You can limit the amount of ERC20 tokens transferable with the policy.

To enable the policy:

const session: Session = {
  owners: {
    type: "ecdsa",
    accounts: [accountA],
  },
  policies: [
    {
      type: "spending-limits",
      limits: [
        {
          token: usdcAddress,
          amount: parseUnits("10", 6),
        },
        {
          token: wethAddress,
          amount: parseUnits("0.1", 18),
        },
      ],
    },
  ],
};

This will cap all transfers within the session to 10 USDC and 0.1 WETH in total.