For normal use, prefer the dep, link, and toolchain commands over manual metadata edits. These commands apply changes transactionally and preserve JSONC comments.

Projects and libraries

c3pm reads two kinds of C3 metadata file. They share the same dependency and native-input formats, but describe different parts of the graph:

File	Describes	Identity and ownership
`project.json`	The root project, its build targets, and direct dependencies	Does not require `provides`; owns the c3pm `toolchain` and `links` settings
`.c3l/manifest.json`	One reusable C3 library and the requirements inherited by its consumers	Must declare `provides`; carries the library’s C3 dependencies and native inputs

Both files can carry c3pm-specific settings under vendor.c3pm. See the c3pm metadata reference for the shared dependency and Nix fields and the project-only toolchain settings.

Project metadata

The standard dependencies array tells c3c which C3 libraries the project uses. See the c3pm metadata reference for the vendor.c3pm fields in this example.

This complete project.json example declares SQLite as both a C3 dependency and a native build input:

{
  "dependencies": ["sqlite3"],
  "dependency-search-paths": ["lib"],
  "vendor": {
    "c3pm": {
      "toolchain": {
        "c3c": "0.8.4",
        "nixpkgs": "github:NixOS/nixpkgs/nixpkgs-unstable"
      },
      "c3": {
        "dependencies": {
          "sqlite3": {
            "source": "github",
            "owner": "SMFloris",
            "repository": "c3c-vendor",
            "rev": "c3pm",
            "subdir": "libraries/sqlite3.c3l"
          }
        }
      },
      "nix": {
        "nativeBuildInputs": ["pkg-config"],
        "buildInputs": ["sqlite"]
      }
    }
  }
}

C3 library metadata

A library manifest describes one .c3l package. Its required provides value is the package name used in dependency lists. The library’s own C3 dependencies and native inputs become part of the graph whenever a project can reach that library. See the c3pm metadata reference for the shared vendor.c3pm fields.

To prepare and version a reusable binding, see Package C3 libraries.

This .c3l/manifest.json example provides the sqlite3 C3 library, asks c3c to link sqlite3, and makes the nixpkgs sqlite package available:

{
  "provides": "sqlite3",
  "dependencies": [],
  "linked-libraries": ["sqlite3"],
  "vendor": {
    "c3pm": {
      "nix": {
        "buildInputs": ["sqlite"]
      }
    }
  }
}