diff --git a/src/loaders/fabric/raw-fabric-metadata.ts b/src/loaders/fabric/raw-fabric-metadata.ts
new file mode 100644
index 0000000..b062a32
--- /dev/null
+++ b/src/loaders/fabric/raw-fabric-metadata.ts
@@ -0,0 +1,195 @@
+import { ACTION_NAME } from "@/action";
+import { FabricContactInformation } from "./fabric-contact-information";
+import { FabricDependencyList } from "./fabric-dependency";
+import { FabricDeveloper } from "./fabric-developer";
+import { FabricEnvironmentType } from "./fabric-environment-type";
+import { FabricMetadataCustomPayload } from "./fabric-metadata-custom-payload";
+
+/**
+ * Metadata file used by Fabric Loader to load mods.
+ */
+export interface RawFabricMetadata {
+    /**
+     * Needed for internal mechanisms.
+     *
+     * Must always be `1`.
+     */
+    schemaVersion: 1;
+
+    /**
+     * Defines the mod's identifier - a string of Latin letters, digits, underscores with length from 2 to 64.
+     */
+    id: string;
+
+    /**
+     * Defines the mod's version - a string value, optionally matching the Semantic Versioning 2.0.0 specification.
+     */
+    version: string;
+
+    /**
+     * Defines the list of ids of mod. It can be seen as the aliases of the mod.
+     *
+     * Fabric Loader will treat these ids as mods that exist. If there are other mods using that id, they will not be loaded.
+     */
+    provides?: string[];
+
+    /**
+     * Defines where mod runs:
+     *
+     *  - Only on the client side (client mod).
+     *  - Only on the server side (plugin).
+     *  - Or on both sides (regular mod).
+     */
+    environment?: FabricEnvironmentType;
+
+    /**
+     * Defines main classes of your mod, that will be loaded.
+     */
+    entrypoints?: {
+        /**
+         * Will be run first.
+         *
+         * For classes implementing `ModInitializer`.
+         */
+        main?: string[];
+
+        /**
+         * Will be run second and only on the client side.
+         *
+         * For classes implementing `ClientModInitializer`.
+         */
+        client?: string[];
+
+        /**
+         * Will be run second and only on the server side.
+         *
+         * For classes implementing `DedicatedServerModInitializer`.
+         */
+        server?: string[];
+
+        /**
+         * Custom entrypoint.
+         */
+        [key: string]: string[] | undefined;
+    };
+
+    /**
+     * A list of nested JARs inside your mod's JAR to load.
+     */
+    jars?: {
+        /**
+         * A path to the nested JAR.
+         */
+        file: string;
+    }[];
+
+    /**
+     * A dictionary of adapters for used languages to their adapter classes full names.
+     */
+    languageAdapters?: Record<string, string>;
+
+    /**
+     * A list of mixin configuration files.
+     */
+    mixins?: (string | {
+        /**
+         * The path to the mixin configuration file inside your mod's JAR.
+         */
+        config: string;
+
+        /**
+         * The same as upper level environment field.
+         */
+        environment?: FabricEnvironmentType;
+    })[];
+
+    /**
+     * For dependencies required to run. Without them a game will crash.
+     */
+    depends?: FabricDependencyList;
+
+    /**
+     * For dependencies not required to run. Without them a game will log a warning.
+     */
+    recommends?: FabricDependencyList;
+
+    /**
+     * For dependencies not required to run. Use this as a kind of metadata.
+     */
+    suggests?: FabricDependencyList;
+
+    /**
+     * For mods whose together with yours might cause a game crash. With them a game will crash.
+     */
+    breaks?: FabricDependencyList;
+
+    /**
+     * For mods whose together with yours cause some kind of bugs, etc. With them a game will log a warning.
+     */
+    conflicts?: FabricDependencyList;
+
+    /**
+     * Defines the user-friendly mod's name.
+     */
+    name?: string;
+
+    /**
+     * Defines the mod's description.
+     */
+    description?: string;
+
+    /**
+     * Defines the contact information for the project.
+     */
+    contact?: FabricContactInformation;
+
+    /**
+     * A list of authors of the mod.
+     */
+    authors?: (string | FabricDeveloper)[];
+
+    /**
+     * A list of contributors to the mod.
+     */
+    contributors?: (string | FabricDeveloper)[];
+
+    /**
+     * Defines the licensing information.
+     */
+    license?: string | string[];
+
+    /**
+     * Defines the mod's icon.
+     */
+    icon?: string | Record<string, string>;
+
+    /**
+     * Custom fields. Loader will ignore them.
+     */
+    custom?: {
+        /**
+         * Custom action payload.
+         */
+        [ACTION_NAME]?: FabricMetadataCustomPayload;
+
+        // TODO: Remove this field in v4.0.
+        /**
+         * Custom `ModManager` payload.
+         *
+         * @deprecated
+         *
+         * Use {@link ACTION_NAME} field instead.
+         */
+        modmanager?: FabricMetadataCustomPayload;
+
+        /**
+         * Custom key-value pairs.
+         */
+        [key: string]: unknown;
+    };
+}
+
+/**
+ * Name of the `fabric.mod.json` file, that contains raw Fabric metadata.
+ */
+export const FABRIC_MOD_JSON = "fabric.mod.json";