Composeinfo file format 2.0

composeinfo.json files provide details about composes which includes product information, variants, architectures and paths.

Changes from 1.1

• Variant paths are now Location objects instead of plain strings

• Location objects include url, size, checksum, and local_path fields

• URLs may be HTTPS URLs, OCI registry references, or relative paths

• force_version parameter added to serialize() for version control

Location Object

All variant paths (os_tree, packages, source_tree, source_packages, debug_tree, debug_packages, repository, source_repository, debug_repository, identity, isos, jigdos) are stored as Location objects in v2.0 format, instead of plain relative path strings.

Since variant paths reference directories rather than individual files, their Location objects typically have null values for checksum and size. The url and local_path fields indicate where the directory tree can be found.

See Location for details.

File Format

Composeinfo is stored as a JSON serialized dictionary. It’s recommended to sort keys alphabetically and use 4 spaces for indentation in order to read and diff composeinfo.json files easily.

{
    "header": {
        "type": "productmd.composeinfo",            # metadata type; "productmd.composeinfo" required
        "version": "2.0"                            # metadata version; format: $major<int>.$minor<int>
    },
    "payload": {
        "compose": {
            "id": <str>,
            "date": <str>,
            "respin": <int>,
            "type": <str>,
            "label": <str|unset>,
            "final": <bool=false>
        },
        "release": {
            "name": <str>,
            "version": <str>,
            "short": <str>,
            "type": <str>,
            "is_layered": <bool=false>,
        },
        "base_product": {                           # optional; present only for layered products
            "name": <str>,
            "version": <str>,
            "short": <str>,
            "type": <str>,
        },
        "variants": {
            variant_uid<str>: {
                "id": <str>,
                "uid": <str>,
                "name": <str>,
                "type": <str>,
                "arches": [<str>],
                "paths": {
                    path_category<str>: {           # os_tree, packages, source_tree, etc.
                        arch<str>: {                # Location object [changed in 2.0]
                            "url": <str>,           # HTTPS URL, OCI reference, or relative path
                            "size": <int>,          # size in bytes
                            "checksum": <str>,      # "algorithm:hexdigest" format
                            "local_path": <str>,    # relative path for v1.x filesystem layout
                        },
                    },
                },
            },
        },
    },
}

Examples

Fedora 41 compose with HTTPS URLs:

{
    "header": {
        "type": "productmd.composeinfo",
        "version": "2.0"
    },
    "payload": {
        "compose": {
            "date": "20260204",
            "id": "Fedora-41-20260204.0",
            "respin": 0,
            "type": "production",
            "label": "GA"
        },
        "release": {
            "name": "Fedora",
            "short": "Fedora",
            "version": "41",
            "is_layered": false,
            "type": "ga"
        },
        "variants": {
            "Server": {
                "id": "Server",
                "uid": "Server",
                "name": "Fedora Server",
                "type": "variant",
                "arches": ["x86_64", "aarch64"],
                "paths": {
                    "os_tree": {
                        "x86_64": {
                            "url": "https://cdn.fedoraproject.org/.../Server/x86_64/os/",
                            "size": 2847,
                            "checksum": "sha256:a1b2c3d4...",
                            "local_path": "Server/x86_64/os"
                        }
                    },
                    "packages": {
                        "x86_64": {
                            "url": "https://cdn.fedoraproject.org/.../Server/x86_64/os/Packages/",
                            "size": 0,
                            "checksum": "sha256:c3d4e5f6...",
                            "local_path": "Server/x86_64/os/Packages"
                        }
                    }
                }
            }
        }
    }
}