Skip to main content

FAQ

Wallet users​

Does becoming a smart account change my address?​

No. Email sign-in uses EIP-7702: your existing address starts using smart-account code, and the address stays the same. (Only browser wallets such as MetaMask get a new address — see How it works.)

What happens after my free operations are used?​

The network fee is taken in USDC.e from your balance — you do not need ETH in the wallet. The wallet shows the most the fee can be before you confirm; you are charged the actual amount, usually less. Free operations are also limited per day and per month, and those limits may change during early access.

What costs a fee and what does not?​

Sends, setting up agents, and revoking agents are operations (free while your free operations last, then a small USDC.e fee). Paying an x402 service — by you or by your agent — is only a signature and has no fee.

Who holds my key? Can HPP move my money?​

Your key is managed by Privy, the sign-in provider; HPP does not store it. HPP can only cover (or charge) the fee for operations you sign — it cannot move your USDC.e.

I lost my device. Is my wallet gone?​

No. Sign in with the same email on a new device and you get the same wallet. If you lose access to the email itself, you lose the wallet — turn on two-factor authentication for your email, and see Settings for exporting your key.

How do I revoke an agent I added on another device?​

Open Agents → Revoke a payment delegation that is not in this list and paste the HPP_PAYMENT_DELEGATION value you saved when you issued it.

What can an agent do with the permission I give it?​

Only pay x402 services in USDC.e, up to the limit and before the expiry you chose. It cannot move your other funds or change your account. See the security model.

Where do I ask for help?​

In HPP Telegram. Never share your email code or private key with anyone.

Developers​

Do I need HPP's SDK?​

No — any ERC-4337 client can use aa.hpp.io/rpc, within these limits: sponsorship goes through HPP's paymaster only, sponsorship is for EntryPoint v0.7, and accounts must be Kernel, SimpleAccount, or EIP-7702. The SDK also saves you from several HPP-specific traps — see Reference → If you bypass the SDK.

Can my users pay gas in USDC.e without a policy from HPP?​

Not yet. Paying gas in USDC.e goes through HPP's token paymaster, which needs a policy. Without a policy, the account pays its own gas in ETH.

How do I get gas sponsorship?​

Open a Gas sponsorship request on GitHub — see Gas sponsorship → Apply. Start on HPP Sepolia.

Can I put policyId and anchorId in my frontend?​

Be careful with anchors. An anchor ID is all the paymaster needs to count an operation against that user's quota, so treat it like a session token: never derive it from public data, and prefer sending sponsored requests from your backend or through a backend proxy. See Keep anchors private.

Why can one account send only one operation at a time?​

Operations from the same account share a nonce, so each waits for the previous one. Batch the calls into one operation with sendCalls([...]).

Payment delegation or session — which do I need?​

A payment delegation if an agent pays x402 services. A session if a bot or backend sends its own operations to specific contracts. Agent permissions compares them.

Which EntryPoint does HPP use?​

v0.7 (0x0000000071727De22E5E9d8BAf0edAc6f37da032) — used by Kernel, the SDK, and sponsorship. The bundler also accepts v0.8 (0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108) for self-paid operations.

Where do I report a bug?​

hpp-io/hpp-aa-sdk issues. Never post private keys, anchors, or policy IDs.