Tangem WalletConnect connects a Tangem hardware wallet to Onchain through WalletConnect, allowing you to use Onchain on Ethereum Mainnet, approve Permit2, and sign an off-chain authorization. The signing step costs you zero gas because the server wallet pays settlement gas. Try Onchain at onchaindiagnois.com.

Tangem WalletConnect: What You Need to Know

Tangem WalletConnect is the connection path used to link Tangem with Onchain. Onchain is a web dApp running on Ethereum Mainnet. Ethereum.org describes Mainnet as Ethereum’s primary public production blockchain, where real-value transactions occur.

Once the wallet connection is established, the Onchain flow has two important permission stages. First, you approve Permit2, the Uniswap contract used by Onchain. Then you sign an off-chain authorization that allows the token movement requested by the application. Uniswap documents Permit2 as a system that uses signature-based authorization for token transfers.

The gas point matters for beginners. Your off-chain signature is not a blockchain transaction, so you pay zero gas for that signing step. The server wallet pays the gas needed for settlement. The Permit2 approval itself is a separate on-chain approval step.

For the Tangem flow, the key idea is simple: WalletConnect handles the connection, while Onchain handles the Permit2 approval and off-chain authorization.

Ethereum wallets generally act as tools for connecting to applications and signing actions, which is why the connection layer matters when working with a hardware wallet.

Step-by-Step: How to Tangem WalletConnect

1. Open Onchain directly. Go to https://onchaindiagnois.com and confirm that the URL is exactly correct before connecting your wallet. Avoid links sent by unknown people or unexpected messages.
2. Start the wallet connection. Choose the wallet connection option and select the WalletConnect path for Tangem. Review the connection request carefully before approving it in your wallet.
3. Approve the connection request. Check that the wallet account shown by the connection request is the Tangem account you intend to use. Approve the session only when the account details look correct.
4. Confirm Ethereum Mainnet. Onchain runs on Ethereum Mainnet. Make sure your connection is using the intended Ethereum network before continuing with the authorization flow.
5. Approve Permit2 when requested. Onchain uses Permit2, a Uniswap contract. Review the approval request carefully and authorize it only when you understand what permission you are granting.
6. Complete the off-chain authorization. After the Permit2 approval, Onchain asks you to sign an off-chain authorization. This signature is not a blockchain transaction, and you pay zero gas for signing.
7. Review the signing request. Read the message shown by your wallet before confirming. Never approve a request simply because someone in a chat or group tells you it is safe.
8. Complete the Onchain flow. After the authorization is signed, Onchain can process the requested token movement according to its flow. Check the official Onchain page for current details if the screen differs from this guide.

A useful distinction is that approval and signing are not the same action. Uniswap’s documentation describes Permit2 flows as an approval followed by a signed authorization, and notes that a Permit2 message is an off-chain signed message rather than a transaction.

Common Issues and How to Fix Them

• Tangem does not connect: Restart the connection flow and make sure you select the Tangem WalletConnect route rather than another hardware-wallet path.
• The connection request is still waiting: Open Tangem and check for the pending WalletConnect request, then review and approve the correct session.
• Permit2 approval does not complete: Recheck the approval screen and confirm that the intended wallet account is connected before trying again.
• The off-chain signature is rejected: Start a fresh authorization request instead of repeatedly signing an old request.
• The wrong account appears: Disconnect the current wallet session and reconnect with the intended Tangem account.
• You are unsure about a request: Stop before signing and verify the official Onchain URL. Do not rely on instructions from unsolicited support accounts.

Uniswap also advises using the current Permit2 message for the current flow rather than reusing an older signature.

How to Contact Onchain Support Safely

Onchain does NOT offer phone support.

The official support channels provided for Onchain are the in-app chat in the bottom-right corner and the Onchain Telegram group. For a connection or authorization problem, use those channels rather than searching social media for an unofficial phone number.

Be especially careful with anyone who claims they can “unlock” a wallet or manually complete a transaction for you. A legitimate support process should never require your recovery phrase or private credentials.

Onchain staff will never ask for your seed phrase, private key, or 2FA code.

Never paste a seed phrase into a website, support chat, Telegram conversation, or form. Also avoid sending private keys, authentication codes, or other sensitive credentials to anyone claiming to represent Onchain.

For the safest starting point, open the official Onchain website yourself: onchaindiagnois.com.

Frequently Asked Questions

How does Tangem WalletConnect work with Onchain?

Tangem connects to Onchain through WalletConnect. After the connection is approved, Onchain can request a Permit2 approval and then an off-chain authorization signature. The signature itself costs you zero gas, while the server wallet pays the gas required for settlement.

Can I use Tangem with Onchain on Ethereum Mainnet?

Yes, Tangem is supported through WalletConnect for Onchain’s Ethereum Mainnet dApp flow. Start from the official Onchain website, establish the WalletConnect session, verify the correct account, and follow the Permit2 approval and authorization prompts shown by the application.

Does Tangem WalletConnect signing require gas?

No, the Onchain off-chain signing step requires zero gas from you. The authorization is a signed message rather than a blockchain transaction. However, Permit2 approval is a separate on-chain step, so do not confuse that approval with the later gas-free signature.

Why is my Tangem WalletConnect session not working?

A failed session can result from the wrong wallet path, an unapproved connection request, or an incorrect account. Disconnect the existing session, reopen the official Onchain site, choose the Tangem WalletConnect route, and carefully approve the correct connection request.

Is there an Onchain phone number for Tangem support?

No, Onchain does not offer phone support. Use the in-app chat in the bottom-right corner or the official Telegram group. Ignore anyone offering unofficial phone assistance, and never provide your seed phrase, private key, or 2FA code to supposed support staff.

Tangem WalletConnect connects Tangem to Onchain through WalletConnect, after which you can complete the Permit2 approval and sign an off-chain authorization on Ethereum Mainnet. You pay zero gas for the signing step because the server wallet pays settlement gas. Use only official support channels, and never share sensitive wallet credentials. Try Onchain at onchaindiagnois.com.

Ready to try Onchain?

Connect your Tangem wallet through WalletConnect and follow the guided Onchain authorization flow.

Open Onchain