diff --git a/package.json b/package.json
index 9634d2b..74c1254 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,9 @@
     "claude": "src/entrypoints/cli.tsx"
   },
   "scripts": {
+    "build": "bun scripts/build-bundle.ts",
+    "build:watch": "bun scripts/build-bundle.ts --watch",
+    "build:prod": "bun scripts/build-bundle.ts --minify",
     "typecheck": "tsc --noEmit",
     "lint": "biome check src/",
     "lint:fix": "biome check --write src/",
@@ -65,6 +68,7 @@
     "@types/semver": "^7.5.8",
     "@types/stack-utils": "^2.0.3",
     "@types/ws": "^8.5.0",
+    "esbuild": "^0.25.0",
     "typescript": "^5.7.0"
   },
   "engines": {
diff --git a/scripts/build-bundle.ts b/scripts/build-bundle.ts
index 0a7ddb4..5cb8b5e 100644
--- a/scripts/build-bundle.ts
+++ b/scripts/build-bundle.ts
@@ -6,10 +6,17 @@
 // Watch mode:       bun scripts/build-bundle.ts --watch
 
 import * as esbuild from 'esbuild'
-import { resolve } from 'path'
-import { chmodSync, readFileSync } from 'fs'
+import { resolve, dirname } from 'path'
+import { chmodSync, readFileSync, existsSync } from 'fs'
+import { fileURLToPath } from 'url'
 
-const ROOT = resolve(import.meta.dir, '..')
+// Bun: import.meta.dir — Node 21+: import.meta.dirname — fallback
+const __dir: string =
+  (import.meta as any).dir ??
+  (import.meta as any).dirname ??
+  dirname(fileURLToPath(import.meta.url))
+
+const ROOT = resolve(__dir, '..')
 const watch = process.argv.includes('--watch')
 const minify = process.argv.includes('--minify')
 const noSourcemap = process.argv.includes('--no-sourcemap')
@@ -18,6 +25,44 @@ const noSourcemap = process.argv.includes('--no-sourcemap')
 const pkg = JSON.parse(readFileSync(resolve(ROOT, 'package.json'), 'utf-8'))
 const version = pkg.version || '0.0.0-dev'
 
+// ── Plugin: resolve bare 'src/' imports (tsconfig baseUrl: ".") ──
+// The codebase uses `import ... from 'src/foo/bar.js'` which relies on
+// TypeScript's baseUrl resolution. This plugin maps those to real TS files.
+const srcResolverPlugin: esbuild.Plugin = {
+  name: 'src-resolver',
+  setup(build) {
+    build.onResolve({ filter: /^src\// }, (args) => {
+      const basePath = resolve(ROOT, args.path)
+
+      // Already exists as-is
+      if (existsSync(basePath)) {
+        return { path: basePath }
+      }
+
+      // Strip .js/.jsx and try TypeScript extensions
+      const withoutExt = basePath.replace(/\.(js|jsx)$/, '')
+      for (const ext of ['.ts', '.tsx', '.js', '.jsx']) {
+        const candidate = withoutExt + ext
+        if (existsSync(candidate)) {
+          return { path: candidate }
+        }
+      }
+
+      // Try as directory with index file
+      const dirPath = basePath.replace(/\.(js|jsx)$/, '')
+      for (const ext of ['.ts', '.tsx', '.js', '.jsx']) {
+        const candidate = resolve(dirPath, 'index' + ext)
+        if (existsSync(candidate)) {
+          return { path: candidate }
+        }
+      }
+
+      // Let esbuild handle it (will error if truly missing)
+      return undefined
+    })
+  },
+}
+
 const buildOptions: esbuild.BuildOptions = {
   entryPoints: [resolve(ROOT, 'src/entrypoints/cli.tsx')],
   bundle: true,
@@ -30,8 +75,10 @@ const buildOptions: esbuild.BuildOptions = {
   // Single-file output — no code splitting for CLI tools
   splitting: false,
 
-  // Inject the MACRO global before all other code
-  inject: [resolve(ROOT, 'src/shims/macro.ts')],
+  plugins: [srcResolverPlugin],
+
+  // Use tsconfig for baseUrl / paths resolution (complements plugin above)
+  tsconfig: resolve(ROOT, 'tsconfig.json'),
 
   // Alias bun:bundle to our runtime shim
   alias: {
@@ -50,6 +97,11 @@ const buildOptions: esbuild.BuildOptions = {
     'node:*',
     // Native addons that can't be bundled
     'fsevents',
+    'sharp',
+    'image-processor-napi',
+    // Anthropic-internal packages (not published externally)
+    '@anthropic-ai/sandbox-runtime',
+    '@anthropic-ai/claude-agent-sdk',
   ],
 
   jsx: 'automatic',
@@ -64,9 +116,14 @@ const buildOptions: esbuild.BuildOptions = {
   treeShaking: true,
 
   // Define replacements — inline constants at build time
-  // Eliminates process.env.USER_TYPE === 'ant' branches (Anthropic-internal code)
-  // Sets NODE_ENV to production for production builds
+  // MACRO.* — originally inlined by Bun's bundler at compile time
+  // process.env.USER_TYPE — eliminates 'ant' (Anthropic-internal) code branches
   define: {
+    'MACRO.VERSION': JSON.stringify(version),
+    'MACRO.PACKAGE_URL': JSON.stringify('@anthropic-ai/claude-code'),
+    'MACRO.ISSUES_EXPLAINER': JSON.stringify(
+      'report issues at https://github.com/anthropics/claude-code/issues'
+    ),
     'process.env.USER_TYPE': '"external"',
     'process.env.NODE_ENV': minify ? '"production"' : '"development"',
   },
diff --git a/src/shims/bun-bundle.ts b/src/shims/bun-bundle.ts
index 43817a3..50c04e9 100644
--- a/src/shims/bun-bundle.ts
+++ b/src/shims/bun-bundle.ts
@@ -6,6 +6,8 @@
 const FEATURE_FLAGS: Record<string, boolean> = {
   PROACTIVE: envBool('CLAUDE_CODE_PROACTIVE', false),
   KAIROS: envBool('CLAUDE_CODE_KAIROS', false),
+  KAIROS_BRIEF: envBool('CLAUDE_CODE_KAIROS_BRIEF', false),
+  KAIROS_GITHUB_WEBHOOKS: envBool('CLAUDE_CODE_KAIROS_GITHUB_WEBHOOKS', false),
   BRIDGE_MODE: envBool('CLAUDE_CODE_BRIDGE_MODE', false),
   DAEMON: envBool('CLAUDE_CODE_DAEMON', false),
   VOICE_MODE: envBool('CLAUDE_CODE_VOICE_MODE', false),
@@ -15,6 +17,17 @@ const FEATURE_FLAGS: Record<string, boolean> = {
   ABLATION_BASELINE: false, // always off for external builds
   DUMP_SYSTEM_PROMPT: envBool('CLAUDE_CODE_DUMP_SYSTEM_PROMPT', false),
   BG_SESSIONS: envBool('CLAUDE_CODE_BG_SESSIONS', false),
+  HISTORY_SNIP: envBool('CLAUDE_CODE_HISTORY_SNIP', false),
+  WORKFLOW_SCRIPTS: envBool('CLAUDE_CODE_WORKFLOW_SCRIPTS', false),
+  CCR_REMOTE_SETUP: envBool('CLAUDE_CODE_CCR_REMOTE_SETUP', false),
+  EXPERIMENTAL_SKILL_SEARCH: envBool('CLAUDE_CODE_EXPERIMENTAL_SKILL_SEARCH', false),
+  ULTRAPLAN: envBool('CLAUDE_CODE_ULTRAPLAN', false),
+  TORCH: envBool('CLAUDE_CODE_TORCH', false),
+  UDS_INBOX: envBool('CLAUDE_CODE_UDS_INBOX', false),
+  FORK_SUBAGENT: envBool('CLAUDE_CODE_FORK_SUBAGENT', false),
+  BUDDY: envBool('CLAUDE_CODE_BUDDY', false),
+  MCP_SKILLS: envBool('CLAUDE_CODE_MCP_SKILLS', false),
+  REACTIVE_COMPACT: envBool('CLAUDE_CODE_REACTIVE_COMPACT', false),
 }
 
 function envBool(key: string, fallback: boolean): boolean {