diff --git a/src/platforms/modrinth/modrinth-api-client.ts b/src/platforms/modrinth/modrinth-api-client.ts
new file mode 100644
index 0000000..ad948e4
--- /dev/null
+++ b/src/platforms/modrinth/modrinth-api-client.ts
@@ -0,0 +1,256 @@
+import { Fetch, HttpRequest, HttpResponse, createFetch, defaultResponse, simpleCache, throwOnError } from "@/utils/net";
+import { asArray } from "@/utils/collections";
+import { ModrinthProject, ModrinthProjectPatch } from "./modrinth-project";
+import { ModrinthVersion, ModrinthVersionInit, ModrinthVersionPatch, ModrinthVersionSearchTemplate, UnfeaturableModrinthVersion, packModrinthVersionInit, packModrinthVersionSearchTemplate } from "./modrinth-version";
+import { ModrinthUnfeatureMode } from "./modrinth-unfeature-mode";
+import { ModrinthLoader } from "./modrinth-loader";
+import { ModrinthGameVersion } from "./modrinth-game-version";
+
+/**
+ * The API version used for making requests to the Modrinth API.
+ */
+const MODRINTH_API_VERSION = 2;
+
+/**
+ * The base URL for the Modrinth API.
+ */
+export const MODRINTH_API_URL = `https://api.modrinth.com/v${MODRINTH_API_VERSION}` as const;
+
+/**
+ * The base URL for the staging Modrinth API.
+ */
+export const MODRINTH_STAGING_API_URL = `https://staging-api.modrinth.com/v${MODRINTH_API_VERSION}` as const;
+
+/**
+ * Describes the configuration options for the Modrinth API client.
+ */
+export interface ModrinthApiOptions {
+    /**
+     * The Fetch implementation used for making HTTP requests.
+     */
+    fetch?: Fetch;
+
+    /**
+     * The base URL for the Modrinth API.
+     *
+     * Defaults to {@link MODRINTH_API_URL}.
+     */
+    baseUrl?: string | URL;
+
+    /**
+     * The API token to be used for authentication with the Modrinth API.
+     */
+    token?: string;
+}
+
+/**
+ * A client for interacting with the Modrinth API.
+ */
+export class ModrinthApiClient {
+    /**
+     * The Fetch implementation used for making HTTP requests.
+     */
+    private readonly _fetch: Fetch;
+
+    /**
+     * Creates a new {@link ModrinthApiClient} instance.
+     *
+     * @param options - The configuration options for the client.
+     */
+    constructor(options?: ModrinthApiOptions) {
+        this._fetch = createFetch({
+            handler: options?.fetch,
+            baseUrl: options?.baseUrl || options?.fetch?.["baseUrl"] || MODRINTH_API_URL,
+            defaultHeaders: {
+                Authorization: options?.token,
+            },
+        })
+        .use(simpleCache())
+        .use(defaultResponse({ response: r => HttpResponse.json(null, r) }))
+        .use(throwOnError({ filter: x => !x.ok && x.status !== 404 }));
+    }
+
+    /**
+     * Gets an array of loaders supported by Modrinth.
+     *
+     * @returns An array of loaders supported by Modrinth.
+     */
+    async getLoaders(): Promise<ModrinthLoader[]> {
+        const response = await this._fetch("/tag/loader?cache=true");
+        return (await response.json()) ?? [];
+    }
+
+    /**
+     * Gets an array of game versions supported by Modrinth.
+     *
+     * @returns An array of game versions supported by Modrinth.
+     */
+    async getGameVersions(): Promise<ModrinthGameVersion[]> {
+        const response = await this._fetch("/tag/game_version?cache=true");
+        return (await response.json()) ?? [];
+    }
+
+    /**
+     * Fetches a project by its id or slug.
+     *
+     * @param idOrSlug - The project id or slug.
+     *
+     * @returns The project, or `undefined` if not found.
+     */
+    async getProject(idOrSlug: string): Promise<ModrinthProject | undefined> {
+        const response = await this._fetch(`/project/${idOrSlug}`);
+        return (await response.json()) ?? undefined;
+    }
+
+    /**
+     * Returns the project id for the given project.
+     *
+     * @param idOrSlug - The project id or slug.
+     *
+     * @returns The project id, or `undefined` if not found.
+     */
+    async getProjectId(idOrSlug: string): Promise<string | undefined> {
+        const response = await this._fetch(`/project/${idOrSlug}/check`);
+        return (await response.json() as ModrinthProject)?.id ?? undefined;
+    }
+
+    /**
+     * Fetches multiple projects by their IDs.
+     *
+     * @param ids - The project IDs.
+     *
+     * @returns An array of projects.
+     *
+     * @remarks
+     *
+     * This method **DOES NOT** support slugs (for some reason).
+     */
+    async getProjects(ids: Iterable<string>): Promise<ModrinthProject[]> {
+        const response = await this._fetch(`/projects`, HttpRequest.get().with({ ids: JSON.stringify(asArray(ids)) }));
+        return (await response.json()) ?? [];
+    }
+
+    /**
+     * Updates an existing project.
+     *
+     * @param project - The project data to update.
+     *
+     * @returns `true` if the update was successful; otherwise, `false`.
+     */
+    async updateProject(project: ModrinthProjectPatch): Promise<boolean> {
+        const response = await this._fetch(`/project/${project.id}`, HttpRequest.patch().json(project));
+        return response.ok;
+    }
+
+    /**
+     * Deletes an existing project.
+     *
+     * @param version - The id or slug of the project to delete.
+     *
+     * @returns `true` if the project was successfully deleted; otherwise, `false`.
+     */
+    async deleteProject(idOrSlug: string): Promise<boolean> {
+        const response = await this._fetch(`/project/${idOrSlug}`, HttpRequest.delete());
+        return response.ok;
+    }
+
+    /**
+     * Fetches a version by its id.
+     *
+     * @param id - The version id.
+     *
+     * @returns The version, or `undefined` if not found.
+     */
+    async getVersion(id: string): Promise<ModrinthVersion | undefined> {
+        const response = await this._fetch(`/version/${id}`);
+        return (await response.json()) ?? undefined;
+    }
+
+    /**
+     * Fetches multiple versions by their IDs.
+     *
+     * @param ids - The version IDs.
+     *
+     * @returns An array of versions.
+     */
+    async getVersions(ids: Iterable<string>): Promise<ModrinthVersion[]> {
+        const response = await this._fetch(`/versions`, HttpRequest.get().with({ ids: JSON.stringify(asArray(ids)) }));
+        return (await response.json()) ?? [];
+    }
+
+    /**
+     * Creates a new version.
+     *
+     * @param version - The version data.
+     *
+     * @returns The created version.
+     */
+    async createVersion(version: ModrinthVersionInit): Promise<ModrinthVersion> {
+        const form = packModrinthVersionInit(version);
+        const response = await this._fetch("/version", HttpRequest.post().with(form));
+        return await response.json();
+    }
+
+    /**
+     * Updates an existing version.
+     *
+     * @param version - The version data to update.
+     *
+     * @returns `true` if the update was successful; otherwise, `false`.
+     */
+    async updateVersion(version: ModrinthVersionPatch): Promise<boolean> {
+        const response = await this._fetch(`/version/${version.id}`, HttpRequest.patch().json(version));
+        return response.ok;
+    }
+
+    /**
+     * Deletes an existing version.
+     *
+     * @param version - The id of the version to delete.
+     *
+     * @returns `true` if the version was successfully deleted; otherwise, `false`.
+     */
+    async deleteVersion(id: string): Promise<boolean> {
+        const response = await this._fetch(`/version/${id}`, HttpRequest.delete());
+        return response.ok;
+    }
+
+    /**
+     * Fetches the versions of a project based on the provided search template.
+     *
+     * @param idOrSlug - The project id or slug.
+     * @param template - The search template to filter versions.
+     *
+     * @returns An array of versions matching the search criteria.
+     */
+    async getProjectVersions(idOrSlug: string, template?: ModrinthVersionSearchTemplate): Promise<ModrinthVersion[]> {
+        const params = packModrinthVersionSearchTemplate(template);
+        const response = await this._fetch(`/project/${idOrSlug}/version`, HttpRequest.get().with(params));
+        return (await response.json()) ?? [];
+    }
+
+    /**
+     * Unfeatures previous project versions based on the provided mode.
+     *
+     * @param currentVersion - The current version to use as an anchor point.
+     * @param mode - The unfeaturing mode (default: `ModrinthUnfeatureMode.SUBSET`).
+     *
+     * @returns A record containing version IDs as keys and a boolean indicating whether the unfeaturing operation was successful for each version.
+     */
+    async unfeaturePreviousProjectVersions(currentVersion: UnfeaturableModrinthVersion, mode?: ModrinthUnfeatureMode): Promise<Record<string, boolean>> {
+        mode ??= ModrinthUnfeatureMode.SUBSET;
+
+        const previousVersions = await this.getProjectVersions(currentVersion.project_id, { featured: true });
+        const unfeaturedVersions = { } as Record<string, boolean>;
+
+        for (const previousVersion of previousVersions) {
+            if (!ModrinthUnfeatureMode.shouldUnfeature(previousVersion, currentVersion, mode)) {
+                continue;
+            }
+
+            unfeaturedVersions[previousVersion.id] = await this.updateVersion({ id: previousVersion.id, featured: false });
+        }
+
+        return unfeaturedVersions;
+    }
+}