Foundry Cheatcode Tutorial - Tenderly

This tutorial builds a modular cheatcode playground in Foundry. You deploy a single contract to a Virtual Environment, then call its functions with cast send to exercise every Solidity precompile cheatcode from inside transactions.

What you build

Three files:

src/IVnetPrecompile.sol: the precompile interface.
src/MyTestSetup.sol: a playground contract. Each function wraps one precompile call, so you deploy once and call individual functions to manipulate one piece of state at a time.
script/Deploy.s.sol: a forge script deploy.

Function map

Category	Function	Wraps
Balance	`forceBalance(account, newBalance)`	`setBalance`
	`topUp(account, amount)`	`addBalance`
ERC-20	`fundToken(token, holders[], amount)`	`setErc20Balance`
	`maxToken(token, account)`	`setMaxErc20Balance`
Nonce	`forceNonce(account, newNonce)`	`setNonce`
Storage	`writeStorage(target, slot, value)`	`setStorageAt`
	`readStorage(target, slot) → bytes32`	`getStorageAt`
Events	`fireTransfer(token, from, to, amount)`	`emitEvent` (ERC-20 `Transfer`)
	`fireEvent(target, topics[], data)`	`emitEvent` (generic, 0–4 topics)
Demo	`demoScenario(account)`	Combines balance, nonce, storage, USDC `Transfer`

Prerequisites

A Tenderly account with a project.
Foundry installed (curl -L https://foundry.paradigm.xyz | bash && foundryup).

See also

Solidity Cheatcodes reference, full interface definition and function table.
Admin RPC, state manipulation from outside a transaction via JSON-RPC.

Bytecode deployment cheatcode The Graph and Virtual Environments

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