> ## Documentation Index > Fetch the complete documentation index at: https://docs.eco.com/llms.txt > Use this file to discover all available pages before exploring further. # Pay USDC from the Pot > One transaction on Base, Ethereum or Arc that pays USDC from the Pot to one recipient and returns the amount the recipient received. The program pays `amount` of USDC from the Pot to `to`, reads the recipient's balance before and after the transfer, and returns the difference. It reverts when the Pot holds less than `amount` or when the recipient's balance rises by anything other than `amount`. **Target chains:** Base, Ethereum and Arc. The same source compiles for all three; the recorded simulation uses a Base fork. ## Prerequisites Install the [Sauce CLI](https://docs.eco.com/sauce-sdk/installation.md) to compile and simulate. To send the transaction, configure a wallet with funds for gas and the Kitchen fee. Provide the required tokens in your Pot once it is deployed, or through `--fund`; see [funding](https://docs.eco.com/sauce-sdk/cli/funding.md). ## Program `pot` is the Pot the program runs on, available without declaring it ([Names](https://docs.eco.com/sauce/names.md#balances)). ```ts pay.sauce.ts theme={null} // Pays `amount` of USDC from the Pot to `to`, measures what `to` received, and returns it. The // cook reverts, and nothing moves, when `amount` or `to` is zero, when the Pot holds less USDC // than `amount`, or when the balance of `to` rises by a different amount. The same file compiles // for Base, Ethereum and Arc: on each, `pot.USDC` is the Pot's balance of that chain's USDC token. // // sauce simulate pay.sauce.ts --chain --owner
\ // --assume-balance USDC:n --args // sauce run pay.sauce.ts --chain --wallet --args // // to: Address who is paid, an address on the chain the program runs on // amount: Uint256 the USDC to pay, in its base units (6 decimals): 1000000 is 1 USDC // // On Base, pay 1 USDC to from a Pot that holds at least 1 USDC: // // sauce run pay.sauce.ts --chain base --wallet me \ // --args 1000000 function main(to: Address, amount: Uint256): Uint256 { require(amount > 0, "amount is zero"); require(to != 0, "no recipient"); require(pot.USDC >= amount, "not enough USDC in the Pot"); const before = USDC.balanceOf(to); USDC.transfer(to, amount); const received = USDC.balanceOf(to) - before; require(received == amount, "recipient received a different amount"); return received; } ``` ## How it works * `pot.USDC` is the Pot's balance of the chain's `USDC` token, and `USDC.balanceOf(to)` the recipient's. On Arc, where USDC is also the native coin, both read the six-decimal token; `pot.balance` would read the 18-decimal coin. * `received` is measured at the recipient, not assumed from the transfer. The `require(received == amount, ...)` line reverts the cook for a token that takes a fee on transfer. * `main` returns `Uint256`, so `sauce simulate` decodes the return value and prints it as `main returns Uint256: ...`. * Each `require` carries a reason. A reverted simulation prints that reason, which is what `--expect-revert` matches. ## Run the example **1. Compile** ```bash theme={null} sauce compile pay.sauce.ts --chain base ``` Replace `base` with `ethereum` or `arc`. Each compile is 433 bytes, but the bytecode differs, because each carries its chain's USDC address. **2. Simulate** ```bash theme={null} sauce simulate pay.sauce.ts --chain base --owner \ --assume-balance USDC:5 --args 1000000 ``` `--assume-balance USDC:5` gives the Pot 5 USDC for this simulation only, by state override. The output lists each transfer and each address's net change. **3. Send** ```bash theme={null} sauce run pay.sauce.ts --chain base --wallet \ --fund USDC:1 --args 1000000 ``` `sauce tx` prints the unsigned transaction instead, for your own signer: ```bash theme={null} sauce tx pay.sauce.ts --chain base --owner \ --fund USDC:1 --args 1000000 ``` ## Simulation result Simulated on a local fork of Base at block 53122821 with the current contracts, with the command above, paying 1 USDC to `0x7099…79C8`. Nothing was signed or sent. ```text theme={null} The cook succeeds from 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266: gas used 117483 for the cook, after the Pot's deploy (1. below), returns 0x00000000000000000000000000000000000000000000000000000000000f4240 main returns Uint256: 1000000 Left in the Pot, not in the owner's wallet: 4 USDC (it held 5 USDC before) ... 2. the cook, from the owner 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266, gas used 117483 Assumed for this simulation only, by state override: the Pot holds 5 USDC: --assume-balance (its balance word 0xcb5320fe60abad81834e0e994e8a7a8eb33991917b05a5c0498fe1c0373a2087: Solidity mapping at slot 9) What moved, in order: ... [3] Pot -> 0x7099…79C8 1 USDC Net balance changes: 0xDcFCc75A3C9a0EC798CAf81B6C84D4c5d5988c49 (the Pot): -1 USDC 0x70997970C51812dc3A010C7d01b50e0d17dc79C8: +1 USDC 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 (owner): -0.00000374478538635 ETH ``` The Pot did not exist yet, so the simulation deployed it first. The recipient's balance rose by exactly 1 USDC, which `main` returned as `1000000`. On the same fork, the guard, with a Pot holding 0.5 USDC: ```bash theme={null} sauce simulate pay.sauce.ts --chain base --owner \ --assume-balance USDC:0.5 --args 1000000 \ --expect-revert "not enough USDC in the Pot" ``` ```text theme={null} As expected, the cook reverts: the program threw "not enough USDC in the Pot" The cook reverts: the program threw "not enough USDC in the Pot" ``` The guard stopped the cook before any USDC moved, and `--expect-revert` exited 0 because the reason matched. ## Next steps * [Pay a list of recipients](https://docs.eco.com/quickstarts/sauce/pay-list.md): the same payment in a loop, with a cap on the total * [Payroll by weight](https://docs.eco.com/quickstarts/sauce/payroll-by-weight.md): split one budget by weight * [Native USDC payment on Arc](https://docs.eco.com/quickstarts/sauce/arc-native-payment.md): pay as native value on Arc * [`sauce simulate`](https://docs.eco.com/sauce-sdk/cli/simulate), [`sauce run`](https://docs.eco.com/sauce-sdk/cli/run), [Names](https://docs.eco.com/sauce/names.md) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.