The Package Manager

Fe includes built-in package management through the fe command-line tool. This handles project creation, building, and dependency resolution.

Core Commands

Building Projects

Compile your Fe project:

fe build

This compiles all source files in src/ and resolves dependencies defined in fe.toml.

Checking Code

Verify your code compiles without producing output:

fe check

Useful for quick validation during development.

Dependency Resolution

When you build a project, the Fe compiler:

1. Reads fe.toml to find dependencies
2. Resolves local path dependencies from the filesystem
3. Fetches git dependencies from remote repositories
4. Compiles dependencies before your project
5. Makes dependency exports available for import

Workflow

A typical development workflow:

1. Create project structure with fe.toml and src/lib.fe
2. Add dependencies to fe.toml as needed
3. Write code in src/ directory
4. Build with fe build to compile and check for errors
5. Iterate on your code

Build Output

When you run fe build, the compiler produces:

• Compiled contract artifacts
• ABI definitions for contract interfaces
• Yul intermediate representation (optional)

Output location and format depend on your build configuration.

Error Messages

The Fe compiler provides helpful error messages:

error: Cannot find value `undefined_var` in this scope
  --> src/lib.fe:10:5
   |
10 |     undefined_var
   |     ^^^^^^^^^^^^^ not found in this scope

Use these messages to locate and fix issues in your code.

Next Steps

See Dependencies to learn how to add external ingots to your project.