Forge

Forge compiles, tests, and deploys Solidity smart contracts. It's the core development tool in the Foundry suite.

Core workflows

Build and test

Compile contracts and run tests with traces.

Clone verified contracts

Create a Forge project from explorer-verified source.

Document contracts

Generate and publish an API site from Solidity NatSpec.

Generate contract bindings

Create typed Alloy bindings and Solidity JSON helpers.

Advanced testing

Fuzz, invariant, and fork-based testing workflows.

Deploy and verify

Ship contracts with scripts and verify on explorers.

Debug and optimize

Trace failures and track gas usage.

Key capabilities

Feature	Description
Compilation	Compile contracts with configurable Solidity versions and optimization
Documentation	Generate a Vocs API site from Solidity source and NatSpec comments
Testing	Write tests in Solidity with fuzzing, forking, and gas reporting
Scripting	Deploy and interact with contracts using Solidity scripts
Verification	Verify source code on Etherscan and other explorers
Analysis	Inspect bytecode, storage layouts, and gas usage
Bindings	Generate typed Alloy crates and Solidity JSON helpers

Common workflows

Build your project

$ forge build

Solc 0.8.36 finished in 855.62ms
Compiler run successful!
warning[empty-block]: empty function body
   ╭▸ script/Counter.s.sol:10:29
   │
10 │     function setUp() public {}
   │                             ━━
   │
   ╰ help: ]8;;https://getfoundry.sh/forge/linting/empty-block\https://getfoundry.sh/forge/linting/empty-block]8;;\

Run all tests

$ forge test

Compiling...
No files changed, compilation skipped
Ran 2 tests for test/Counter.t.sol:CounterTest
[PASS] testFuzz_SetNumber(uint256) (runs: 256, μ: 50747, ~: 52565)
[PASS] test_Increment() (gas: 51847)
Suite result: ok. 2 passed; 0 failed; 0 skipped; finished in 4.09ms (3.85ms CPU time)
Ran 1 test suite in 8.57ms (4.09ms CPU time): 2 tests passed, 0 failed, 0 skipped (2 total tests)

Run tests with verbose output

$ forge test -vvvv

Compiling...
No files changed, compilation skipped
Ran 1 test for test/OwnerUpOnly.t.sol:OwnerUpOnlyTest
[PASS] test_IncrementAsOwner() (gas: 59372)
Traces:
  [59372] OwnerUpOnlyTest::test_IncrementAsOwner()
    ├─ [2407] OwnerUpOnly::count() [staticcall]
    │   └─ ← [Return] 0
    ├─ [43524] OwnerUpOnly::increment()
    │   └─ ← [Stop]
    ├─ [2407] OwnerUpOnly::count() [staticcall]
    │   └─ ← [Return] 1
    └─ ← [Stop]
Suite result: ok. 1 passed; 0 failed; 0 skipped; finished in 287.16µs (62.42µs CPU time)
Ran 1 test suite in 6.97ms (287.16µs CPU time): 1 tests passed, 0 failed, 0 skipped (1 total tests)

Deploy via script

$ forge script script/Deploy.s.sol --broadcast --rpc-url $RPC_URL

Verify a deployed contract

$ forge verify-contract $ADDRESS src/Counter.sol:Counter --etherscan-api-key $KEY

Learn more

Building contracts — Compilation, artifacts, and optimization
Cloning verified contracts — Recreate a project from an address or proxy implementation
Contract documentation — NatSpec, generated API pages, and publishing
Contract bindings — Alloy bindings and Solidity JSON helpers
Testing — Writing and running tests
Scripting — Deployment and on-chain interactions
Debugging — Traces, debugger, and troubleshooting
Gas tracking — Snapshots and reports
Linting — Code style enforcement
Reference — Full CLI reference

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