Cherry-pick: perf(sdk): load js-yaml, semver and the uipack renderer on first use under require()

eslint.config.mjs

@@ -65,7 +65,7 @@ export default [
             '@frontmcp/protocol',
             '@frontmcp/testing',
             '@frontmcp/observability',
-            '^#(mcp-.+|crypto-.+|async-.+|event-.+|langchain-.+|sse-.+|express-.+|server-.+|stdio-.+|env|runtime-context|path|client|import-computed)$',
+            '^#(mcp-.+|crypto-.+|async-.+|event-.+|langchain-.+|sse-.+|express-.+|server-.+|stdio-.+|env|runtime-context|path|client|import-computed|js-yaml|semver|uipack-render)$',
           ],
           depConstraints: [
             {

jest.imports-mapper.js

@@ -26,4 +26,7 @@ module.exports = {
   '^#sse-transport$': path.resolve(root, 'libs/sdk/src/transport/adapters/polyfills/node-sse-transport.ts'),
   '^#express-host$': path.resolve(root, 'libs/sdk/src/server/adapters/polyfills/node-express-host.ts'),
   '^#import-computed$': path.resolve(root, 'libs/sdk/src/esm-loader/import-computed.ts'),
+  '^#js-yaml$': path.resolve(root, 'libs/sdk/src/third-party/js-yaml.ts'),
+  '^#semver$': path.resolve(root, 'libs/sdk/src/third-party/semver.ts'),
+  '^#uipack-render$': path.resolve(root, 'libs/sdk/src/third-party/uipack-render.ts'),
 };

libs/sdk/package.json

@@ -39,6 +39,21 @@
     "#import-computed": {
       "import": "./src/esm-loader/import-computed.ts",
       "default": "./src/esm-loader/import-computed.ts"
+    },
+    "#js-yaml": {
+      "types": "./src/third-party/js-yaml.ts",
+      "require": "./src/third-party/lazy-js-yaml.ts",
+      "default": "./src/third-party/js-yaml.ts"
+    },
+    "#semver": {
+      "types": "./src/third-party/semver.ts",
+      "require": "./src/third-party/lazy-semver.ts",
+      "default": "./src/third-party/semver.ts"
+    },
+    "#uipack-render": {
+      "types": "./src/third-party/uipack-render.ts",
+      "require": "./src/third-party/lazy-uipack-render.ts",
+      "default": "./src/third-party/uipack-render.ts"
     }
   },
   "type": "commonjs",

libs/sdk/project.json

@@ -20,11 +20,22 @@
         "bundle": true,
         "thirdParty": false,
         "platform": "node",
+        "additionalEntryPoints": [
+          "libs/sdk/src/third-party/js-yaml.ts",
+          "libs/sdk/src/third-party/lazy-js-yaml.ts",
+          "libs/sdk/src/third-party/semver.ts",
+          "libs/sdk/src/third-party/lazy-semver.ts",
+          "libs/sdk/src/third-party/uipack-render.ts",
+          "libs/sdk/src/third-party/lazy-uipack-render.ts"
+        ],
         "assets": ["libs/sdk/README.md", "LICENSE", "libs/sdk/package.json"],
         "esbuildOptions": {
           "minifyWhitespace": true,
           "outExtension": { ".js": ".js" },
           "external": [
+            "#js-yaml",
+            "#semver",
+            "#uipack-render",
             "@frontmcp/sdk",
             "@frontmcp/utils",
             "@frontmcp/di",

libs/sdk/src/auth/auth-ui/auth-ui.render.ts

@@ -38,12 +38,9 @@
  *
  * @packageDocumentation
  */
-import {
-  createResolverWithOverrides,
-  renderComponent,
-  type ShellConfig,
-  type ShellMountDescriptor,
-} from '@frontmcp/uipack';
+import type { ShellConfig, ShellMountDescriptor } from '@frontmcp/uipack';
+
+import { createResolverWithOverrides, renderComponent } from '#uipack-render';
 
 import { AUTH_FLOW_GLOBAL_KEY, AUTH_MOUNT_ID, type AuthFlowState, type AuthSlot } from './auth-ui.contract';
 import { type AuthUiRegistry } from './auth-ui.registry';

libs/sdk/src/builtin/config/providers/config-loader.ts

@@ -1,8 +1,8 @@
-import * as yaml from 'js-yaml';
-
 import { type z } from '@frontmcp/lazy-zod';
 import { fileExists, getCwd, pathResolve, readFile } from '@frontmcp/utils';
 
+import * as yaml from '#js-yaml';
+
 import { ConfigValidationError } from './config.service';
 import {
   canReadConfigFiles,

libs/sdk/src/esm-loader/semver.utils.ts

@@ -4,13 +4,15 @@
  * Isolates the semver dependency to a single file for easier maintenance.
  */
 
-import semverCompare from 'semver/functions/compare.js';
-import semverGt from 'semver/functions/gt.js';
-import semverRcompare from 'semver/functions/rcompare.js';
-import semverSatisfies from 'semver/functions/satisfies.js';
-import semverValid from 'semver/functions/valid.js';
-import semverMaxSatisfying from 'semver/ranges/max-satisfying.js';
-import semverValidRange from 'semver/ranges/valid.js';
+import {
+  compare as semverCompare,
+  gt as semverGt,
+  maxSatisfying as semverMaxSatisfying,
+  rcompare as semverRcompare,
+  satisfies as semverSatisfies,
+  valid as semverValid,
+  validRange as semverValidRange,
+} from '#semver';
 
 /**
  * Check if a range string is a dist-tag (not a semver range).

libs/sdk/src/skill/sep-2640/sep-2640.builders.ts

@@ -8,7 +8,7 @@
  *   guidance in the SEP.
  */
 
-import * as yaml from 'js-yaml';
+import * as yaml from '#js-yaml';
 
 import type { SkillContent } from '../../common/interfaces';
 import type { SkillMetadata } from '../../common/metadata';

libs/sdk/src/skill/skill-md-parser.ts

@@ -9,10 +9,10 @@
  * @module skill/skill-md-parser
  */
 
-import * as yaml from 'js-yaml';
-
 import { readFile } from '@frontmcp/utils';
 
+import * as yaml from '#js-yaml';
+
 import type {
   SkillExample,
   SkillMetadata,

libs/sdk/src/third-party/__tests__/lazy-js-yaml.spec.ts

@@ -0,0 +1,30 @@
+describe('lazy-js-yaml', () => {
+  afterEach(() => {
+    jest.dontMock('js-yaml');
+    jest.resetModules();
+  });
+
+  it('loads js-yaml the first time one of its functions is read', () => {
+    const load = jest.fn();
+    const loadJsYaml = jest.fn(() => ({ load, dump: jest.fn() }));
+    jest.doMock('js-yaml', loadJsYaml);
+
+    jest.isolateModules(() => {
+      const lazyYaml = require('../lazy-js-yaml');
+      expect(loadJsYaml).not.toHaveBeenCalled();
+
+      expect(lazyYaml.load).toBe(load);
+      expect(loadJsYaml).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  it('exports the functions the eager module exports', () => {
+    const lazyYaml = require('../lazy-js-yaml');
+    const eagerYaml = require('../js-yaml');
+
+    expect(Object.keys(lazyYaml).sort()).toEqual(Object.keys(eagerYaml).sort());
+    expect(lazyYaml.load).toBe(eagerYaml.load);
+    expect(lazyYaml.dump).toBe(eagerYaml.dump);
+    expect(lazyYaml.load('a: 1')).toEqual({ a: 1 });
+  });
+});

libs/sdk/src/third-party/__tests__/lazy-semver.spec.ts

@@ -0,0 +1,33 @@
+const SEMVER_FUNCTIONS = ['compare', 'gt', 'maxSatisfying', 'rcompare', 'satisfies', 'valid', 'validRange'];
+
+describe('lazy-semver', () => {
+  afterEach(() => {
+    jest.dontMock('semver/functions/satisfies.js');
+    jest.resetModules();
+  });
+
+  it('loads a semver function module the first time the function is read', () => {
+    const satisfies = jest.fn();
+    const loadSatisfies = jest.fn(() => satisfies);
+    jest.doMock('semver/functions/satisfies.js', loadSatisfies);
+
+    jest.isolateModules(() => {
+      const lazySemver = require('../lazy-semver');
+      expect(loadSatisfies).not.toHaveBeenCalled();
+
+      expect(lazySemver.satisfies).toBe(satisfies);
+      expect(loadSatisfies).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  it('exports the functions the eager module exports', () => {
+    const lazySemver = require('../lazy-semver');
+    const eagerSemver = require('../semver');
+
+    expect(Object.keys(lazySemver).sort()).toEqual(SEMVER_FUNCTIONS);
+    for (const name of SEMVER_FUNCTIONS) {
+      expect(lazySemver[name]).toBe(eagerSemver[name]);
+    }
+    expect(lazySemver.satisfies('1.2.3', '^1.0.0')).toBe(true);
+  });
+});

libs/sdk/src/third-party/__tests__/lazy-uipack-render.spec.ts

@@ -0,0 +1,29 @@
+describe('lazy-uipack-render', () => {
+  afterEach(() => {
+    jest.dontMock('@frontmcp/uipack');
+    jest.resetModules();
+  });
+
+  it('loads @frontmcp/uipack the first time one of its functions is read', () => {
+    const renderComponent = jest.fn();
+    const loadUipack = jest.fn(() => ({ renderComponent, createResolverWithOverrides: jest.fn() }));
+    jest.doMock('@frontmcp/uipack', loadUipack);
+
+    jest.isolateModules(() => {
+      const lazyRender = require('../lazy-uipack-render');
+      expect(loadUipack).not.toHaveBeenCalled();
+
+      expect(lazyRender.renderComponent).toBe(renderComponent);
+      expect(loadUipack).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  it('exports the functions the eager module exports', () => {
+    const lazyRender = require('../lazy-uipack-render');
+    const eagerRender = require('../uipack-render');
+
+    expect(Object.keys(lazyRender).sort()).toEqual(Object.keys(eagerRender).sort());
+    expect(lazyRender.renderComponent).toBe(eagerRender.renderComponent);
+    expect(lazyRender.createResolverWithOverrides).toBe(eagerRender.createResolverWithOverrides);
+  });
+});

libs/sdk/src/third-party/js-yaml.ts

@@ -0,0 +1,2 @@
+// `#js-yaml` everywhere but a require(): the YAML functions the SDK uses, from js-yaml.
+export { dump, load } from 'js-yaml';

libs/sdk/src/third-party/lazy-js-yaml.ts

@@ -0,0 +1,5 @@
+// The `require` variant of `#js-yaml`: js-yaml loads the first time one of its functions is read.
+Object.defineProperties(exports, {
+  dump: { enumerable: true, get: () => require('js-yaml').dump },
+  load: { enumerable: true, get: () => require('js-yaml').load },
+});

libs/sdk/src/third-party/lazy-semver.ts

@@ -0,0 +1,10 @@
+// The `require` variant of `#semver`: each semver function loads its module the first time it is read.
+Object.defineProperties(exports, {
+  compare: { enumerable: true, get: () => require('semver/functions/compare.js') },
+  gt: { enumerable: true, get: () => require('semver/functions/gt.js') },
+  rcompare: { enumerable: true, get: () => require('semver/functions/rcompare.js') },
+  satisfies: { enumerable: true, get: () => require('semver/functions/satisfies.js') },
+  valid: { enumerable: true, get: () => require('semver/functions/valid.js') },
+  maxSatisfying: { enumerable: true, get: () => require('semver/ranges/max-satisfying.js') },
+  validRange: { enumerable: true, get: () => require('semver/ranges/valid.js') },
+});

libs/sdk/src/third-party/lazy-uipack-render.ts

@@ -0,0 +1,5 @@
+// The `require` variant of `#uipack-render`: @frontmcp/uipack loads the first time an auth-UI page is built.
+Object.defineProperties(exports, {
+  createResolverWithOverrides: { enumerable: true, get: () => require('@frontmcp/uipack').createResolverWithOverrides },
+  renderComponent: { enumerable: true, get: () => require('@frontmcp/uipack').renderComponent },
+});

libs/sdk/src/third-party/semver.ts

@@ -0,0 +1,8 @@
+// `#semver` everywhere but a require(): the semver functions the ESM loader uses, each from its own module.
+export { default as compare } from 'semver/functions/compare.js';
+export { default as gt } from 'semver/functions/gt.js';
+export { default as rcompare } from 'semver/functions/rcompare.js';
+export { default as satisfies } from 'semver/functions/satisfies.js';
+export { default as valid } from 'semver/functions/valid.js';
+export { default as maxSatisfying } from 'semver/ranges/max-satisfying.js';
+export { default as validRange } from 'semver/ranges/valid.js';

libs/sdk/src/third-party/uipack-render.ts

@@ -0,0 +1,2 @@
+// `#uipack-render` everywhere but a require(): the uipack functions that build the auth-UI pages.
+export { createResolverWithOverrides, renderComponent } from '@frontmcp/uipack';

tsconfig.base.json

@@ -118,7 +118,10 @@
       "#langchain-anthropic": ["libs/sdk/src/agent/adapters/polyfills/node-langchain-anthropic.ts"],
       "#sse-transport": ["libs/sdk/src/transport/adapters/polyfills/node-sse-transport.ts"],
       "#express-host": ["libs/sdk/src/server/adapters/polyfills/node-express-host.ts"],
-      "#import-computed": ["libs/sdk/src/esm-loader/import-computed.ts"]
+      "#import-computed": ["libs/sdk/src/esm-loader/import-computed.ts"],
+      "#js-yaml": ["libs/sdk/src/third-party/js-yaml.ts"],
+      "#semver": ["libs/sdk/src/third-party/semver.ts"],
+      "#uipack-render": ["libs/sdk/src/third-party/uipack-render.ts"]
     }
   },
   "exclude": ["node_modules", "tmp"]