diff --git a/client/src/lib/__tests__/codexConfigApi.test.ts b/client/src/lib/__tests__/codexConfigApi.test.ts
new file mode 100644
index 00000000..89bdf008
--- /dev/null
+++ b/client/src/lib/__tests__/codexConfigApi.test.ts
@@ -0,0 +1,47 @@
+/**
+ * @file Pins the codexConfig API routes and payloads. Tests that the client
+ * sends the right method, URL, and body shape to the Codex config backend.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, it, expect, vi, afterEach } from "vitest";
+import { api } from "../api";
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+function stubFetch(response: unknown) {
+  const spy = vi.fn().mockResolvedValue({
+    ok: true,
+    status: 200,
+    headers: { get: () => "application/json" },
+    json: async () => response,
+    text: async () => JSON.stringify(response),
+  });
+  vi.stubGlobal("fetch", spy);
+  return spy;
+}
+
+describe("api.codexConfig", () => {
+  it("sends a write as a single PUT with the artifact envelope", async () => {
+    const spy = stubFetch({ ok: true, file: "/x", created: true });
+
+    await api.codexConfig.write({
+      scope: "user",
+      type: "rules",
+      name: "default",
+      content: "allow",
+    });
+
+    expect(spy).toHaveBeenCalledTimes(1);
+    const [, options] = spy.mock.calls[0] as [string, RequestInit | undefined];
+    expect(options?.method).toBe("PUT");
+    expect(JSON.parse(options?.body as string)).toEqual({
+      scope: "user",
+      type: "rules",
+      name: "default",
+      content: "allow",
+    });
+  });
+});
diff --git a/client/src/lib/api.ts b/client/src/lib/api.ts
index 03b29cc9..ad6c5844 100644
--- a/client/src/lib/api.ts
+++ b/client/src/lib/api.ts
@@ -1609,6 +1609,162 @@ export const api = {
       }),
   },
 
+  // ─────────────────────────────── Codex-Config API ──────────────────────────────
+  /** Read/write access to on-disk Codex CLI configuration - skills, agents,
+   *  rules, memory (AGENTS.md), config.toml, MCP servers, plugins, and
+   *  marketplaces - for the dashboard's "Codex Config" explorer/editor pages. */
+  codexConfig: {
+    /**
+     * GET /api/codex-config/overview - counts of every artifact kind, for the
+     * explorer's landing page.
+     * @returns {@link CodexOverview} — filesystem roots plus per-kind counts.
+     */
+    overview: () => request<CodexOverview>("/codex-config/overview"),
+    /**
+     * GET /api/codex-config/skills - user and/or project skill definitions.
+     *
+     * The optional `scope` is appended as `?scope=` only when provided; omitting
+     * it lets the server apply its default scope.
+     *
+     * @param scope Optional {@link CodexScope} ("user"|"project"|"all") filter.
+     * @returns `{ skills }` — the {@link CodexSkill} items for each skill.
+     */
+    skills: (scope?: CodexScope) =>
+      request<{ skills: CodexSkill[] }>(`/codex-config/skills${scope ? `?scope=${scope}` : ""}`),
+    /**
+     * GET /api/codex-config/agents - user and/or project agent definitions.
+     * @param scope Optional {@link CodexScope} filter.
+     * @returns `{ agents }` — {@link CodexAgent} items for each agent.
+     */
+    agents: (scope?: CodexScope) =>
+      request<{ agents: CodexAgent[] }>(`/codex-config/agents${scope ? `?scope=${scope}` : ""}`),
+    /**
+     * GET /api/codex-config/rules - user and/or project rules files.
+     * @param scope Optional {@link CodexScope} filter.
+     * @returns `{ rules }` — {@link CodexRule} items for each rule file.
+     */
+    rules: (scope?: CodexScope) =>
+      request<{ rules: CodexRule[] }>(`/codex-config/rules${scope ? `?scope=${scope}` : ""}`),
+    /**
+     * GET /api/codex-config/memory - AGENTS.md files at both scopes.
+     * @returns `{ memory }` — {@link CodexMemoryFile} items.
+     */
+    memory: () => request<{ memory: CodexMemoryFile[] }>("/codex-config/memory"),
+    /**
+     * GET /api/codex-config/config - config.toml files at both scopes.
+     * @returns `{ config }` — {@link CodexConfigFile} items.
+     */
+    config: () => request<{ config: CodexConfigFile[] }>("/codex-config/config"),
+    /**
+     * GET /api/codex-config/file - raw contents of one config file by absolute path.
+     *
+     * The absolute path is passed as a URL-encoded `path` query param (not a
+     * path segment) so arbitrary filesystem paths survive intact.
+     *
+     * @param path Absolute path of the config file to read.
+     * @returns {@link CodexFileResponse} — file text + metadata.
+     */
+    file: (path: string) =>
+      request<CodexFileResponse>(`/codex-config/file?path=${encodeURIComponent(path)}`),
+    /**
+     * PUT /api/codex-config/file - create/overwrite a config artifact; the
+     * server writes a backup of any previous content first.
+     *
+     * @param args {@link CodexWriteArgs} — scope/type/name/content.
+     * @returns {@link CodexMutationResult} — the written path and whether a new file was created.
+     */
+    write: (args: CodexWriteArgs) =>
+      request<CodexMutationResult>("/codex-config/file", {
+        method: "PUT",
+        body: JSON.stringify(args),
+      }),
+    /**
+     * DELETE /api/codex-config/file - remove a config artifact (also backed up).
+     *
+     * @param args {@link CodexDeleteArgs} — which artifact to delete.
+     * @returns {@link CodexMutationResult} — the deleted path and its backup path.
+     */
+    remove: (args: CodexDeleteArgs) =>
+      request<CodexMutationResult>("/codex-config/file", {
+        method: "DELETE",
+        body: JSON.stringify(args),
+      }),
+    /**
+     * GET /api/codex-config/backups - timestamped backups written by `write`/
+     * `remove`, optionally filtered by scope/artifact type.
+     *
+     * @param params Optional `{ scope, type }` filter for the backup listing.
+     * @returns `{ items }` — the matching {@link CodexBackup} entries.
+     */
+    backups: (params?: { scope?: "user" | "project"; type?: CodexArtifactType }) =>
+      requestCodexBackupsHelper(params),
+    /**
+     * GET /api/codex-config/mcp - configured MCP servers from the codex CLI.
+     * @returns `{ mcp }` — {@link CodexMcpServer} items.
+     */
+    mcp: () => request<{ mcp: CodexMcpServer[] }>("/codex-config/mcp"),
+    /**
+     * GET /api/codex-config/plugins - installed plugins from the codex CLI.
+     * @returns `{ plugins }` — {@link CodexPlugin} items.
+     */
+    plugins: () => request<{ plugins: CodexPlugin[] }>("/codex-config/plugins"),
+    /**
+     * GET /api/codex-config/marketplaces - registered marketplaces from the codex CLI.
+     * @returns `{ marketplaces }` — {@link CodexMarketplace} items.
+     */
+    marketplaces: () => request<{ marketplaces: CodexMarketplace[] }>("/codex-config/marketplaces"),
+    /**
+     * POST /api/codex-config/mcp/add - add an MCP server via the `codex` CLI.
+     * @param args Arguments for `codex mcp add`.
+     * @returns `{ ok, stdout, stderr }` — success and CLI output.
+     */
+    mcpAdd: (args: unknown) =>
+      request<{ ok: true; stdout: string; stderr: string }>("/codex-config/mcp/add", {
+        method: "POST",
+        body: JSON.stringify(args),
+      }),
+    /**
+     * POST /api/codex-config/mcp/remove - remove an MCP server via the `codex` CLI.
+     * @param name The MCP server name to remove.
+     * @returns `{ ok, stdout, stderr }` — success and CLI output.
+     */
+    mcpRemove: (name: string) =>
+      request<{ ok: true; stdout: string; stderr: string }>("/codex-config/mcp/remove", {
+        method: "POST",
+        body: JSON.stringify({ name }),
+      }),
+    /**
+     * POST /api/codex-config/plugins/action - add or remove a plugin via the `codex` CLI.
+     * @param args Arguments with `spec` and `action` fields.
+     * @returns `{ ok, stdout, stderr }` — success and CLI output.
+     */
+    pluginAction: (args: unknown) =>
+      request<{ ok: true; stdout: string; stderr: string }>("/codex-config/plugins/action", {
+        method: "POST",
+        body: JSON.stringify(args),
+      }),
+    /**
+     * POST /api/codex-config/marketplaces/add - register a marketplace via the `codex` CLI.
+     * @param url The marketplace URL to register.
+     * @returns `{ ok, stdout, stderr }` — success and CLI output.
+     */
+    marketplaceAdd: (url: string) =>
+      request<{ ok: true; stdout: string; stderr: string }>("/codex-config/marketplaces/add", {
+        method: "POST",
+        body: JSON.stringify({ url }),
+      }),
+    /**
+     * POST /api/codex-config/marketplaces/action - update or remove a marketplace via the `codex` CLI.
+     * @param args Arguments with `name` and `action` fields.
+     * @returns `{ ok, stdout, stderr }` — success and CLI output.
+     */
+    marketplaceAction: (args: unknown) =>
+      request<{ ok: true; stdout: string; stderr: string }>("/codex-config/marketplaces/action", {
+        method: "POST",
+        body: JSON.stringify(args),
+      }),
+  },
+
   // ────────────────────────────────── Run API ─────────────────────────────────
   /** Spawn/manage headless or conversational `claude` CLI child processes
    *  launched from the dashboard's Run page, and stream their output. */
@@ -2230,6 +2386,23 @@ function requestBackupsHelper(params?: { scope?: "user" | "project"; type?: CcAr
   return request<{ items: CcBackup[] }>(`/cc-config/backups${q ? `?${q}` : ""}`);
 }
 
+/** Helper for GET /api/codex-config/backups with optional `scope` and `type` filters.
+ *  Builds an optional `?scope=&type=` query string (each part appended only when
+ *  present) and calls {@link request} for GET /api/codex-config/backups.
+ *
+ *  @param params Optional `{ scope, type }` filter for the backup listing.
+ *  @returns `{ items }` — the matching {@link CodexBackup} entries. */
+function requestCodexBackupsHelper(params?: {
+  scope?: "user" | "project";
+  type?: CodexArtifactType;
+}) {
+  const qs = new URLSearchParams();
+  if (params?.scope) qs.set("scope", params.scope);
+  if (params?.type) qs.set("type", params.type);
+  const q = qs.toString();
+  return request<{ items: CodexBackup[] }>(`/codex-config/backups${q ? `?${q}` : ""}`);
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // CC-Config types — request/response shapes for the "CC Config" explorer/editor.
 // These describe on-disk Claude Code configuration artifacts (skills, agents,
@@ -2675,6 +2848,152 @@ export interface CcHookScripts {
   items: { name: string; file: string; size: number; mtime: number }[];
 }
 
+// ─────────────────────────────────────────────────────────────────────────────
+// Codex-Config types — request/response shapes for the "Codex Config" explorer/editor.
+// These describe on-disk Codex CLI configuration artifacts (skills, agents, rules,
+// memory, config, MCP servers, plugins, marketplaces) as surfaced by the
+// /api/codex-config/* routes. They live in this client because they are specific
+// to the explorer UI.
+// ─────────────────────────────────────────────────────────────────────────────
+
+/** Kind of Codex config artifact manageable via `api.codexConfig.write`/
+ *  `remove` - each maps to a distinct on-disk location. */
+export type CodexArtifactType = "skills" | "agents" | "rules" | "memory" | "config";
+
+/** Scope filter accepted by most `codexConfig` list endpoints; "all" merges
+ *  user + project scope in one response. */
+export type CodexScope = "user" | "project" | "all";
+
+/** Body for PUT /api/codex-config/file - create or overwrite one artifact. */
+export interface CodexWriteArgs {
+  scope: "user" | "project";
+  type: CodexArtifactType;
+  /** Artifact name (e.g. skill/agent/rule name); omitted for singleton
+   *  artifacts like memory/config. */
+  name?: string;
+  /** Full file contents to write. */
+  content: string;
+}
+
+/** Body for DELETE /api/codex-config/file - remove one artifact. */
+export interface CodexDeleteArgs {
+  scope: "user" | "project";
+  type: CodexArtifactType;
+  name?: string;
+}
+
+/** Response shape of a successful `codexConfig.write`/`remove` call. */
+export interface CodexMutationResult {
+  file: string;
+  created?: boolean;
+  backup?: { [key: string]: unknown } | null;
+}
+
+/** One timestamped backup of a config artifact, from GET /api/codex-config/backups. */
+export interface CodexBackup {
+  type: string;
+  name: string;
+  file: string;
+  mtime: number;
+  size: number | null;
+}
+
+/** A discovered skill: a directory containing a SKILL.md under skills/<name>/. */
+export interface CodexSkill {
+  scope: "user" | "project";
+  name: string;
+  path: string;
+  file: string;
+  size: number;
+  mtime: number;
+  truncated: boolean;
+  frontmatter: Record<string, string>;
+  preview: string;
+}
+
+/** A discovered agent definition (TOML file). */
+export interface CodexAgent {
+  scope: "user" | "project";
+  name: string;
+  file: string;
+  size: number;
+  mtime: number;
+  meta: Record<string, unknown>;
+  preview: string;
+}
+
+/** A discovered rules file. */
+export interface CodexRule {
+  scope: "user" | "project";
+  name: string;
+  file: string;
+  size: number;
+  mtime: number;
+  preview: string;
+}
+
+/** AGENTS.md file at either user or project scope. */
+export interface CodexMemoryFile {
+  scope: "user" | "project";
+  file: string;
+  exists: boolean;
+  size?: number;
+  mtime?: number;
+  preview?: string;
+}
+
+/** config.toml file at either user or project scope. */
+export interface CodexConfigFile {
+  scope: "user" | "project";
+  file: string;
+  exists: boolean;
+  size?: number;
+  mtime?: number;
+  content?: string;
+  truncated?: boolean;
+}
+
+/** Response shape of GET /api/codex-config/file - full contents of one config artifact. */
+export interface CodexFileResponse {
+  ok: true;
+  file: string;
+  size: number;
+  mtime: number;
+  truncated: boolean;
+  text: string;
+}
+
+/** Response shape of GET /api/codex-config/overview. */
+export interface CodexOverview {
+  roots: {
+    codexHome: string;
+    projectCodexDir: string;
+    projectRoot: string;
+  };
+  counts: {
+    skills: { user: number; project: number };
+    agents: { user: number; project: number };
+    rules: { user: number; project: number };
+    memory: { user: number; project: number };
+    config: { user: number; project: number };
+  };
+}
+
+/** One configured MCP server, from GET /api/codex-config/mcp. */
+export interface CodexMcpServer {
+  [key: string]: unknown;
+}
+
+/** One installed plugin, from GET /api/codex-config/plugins. */
+export interface CodexPlugin {
+  [key: string]: unknown;
+}
+
+/** One registered marketplace, from GET /api/codex-config/marketplaces. */
+export interface CodexMarketplace {
+  [key: string]: unknown;
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Run types — request/response shapes for the Run page's `claude` process
 // spawning/management. `RunMode`/`RunStatus`/`PermissionMode`/`EffortLevel`