diff --git a/.github/workflows/sync-asyncapi.yml b/.github/workflows/sync-asyncapi.yml
index 27d45f50..78f2b969 100644
--- a/.github/workflows/sync-asyncapi.yml
+++ b/.github/workflows/sync-asyncapi.yml
@@ -62,7 +62,7 @@ jobs:
       - name: Check for changes
         id: changes
         run: |
-          if git diff --quiet -- packages/platform/asyncapi.json packages/platform/src/modules/builder.events.generated.ts; then
+          if git diff --quiet -- packages/platform/asyncapi.json packages/platform/src/client/modules/builder.events.generated.ts; then
             echo "changed=false" >> "$GITHUB_OUTPUT"
             echo "✅ asyncapi.json and the event types are up to date"
           else
@@ -91,7 +91,7 @@ jobs:
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
           git checkout -B "$BRANCH"
-          git add packages/platform/asyncapi.json packages/platform/src/modules/builder.events.generated.ts
+          git add packages/platform/asyncapi.json packages/platform/src/client/modules/builder.events.generated.ts
           git commit -m "chore(platform): sync asyncapi.json and the event types from production"
 
           pr=$(gh pr list --head "$BRANCH" --state open --json number --jq '.[0].number')
diff --git a/packages/platform/README.md b/packages/platform/README.md
index e311d789..8f47f96c 100644
--- a/packages/platform/README.md
+++ b/packages/platform/README.md
@@ -124,7 +124,7 @@ redaction of generated prose or user content.
 ## Event types
 
 The socket protocol is defined by the service's AsyncAPI document, committed as
-`asyncapi.json`. `src/modules/builder.events.generated.ts` is generated from it with
+`asyncapi.json`. `src/client/modules/builder.events.generated.ts` is generated from it with
 `json-schema-to-typescript`: one type per schema, named after the backend model
 (`Message`, `StatusObject`, `QueueState`, one `*Call` per tool, one `*Approval` per
 guard), plus `ServerEventMap` and `ClientMessageMap`. Never edit it by hand.
diff --git a/packages/platform/package.json b/packages/platform/package.json
index 541238eb..175dc185 100644
--- a/packages/platform/package.json
+++ b/packages/platform/package.json
@@ -1,17 +1,28 @@
 {
   "name": "@base44/platform",
   "version": "0.2.0",
-  "description": "Browser client for building on the Base44 platform",
-  "main": "dist/index.js",
-  "types": "dist/index.d.ts",
+  "description": "Client and server SDK for building on the Base44 platform",
+  "main": "dist/client/index.js",
+  "types": "dist/client/index.d.ts",
   "type": "module",
   "exports": {
     ".": {
-      "types": "./dist/index.d.ts",
-      "default": "./dist/index.js"
+      "types": "./dist/client/index.d.ts",
+      "default": "./dist/client/index.js"
+    },
+    "./server": {
+      "types": "./dist/server/index.d.ts",
+      "default": "./dist/server/index.js"
     },
     "./package.json": "./package.json"
   },
+  "typesVersions": {
+    "*": {
+      "server": [
+        "dist/server/index.d.ts"
+      ]
+    }
+  },
   "files": [
     "dist"
   ],
diff --git a/packages/platform/scripts/gen-events.mjs b/packages/platform/scripts/gen-events.mjs
index 9fc4fa31..c9817795 100644
--- a/packages/platform/scripts/gen-events.mjs
+++ b/packages/platform/scripts/gen-events.mjs
@@ -1,10 +1,10 @@
 #!/usr/bin/env node
-// Generates src/modules/builder.events.generated.ts from asyncapi.json. `--check` fails on drift instead.
+// Generates src/client/modules/builder.events.generated.ts from asyncapi.json. `--check` fails on drift instead.
 import { readFile, writeFile } from "node:fs/promises";
 import { compile } from "json-schema-to-typescript";
 
 const source = new URL("../asyncapi.json", import.meta.url);
-const target = new URL("../src/modules/builder.events.generated.ts", import.meta.url);
+const target = new URL("../src/client/modules/builder.events.generated.ts", import.meta.url);
 const doc = JSON.parse(await readFile(source, "utf8"));
 const schemas = doc.components.schemas;
 const refName = (ref) => ref.split("/").pop();
diff --git a/packages/platform/src/client.ts b/packages/platform/src/client/client.ts
similarity index 100%
rename from packages/platform/src/client.ts
rename to packages/platform/src/client/client.ts
diff --git a/packages/platform/src/client.types.ts b/packages/platform/src/client/client.types.ts
similarity index 100%
rename from packages/platform/src/client.types.ts
rename to packages/platform/src/client/client.types.ts
diff --git a/packages/platform/src/errors.ts b/packages/platform/src/client/errors.ts
similarity index 100%
rename from packages/platform/src/errors.ts
rename to packages/platform/src/client/errors.ts
diff --git a/packages/platform/src/errors.types.ts b/packages/platform/src/client/errors.types.ts
similarity index 100%
rename from packages/platform/src/errors.types.ts
rename to packages/platform/src/client/errors.types.ts
diff --git a/packages/platform/src/index.ts b/packages/platform/src/client/index.ts
similarity index 100%
rename from packages/platform/src/index.ts
rename to packages/platform/src/client/index.ts
diff --git a/packages/platform/src/modules/builder-protocol.ts b/packages/platform/src/client/modules/builder-protocol.ts
similarity index 100%
rename from packages/platform/src/modules/builder-protocol.ts
rename to packages/platform/src/client/modules/builder-protocol.ts
diff --git a/packages/platform/src/modules/builder-socket.ts b/packages/platform/src/client/modules/builder-socket.ts
similarity index 100%
rename from packages/platform/src/modules/builder-socket.ts
rename to packages/platform/src/client/modules/builder-socket.ts
diff --git a/packages/platform/src/modules/builder-subscription.ts b/packages/platform/src/client/modules/builder-subscription.ts
similarity index 100%
rename from packages/platform/src/modules/builder-subscription.ts
rename to packages/platform/src/client/modules/builder-subscription.ts
diff --git a/packages/platform/src/modules/builder.events.generated.ts b/packages/platform/src/client/modules/builder.events.generated.ts
similarity index 100%
rename from packages/platform/src/modules/builder.events.generated.ts
rename to packages/platform/src/client/modules/builder.events.generated.ts
diff --git a/packages/platform/src/modules/builder.events.types.ts b/packages/platform/src/client/modules/builder.events.types.ts
similarity index 100%
rename from packages/platform/src/modules/builder.events.types.ts
rename to packages/platform/src/client/modules/builder.events.types.ts
diff --git a/packages/platform/src/modules/builder.ts b/packages/platform/src/client/modules/builder.ts
similarity index 100%
rename from packages/platform/src/modules/builder.ts
rename to packages/platform/src/client/modules/builder.ts
diff --git a/packages/platform/src/modules/builder.types.ts b/packages/platform/src/client/modules/builder.types.ts
similarity index 100%
rename from packages/platform/src/modules/builder.types.ts
rename to packages/platform/src/client/modules/builder.types.ts
diff --git a/packages/platform/src/server/index.ts b/packages/platform/src/server/index.ts
new file mode 100644
index 00000000..c2d81d08
--- /dev/null
+++ b/packages/platform/src/server/index.ts
@@ -0,0 +1,3 @@
+/** Server platform modules, authenticated with a workspace API key. */
+export { createPlatformServer } from "./server.js";
+export type { PlatformServer, PlatformServerOptions } from "./server.types.js";
diff --git a/packages/platform/src/server/server-url.ts b/packages/platform/src/server/server-url.ts
new file mode 100644
index 00000000..99424bba
--- /dev/null
+++ b/packages/platform/src/server/server-url.ts
@@ -0,0 +1,8 @@
+/** Validate a platform origin and return it normalized. Used by the server entrypoint. */
+export function normalizeServerUrl(serverUrl: string): string {
+  const url = new URL(serverUrl);
+  if (!["https:", "http:"].includes(url.protocol) || url.username || url.password || url.search || url.hash || url.pathname !== "/") {
+    throw new TypeError("serverUrl must be an HTTP(S) origin without credentials, path, query or fragment");
+  }
+  return url.origin;
+}
diff --git a/packages/platform/src/server/server.ts b/packages/platform/src/server/server.ts
new file mode 100644
index 00000000..559f846e
--- /dev/null
+++ b/packages/platform/src/server/server.ts
@@ -0,0 +1,9 @@
+import { normalizeServerUrl } from "./server-url.js";
+import type { PlatformServer, PlatformServerOptions } from "./server.types.js";
+
+/** Create a server platform client, authenticated with a workspace API key. Performs no network requests. */
+export function createPlatformServer(options: PlatformServerOptions): PlatformServer {
+  if (!options.apiKey) throw new TypeError("apiKey is required");
+  normalizeServerUrl(options.serverUrl);
+  return Object.freeze({});
+}
diff --git a/packages/platform/src/server/server.types.ts b/packages/platform/src/server/server.types.ts
new file mode 100644
index 00000000..861e7d49
--- /dev/null
+++ b/packages/platform/src/server/server.types.ts
@@ -0,0 +1,10 @@
+/** Shared configuration for server platform modules. */
+export interface PlatformServerOptions {
+  /** Origin of the platform service, e.g. https://base44.app. No path/query/credentials. */
+  serverUrl: string;
+  /** Workspace API key. Keep it on your server; never ship it to a browser. */
+  apiKey: string;
+}
+
+/** Server platform client, returned by `createPlatformServer`. Modules are added as properties. */
+export interface PlatformServer {}
diff --git a/packages/platform/tests/package.test.mjs b/packages/platform/tests/package.test.mjs
index 9bfb5ed6..346dabe2 100644
--- a/packages/platform/tests/package.test.mjs
+++ b/packages/platform/tests/package.test.mjs
@@ -26,7 +26,7 @@ for (const name of Object.keys(manifest.dependencies)) {
 
 test("the tarball contains the compiled entry point and no source or test trees", () => {
   const files = new Set(packed.files.map(file => file.path));
-  for (const file of ["dist/index.js", "dist/index.d.ts", "README.md"]) assert.ok(files.has(file), file);
+  for (const file of ["dist/client/index.js", "dist/client/index.d.ts", "dist/server/index.js", "dist/server/index.d.ts", "README.md"]) assert.ok(files.has(file), file);
   assert.equal([...files].some(file => /^(src|tests|examples)\//.test(file)), false);
 });
 
@@ -41,7 +41,20 @@ test("the client resolves from the installed package without the runtime SDK", (
   `]);
 });
 
+test("the server entrypoint resolves from the installed package", () => {
+  run(process.execPath, ["--input-type=module", "--eval", `
+    import assert from "node:assert/strict";
+    import { createPlatformServer } from "@base44/platform/server";
+    assert.ok(Object.isFrozen(createPlatformServer({ serverUrl: "https://example.test", apiKey: "key" })));
+    assert.throws(() => createPlatformServer({ serverUrl: "https://example.test/path", apiKey: "key" }), TypeError);
+  `]);
+});
+
 const consumer = `
+import { createPlatformServer, type PlatformServer } from "@base44/platform/server";
+const server: PlatformServer = createPlatformServer({ serverUrl: "https://example.test", apiKey: "key" });
+void server;
+
 import { createPlatformClient, type PlatformEvent } from "@base44/platform";
 const platform = createPlatformClient();
 platform.builder.init({ getSession: async () => (await fetch("/session")).json(), onError() {} }).subscribe("a".repeat(24), {
diff --git a/packages/platform/tests/unit/client.test.ts b/packages/platform/tests/unit/client.test.ts
index 6e936cc4..6d884f6f 100644
--- a/packages/platform/tests/unit/client.test.ts
+++ b/packages/platform/tests/unit/client.test.ts
@@ -1,5 +1,5 @@
 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
-import { createPlatformClient, PlatformSocketError, type BuilderSession } from "../../src/index.js";
+import { createPlatformClient, PlatformSocketError, type BuilderSession } from "../../src/client/index.js";
 
 const fake = vi.hoisted(() => {
   const handlers: Record<string, (...args: any[]) => void> = {};
diff --git a/packages/platform/tests/unit/server.test.ts b/packages/platform/tests/unit/server.test.ts
new file mode 100644
index 00000000..91c6f19e
--- /dev/null
+++ b/packages/platform/tests/unit/server.test.ts
@@ -0,0 +1,18 @@
+import { describe, expect, test } from "vitest";
+import { createPlatformServer } from "../../src/server/index.js";
+
+describe("createPlatformServer", () => {
+  test("creates a frozen client without side effects", () => {
+    expect(Object.isFrozen(createPlatformServer({ serverUrl: "https://api.example.test", apiKey: "key" }))).toBe(true);
+  });
+
+  test("rejects a serverUrl that is not a bare HTTP(S) origin", () => {
+    for (const serverUrl of ["ftp://example.test", "https://example.test/path", "https://u:p@example.test", "https://example.test?x=1"]) {
+      expect(() => createPlatformServer({ serverUrl, apiKey: "key" })).toThrow(TypeError);
+    }
+  });
+
+  test("requires an apiKey", () => {
+    expect(() => createPlatformServer({ serverUrl: "https://example.test", apiKey: "" })).toThrow(TypeError);
+  });
+});
diff --git a/packages/platform/tests/unit/socket.test.js b/packages/platform/tests/unit/socket.test.js
index e98bfe11..b6b5accc 100644
--- a/packages/platform/tests/unit/socket.test.js
+++ b/packages/platform/tests/unit/socket.test.js
@@ -1,7 +1,7 @@
 import { createServer } from "node:http";
 import { WebSocketServer } from "ws";
 import { expect, test, vi } from "vitest";
-import { createPlatformClient } from "../../src/index.js";
+import { createPlatformClient } from "../../src/client/index.js";
 
 // Minimal Engine.IO/Socket.IO peer exercises the real client without a new server dependency.
 test("real Socket.IO handshake, join, snapshot, reconnect and session renewal", async () => {
diff --git a/packages/platform/tsconfig.type-tests.json b/packages/platform/tsconfig.type-tests.json
index c4630f01..163e9b78 100644
--- a/packages/platform/tsconfig.type-tests.json
+++ b/packages/platform/tsconfig.type-tests.json
@@ -5,7 +5,8 @@
     "rootDir": ".",
     "baseUrl": ".",
     "paths": {
-      "@base44/platform": ["src/index.ts"]
+      "@base44/platform": ["src/client/index.ts"],
+      "@base44/platform/server": ["src/server/index.ts"]
     }
   },
   "include": ["src/**/*.ts", "tests/types/**/*.ts", "examples/**/*.ts"]
diff --git a/packages/platform/typedoc.json b/packages/platform/typedoc.json
index 3e29c0b0..d3206d71 100644
--- a/packages/platform/typedoc.json
+++ b/packages/platform/typedoc.json
@@ -1,7 +1,8 @@
 {
   "$schema": "https://typedoc.org/schema.json",
   "entryPoints": [
-    "./src/index.ts"
+    "./src/client/index.ts",
+    "./src/server/index.ts"
   ],
   "tsconfig": "./tsconfig.json",
   "out": "docs",
diff --git a/packages/platform/typedoc.mintlify.json b/packages/platform/typedoc.mintlify.json
index f317419a..d295b487 100644
--- a/packages/platform/typedoc.mintlify.json
+++ b/packages/platform/typedoc.mintlify.json
@@ -1,6 +1,7 @@
 {
   "$schema": "https://typedoc.org/schema.json",
   "extends": ["./typedoc.json"],
+  "entryPoints": ["./src/client/index.ts"],
   "out": "docs/content",
   "plugin": [
     "typedoc-plugin-markdown",