Forge

Forge is a command-line tool that ships with Foundry. Forge tests, builds, and deploys your smart contracts.

Forge is part of the Foundry suite and is installed alongside cast, chisel, and anvil. If you haven’t installed Foundry yet, see Foundry installation.

Getting started

The best way to understand Forge is to simply try it (in less than 30 seconds!).

First, let’s initialize a new counter example repository:

$ forge init counter

Next cd into counter and build :

$ forge build

[⠊] Compiling...
[⠔] Compiling 27 files with Solc 0.8.28
[⠒] Solc 0.8.28 finished in 452.13ms
Compiler run successful!

Let’s test our contracts:

$ forge test

[⠊] Compiling...
No files changed, compilation skipped

Ran 2 tests for test/Counter.t.sol:CounterTest
[PASS] testFuzz_SetNumber(uint256) (runs: 256, μ: 31121, ~: 31277)
[PASS] test_Increment() (gas: 31293)
Suite result: ok. 2 passed; 0 failed; 0 skipped; finished in 5.35ms (4.86ms CPU time)

Ran 1 test suite in 5.91ms (5.35ms CPU time): 2 tests passed, 0 failed, 0 skipped (2 total tests)

Finally, let’s run our deployment script:

$ forge script script/Counter.s.sol

[⠊] Compiling...
No files changed, compilation skipped
Script ran successfully.
Gas used: 109037

If you wish to simulate on-chain transactions pass a RPC URL.

📚 Reference

See the forge Reference for a complete overview of all the available subcommands.