​
What Are Smart Sessions?

Smart Sessions are the key to unlocking a seamless, Web2-like user experience in your dApp. Instead of asking users to approve every single transaction, a Smart Session allows a user to grant your dApp a temporary, secure, and strictly limited set of permissions. Think of it less like handing over a master key, and more like giving your application a special-purpose keycard with clear rules and an expiration date. This is extremely useful for enabling powerful features like:
  • Seamless UX: Eliminate repetitive wallet pop-ups for common actions like staking, swapping, or listing items.
  • Automation: Execute transactions on a user’s behalf, even when they are offline, for features like automated strategies or subscription services.
  • Granular Security: Define exactly what your dApp can and cannot do, minimizing risk and building user trust.

​
How It Works: Key Concepts

When you configure a Smart Session, there are a few important concepts that the SDK handles to make the developer experience as simple as possible.

​
Paying for Gas with Native Tokens (ETH, MATIC, etc.)

To enable your dApp to pay for transaction fees using the user’s native tokens, a budget must be set. You define this budget in the nativeTokenSpending.valueLimit property of your session configuration. To make this possible, the SDK automatically adds a permission for the Sequence Trusted Forwarder contract (0xABAAd93EeE2a569cF0632f39B10A9f5D734777ca). This special contract securely handles the gas payment on the user’s behalf, and its spending is strictly limited by the valueLimit you set.

​
Paying for Gas with ERC-20 Tokens (USDC, etc.)

Our SDK simplifies paying for gas with ERC-20 tokens immensely. You do not need to configure any special permissions for this. When a transaction requires a fee and the user selects the fee option, the SDK automatically handles the payment using that token.

​
Security Best Practice: The Principle of Least Privilege

We strongly recommend adding specific rules to every function permission you define.
This enforces the principle of least privilege: granting a session only the exact permissions it needs to perform its job, and nothing more. While you can grant unrestricted access to a contract by providing an empty functions array, this should be done with caution as it gives the session broad authority. It is always more secure to be explicit. For example, locking an approve function to a specific spender address is always safer than leaving it open for any address. By defining clear rules, you build more secure Smart Sessions and provide greater peace of mind for your users.

​
More Information

For a more detailed explanation of how Smart Sessions work, see here.