diff --git a/gitnexus/src/cli/doctor.ts b/gitnexus/src/cli/doctor.ts
index b137d9d50..0fb2a98a0 100644
--- a/gitnexus/src/cli/doctor.ts
+++ b/gitnexus/src/cli/doctor.ts
@@ -1,6 +1,7 @@
 import { getRuntimeCapabilities, getRuntimeFingerprint } from '../core/platform/capabilities.js';
 import { resolveEmbeddingConfig } from '../core/embeddings/config.js';
 import { isHttpMode } from '../core/embeddings/http-client.js';
+import { checkLbugNative } from '../core/lbug/native-check.js';
 import { t } from './i18n/index.js';
 
 function isCombiningMark(codePoint: number): boolean {
@@ -59,6 +60,13 @@ export const doctorCommand = async () => {
   console.log(`  ${label('doctor.labels.node', 10)}${fingerprint.node}`);
   console.log(`  ${label('doctor.labels.gitnexus', 10)}${fingerprint.gitnexus}`);
   console.log(`  ${label('doctor.labels.ladybugdb', 10)}${fingerprint.ladybugdb ?? 'unknown'}`);
+  const nativeCheck = checkLbugNative();
+  if (nativeCheck.ok) {
+    console.log(`  ${padDisplayEnd('native', 10)}✓ lbugjs.node loaded`);
+  } else {
+    console.log(`  ${padDisplayEnd('native', 10)}✗ lbugjs.node missing`);
+    process.stderr.write(`\n${nativeCheck.message?.replace(/^/gm, '  ')}\n\n`);
+  }
   console.log(`  ${label('doctor.labels.onnx', 10)}${fingerprint.onnxruntime ?? 'unknown'}`);
   console.log('');
   console.log(t('doctor.capabilities'));
diff --git a/gitnexus/src/cli/index.ts b/gitnexus/src/cli/index.ts
index 91f6cdc13..67b34387a 100644
--- a/gitnexus/src/cli/index.ts
+++ b/gitnexus/src/cli/index.ts
@@ -5,7 +5,7 @@
 
 import { Command } from 'commander';
 import { createRequire } from 'node:module';
-import { createLazyAction } from './lazy-action.js';
+import { createLazyAction, createLbugLazyAction } from './lazy-action.js';
 import { registerGroupCommands } from './group.js';
 import { localizeCliHelp } from './help-i18n.js';
 import { t } from './i18n/index.js';
@@ -89,7 +89,7 @@ program
   .option('--embedding-sub-batch-size <n>', 'Number of chunks per embedding model call')
   .option('--embedding-device <device>', 'Embedding device: auto, cpu, dml, cuda, or wasm')
   .addHelpText('after', () => t('help.analyze.environment'))
-  .action(createLazyAction(() => import('./analyze.js'), 'analyzeCommand'));
+  .action(createLbugLazyAction(() => import('./analyze.js'), 'analyzeCommand'));
 
 program
   .command('index [path...]')
@@ -105,12 +105,12 @@ program
   .description('Start local HTTP server for web UI connection')
   .option('-p, --port <port>', 'Port number', '4747')
   .option('--host <host>', 'Bind address (default: 127.0.0.1, use 0.0.0.0 for remote access)')
-  .action(createLazyAction(() => import('./serve.js'), 'serveCommand'));
+  .action(createLbugLazyAction(() => import('./serve.js'), 'serveCommand'));
 
 program
   .command('mcp')
   .description('Start MCP server (stdio) — serves all indexed repos')
-  .action(createLazyAction(() => import('./mcp.js'), 'mcpCommand'));
+  .action(createLbugLazyAction(() => import('./mcp.js'), 'mcpCommand'));
 
 program
   .command('list')
@@ -177,12 +177,12 @@ program
     '--lang <lang>',
     'Output language for generated documentation (e.g. english, chinese, spanish, japanese)',
   )
-  .action(createLazyAction(() => import('./wiki.js'), 'wikiCommand'));
+  .action(createLbugLazyAction(() => import('./wiki.js'), 'wikiCommand'));
 
 program
   .command('augment <pattern>')
   .description('Augment a search pattern with knowledge graph context (used by hooks)')
-  .action(createLazyAction(() => import('./augment.js'), 'augmentCommand'));
+  .action(createLbugLazyAction(() => import('./augment.js'), 'augmentCommand'));
 
 program
   .command('publish [path]')
@@ -207,7 +207,7 @@ program
   .option('-g, --goal <text>', 'What you want to find')
   .option('-l, --limit <n>', 'Max processes to return (default: 5)')
   .option('--content', 'Include full symbol source code')
-  .action(createLazyAction(() => import('./tool.js'), 'queryCommand'));
+  .action(createLbugLazyAction(() => import('./tool.js'), 'queryCommand'));
 
 program
   .command('context [name]')
@@ -216,7 +216,7 @@ program
   .option('-u, --uid <uid>', 'Direct symbol UID (zero-ambiguity lookup)')
   .option('-f, --file <path>', 'File path to disambiguate common names')
   .option('--content', 'Include full symbol source code')
-  .action(createLazyAction(() => import('./tool.js'), 'contextCommand'));
+  .action(createLbugLazyAction(() => import('./tool.js'), 'contextCommand'));
 
 program
   .command('impact <target>')
@@ -228,13 +228,13 @@ program
   .option('--limit <n>', 'Max symbols per depth level (default: 100)')
   .option('--offset <n>', 'Skip N symbols per depth level for pagination')
   .option('--summary-only', 'Return counts and risk only, omit symbol list')
-  .action(createLazyAction(() => import('./tool.js'), 'impactCommand'));
+  .action(createLbugLazyAction(() => import('./tool.js'), 'impactCommand'));
 
 program
   .command('cypher <query>')
   .description('Execute raw Cypher query against the knowledge graph')
   .option('-r, --repo <name>', 'Target repository')
-  .action(createLazyAction(() => import('./tool.js'), 'cypherCommand'));
+  .action(createLbugLazyAction(() => import('./tool.js'), 'cypherCommand'));
 
 program
   .command('detect-changes')
@@ -243,7 +243,7 @@ program
   .option('-s, --scope <scope>', 'What to analyze: unstaged, staged, all, or compare', 'unstaged')
   .option('-b, --base-ref <ref>', 'Branch/commit for compare scope (e.g. main)')
   .option('-r, --repo <name>', 'Target repository')
-  .action(createLazyAction(() => import('./tool.js'), 'detectChangesCommand'));
+  .action(createLbugLazyAction(() => import('./tool.js'), 'detectChangesCommand'));
 
 // ─── Eval Server (persistent daemon for SWE-bench) ─────────────────
 
@@ -256,7 +256,7 @@ program
     'Bind address (default: 127.0.0.1, use 0.0.0.0 to expose to all interfaces)',
   )
   .option('--idle-timeout <seconds>', 'Auto-shutdown after N seconds idle (0 = disabled)', '0')
-  .action(createLazyAction(() => import('./eval-server.js'), 'evalServerCommand'));
+  .action(createLbugLazyAction(() => import('./eval-server.js'), 'evalServerCommand'));
 
 registerGroupCommands(program);
 localizeCliHelp(program);
diff --git a/gitnexus/src/cli/lazy-action.ts b/gitnexus/src/cli/lazy-action.ts
index 0655a8f4b..3a7bea846 100644
--- a/gitnexus/src/cli/lazy-action.ts
+++ b/gitnexus/src/cli/lazy-action.ts
@@ -4,6 +4,8 @@
  * at compile time — catching typos when used with concrete module imports.
  */
 
+import { checkLbugNative } from '../core/lbug/native-check.js';
+
 function isCallable(value: unknown): value is (...args: unknown[]) => unknown {
   return typeof value === 'function';
 }
@@ -21,3 +23,23 @@ export function createLazyAction<
     await action(...args);
   };
 }
+
+export function createLbugLazyAction<
+  TModule extends Record<string, unknown>,
+  TKey extends string & keyof TModule,
+>(loader: () => Promise<TModule>, exportName: TKey): (...args: unknown[]) => Promise<void> {
+  return async (...args: unknown[]): Promise<void> => {
+    const check = checkLbugNative();
+    if (!check.ok) {
+      process.stderr.write(`\n  ${check.message?.replace(/\n/g, '\n  ')}\n\n`);
+      process.exitCode = 1;
+      return;
+    }
+    const module = await loader();
+    const action = module[exportName];
+    if (!isCallable(action)) {
+      throw new Error(`Lazy action export not found: ${exportName}`);
+    }
+    await action(...args);
+  };
+}
diff --git a/gitnexus/src/core/lbug/native-check.ts b/gitnexus/src/core/lbug/native-check.ts
new file mode 100644
index 000000000..54d435bfd
--- /dev/null
+++ b/gitnexus/src/core/lbug/native-check.ts
@@ -0,0 +1,79 @@
+import fs from 'fs';
+import path from 'path';
+import { createRequire } from 'node:module';
+
+export interface NativeCheckResult {
+  ok: boolean;
+  binaryPath?: string;
+  message?: string;
+}
+
+export function checkLbugNative(overridePkgDir?: string): NativeCheckResult {
+  let pkgDir: string;
+
+  if (overridePkgDir) {
+    pkgDir = overridePkgDir;
+  } else {
+    try {
+      const _require = createRequire(import.meta.url);
+      const mainEntry = _require.resolve('@ladybugdb/core');
+      pkgDir = path.dirname(mainEntry);
+    } catch {
+      return {
+        ok: false,
+        message: [
+          'LadybugDB package (@ladybugdb/core) is not installed.',
+          '',
+          'Run:  npm install',
+        ].join('\n'),
+      };
+    }
+  }
+
+  const binaryPath = path.join(pkgDir, 'lbugjs.node');
+  if (!fs.existsSync(binaryPath)) {
+    return {
+      ok: false,
+      binaryPath,
+      message: [
+        'LadybugDB native binary (lbugjs.node) is missing.',
+        '',
+        'This usually happens when the install lifecycle script was skipped.',
+        '',
+        'To repair:',
+        `  node ${path.join(pkgDir, 'install.js')}`,
+        '',
+        'If using bun, add to package.json and reinstall:',
+        '  "trustedDependencies": ["@ladybugdb/core"]',
+        '',
+        'Also check that npm is not configured with ignore-scripts=true',
+        '(in .npmrc or via --ignore-scripts).',
+      ].join('\n'),
+    };
+  }
+
+  try {
+    const _require = createRequire(import.meta.url);
+    _require(binaryPath);
+  } catch (err: unknown) {
+    const nativeError = err instanceof Error ? err.message : String(err);
+    return {
+      ok: false,
+      binaryPath,
+      message: [
+        'LadybugDB native binary (lbugjs.node) exists but failed to load:',
+        `  ${nativeError}`,
+        '',
+        'This can happen with a truncated file, ABI mismatch, or wrong-platform binary.',
+        '',
+        'To repair:',
+        `  node ${path.join(pkgDir, 'install.js')}`,
+        '',
+        'If using bun, add to package.json and reinstall:',
+        '  "trustedDependencies": ["@ladybugdb/core"]',
+      ].join('\n'),
+    };
+  }
+
+  return { ok: true, binaryPath };
+}
diff --git a/gitnexus/test/unit/lbug-native-check.test.ts b/gitnexus/test/unit/lbug-native-check.test.ts
new file mode 100644
index 000000000..19bbab94a
--- /dev/null
+++ b/gitnexus/test/unit/lbug-native-check.test.ts
@@ -0,0 +1,46 @@
+import { describe, it, expect } from 'vitest';
+import os from 'os';
+import path from 'path';
+import fs from 'fs/promises';
+import { checkLbugNative } from '../../src/core/lbug/native-check.js';
+
+describe('checkLbugNative', () => {
+  it('returns ok:true when the real @ladybugdb/core binary is present', () => {
+    const result = checkLbugNative();
+    expect(result.ok).toBe(true);
+    expect(result.binaryPath).toBeDefined();
+    expect(result.message).toBeUndefined();
+  });
+
+  it('returns ok:false with repair instructions when lbugjs.node is missing', async () => {
+    const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'lbug-check-'));
+    try {
+      await fs.writeFile(path.join(tmpDir, 'install.js'), '');
+
+      const result = checkLbugNative(tmpDir);
+
+      expect(result.ok).toBe(false);
+      expect(result.message).toContain('missing');
+      expect(result.message).toContain('install.js');
+      expect(result.message).toContain('trustedDependencies');
+      expect(result.message).toContain('ignore-scripts');
+    } finally {
+      await fs.rm(tmpDir, { recursive: true, force: true });
+    }
+  });
+
+  it('returns ok:false when lbugjs.node exists but is unloadable (zero-byte)', async () => {
+    const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'lbug-check-'));
+    try {
+      await fs.writeFile(path.join(tmpDir, 'lbugjs.node'), Buffer.alloc(0));
+
+      const result = checkLbugNative(tmpDir);
+
+      expect(result.ok).toBe(false);
+      expect(result.message).toContain('failed to load');
+      expect(result.message).toContain('install.js');
+    } finally {
+      await fs.rm(tmpDir, { recursive: true, force: true });
+    }
+  });
+});