diff --git a/lib/services/__tests__/platform.test.ts b/lib/services/__tests__/platform.test.ts
new file mode 100644
index 0000000..012e707
--- /dev/null
+++ b/lib/services/__tests__/platform.test.ts
@@ -0,0 +1,182 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import api from "@/lib/api";
+import {
+  getApplication,
+  listApplications,
+  listEnvironments,
+  listWorkspaces,
+} from "@/lib/services/platform";
+import type {
+  Application,
+  ApplicationListResponse,
+  EnvironmentListResponse,
+  WorkspaceListResponse,
+} from "@/lib/types/platform";
+
+vi.mock("@/lib/api", () => ({
+  default: {
+    get: vi.fn(),
+  },
+}));
+
+const mockedGet = vi.mocked(api.get);
+
+describe("platform read client", () => {
+  beforeEach(() => {
+    mockedGet.mockReset();
+  });
+
+  it("lists workspaces with cursor pagination", async () => {
+    const data: WorkspaceListResponse = {
+      items: [
+        {
+          id: "workspace-1",
+          name: "Platform",
+          description: "Production workspace",
+          role: "owner",
+          createdAt: "2026-09-01T10:00:00Z",
+          updatedAt: "2026-09-02T10:00:00Z",
+        },
+      ],
+      pageInfo: {
+        nextCursor: "workspace-cursor-2",
+        hasMore: true,
+      },
+    };
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await expect(
+      listWorkspaces({ cursor: "workspace-cursor-1", limit: 25 })
+    ).resolves.toEqual(data);
+
+    expect(mockedGet).toHaveBeenCalledWith("/workspaces", {
+      params: {
+        cursor: "workspace-cursor-1",
+        limit: 25,
+      },
+    });
+  });
+
+  it("omits pagination query parameters that are not supplied", async () => {
+    const data: WorkspaceListResponse = {
+      items: [],
+      pageInfo: {
+        nextCursor: null,
+        hasMore: false,
+      },
+    };
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await listWorkspaces();
+
+    expect(mockedGet).toHaveBeenCalledWith("/workspaces", {
+      params: {},
+    });
+  });
+
+  it("lists workspace environments using the supplied workspace id", async () => {
+    const data: EnvironmentListResponse = {
+      items: [
+        {
+          id: "environment-1",
+          workspaceId: "workspace-1",
+          name: "Production",
+          createdAt: "2026-09-01T10:00:00Z",
+          updatedAt: "2026-09-02T10:00:00Z",
+        },
+      ],
+      pageInfo: {
+        nextCursor: null,
+        hasMore: false,
+      },
+    };
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await expect(
+      listEnvironments("workspace-1", { limit: 10 })
+    ).resolves.toEqual(data);
+
+    expect(mockedGet).toHaveBeenCalledWith(
+      "/workspaces/workspace-1/environments",
+      {
+        params: {
+          limit: 10,
+        },
+      }
+    );
+  });
+
+  it("serializes application filters only when they are supplied", async () => {
+    const data: ApplicationListResponse = {
+      items: [],
+      pageInfo: {
+        nextCursor: null,
+        hasMore: false,
+      },
+    };
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await listApplications("workspace-1", {
+      cursor: "application-cursor",
+      limit: 50,
+      environmentId: "environment-1",
+      includeArchived: false,
+    });
+
+    expect(mockedGet).toHaveBeenCalledWith(
+      "/workspaces/workspace-1/applications",
+      {
+        params: {
+          cursor: "application-cursor",
+          limit: 50,
+          environmentId: "environment-1",
+          includeArchived: false,
+        },
+      }
+    );
+
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await listApplications("workspace-1");
+
+    expect(mockedGet).toHaveBeenLastCalledWith(
+      "/workspaces/workspace-1/applications",
+      {
+        params: {},
+      }
+    );
+  });
+
+  it("gets one application and returns the Core response shape unchanged", async () => {
+    const data: Application = {
+      id: "application-1",
+      workspaceId: "workspace-1",
+      environmentId: "environment-1",
+      name: "checkout-api",
+      description: "Checkout service",
+      desiredState: {
+        image: "example/checkout:v1",
+        replicas: 3,
+      },
+      status: "draft",
+      createdAt: "2026-09-01T10:00:00Z",
+      updatedAt: "2026-09-02T10:00:00Z",
+    };
+    mockedGet.mockResolvedValueOnce({ data } as never);
+
+    await expect(
+      getApplication("workspace-1", "application-1")
+    ).resolves.toEqual(data);
+
+    expect(mockedGet).toHaveBeenCalledWith(
+      "/workspaces/workspace-1/applications/application-1"
+    );
+  });
+
+  it("lets shared-client request failures reject to the caller", async () => {
+    const error = new Error("request failed");
+    mockedGet.mockRejectedValueOnce(error);
+
+    await expect(listWorkspaces()).rejects.toBe(error);
+  });
+});
diff --git a/lib/services/platform.ts b/lib/services/platform.ts
new file mode 100644
index 0000000..8f407e1
--- /dev/null
+++ b/lib/services/platform.ts
@@ -0,0 +1,67 @@
+import api from "@/lib/api";
+import type {
+  Application,
+  ApplicationListQuery,
+  ApplicationListResponse,
+  EnvironmentListResponse,
+  PaginationQuery,
+  WorkspaceListResponse,
+} from "@/lib/types/platform";
+
+function paginationParams(query: PaginationQuery) {
+  return {
+    ...(query.cursor !== undefined ? { cursor: query.cursor } : {}),
+    ...(query.limit !== undefined ? { limit: query.limit } : {}),
+  };
+}
+
+export async function listWorkspaces(
+  query: PaginationQuery = {}
+): Promise<WorkspaceListResponse> {
+  const response = await api.get<WorkspaceListResponse>("/workspaces", {
+    params: paginationParams(query),
+  });
+  return response.data;
+}
+
+export async function listEnvironments(
+  workspaceId: string,
+  query: PaginationQuery = {}
+): Promise<EnvironmentListResponse> {
+  const response = await api.get<EnvironmentListResponse>(
+    `/workspaces/${workspaceId}/environments`,
+    { params: paginationParams(query) }
+  );
+  return response.data;
+}
+
+export async function listApplications(
+  workspaceId: string,
+  query: ApplicationListQuery = {}
+): Promise<ApplicationListResponse> {
+  const response = await api.get<ApplicationListResponse>(
+    `/workspaces/${workspaceId}/applications`,
+    {
+      params: {
+        ...paginationParams(query),
+        ...(query.environmentId !== undefined
+          ? { environmentId: query.environmentId }
+          : {}),
+        ...(query.includeArchived !== undefined
+          ? { includeArchived: query.includeArchived }
+          : {}),
+      },
+    }
+  );
+  return response.data;
+}
+
+export async function getApplication(
+  workspaceId: string,
+  applicationId: string
+): Promise<Application> {
+  const response = await api.get<Application>(
+    `/workspaces/${workspaceId}/applications/${applicationId}`
+  );
+  return response.data;
+}
diff --git a/lib/types/platform.ts b/lib/types/platform.ts
new file mode 100644
index 0000000..18e963d
--- /dev/null
+++ b/lib/types/platform.ts
@@ -0,0 +1,64 @@
+export type MembershipRole = "owner" | "admin" | "member";
+
+export interface PageInfo {
+  nextCursor: string | null;
+  hasMore: boolean;
+}
+
+export interface Workspace {
+  id: string;
+  name: string;
+  description?: string;
+  role: MembershipRole;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface WorkspaceListResponse {
+  items: Workspace[];
+  pageInfo: PageInfo;
+}
+
+export interface Environment {
+  id: string;
+  workspaceId: string;
+  name: string;
+  description?: string;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface EnvironmentListResponse {
+  items: Environment[];
+  pageInfo: PageInfo;
+}
+
+export type ApplicationStatus = "draft" | "archived";
+
+export interface Application {
+  id: string;
+  workspaceId: string;
+  environmentId: string;
+  name: string;
+  description?: string;
+  desiredState: Record<string, unknown>;
+  status: ApplicationStatus;
+  archivedAt?: string;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface ApplicationListResponse {
+  items: Application[];
+  pageInfo: PageInfo;
+}
+
+export interface PaginationQuery {
+  cursor?: string;
+  limit?: number;
+}
+
+export interface ApplicationListQuery extends PaginationQuery {
+  environmentId?: string;
+  includeArchived?: boolean;
+}