Flowther (VSCode extension)

Flowther shows state-changing entry points in a Solidity workspace and renders their call graphs as an interactive tree.

Screenshots

Default panel view (All entry points grouped by file)

Features

• Groups workflows by file
• Entry points = public/external functions that are not view/pure + constructor/receive/fallback
• Inherited functions from abstract contracts are shown in concrete contract files with dimmed from ContractName indicator
• Call trees preserve execution order (including repeated calls) and include modifier/base-constructor paths
• Interface/abstract targets are resolved to concrete override implementations when possible
• Click any node to jump to its definition (or to the callsite when no definition exists, e.g. abi.encode, keccak256, bytes.concat)
• Jump highlights the target line for ~0.5s
• Right click an entry point to Hide Flow
• Right click an entry point to Show Only This Flow (focus mode, auto-expands all calls)
• Right click any function to Expand All nested calls
• Right click a file to Hide File or Unhide All Flows In File
• Call nodes show icons + call-type badges, and can optionally display call order numbers
• Variables panel: shows state variables (excluding constants/immutables) and which entry points can modify them (directly or through internal calls); inherited variables show from ContractName indicator

Show Only This Flow (focus mode)

Variables panel (State variables grouped by file/contract with modifying entry points)

Installation

git clone https://github.com/nisedo/Flowther.git && cd Flowther && npm install && npx @vscode/vsce package && code --install-extension flowther-*.vsix

Requirements

• Slither - one of:
  • Slither installed in your Python environment (uv pip install slither-analyzer)
  • uv installed (Flowther will use uvx --from slither-analyzer automatically)
  • pipx installed (Flowther will use pipx run --spec slither-analyzer automatically)
• A working Solidity build setup (e.g. Foundry/Hardhat) or solc for single-file analysis

Usage

1. Open a Solidity workspace in VSCode
2. Open the Flowther activity bar icon
   • Workflows: entry points and their call trees
   • Variables: state variables and entry points that modify them
3. Run "Flowther: Refresh Workflows" (command palette) if it doesn't auto-load

Settings

• flowther.targetPath: optional analysis target inside the workspace (useful for monorepos / nested Foundry/Hardhat projects). Can be a Solidity file or a project root; if empty, Flowther auto-detects a supported project in the workspace.
• flowther.pythonPath: python interpreter (leave empty to auto-detect from the slither CLI)
• flowther.slitherRepoPath: optional path to a Slither checkout (leave empty to use the installed slither python package)
• flowther.solcPath: optional solc path
• flowther.solcArgs: optional solc args string
• flowther.filterPaths: optional filter paths passed to Slither
• flowther.excludeDependencies: hide dependency-defined entry points (default true)
• flowther.expandDependencies: expand call graphs into dependency-defined functions (default true)
• flowther.showCallOrderNumbers: prefix call nodes with execution order (default true)
• flowther.maxCallDepth: call graph depth cap (default 10)

Troubleshooting

• “Failed to import Slither”: set flowther.pythonPath to the interpreter where slither is installed, or set flowther.slitherRepoPath to a Slither checkout.
• “Invalid compilation: … is a directory”: set flowther.targetPath to your Foundry/Hardhat/etc project root (folder containing foundry.toml / hardhat.config.*) or to a specific .sol file.