General
Q: What is USDCx?
A: USDCx is a dollar-denominated stablecoin issued by Stacks, fully backed by USDC held in Circle xReserve. xReserve is a non-custodial smart contract and interoperability infrastructure that provides deposit and minting attestations for USDCx on Stacks, enabling secure and verifiable asset issuance and crosschain transfers. It is 1:1 interoperable with native USDC on other supported chains.
Q: Who issues USDCx?
A: USDCx is issued by Stacks via Circle's xReserve infrastructure. The USDC backing is held and managed by Circle—the largest and most regulated stablecoin issuer in the world.
Q: Is USDCx safe?
A: Yes. USDCx is backed 1:1 by USDC held in Circle-managed reserves. Circle is the largest and most regulated stablecoin issuer. xReserve provides transparent, verifiable asset backing with cryptographic attestations for deposits and minting. There are no third-party bridges or wrapped assets involved.
Q: What's the USDCx token contract address?
A:
Mainnet: SP120SBRBQJ00MCWS7TM5R8WJNTTKD5K0HFRC2CNE.usdcx
Testnet: ST1PQHQKV0RJXZFY1DGX8MNSNYVE3VGZJSRTPGZGM.usdcx
Q: Where can I find official USDCx documentation?
A: Visit docs.stacks.co/learn under the "Bridging" section for the official USDCx overview and migration guide.
USDCx vs aeUSDC
Q: What's the difference between USDCx and aeUSDC?
A:
aeUSDC is bridged USDC via Allbridge—a third-party bridge.
USDCx is issued directly through Circle's xReserve system—no third-party bridge required.
USDCx offers better security guarantees and is the official Circle-supported path for USDC on Stacks.
Q: Should I migrate from aeUSDC to USDCx?
A: Yes. The ecosystem will gradually deprecate aeUSDC in favor of USDCx to consolidate liquidity over the coming months. Migrating ensures you're on the official, Circle-supported stablecoin path.
Q: How do I migrate from aeUSDC to USDCx?
A: There are two paths:
Option 2: Manual Bridge Path (Available Now)
Bridge aeUSDC out to Ethereum via Allbridge
Bridge USDC back in via bridge.stacks.com
Receive USDCx on Stacks
Option 2: Direct Swap on Bitflow (Coming January)
Go to app.bitflow.finance/swap
Connect your wallet (Leather or Xverse)
Select aeUSDC as "From" token
Select USDCx as "To" token
Enter amount and click "Swap"
Confirm in your wallet
Q: Will aeUSDC stop working?
A: aeUSDC will continue to function, but the ecosystem will gradually deprecate it in favor of USDCx over the coming months. We recommend migrating to USDCx to benefit from consolidated liquidity and Circle's native infrastructure.
Getting USDCx
Q: How do I get USDCx?
A: Bridge USDC from Ethereum to Stacks via the official bridge:
Go to bridge.stacks.com
Connect your Ethereum wallet
Select USDC as the token to bridge
Enter amount
Connect your Stacks wallet (Leather or Xverse)
Confirm the bridge transaction
Wait for confirmation (may take 10-30 minutes)
USDCx appears in your Stacks wallet
Q: Can I buy USDCx directly?
A: Currently, you need to bridge USDC from Ethereum via bridge.stacks.com. Direct on-ramps may be available in the future.
Q: How long does bridging take?
A: Bridge transactions typically take 10-30 minutes to complete. Do not attempt to bridge again until your first transaction confirms.
Trading on Bitflow
Q: Can I swap USDCx on Bitflow?
A: Bitflow's USDCx liquidity pools are launching in early January 2026. Once live, you'll be able to swap USDCx with hundreds of tokens on Stacks.
Q: What pairs will be available on Bitflow?
A: At launch in January:
BTC/USDCx (flagship pair)
aeUSDC/USDCx (for migration)
Multi-hop swaps to hundreds of tokens (STX, sBTC, Runes, memecoins, etc.)
More pairs will be added over time.
Q: When do Bitflow's USDCx pools go live?
A: January 2026. Follow @BitflowFinance on X for the exact launch date.
Q: Why can't I swap USDCx on Bitflow yet?
A: USDCx liquidity pools are launching in January. For now, you can bridge USDCx via bridge.stacks.com. Swaps on Bitflow will be available once pools go live.
Wallets & Compatibility
Q: Which wallets support USDCx?
A: USDCx is supported by:
Leather
Xverse
Fordefi
Asigna
Q: I don't see USDCx in my wallet. What do I do?
A: USDCx may need to be manually added as a token. Use the contract address: SP120SBRBQJ00MCWS7TM5R8WJNTTKD5K0HFRC2CNE.usdcx
You can also check the Stacks explorer to confirm your bridge transaction completed successfully.
Troubleshooting
Q: My bridge transaction is pending. What should I do?
A: Bridge transactions can take 10-30 minutes. Check the transaction status on bridge.stacks.com. Do not attempt to bridge again until the first transaction confirms or fails.
Q: My bridge transaction failed. What happened?
A: Common causes:
Insufficient ETH for gas fees on Ethereum
Network congestion
Wallet connection issues
Try refreshing the page, reconnecting your wallet, and attempting again. Ensure you have enough ETH for gas.
Q: I bridged but don't see USDCx in my wallet.
A:
Confirm the transaction completed on the Stacks explorer
Manually add the USDCx token using the contract address
If the transaction shows complete but tokens haven't arrived, wait a few more minutes—there can be delays
Q: Who do I contact for USDCx issues?
A:
For bridge issues: Check bridge.stacks.com or contact Stacks support
For Bitflow swap issues (after January launch): Contact Bitflow support
For Circle/xReserve questions: Refer to Circle documentation
Why USDCx Matters
Q: Why is USDCx important for Bitcoin DeFi?
A: Stablecoins are the backbone of crypto liquidity. BTC/USDC is the most traded pair in crypto—and until now, Bitcoin didn't have a native, trusted path to access it. USDCx brings Circle's institutional-grade stablecoin infrastructure to Bitcoin, allowing capital to flow INTO Bitcoin DeFi rather than around it. This is the foundation for scaling BTCFi.
Q: What can I do with USDCx?
A: USDCx unlocks new use cases on Bitcoin:
Swap: Trade BTC ↔ USDC on Bitflow (January)
Lend/Borrow: Use USDCx in lending protocols like Zest
Collateral: Borrow USDCx against BTC on Granite
Liquidity: Provide liquidity to earn yields