Stress-test governance proposals
before they execute_

FPS is a Foundry framework for simulating governance proposals from end-to-end, covering deployment scripts, calldata generation and post-execution validation. Catch bugs before they reach mainnet.

Read the Docs View on GitHub

Governance is the single point of failure

[CRITICAL] Governance bugs cost protocols millions in locked or lost funds
[WARNING] Manual calldata encoding is error-prone and hard to review
[WARNING] No standard way to test proposals against live state pre-execution
[FPS] Simulate the full lifecycle. Validate transactions before you execute.
How It Works

Three steps. Full coverage.

01

Write

Define proposal actions in Solidity using FPS's build() pattern. Deploy contracts, set parameters, transfer ownership. Write it like normal code.

$ function build() override { ... }
02

Simulate

FPS forks mainnet and simulates the full governance lifecycle (propose, vote, queue, execute) using Foundry cheat codes to bypass delays.

$ forge script proposals/MyProposal.sol
03

Validate

Automated checks verify post-execution state matches expectations. Confirm ownership, balances, and configuration before anything touches mainnet.

$ function validate() override { ... }
Governance Types

Works with your governance stack

FPS supports four governance architectures out of the box, with an extensible base for adding more.

Multisig

Gnosis Safe

Generate multicall calldata and paste directly into the Safe UI. Simulate actions from the actual multisig address.

View guide →

Timelock

OZ TimelockController

Simulate scheduleBatch and executeBatch with automatic delay bypass. Full lifecycle testing.

View guide →

Governor Bravo

Compound

Propose, vote, queue, execute. The complete governance lifecycle simulated in a single test run.

View guide →

OZ Governor

OpenZeppelin

OpenZeppelin Governor with timelock controller support. Compatible with all OZ governance extensions.

View guide →
Mainnet Examples

Tested against real governance contracts

FPS ships with examples that fork mainnet state and simulate against live governance contracts.

Timelock TimelockController with scheduled execution and delay bypass Governor Bravo Full propose → vote → queue → execute lifecycle Multisig Gnosis Safe multicall generation and simulation OZ Governor OpenZeppelin Governor with timelock support
Quick Start

Get started

# Install FPS into your Foundry project
$ forge install solidity-labs-io/forge-proposal-simulator

# Set up remappings
$ echo @forge-proposal-simulator=lib/forge-proposal-simulator/ >> remappings.txt

# Create your addresses JSON and proposal contract (see docs)
# Then run it
$ forge script proposals/MyProposal.sol --fork-url $RPC_URL
Full getting started guide → Example repository →
86 GitHub Stars
17 Forks
6 Contributors
MIT License
Open Source Public Good

Support FPS development

FPS is free, fully open source, and MIT licensed. It's built and maintained as a public good by Solidity Labs. If FPS has helped your protocol ship safer governance, consider supporting continued development.

100% of donations go directly to development.

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