bet→ProphetX→Kalshi→BettorEdge→BetOpenly→Kutt→4Casters→AlphaArcade→SX Bet→ProphetX→Kalshi→BettorEdge→BetOpenly→

If a screen doesn't match these steps, Polymarket may have updated its flow — email support@openmarkets.ai.

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