The issue of not receiving a gas fee quote for USDC transactions in Slush wallet could be caused by a few different factors related to how Sui handles gas and token transfers, especially with stablecoins like USDC. Here's a breakdown of potential causes and how to resolve them:

Possible Causes:

1. Sui Gas Fees Are Separate: Sui has a separate gas fee structure for transactions. If you're trying to use USDC to pay for gas or if the wallet doesn't have enough Sui (native token) for gas fees, it may not be able to quote the fee for the transaction.

2. Gas Payment in Sui, Not USDC: Sui uses its native token (SUI) for gas fees, not USDC or any other tokens. If your wallet doesn’t have enough SUI, it can't calculate the gas fee for the transaction.

3. Network Congestion or Issues: Sometimes, wallet services might not provide accurate gas fee quotes due to temporary network congestion or issues with the backend service that handles fee estimation.

4. Incorrect Wallet Configuration: If your wallet is not properly configured to interact with the Sui network or if it's set to a testnet or different network, it may fail to quote the correct fees.

How to Resolve the Issue:

1. Ensure SUI Balance: Check if you have enough SUI tokens in your wallet to cover the gas fees. You need SUI for gas, even when using USDC for the transfer.

2. Switch to Mainnet: Ensure that you’re connected to the correct network (Mainnet) if you're trying to perform transactions on the main chain, not a testnet or local network.

3. Check Wallet Settings: Verify your wallet configuration. Ensure that Slush wallet is properly connected to Sui and correctly set up to handle gas fees and token transfers.

4. Use the Sui CLI for Gas Estimation: If the wallet interface is not working, you can try using the Sui CLI to estimate gas fees for the transaction and check the state of your wallet.

5. Contact Support: If none of these work, there may be a bug or issue with the wallet itself. Reaching out to Slush wallet support or checking for any recent updates or known issues may help resolve the problem.

Example (Using SUI CLI):

To estimate the gas fees using the SUI CLI:

sui client gas-estimate --package <package-id> --module <module-name> --function <function-name> --args <arguments>

This will help you verify if the issue is with the wallet or the network configuration.

The issue with Slush Wallet not quoting gas fees for USDC transactions likely stems from incorrect gas token configuration or insufficient SUI balance to cover network fees. Since Sui requires SUI (not USDC) for gas, the wallet may fail to calculate fees if your SUI balance is empty or the token pairing isn’t properly recognized. Try ensuring you hold enough SUI for gas, refreshing the wallet, or checking for app updates that might fix quoting logic. If the problem persists, switching to another wallet like Sui Wallet or Ethos for the transaction could serve as a temporary workaround.

Slush wallet might not quote gas fees for USDC due to:

1. Insufficient ETH – You need ETH for gas, even for USDC transactions.
2. Network issues – Check your connection or try later.
3. Outdated app – Update Slush wallet.
4. Token compatibility – Ensure USDC is on a supported network (e.g., Ethereum).
5. Wallet bug – Restart the app or reinstall.

Fix: Make sure you have enough ETH for gas, switch networks if needed, or contact Slush support.

Slush Wallet might not quote gas fees for USDC because:

1. Insufficient SUI for gas (you need SUI to pay fees, even for USDC transfers).
2. Token not whitelisted for gas sponsorship.
3. Network/RPC issues affecting fee estimation.

Quick Fixes:

1. Ensure You Have SUI for Gas

   // Check SUI balance (Sui TS SDK)
   const balance = await client.getBalance({
     owner: "0xYourAddress",
     coinType: "0x2::sui::SUI",
   });
   

   • Deposit SUI if balance is 0.

2. Manually Set Gas Budget (if automatic quoting fails):

   const tx = new Transaction().setGasBudget(5_000_000); // 0.005 SUI
   

3. Switch RPC (if Slush uses a faulty endpoint):

   const client = new SuiClient({ url: "https://fullnode.testnet.sui.io" });
   

Common Causes:

• Slush Wallet may not support gasless USDC transactions.
• The USDC token contract might lack gas sponsorship permissions.

Slush Wallet may not quote gas fees for USDC if:

1. No SUI for gas: USDC transactions require SUI to pay gas. Ensure you have enough SUI in your wallet.
2. Network/RPC issue: The wallet can’t reach the Sui node to estimate gas. Check connectivity or switch networks.
3. USDC object problem: The USDC coin might be locked (e.g., in a stake) or malformed. Verify ownership and type.
4. Unsupported token: Confirm USDC is the official Circle token (0x5d4b...cec2). Some tokens may not be fully supported.
5. App bug: Try refreshing, updating Slush, or testing the transaction in another wallet like Sui Wallet.

Ensure you have SUI for gas and valid USDC objects—this resolves most gas estimation failures.

Root Causes

1. USDC Gas Fee Payment Restriction

   • Sui requires gas fees to be paid in SUI, not USDC. Slush may fail to auto-convert the quote if your wallet lacks SUI balance.

2. Token Metadata Issue

   • The USDC token’s CoinMetadata might not be properly indexed (common for newly added tokens).

3. RPC Node Sync Problem

   • Slush’s connected RPC node could be out of sync with the latest USDC object data.

Quick Fixes

1. Ensure SUI Balance

• Deposit at least 0.1 SUI for gas fees, even if swapping USDC.

2. Manual Gas Override (Slush Wallet)

// If using SDK integration
const tx = await slushWallet.signAndExecuteTransactionBlock({
  transactionBlock: txBytes,
  gasBudget: 50_000_000, // Manually set budget
  gasPayment: suiCoinObjectId // Explicit SUI coin for fees
});

3. Refresh Token Registry

• Go to Slush settings → "Refresh Token List" to refetch USDC metadata.

Advanced Debugging

Check USDC Metadata (CLI)

sui client object <USDC_COIN_METADATA_OBJECT_ID> --json

Look for:

{
  "type": "0x2::coin::CoinMetadata<0x5d4b302506645c37ff133b98c4b50a5ae14841659738d6d733dba0baf3b80148::usdc::USDC>",
  "symbol": "USDC",
  "decimals": 6
}

Alternative RPC

Switch Slush to a different Sui RPC endpoint:

Settings → Network → Custom RPC → https://fullnode.testnet.sui.io

Permanent Solutions

1. Slush Wallet Update
   Wait for a patch if this is a known app issue (check their GitHub).

2. Direct SUI Payment
   Use Sui’s Programmable Transaction Blocks to explicitly specify SUI for gas:

   let gas_payment = ctx.take_gas_coin(SUI_COIN_ID)?;
   

`

The Slush wallet may not be quoting gas fees for USDC transactions due to missing or incorrect transaction configuration, unsupported asset handling, or network connectivity issues. Based on Sui's architecture and standard wallet behavior:

1. Gas Payment Asset: On Sui, gas fees must be paid in SUI, not USDC. Wallets require a sufficient SUI balance in the sending account to cover gas. If your wallet has only USDC and no SUI, it cannot quote or pay gas fees. Acquire a small amount of SUI for gas.

2. Object Ownership and Availability: Ensure the USDC coin object is owned by your address and not currently locked in another transaction or shared object. Use sui_getObject to verify its status.

3. Transaction Construction: If the wallet attempts to build a programmable transaction block (PTB) involving USDC, it may fail to estimate gas if inputs are invalid or dependencies are unresolved. Ensure the wallet is up to date and supports the latest PTB standards.

4. Network or RPC Issues: The wallet may not be able to reach the Sui network or fetch current gas price data. Check your network connection and ensure the wallet is connected to the correct network (mainnet, testnet, etc.).

5. Wallet Support for USDC: Confirm that Slush wallet fully supports the specific USDC token contract on Sui (e.g., correct package and module ID). Incomplete token integration can prevent transaction estimation.

To resolve:

• Add SUI to your wallet for gas.
• Refresh asset balances.
• Restart the wallet and retry.
• Check Slush wallet’s status page or support channel for known issues.

If the problem persists, test the transaction using the Sui TypeScript SDK or an alternative wallet like Sui Wallet to isolate the issue.

you not have enough native token (Sui) to pay for the gas fee

It seems like you need to make sure you have enough of the native cryptocurrency in your wallet to cover the gas fees. For Slush wallet operations, you may need SUI to cover these costs. Check if you have enough SUI in your wallet to proceed with the transaction.

You’re seeing the issue where Slush wallet doesn’t quote a gas fee for USDC because, on Sui, gas fees must be paid in SUI, not in USDC or any other token. If your wallet holds only USDC and no SUI, the transaction can’t be simulated or submitted, and that’s why you’re not getting a gas quote or a “Proceed” button.

To fix this, you need to fund your wallet with a small amount of SUI. Even just a few thousandths of a SUI is enough to cover basic transfers or swaps. Once you have SUI in your wallet, Slush (and most Sui wallets) will be able to estimate the gas fee, simulate the transaction, and let you complete it.

This differs from some EVM chains where you can pay gas in wrapped tokens or alternative tokens on Layer 2. In Sui, only SUI is used for gas, which is enforced by the protocol.

Common mistakes include assuming USDC alone is enough to transact or not noticing that gas quotes fail silently due to missing SUI balance.

If Slush wallet isn’t quoting gas fees when you try to send or swap USDC, it usually means the wallet is unable to calculate the fee for the transaction because of a missing or outdated dependency, an RPC issue, or a misconfigured asset like USDC on the network you're using. Gas fees are computed based on simulated transaction blocks, and if the RPC endpoint Slush is using can’t fetch the USDC object, or if there’s no clear gas coin in your account, the quote step can silently fail.

To fix this, make sure your wallet holds enough SUI (or the native token of the network you're on) to cover the gas. Even if you're sending USDC, SUI is still needed for the gas fee. Also check that Slush is connected to a responsive and up-to-date RPC endpoint—try switching RPC nodes in the wallet settings if supported. In some cases, Slush might fail to fetch metadata for wrapped or bridged assets like USDC if the token registry is out of sync or the object IDs have changed after recent upgrades.

If the problem persists, a workaround is to manually construct the transaction using the Sui CLI or TypeScript SDK where you explicitly set the gas budget and input coin types. You can also follow the Slush development updates or file an issue if this behavior is affecting multiple users: https://github.com/slush-wallet/slush.