diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index 670b8b9e..736fb7cb 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -89,15 +89,18 @@ jobs:
       - name: Run build benchmark
         if: steps.existing.outputs.skip != 'true'
         run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
           ARGS="--version ${{ steps.mode.outputs.version }}"
           if [ "${{ steps.mode.outputs.source }}" = "npm" ]; then
             ARGS="$ARGS --npm"
           fi
-          node scripts/benchmark.js $ARGS 2>/dev/null > benchmark-result.json
+          node $STRIP_FLAG --import ./scripts/ts-resolve-loader.js scripts/benchmark.ts $ARGS 2>/dev/null > benchmark-result.json
 
       - name: Update build report
         if: steps.existing.outputs.skip != 'true'
-        run: node scripts/update-benchmark-report.js benchmark-result.json
+        run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/update-benchmark-report.ts benchmark-result.json
 
       - name: Upload build result
         if: steps.existing.outputs.skip != 'true'
@@ -240,15 +243,18 @@ jobs:
         env:
           HF_TOKEN: ${{ secrets.HF_TOKEN }}
         run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
           ARGS="--version ${{ steps.mode.outputs.version }}"
           if [ "${{ steps.mode.outputs.source }}" = "npm" ]; then
             ARGS="$ARGS --npm"
           fi
-          node scripts/embedding-benchmark.js $ARGS 2>/dev/null > embedding-benchmark-result.json
+          node $STRIP_FLAG --import ./scripts/ts-resolve-loader.js scripts/embedding-benchmark.ts $ARGS 2>/dev/null > embedding-benchmark-result.json
 
       - name: Update embedding report
         if: steps.existing.outputs.skip != 'true'
-        run: node scripts/update-embedding-report.js embedding-benchmark-result.json
+        run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/update-embedding-report.ts embedding-benchmark-result.json
 
       - name: Upload embedding result
         if: steps.existing.outputs.skip != 'true'
@@ -377,15 +383,18 @@ jobs:
       - name: Run query benchmark
         if: steps.existing.outputs.skip != 'true'
         run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
           ARGS="--version ${{ steps.mode.outputs.version }}"
           if [ "${{ steps.mode.outputs.source }}" = "npm" ]; then
             ARGS="$ARGS --npm"
           fi
-          node scripts/query-benchmark.js $ARGS 2>/dev/null > query-benchmark-result.json
+          node $STRIP_FLAG --import ./scripts/ts-resolve-loader.js scripts/query-benchmark.ts $ARGS 2>/dev/null > query-benchmark-result.json
 
       - name: Update query report
         if: steps.existing.outputs.skip != 'true'
-        run: node scripts/update-query-report.js query-benchmark-result.json
+        run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/update-query-report.ts query-benchmark-result.json
 
       - name: Upload query result
         if: steps.existing.outputs.skip != 'true'
@@ -514,15 +523,18 @@ jobs:
       - name: Run incremental benchmark
         if: steps.existing.outputs.skip != 'true'
         run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
           ARGS="--version ${{ steps.mode.outputs.version }}"
           if [ "${{ steps.mode.outputs.source }}" = "npm" ]; then
             ARGS="$ARGS --npm"
           fi
-          node scripts/incremental-benchmark.js $ARGS 2>/dev/null > incremental-benchmark-result.json
+          node $STRIP_FLAG --import ./scripts/ts-resolve-loader.js scripts/incremental-benchmark.ts $ARGS 2>/dev/null > incremental-benchmark-result.json
 
       - name: Update incremental report
         if: steps.existing.outputs.skip != 'true'
-        run: node scripts/update-incremental-report.js incremental-benchmark-result.json
+        run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/update-incremental-report.ts incremental-benchmark-result.json
 
       - name: Upload incremental result
         if: steps.existing.outputs.skip != 'true'
diff --git a/.github/workflows/build-native.yml b/.github/workflows/build-native.yml
index fb6760a2..77eb428d 100644
--- a/.github/workflows/build-native.yml
+++ b/.github/workflows/build-native.yml
@@ -60,7 +60,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: 22
 
       - name: Setup Rust
         uses: dtolnay/rust-toolchain@stable
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a80097ce..26bd4f16 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -43,7 +43,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        node-version: [20, 22]
+        node-version: [22]
 
     runs-on: ${{ matrix.os }}
     name: Test Node ${{ matrix.node-version }} (${{ matrix.os }})
@@ -113,7 +113,9 @@ jobs:
           node-version: 22
 
       - name: Verify all dynamic imports resolve
-        run: node scripts/verify-imports.js
+        run: |
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/verify-imports.ts
 
   rust-check:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/embedding-regression.yml b/.github/workflows/embedding-regression.yml
index a42cc6e7..e049911d 100644
--- a/.github/workflows/embedding-regression.yml
+++ b/.github/workflows/embedding-regression.yml
@@ -38,4 +38,4 @@ jobs:
           key: hf-models-minilm-v1
 
       - name: Run embedding regression tests
-        run: npx vitest run tests/search/embedding-regression.test.js
+        run: npx vitest run tests/search/embedding-regression.test.ts
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index df34445c..af3e79b7 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -142,7 +142,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: 22
 
       - name: Setup Rust
         uses: dtolnay/rust-toolchain@stable
@@ -224,7 +224,8 @@ jobs:
           VERSION: ${{ needs.compute-version.outputs.version }}
         run: |
           npm version "$VERSION" --no-git-tag-version --allow-same-version
-          node scripts/sync-native-versions.js --strip
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/sync-native-versions.ts --strip
           echo "Packaging version $VERSION"
 
       - name: Build TypeScript
@@ -405,7 +406,8 @@ jobs:
         run: |
           git checkout -- package-lock.json
           npm version "$VERSION" --no-git-tag-version --allow-same-version
-          node scripts/sync-native-versions.js
+          STRIP_FLAG=$(node -e "const [M]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+          node $STRIP_FLAG scripts/sync-native-versions.ts
           echo "Publishing version $VERSION"
 
       - name: Build TypeScript
diff --git a/.npmignore b/.npmignore
index 733a7a49..3977f0ea 100644
--- a/.npmignore
+++ b/.npmignore
@@ -7,5 +7,5 @@ docs/
 *.db
 .codegraphrc.json
 .versionrc.json
-commitlint.config.js
+commitlint.config.ts
 codegraph-improvements.md
diff --git a/CLAUDE.md b/CLAUDE.md
index 6d441c78..5c97e60a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -218,4 +218,4 @@ This repo uses [Greptile](https://greptile.com) for automated PR reviews. After
 
 ## Node Version
 
-Requires Node >= 20.
+Requires Node >= 22.6.
diff --git a/commitlint.config.js b/commitlint.config.ts
similarity index 100%
rename from commitlint.config.js
rename to commitlint.config.ts
diff --git a/docs/examples/claude-code-hooks/pre-commit-checks.js b/docs/examples/claude-code-hooks/pre-commit-checks.ts
similarity index 95%
rename from docs/examples/claude-code-hooks/pre-commit-checks.js
rename to docs/examples/claude-code-hooks/pre-commit-checks.ts
index f6bd6cfb..c863d8fd 100644
--- a/docs/examples/claude-code-hooks/pre-commit-checks.js
+++ b/docs/examples/claude-code-hooks/pre-commit-checks.ts
@@ -1,8 +1,8 @@
 /**
- * pre-commit-checks.js — Consolidated pre-commit codegraph checks.
+ * pre-commit-checks.ts — Consolidated pre-commit codegraph checks.
  * Single Node.js process that runs all checks and returns structured JSON.
  *
- * Usage: node pre-commit-checks.js <WORK_ROOT> <EDITED_FILES> <STAGED_FILES>
+ * Usage: node pre-commit-checks.ts <WORK_ROOT> <EDITED_FILES> <STAGED_FILES>
  *
  * Output JSON: { action: "deny"|"allow", reason?: string, context?: string[] }
  *
@@ -12,8 +12,11 @@
  *   3. Diff-impact (informational) — shows blast radius of staged changes
  */
 
-const fs = require('fs');
-const path = require('path');
+import fs from 'node:fs';
+import path from 'node:path';
+import { createRequire } from 'node:module';
+
+const require = createRequire(import.meta.url);
 
 const root = process.argv[2];
 const editedRaw = process.argv[3] || '';
@@ -124,7 +127,7 @@ try {
 
         // Scan for dynamic import() consumers
         const srcDir = path.join(root, 'src');
-        function scanDynamic(dir) {
+        function scanDynamic(dir: string) {
           for (const ent of fs.readdirSync(dir, { withFileTypes: true })) {
             if (ent.isDirectory()) { scanDynamic(path.join(dir, ent.name)); continue; }
             if (!/\.(js|ts|tsx)$/.test(ent.name)) continue;
diff --git a/docs/examples/claude-code-hooks/pre-commit.sh b/docs/examples/claude-code-hooks/pre-commit.sh
index dfa1f3d2..96f3e23f 100644
--- a/docs/examples/claude-code-hooks/pre-commit.sh
+++ b/docs/examples/claude-code-hooks/pre-commit.sh
@@ -48,7 +48,8 @@ fi
 
 # Run all checks in a single Node.js process
 HOOK_DIR="$(cd "$(dirname "$0")" && pwd)"
-RESULT=$(node "$HOOK_DIR/pre-commit-checks.js" "$WORK_ROOT" "$EDITED_FILES" "$STAGED" 2>/dev/null) || true
+STRIP_FLAG=$(node -e "const [M,m]=process.versions.node.split('.').map(Number); console.log(M>=23?'--strip-types':'--experimental-strip-types')")
+RESULT=$(node $STRIP_FLAG "$HOOK_DIR/pre-commit-checks.ts" "$WORK_ROOT" "$EDITED_FILES" "$STAGED" 2>/dev/null) || true
 
 if [ -z "$RESULT" ]; then
   exit 0
diff --git a/package.json b/package.json
index 01115f82..36805d53 100644
--- a/package.json
+++ b/package.json
@@ -26,26 +26,26 @@
     "README.md"
   ],
   "engines": {
-    "node": ">=20"
+    "node": ">=22.6"
   },
   "scripts": {
-    "build": "tsc",
-    "build:wasm": "node scripts/build-wasm.js",
+    "build": "tsc && node -e \"require('fs').writeFileSync('dist/index.cjs',require('fs').readFileSync('src/index.cjs','utf8').replaceAll('./index.ts','./index.js'))\"",
+    "build:wasm": "node --experimental-strip-types scripts/build-wasm.ts",
     "typecheck": "tsc --noEmit",
-    "verify-imports": "node scripts/verify-imports.js",
-    "test": "node scripts/test.js run",
-    "test:watch": "node scripts/test.js",
-    "test:coverage": "node scripts/test.js run --coverage",
+    "verify-imports": "node --experimental-strip-types scripts/verify-imports.ts",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
     "lint": "biome check src/ tests/",
     "lint:fix": "biome check --write src/ tests/",
     "format": "biome format --write src/ tests/",
     "prepack": "npm run build",
     "clean": "node -e \"require('fs').rmSync('dist',{recursive:true,force:true});require('fs').rmSync('.tsbuildinfo',{force:true})\"",
     "prepare": "npm run build:wasm && npm run build && husky && npm run deps:tree",
-    "deps:tree": "node scripts/gen-deps.cjs",
+    "deps:tree": "node --experimental-strip-types scripts/gen-deps.ts",
     "release": "commit-and-tag-version",
     "release:dry-run": "commit-and-tag-version --dry-run",
-    "version": "node scripts/sync-native-versions.js && git add package.json crates/codegraph-core/Cargo.toml"
+    "version": "node --experimental-strip-types scripts/sync-native-versions.ts && git add package.json crates/codegraph-core/Cargo.toml"
   },
   "keywords": [
     "codegraph",
diff --git a/scripts/bench-version.js b/scripts/bench-version.ts
similarity index 100%
rename from scripts/bench-version.js
rename to scripts/bench-version.ts
diff --git a/scripts/benchmark.js b/scripts/benchmark.ts
similarity index 100%
rename from scripts/benchmark.js
rename to scripts/benchmark.ts
diff --git a/scripts/build-wasm.js b/scripts/build-wasm.ts
similarity index 100%
rename from scripts/build-wasm.js
rename to scripts/build-wasm.ts
diff --git a/scripts/embedding-benchmark.js b/scripts/embedding-benchmark.ts
similarity index 100%
rename from scripts/embedding-benchmark.js
rename to scripts/embedding-benchmark.ts
diff --git a/scripts/gen-deps.cjs b/scripts/gen-deps.ts
similarity index 51%
rename from scripts/gen-deps.cjs
rename to scripts/gen-deps.ts
index 32072004..6c7ec148 100644
--- a/scripts/gen-deps.cjs
+++ b/scripts/gen-deps.ts
@@ -1,18 +1,19 @@
-const { execSync } = require('child_process');
-const fs = require('fs');
-const path = require('path');
+#!/usr/bin/env node
+import { execSync } from 'node:child_process';
+import { mkdirSync, writeFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
 
-const outFile = path.join('generated', 'DEPENDENCIES.md');
-fs.mkdirSync(path.dirname(outFile), { recursive: true });
+const outFile = join('generated', 'DEPENDENCIES.md');
+mkdirSync(dirname(outFile), { recursive: true });
 
 try {
   const tree = execSync('npm ls --all --omit=dev', { encoding: 'utf8' });
-  fs.writeFileSync(outFile, '# Dependencies\n\n```\n' + tree + '```\n');
-} catch (err) {
+  writeFileSync(outFile, '# Dependencies\n\n```\n' + tree + '```\n');
+} catch (err: any) {
   // npm ls exits non-zero on ELSPROBLEMS (version mismatches in optional deps).
   // If stdout still has content, write it; otherwise skip silently.
   if (err.stdout) {
-    fs.writeFileSync(
+    writeFileSync(
       outFile,
       '# Dependencies\n\n```\n' + err.stdout + '```\n',
     );
diff --git a/scripts/incremental-benchmark.js b/scripts/incremental-benchmark.ts
similarity index 100%
rename from scripts/incremental-benchmark.js
rename to scripts/incremental-benchmark.ts
diff --git a/scripts/lib/bench-config.js b/scripts/lib/bench-config.ts
similarity index 100%
rename from scripts/lib/bench-config.js
rename to scripts/lib/bench-config.ts
diff --git a/scripts/lib/fork-engine.js b/scripts/lib/fork-engine.ts
similarity index 100%
rename from scripts/lib/fork-engine.js
rename to scripts/lib/fork-engine.ts
diff --git a/scripts/query-benchmark.js b/scripts/query-benchmark.ts
similarity index 100%
rename from scripts/query-benchmark.js
rename to scripts/query-benchmark.ts
diff --git a/scripts/sync-native-versions.js b/scripts/sync-native-versions.ts
similarity index 100%
rename from scripts/sync-native-versions.js
rename to scripts/sync-native-versions.ts
diff --git a/scripts/test.js b/scripts/test.js
deleted file mode 100644
index ea317a7d..00000000
--- a/scripts/test.js
+++ /dev/null
@@ -1,46 +0,0 @@
-#!/usr/bin/env node
-/**
- * Test runner wrapper that configures Node.js for the TypeScript migration
- * before spawning vitest. Adds --experimental-strip-types on Node >= 22.6
- * so child processes can execute .ts files natively.
- */
-
-import { spawnSync } from 'node:child_process';
-import { fileURLToPath, pathToFileURL } from 'node:url';
-import { dirname, resolve } from 'node:path';
-
-const __dirname = dirname(fileURLToPath(import.meta.url));
-const hook = pathToFileURL(resolve(__dirname, 'ts-resolver-hook.js')).href;
-
-const args = process.argv.slice(2);
-const vitestBin = resolve(__dirname, '..', 'node_modules', 'vitest', 'vitest.mjs');
-
-const [major, minor] = process.versions.node.split('.').map(Number);
-const supportsStripTypes = major > 22 || (major === 22 && minor >= 6);
-
-// Build NODE_OPTIONS: resolver hook + type stripping (Node >= 22.6)
-const hookImport = `--import ${hook}`;
-const existing = process.env.NODE_OPTIONS || '';
-const parts = [
-  existing.includes(hookImport) ? null : hookImport,
-  supportsStripTypes && !existing.includes('--experimental-strip-types') && !existing.includes('--strip-types')
-    ? (major >= 23 ? '--strip-types' : '--experimental-strip-types')
-    : null,
-  existing || null,
-].filter(Boolean);
-
-// Spawn vitest via node directly — avoids shell: true and works cross-platform
-const result = spawnSync(process.execPath, [vitestBin, ...args], {
-  stdio: 'inherit',
-  env: {
-    ...process.env,
-    NODE_OPTIONS: parts.join(' '),
-  },
-});
-
-if (result.error) {
-  process.stderr.write(`[test runner] Failed to spawn vitest: ${result.error.message}\n`);
-  process.exit(1);
-}
-
-process.exit(result.status ?? 1);
diff --git a/scripts/token-benchmark-issues.js b/scripts/token-benchmark-issues.ts
similarity index 100%
rename from scripts/token-benchmark-issues.js
rename to scripts/token-benchmark-issues.ts
diff --git a/scripts/token-benchmark.js b/scripts/token-benchmark.ts
similarity index 98%
rename from scripts/token-benchmark.js
rename to scripts/token-benchmark.ts
index 1598e6dc..02e053bc 100644
--- a/scripts/token-benchmark.js
+++ b/scripts/token-benchmark.ts
@@ -12,9 +12,9 @@
  *   ANTHROPIC_API_KEY set in environment
  *
  * Usage:
- *   node scripts/token-benchmark.js > result.json
- *   node scripts/token-benchmark.js --runs 1 --issues csrf-case-insensitive
- *   node scripts/token-benchmark.js --nextjs-dir /tmp/next.js --skip-graph
+ *   node --experimental-strip-types --import ./scripts/ts-resolve-loader.js scripts/token-benchmark.ts > result.json
+ *   node --experimental-strip-types --import ./scripts/ts-resolve-loader.js scripts/token-benchmark.ts --runs 1 --issues csrf-case-insensitive
+ *   node --experimental-strip-types --import ./scripts/ts-resolve-loader.js scripts/token-benchmark.ts --nextjs-dir /tmp/next.js --skip-graph
  */
 
 import { execFileSync, execSync } from 'node:child_process';
diff --git a/scripts/ts-resolve-hooks.ts b/scripts/ts-resolve-hooks.ts
new file mode 100644
index 00000000..572fbf37
--- /dev/null
+++ b/scripts/ts-resolve-hooks.ts
@@ -0,0 +1,28 @@
+/**
+ * ESM resolve hook — rewrites .js specifiers to .ts when the .js file
+ * does not exist on disk. Needed because TypeScript's moduleResolution
+ * "nodenext" convention uses .js extensions in imports, but at runtime
+ * the source files are .ts.
+ *
+ * Loaded via module.register() from ts-resolve-loader.ts.
+ */
+
+import { existsSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+
+export async function resolve(
+  specifier: string,
+  context: { parentURL?: string; conditions: string[] },
+  nextResolve: (specifier: string, context?: { parentURL?: string; conditions: string[] }) => Promise<{ url: string; shortCircuit?: boolean }>,
+): Promise<{ url: string; shortCircuit?: boolean }> {
+  try {
+    return await nextResolve(specifier, context);
+  } catch (err: any) {
+    // Only attempt .js → .ts fallback for file-relative specifiers
+    if (err?.code === 'ERR_MODULE_NOT_FOUND' && specifier.endsWith('.js')) {
+      const tsSpecifier = specifier.slice(0, -3) + '.ts';
+      return nextResolve(tsSpecifier, context);
+    }
+    throw err;
+  }
+}
diff --git a/scripts/ts-resolve-loader.ts b/scripts/ts-resolve-loader.ts
new file mode 100644
index 00000000..241c87ec
--- /dev/null
+++ b/scripts/ts-resolve-loader.ts
@@ -0,0 +1,9 @@
+/**
+ * Registers the .js → .ts ESM resolve hook.
+ *
+ * Usage: node --experimental-strip-types --import ./scripts/ts-resolve-loader.ts src/cli.ts
+ */
+
+import { register } from 'node:module';
+
+register(new URL('./ts-resolve-hooks.ts', import.meta.url));
diff --git a/scripts/update-benchmark-report.js b/scripts/update-benchmark-report.ts
similarity index 100%
rename from scripts/update-benchmark-report.js
rename to scripts/update-benchmark-report.ts
diff --git a/scripts/update-embedding-report.js b/scripts/update-embedding-report.ts
similarity index 100%
rename from scripts/update-embedding-report.js
rename to scripts/update-embedding-report.ts
diff --git a/scripts/update-incremental-report.js b/scripts/update-incremental-report.ts
similarity index 100%
rename from scripts/update-incremental-report.js
rename to scripts/update-incremental-report.ts
diff --git a/scripts/update-query-report.js b/scripts/update-query-report.ts
similarity index 100%
rename from scripts/update-query-report.js
rename to scripts/update-query-report.ts
diff --git a/scripts/update-token-report.js b/scripts/update-token-report.ts
similarity index 100%
rename from scripts/update-token-report.js
rename to scripts/update-token-report.ts
diff --git a/scripts/verify-imports.js b/scripts/verify-imports.ts
similarity index 100%
rename from scripts/verify-imports.js
rename to scripts/verify-imports.ts
diff --git a/src/index.cjs b/src/index.cjs
index 811e449c..2b06f4a6 100644
--- a/src/index.cjs
+++ b/src/index.cjs
@@ -13,4 +13,4 @@
 // Note: if import() rejects (e.g. missing dependency), the rejected Promise is cached
 // by the CJS module system and every subsequent require() call will re-surface the same
 // rejection without re-attempting the load.
-module.exports = import('./index.js');
+module.exports = import('./index.ts');
diff --git a/tests/benchmarks/resolution/resolution-benchmark.test.js b/tests/benchmarks/resolution/resolution-benchmark.test.ts
similarity index 86%
rename from tests/benchmarks/resolution/resolution-benchmark.test.js
rename to tests/benchmarks/resolution/resolution-benchmark.test.ts
index fa7c248d..599c60cc 100644
--- a/tests/benchmarks/resolution/resolution-benchmark.test.js
+++ b/tests/benchmarks/resolution/resolution-benchmark.test.ts
@@ -17,6 +17,42 @@ import { afterAll, beforeAll, describe, expect, test } from 'vitest';
 import { openReadonlyOrFail } from '../../../src/db/index.js';
 import { buildGraph } from '../../../src/domain/graph/builder.js';
 
+// ── Types ─────────────────────────────────────────────────────────────────
+
+interface ResolvedEdge {
+  source_name: string;
+  source_file: string;
+  target_name: string;
+  target_file: string;
+  kind: string;
+  confidence: number;
+}
+
+interface ExpectedEdge {
+  source: { name: string; file: string };
+  target: { name: string; file: string };
+  mode?: string;
+}
+
+interface ModeMetrics {
+  expected: number;
+  resolved: number;
+  recall?: number;
+}
+
+interface BenchmarkMetrics {
+  precision: number;
+  recall: number;
+  truePositives: number;
+  falsePositives: number;
+  falseNegatives: number;
+  totalResolved: number;
+  totalExpected: number;
+  byMode: Record<string, ModeMetrics>;
+  falsePositiveEdges: string[];
+  falseNegativeEdges: string[];
+}
+
 // ── Configuration ────────────────────────────────────────────────────────
 
 const FIXTURES_DIR = path.join(import.meta.dirname, 'fixtures');
@@ -40,7 +76,7 @@ const THRESHOLDS = {
  * Copy fixture to a temp directory so buildGraph can write .codegraph/ without
  * polluting the repo.
  */
-function copyFixture(lang) {
+function copyFixture(lang: string): string {
   const src = path.join(FIXTURES_DIR, lang);
   const tmp = fs.mkdtempSync(path.join(os.tmpdir(), `codegraph-resolution-${lang}-`));
   for (const entry of fs.readdirSync(src, { withFileTypes: true })) {
@@ -54,7 +90,7 @@ function copyFixture(lang) {
 /**
  * Build graph for a fixture directory.
  */
-async function buildFixtureGraph(fixtureDir) {
+async function buildFixtureGraph(fixtureDir: string): Promise<void> {
   await buildGraph(fixtureDir, {
     incremental: false,
     engine: 'wasm',
@@ -68,7 +104,7 @@ async function buildFixtureGraph(fixtureDir) {
  * Extract all call edges from the built graph DB.
  * Returns array of { sourceName, sourceFile, targetName, targetFile, kind, confidence }.
  */
-function extractResolvedEdges(fixtureDir) {
+function extractResolvedEdges(fixtureDir: string) {
   const dbPath = path.join(fixtureDir, '.codegraph', 'graph.db');
   const db = openReadonlyOrFail(dbPath);
   try {
@@ -97,14 +133,19 @@ function extractResolvedEdges(fixtureDir) {
 /**
  * Normalize a file path to just the basename for comparison.
  */
-function normalizeFile(filePath) {
+function normalizeFile(filePath: string): string {
   return path.basename(filePath);
 }
 
 /**
  * Build a string key for an edge to enable set-based comparison.
  */
-function edgeKey(sourceName, sourceFile, targetName, targetFile) {
+function edgeKey(
+  sourceName: string,
+  sourceFile: string,
+  targetName: string,
+  targetFile: string,
+): string {
   return `${sourceName}@${normalizeFile(sourceFile)} -> ${targetName}@${normalizeFile(targetFile)}`;
 }
 
@@ -112,7 +153,10 @@ function edgeKey(sourceName, sourceFile, targetName, targetFile) {
  * Compare resolved edges against expected edges manifest.
  * Returns precision, recall, and detailed breakdown by mode.
  */
-function computeMetrics(resolvedEdges, expectedEdges) {
+function computeMetrics(
+  resolvedEdges: ResolvedEdge[],
+  expectedEdges: ExpectedEdge[],
+): BenchmarkMetrics {
   // Build sets for overall comparison
   const resolvedSet = new Set(
     resolvedEdges.map((e) => edgeKey(e.source_name, e.source_file, e.target_name, e.target_file)),
@@ -135,7 +179,7 @@ function computeMetrics(resolvedEdges, expectedEdges) {
   const recall = expectedSet.size > 0 ? truePositives.size / expectedSet.size : 0;
 
   // Break down by resolution mode
-  const byMode = {};
+  const byMode: Record<string, ModeMetrics> = {};
   for (const edge of expectedEdges) {
     const mode = edge.mode || 'unknown';
     if (!byMode[mode]) byMode[mode] = { expected: 0, resolved: 0 };
@@ -168,7 +212,7 @@ function computeMetrics(resolvedEdges, expectedEdges) {
 /**
  * Format a metrics report for console output.
  */
-function formatReport(lang, metrics) {
+function formatReport(lang: string, metrics: BenchmarkMetrics): string {
   const lines = [
     `\n  ── ${lang.toUpperCase()} Resolution Metrics ──`,
     `  Precision: ${(metrics.precision * 100).toFixed(1)}% (${metrics.truePositives} correct / ${metrics.totalResolved} resolved)`,
@@ -208,9 +252,9 @@ function formatReport(lang, metrics) {
 /**
  * Discover all fixture languages that have an expected-edges.json manifest.
  */
-function discoverFixtures() {
+function discoverFixtures(): string[] {
   if (!fs.existsSync(FIXTURES_DIR)) return [];
-  const languages = [];
+  const languages: string[] = [];
   for (const dir of fs.readdirSync(FIXTURES_DIR)) {
     const manifestPath = path.join(FIXTURES_DIR, dir, 'expected-edges.json');
     if (fs.existsSync(manifestPath)) {
@@ -223,7 +267,7 @@ function discoverFixtures() {
 const languages = discoverFixtures();
 
 /** Stores all results for the final summary */
-const allResults = {};
+const allResults: Record<string, BenchmarkMetrics> = {};
 
 describe('Call Resolution Precision/Recall', () => {
   afterAll(() => {
@@ -242,10 +286,10 @@ describe('Call Resolution Precision/Recall', () => {
 
   for (const lang of languages) {
     describe(lang, () => {
-      let fixtureDir;
-      let resolvedEdges;
-      let expectedEdges;
-      let metrics;
+      let fixtureDir: string;
+      let resolvedEdges: ResolvedEdge[];
+      let expectedEdges: ExpectedEdge[];
+      let metrics: BenchmarkMetrics;
 
       beforeAll(async () => {
         fixtureDir = copyFixture(lang);
diff --git a/tests/builder/collect-files.test.js b/tests/builder/collect-files.test.ts
similarity index 99%
rename from tests/builder/collect-files.test.js
rename to tests/builder/collect-files.test.ts
index 4d4955c5..8cc0c937 100644
--- a/tests/builder/collect-files.test.js
+++ b/tests/builder/collect-files.test.ts
@@ -8,7 +8,7 @@ import { afterAll, beforeAll, describe, expect, it } from 'vitest';
 import { PipelineContext } from '../../src/domain/graph/builder/context.js';
 import { collectFiles } from '../../src/domain/graph/builder/stages/collect-files.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-stage-collect-'));
diff --git a/tests/builder/context.test.js b/tests/builder/context.test.ts
similarity index 100%
rename from tests/builder/context.test.js
rename to tests/builder/context.test.ts
diff --git a/tests/builder/detect-changes.test.js b/tests/builder/detect-changes.test.ts
similarity index 99%
rename from tests/builder/detect-changes.test.js
rename to tests/builder/detect-changes.test.ts
index 2555b097..0d13fd72 100644
--- a/tests/builder/detect-changes.test.js
+++ b/tests/builder/detect-changes.test.ts
@@ -10,7 +10,7 @@ import { PipelineContext } from '../../src/domain/graph/builder/context.js';
 import { detectChanges } from '../../src/domain/graph/builder/stages/detect-changes.js';
 import { writeJournalHeader } from '../../src/domain/graph/journal.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-stage-detect-'));
diff --git a/tests/builder/pipeline.test.js b/tests/builder/pipeline.test.ts
similarity index 99%
rename from tests/builder/pipeline.test.js
rename to tests/builder/pipeline.test.ts
index 76624d61..350808fb 100644
--- a/tests/builder/pipeline.test.js
+++ b/tests/builder/pipeline.test.ts
@@ -11,7 +11,7 @@ import { afterAll, beforeAll, describe, expect, it } from 'vitest';
 import { buildGraph } from '../../src/domain/graph/builder/pipeline.js';
 
 const FIXTURE_DIR = path.join(import.meta.dirname, '..', 'fixtures', 'sample-project');
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-pipeline-'));
diff --git a/tests/engines/dataflow-parity.test.js b/tests/engines/dataflow-parity.test.ts
similarity index 99%
rename from tests/engines/dataflow-parity.test.js
rename to tests/engines/dataflow-parity.test.ts
index 0ed2d996..ce1c314d 100644
--- a/tests/engines/dataflow-parity.test.js
+++ b/tests/engines/dataflow-parity.test.ts
@@ -16,8 +16,8 @@ import { createParsers, getParser } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 import { isNativeAvailable } from '../../src/infrastructure/native.js';
 
-let native;
-let parsers;
+let native: any;
+let parsers: any;
 let nativeHasDataflow = false;
 
 /**
diff --git a/tests/engines/parity.test.js b/tests/engines/parity.test.ts
similarity index 99%
rename from tests/engines/parity.test.js
rename to tests/engines/parity.test.ts
index ef966af3..d90fd42d 100644
--- a/tests/engines/parity.test.js
+++ b/tests/engines/parity.test.ts
@@ -23,8 +23,8 @@ import {
 } from '../../src/domain/parser.js';
 import { isNativeAvailable } from '../../src/infrastructure/native.js';
 
-let native;
-let parsers;
+let native: any;
+let parsers: any;
 
 function wasmExtract(code, filePath) {
   const parser = getParser(parsers, filePath);
diff --git a/tests/engines/query-walk-parity.test.js b/tests/engines/query-walk-parity.test.ts
similarity index 99%
rename from tests/engines/query-walk-parity.test.js
rename to tests/engines/query-walk-parity.test.ts
index 05335c5c..2b1f3e78 100644
--- a/tests/engines/query-walk-parity.test.js
+++ b/tests/engines/query-walk-parity.test.ts
@@ -12,7 +12,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, getParser, parseFileAuto } from '../../src/domain/parser.js';
 import { extractSymbols } from '../../src/extractors/javascript.js';
 
-let parsers;
+let parsers: any;
 
 beforeAll(async () => {
   parsers = await createParsers();
diff --git a/tests/graph/algorithms/bfs.test.js b/tests/graph/algorithms/bfs.test.ts
similarity index 100%
rename from tests/graph/algorithms/bfs.test.js
rename to tests/graph/algorithms/bfs.test.ts
diff --git a/tests/graph/algorithms/centrality.test.js b/tests/graph/algorithms/centrality.test.ts
similarity index 100%
rename from tests/graph/algorithms/centrality.test.js
rename to tests/graph/algorithms/centrality.test.ts
diff --git a/tests/graph/algorithms/leiden.test.js b/tests/graph/algorithms/leiden.test.ts
similarity index 100%
rename from tests/graph/algorithms/leiden.test.js
rename to tests/graph/algorithms/leiden.test.ts
diff --git a/tests/graph/algorithms/louvain.test.js b/tests/graph/algorithms/louvain.test.ts
similarity index 100%
rename from tests/graph/algorithms/louvain.test.js
rename to tests/graph/algorithms/louvain.test.ts
diff --git a/tests/graph/algorithms/shortest-path.test.js b/tests/graph/algorithms/shortest-path.test.ts
similarity index 100%
rename from tests/graph/algorithms/shortest-path.test.js
rename to tests/graph/algorithms/shortest-path.test.ts
diff --git a/tests/graph/algorithms/tarjan.test.js b/tests/graph/algorithms/tarjan.test.ts
similarity index 100%
rename from tests/graph/algorithms/tarjan.test.js
rename to tests/graph/algorithms/tarjan.test.ts
diff --git a/tests/graph/builders/dependency.test.js b/tests/graph/builders/dependency.test.ts
similarity index 100%
rename from tests/graph/builders/dependency.test.js
rename to tests/graph/builders/dependency.test.ts
diff --git a/tests/graph/builders/structure.test.js b/tests/graph/builders/structure.test.ts
similarity index 100%
rename from tests/graph/builders/structure.test.js
rename to tests/graph/builders/structure.test.ts
diff --git a/tests/graph/builders/temporal.test.js b/tests/graph/builders/temporal.test.ts
similarity index 100%
rename from tests/graph/builders/temporal.test.js
rename to tests/graph/builders/temporal.test.ts
diff --git a/tests/graph/classifiers/risk.test.js b/tests/graph/classifiers/risk.test.ts
similarity index 100%
rename from tests/graph/classifiers/risk.test.js
rename to tests/graph/classifiers/risk.test.ts
diff --git a/tests/graph/classifiers/roles.test.js b/tests/graph/classifiers/roles.test.ts
similarity index 100%
rename from tests/graph/classifiers/roles.test.js
rename to tests/graph/classifiers/roles.test.ts
diff --git a/tests/graph/cycles.test.js b/tests/graph/cycles.test.ts
similarity index 100%
rename from tests/graph/cycles.test.js
rename to tests/graph/cycles.test.ts
diff --git a/tests/graph/export.test.js b/tests/graph/export.test.ts
similarity index 100%
rename from tests/graph/export.test.js
rename to tests/graph/export.test.ts
diff --git a/tests/graph/model.test.js b/tests/graph/model.test.ts
similarity index 100%
rename from tests/graph/model.test.js
rename to tests/graph/model.test.ts
diff --git a/tests/graph/viewer.test.js b/tests/graph/viewer.test.ts
similarity index 100%
rename from tests/graph/viewer.test.js
rename to tests/graph/viewer.test.ts
diff --git a/tests/helpers/fixtures.js b/tests/helpers/fixtures.ts
similarity index 58%
rename from tests/helpers/fixtures.js
rename to tests/helpers/fixtures.ts
index e9225b12..33154720 100644
--- a/tests/helpers/fixtures.js
+++ b/tests/helpers/fixtures.ts
@@ -10,84 +10,89 @@ import { InMemoryRepository } from '../../src/db/repository/in-memory-repository
  *     .calls('authMiddleware', 'authenticate')
  *     .build();
  */
-class TestRepoBuilder {
-  #pending = { nodes: [], edges: [], complexity: [] };
+interface PendingNode {
+  name: string;
+  kind: string;
+  file: string;
+  line: number;
+  [key: string]: unknown;
+}
 
-  /**
-   * Add a function node.
-   * @param {string} name
-   * @param {string} file
-   * @param {number} line
-   * @param {object} [extra] - Additional node attrs (role, end_line, scope, etc.)
-   */
-  fn(name, file, line, extra = {}) {
+interface PendingEdge {
+  source: string;
+  target: string;
+  kind: string;
+}
+
+interface PendingComplexity {
+  name: string;
+  metrics: Record<string, unknown>;
+}
+
+class TestRepoBuilder {
+  #pending: { nodes: PendingNode[]; edges: PendingEdge[]; complexity: PendingComplexity[] } = {
+    nodes: [],
+    edges: [],
+    complexity: [],
+  };
+
+  /** Add a function node. */
+  fn(name: string, file: string, line: number, extra: Record<string, unknown> = {}): this {
     return this.#addNode(name, 'function', file, line, extra);
   }
 
-  /**
-   * Add a method node.
-   */
-  method(name, file, line, extra = {}) {
+  /** Add a method node. */
+  method(name: string, file: string, line: number, extra: Record<string, unknown> = {}): this {
     return this.#addNode(name, 'method', file, line, extra);
   }
 
-  /**
-   * Add a class node.
-   */
-  cls(name, file, line, extra = {}) {
+  /** Add a class node. */
+  cls(name: string, file: string, line: number, extra: Record<string, unknown> = {}): this {
     return this.#addNode(name, 'class', file, line, extra);
   }
 
-  /**
-   * Add a file node.
-   */
-  file(filePath) {
+  /** Add a file node. */
+  file(filePath: string): this {
     return this.#addNode(filePath, 'file', filePath, 0);
   }
 
-  /**
-   * Add an arbitrary node.
-   */
-  node(name, kind, file, line, extra = {}) {
+  /** Add an arbitrary node. */
+  node(
+    name: string,
+    kind: string,
+    file: string,
+    line: number,
+    extra: Record<string, unknown> = {},
+  ): this {
     return this.#addNode(name, kind, file, line, extra);
   }
 
-  /**
-   * Add a 'calls' edge between two named nodes.
-   */
-  calls(sourceName, targetName) {
+  /** Add a 'calls' edge between two named nodes. */
+  calls(sourceName: string, targetName: string): this {
     this.#pending.edges.push({ source: sourceName, target: targetName, kind: 'calls' });
     return this;
   }
 
-  /**
-   * Add an 'imports' edge.
-   */
-  imports(sourceName, targetName) {
+  /** Add an 'imports' edge. */
+  imports(sourceName: string, targetName: string): this {
     this.#pending.edges.push({ source: sourceName, target: targetName, kind: 'imports' });
     return this;
   }
 
-  /**
-   * Add an 'extends' edge.
-   */
-  extends(sourceName, targetName) {
+  /** Add an 'extends' edge. */
+  extends(sourceName: string, targetName: string): this {
     this.#pending.edges.push({ source: sourceName, target: targetName, kind: 'extends' });
     return this;
   }
 
-  /**
-   * Add an edge of any kind.
-   */
-  edge(sourceName, targetName, kind) {
+  /** Add an edge of any kind. */
+  edge(sourceName: string, targetName: string, kind: string): this {
     this.#pending.edges.push({ source: sourceName, target: targetName, kind });
     return this;
   }
 
-  /**
-   * Add complexity metrics for a named node.
-   */
-  complexity(name, metrics) {
+  /** Add complexity metrics for a named node. */
+  complexity(name: string, metrics: Record<string, unknown>): this {
     this.#pending.complexity.push({ name, metrics });
     return this;
   }
@@ -129,16 +134,19 @@ class TestRepoBuilder {
     return { repo, ids };
   }
 
-  #addNode(name, kind, file, line, extra = {}) {
+  #addNode(
+    name: string,
+    kind: string,
+    file: string,
+    line: number,
+    extra: Record<string, unknown> = {},
+  ): this {
     this.#pending.nodes.push({ name, kind, file, line, ...extra });
     return this;
   }
 }
 
-/**
- * Create a new TestRepoBuilder.
- * @returns {TestRepoBuilder}
- */
-export function createTestRepo() {
+/** Create a new TestRepoBuilder. */
+export function createTestRepo(): TestRepoBuilder {
   return new TestRepoBuilder();
 }
diff --git a/tests/helpers/node-version.js b/tests/helpers/node-version.js
deleted file mode 100644
index f8603a82..00000000
--- a/tests/helpers/node-version.js
+++ /dev/null
@@ -1,6 +0,0 @@
-/**
- * Node >= 22.6 supports --experimental-strip-types, required for tests that
- * spawn child processes loading .ts source files directly.
- */
-const [major, minor] = process.versions.node.split('.').map(Number);
-export const canStripTypes = major > 22 || (major === 22 && minor >= 6);
diff --git a/tests/incremental/cache.test.js b/tests/incremental/cache.test.ts
similarity index 99%
rename from tests/incremental/cache.test.js
rename to tests/incremental/cache.test.ts
index 46ee6290..0cfc2b92 100644
--- a/tests/incremental/cache.test.js
+++ b/tests/incremental/cache.test.ts
@@ -10,7 +10,7 @@ import { isNativeAvailable, loadNative } from '../../src/infrastructure/native.j
 const hasNative = isNativeAvailable();
 
 describe.skipIf(!hasNative)('ParseTreeCache', () => {
-  let cache;
+  let cache: any;
 
   beforeEach(() => {
     const native = loadNative();
diff --git a/tests/incremental/watcher-incremental.test.js b/tests/incremental/watcher-incremental.test.ts
similarity index 98%
rename from tests/incremental/watcher-incremental.test.js
rename to tests/incremental/watcher-incremental.test.ts
index 8c273203..e8220d5d 100644
--- a/tests/incremental/watcher-incremental.test.js
+++ b/tests/incremental/watcher-incremental.test.ts
@@ -17,8 +17,8 @@ import { isNativeAvailable } from '../../src/infrastructure/native.js';
 const hasNative = isNativeAvailable();
 
 describe.skipIf(!hasNative)('Watcher incremental flow', () => {
-  let tmpDir;
-  let cache;
+  let tmpDir: string;
+  let cache: any;
 
   beforeEach(() => {
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-inc-'));
diff --git a/tests/integration/ast.test.js b/tests/integration/ast.test.ts
similarity index 99%
rename from tests/integration/ast.test.js
rename to tests/integration/ast.test.ts
index 706684d9..8c731322 100644
--- a/tests/integration/ast.test.js
+++ b/tests/integration/ast.test.ts
@@ -30,7 +30,7 @@ function insertAstNode(db, file, line, kind, name, text, receiver, parentNodeId)
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ast-'));
diff --git a/tests/integration/audit.test.js b/tests/integration/audit.test.ts
similarity index 99%
rename from tests/integration/audit.test.js
rename to tests/integration/audit.test.ts
index f6d00768..547bb32e 100644
--- a/tests/integration/audit.test.js
+++ b/tests/integration/audit.test.ts
@@ -46,7 +46,7 @@ function insertComplexity(db, nodeId, opts = {}) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-audit-'));
diff --git a/tests/integration/batch.test.js b/tests/integration/batch.test.ts
similarity index 95%
rename from tests/integration/batch.test.js
rename to tests/integration/batch.test.ts
index 216c98e3..5fbb2172 100644
--- a/tests/integration/batch.test.js
+++ b/tests/integration/batch.test.ts
@@ -25,10 +25,6 @@ import {
   splitTargets,
 } from '../../src/features/batch.js';
 
-// Child processes load .ts files natively — requires Node >= 22.6 type stripping
-const [_major, _minor] = process.versions.node.split('.').map(Number);
-const canStripTypes = _major > 22 || (_major === 22 && _minor >= 6);
-
 // ─── Helpers ───────────────────────────────────────────────────────────
 
 function insertNode(db, name, kind, file, line) {
@@ -45,7 +41,7 @@ function insertEdge(db, sourceId, targetId, kind = 'calls', confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-batch-'));
@@ -212,17 +208,23 @@ describe('batchData — complexity (dbOnly signature)', () => {
 
 // ─── CLI smoke test ──────────────────────────────────────────────────
 
-describe.skipIf(!canStripTypes)('batch CLI', () => {
+describe('batch CLI', () => {
   const cliPath = path.resolve(
     path.dirname(new URL(import.meta.url).pathname.replace(/^\/([A-Z]:)/i, '$1')),
-    '../../src/cli.js',
+    '../../src/cli.ts',
   );
+  const loaderUrl = new URL('../../scripts/ts-resolve-loader.ts', import.meta.url).href;
+  const NODE_TS_FLAGS = ['--experimental-strip-types', '--import', loaderUrl];
 
   test('outputs valid JSON', () => {
-    const out = execFileSync('node', [cliPath, 'batch', 'query', 'authenticate', '--db', dbPath], {
-      encoding: 'utf-8',
-      timeout: 30_000,
-    });
+    const out = execFileSync(
+      'node',
+      [...NODE_TS_FLAGS, cliPath, 'batch', 'query', 'authenticate', '--db', dbPath],
+      {
+        encoding: 'utf-8',
+        timeout: 30_000,
+      },
+    );
     const parsed = JSON.parse(out);
     expect(parsed.command).toBe('query');
     expect(parsed.total).toBe(1);
@@ -232,7 +234,7 @@ describe.skipIf(!canStripTypes)('batch CLI', () => {
   test('batch accepts comma-separated positional targets', () => {
     const out = execFileSync(
       'node',
-      [cliPath, 'batch', 'where', 'authenticate,validateToken', '--db', dbPath],
+      [...NODE_TS_FLAGS, cliPath, 'batch', 'where', 'authenticate,validateToken', '--db', dbPath],
       { encoding: 'utf-8', timeout: 30_000 },
     );
     const parsed = JSON.parse(out);
diff --git a/tests/integration/branch-compare.test.js b/tests/integration/branch-compare.test.ts
similarity index 99%
rename from tests/integration/branch-compare.test.js
rename to tests/integration/branch-compare.test.ts
index 0a276117..b67326ae 100644
--- a/tests/integration/branch-compare.test.js
+++ b/tests/integration/branch-compare.test.ts
@@ -12,7 +12,7 @@ import path from 'node:path';
 import { afterAll, beforeAll, describe, expect, test } from 'vitest';
 import { branchCompareData, branchCompareMermaid } from '../../src/features/branch-compare.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-bc-test-'));
diff --git a/tests/integration/build-parity.test.js b/tests/integration/build-parity.test.ts
similarity index 98%
rename from tests/integration/build-parity.test.js
rename to tests/integration/build-parity.test.ts
index 98ce843d..a059d452 100644
--- a/tests/integration/build-parity.test.js
+++ b/tests/integration/build-parity.test.ts
@@ -61,8 +61,8 @@ function readGraph(dbPath) {
 }
 
 describeOrSkip('Build parity: native vs WASM', () => {
-  let wasmDir;
-  let nativeDir;
+  let wasmDir: string;
+  let nativeDir: string;
 
   beforeAll(async () => {
     // Create two temp copies of the fixture
diff --git a/tests/integration/build.test.js b/tests/integration/build.test.ts
similarity index 98%
rename from tests/integration/build.test.js
rename to tests/integration/build.test.ts
index cfa1ebac..8ced90fe 100644
--- a/tests/integration/build.test.js
+++ b/tests/integration/build.test.ts
@@ -39,7 +39,7 @@ export function main() {
 `.trimStart(),
 };
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(async () => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-build-'));
@@ -154,7 +154,7 @@ describe('buildGraph', () => {
 });
 
 describe('three-tier incremental builds', () => {
-  let incrDir, incrDbPath;
+  let incrDir: string, incrDbPath: string;
 
   beforeAll(async () => {
     incrDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-tier-'));
@@ -361,7 +361,7 @@ describe('three-tier incremental builds', () => {
 });
 
 describe('nested function caller attribution', () => {
-  let nestDir, nestDbPath;
+  let nestDir: string, nestDbPath: string;
 
   beforeAll(async () => {
     nestDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-nested-'));
@@ -406,7 +406,7 @@ describe('nested function caller attribution', () => {
 });
 
 describe('version/engine mismatch auto-promotes to full rebuild', () => {
-  let promoDir, promoDbPath;
+  let promoDir: string, promoDbPath: string;
 
   beforeAll(async () => {
     promoDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-promo-'));
@@ -480,7 +480,7 @@ describe('version/engine mismatch auto-promotes to full rebuild', () => {
 });
 
 describe('typed method call resolution', () => {
-  let typedDir, typedDbPath;
+  let typedDir: string, typedDbPath: string;
 
   beforeAll(async () => {
     typedDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-typed-'));
diff --git a/tests/integration/cfg.test.js b/tests/integration/cfg.test.ts
similarity index 99%
rename from tests/integration/cfg.test.js
rename to tests/integration/cfg.test.ts
index 548042ea..33284ce6 100644
--- a/tests/integration/cfg.test.js
+++ b/tests/integration/cfg.test.ts
@@ -36,7 +36,7 @@ function insertEdge(db, fnNodeId, sourceBlockId, targetBlockId, kind) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-cfg-'));
diff --git a/tests/integration/check.test.js b/tests/integration/check.test.ts
similarity index 99%
rename from tests/integration/check.test.js
rename to tests/integration/check.test.ts
index 1e339188..9866f20e 100644
--- a/tests/integration/check.test.js
+++ b/tests/integration/check.test.ts
@@ -36,7 +36,7 @@ function insertEdge(db, sourceId, targetId, kind) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath, db;
+let tmpDir: string, dbPath: string, db: any;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-check-'));
diff --git a/tests/integration/cli.test.js b/tests/integration/cli.test.ts
similarity index 95%
rename from tests/integration/cli.test.js
rename to tests/integration/cli.test.ts
index 52cc8ff1..d254a578 100644
--- a/tests/integration/cli.test.js
+++ b/tests/integration/cli.test.ts
@@ -9,11 +9,9 @@ import os from 'node:os';
 import path from 'node:path';
 import { afterAll, beforeAll, describe, expect, test } from 'vitest';
 
-// All tests spawn child processes that load .ts files — requires Node >= 22.6
-const [_major, _minor] = process.versions.node.split('.').map(Number);
-const canStripTypes = _major > 22 || (_major === 22 && _minor >= 6);
-
-const CLI = path.resolve('src/cli.js');
+const CLI = path.resolve('src/cli.ts');
+const LOADER = new URL('../../scripts/ts-resolve-loader.ts', import.meta.url).href;
+const NODE_TS_FLAGS = ['--experimental-strip-types', '--import', LOADER];
 
 const FIXTURE_FILES = {
   'math.js': `
@@ -40,11 +38,11 @@ export function main() {
 `.trimStart(),
 };
 
-let tmpDir, tmpHome, dbPath;
+let tmpDir: string, tmpHome: string, dbPath: string;
 
 /** Run the CLI and return stdout as a string. Throws on non-zero exit. */
 function run(...args) {
-  return execFileSync('node', [CLI, ...args], {
+  return execFileSync('node', [...NODE_TS_FLAGS, CLI, ...args], {
     cwd: tmpDir,
     encoding: 'utf-8',
     timeout: 30_000,
@@ -69,7 +67,7 @@ afterAll(() => {
   if (tmpHome) fs.rmSync(tmpHome, { recursive: true, force: true });
 });
 
-describe.skipIf(!canStripTypes)('CLI smoke tests', () => {
+describe('CLI smoke tests', () => {
   // ─── Build ───────────────────────────────────────────────────────────
   test('build creates graph.db', () => {
     expect(fs.existsSync(dbPath)).toBe(true);
@@ -200,7 +198,7 @@ describe.skipIf(!canStripTypes)('CLI smoke tests', () => {
     const { spawnSync } = require('node:child_process');
     const result = spawnSync(
       'node',
-      [CLI, 'query', 'sumOfSquares', '--path', 'add', '--db', dbPath, '--json'],
+      [...NODE_TS_FLAGS, CLI, 'query', 'sumOfSquares', '--path', 'add', '--db', dbPath, '--json'],
       {
         cwd: tmpDir,
         encoding: 'utf-8',
@@ -241,12 +239,12 @@ describe.skipIf(!canStripTypes)('CLI smoke tests', () => {
 
 // ─── Registry CLI ───────────────────────────────────────────────────────
 
-describe.skipIf(!canStripTypes)('Registry CLI commands', () => {
-  let tmpHome;
+describe('Registry CLI commands', () => {
+  let tmpHome: string;
 
   /** Run CLI with isolated HOME to avoid touching real registry */
   function runReg(...args) {
-    return execFileSync('node', [CLI, ...args], {
+    return execFileSync('node', [...NODE_TS_FLAGS, CLI, ...args], {
       cwd: tmpDir,
       encoding: 'utf-8',
       timeout: 30_000,
diff --git a/tests/integration/cochange.test.js b/tests/integration/cochange.test.ts
similarity index 99%
rename from tests/integration/cochange.test.js
rename to tests/integration/cochange.test.ts
index 5dbed8fb..e33dc9d8 100644
--- a/tests/integration/cochange.test.js
+++ b/tests/integration/cochange.test.ts
@@ -111,7 +111,7 @@ describe('computeCoChanges', () => {
 // ─── B. DB integration (coChangeData / coChangeTopData) ──────────────
 
 describe('coChangeData + coChangeTopData', () => {
-  let tmpDir, dbPath;
+  let tmpDir: string, dbPath: string;
 
   beforeAll(() => {
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-cochange-'));
@@ -207,7 +207,7 @@ describe('coChangeData + coChangeTopData', () => {
 // ─── C. scanGitHistory (real git repo) ───────────────────────────────
 
 describe('scanGitHistory', () => {
-  let tmpDir;
+  let tmpDir: string;
 
   beforeAll(() => {
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-git-'));
diff --git a/tests/integration/communities.test.js b/tests/integration/communities.test.ts
similarity index 99%
rename from tests/integration/communities.test.js
rename to tests/integration/communities.test.ts
index 90324367..b48df12f 100644
--- a/tests/integration/communities.test.js
+++ b/tests/integration/communities.test.ts
@@ -16,7 +16,7 @@ import { createTestRepo } from '../helpers/fixtures.js';
 
 // ─── Fixture ──────────────────────────────────────────────────────────
 
-let repo;
+let repo: any;
 
 beforeAll(() => {
   ({ repo } = createTestRepo()
diff --git a/tests/integration/complexity.test.js b/tests/integration/complexity.test.ts
similarity index 99%
rename from tests/integration/complexity.test.js
rename to tests/integration/complexity.test.ts
index 8d7ea175..ddfbd8a8 100644
--- a/tests/integration/complexity.test.js
+++ b/tests/integration/complexity.test.ts
@@ -76,7 +76,7 @@ function insertComplexity(
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-complexity-'));
diff --git a/tests/integration/context.test.js b/tests/integration/context.test.ts
similarity index 99%
rename from tests/integration/context.test.js
rename to tests/integration/context.test.ts
index 14e39b05..1ee3e91e 100644
--- a/tests/integration/context.test.js
+++ b/tests/integration/context.test.ts
@@ -29,7 +29,7 @@ function insertEdge(db, sourceId, targetId, kind) {
 
 // ─── Fixture ──────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-context-'));
diff --git a/tests/integration/dataflow.test.js b/tests/integration/dataflow.test.ts
similarity index 99%
rename from tests/integration/dataflow.test.js
rename to tests/integration/dataflow.test.ts
index 78eb679d..29bd7c95 100644
--- a/tests/integration/dataflow.test.js
+++ b/tests/integration/dataflow.test.ts
@@ -43,7 +43,7 @@ function insertDataflow(db, sourceId, targetId, kind, opts = {}) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-dataflow-'));
@@ -300,7 +300,7 @@ describe('dataflowImpactData', () => {
 // ─── Empty dataflow table ──────────────────────────────────────────────
 
 describe('empty dataflow', () => {
-  let emptyDbPath;
+  let emptyDbPath: string;
 
   beforeAll(() => {
     const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-df-empty-'));
diff --git a/tests/integration/exports.test.js b/tests/integration/exports.test.ts
similarity index 99%
rename from tests/integration/exports.test.js
rename to tests/integration/exports.test.ts
index 390bf7c1..46762128 100644
--- a/tests/integration/exports.test.js
+++ b/tests/integration/exports.test.ts
@@ -47,7 +47,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-exports-'));
diff --git a/tests/integration/flow.test.js b/tests/integration/flow.test.ts
similarity index 99%
rename from tests/integration/flow.test.js
rename to tests/integration/flow.test.ts
index fc4ca7aa..8e1eba6f 100644
--- a/tests/integration/flow.test.js
+++ b/tests/integration/flow.test.ts
@@ -37,7 +37,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-flow-'));
diff --git a/tests/integration/implementations.test.js b/tests/integration/implementations.test.ts
similarity index 99%
rename from tests/integration/implementations.test.js
rename to tests/integration/implementations.test.ts
index bdd56389..c4945dd3 100644
--- a/tests/integration/implementations.test.js
+++ b/tests/integration/implementations.test.ts
@@ -48,7 +48,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-impl-'));
diff --git a/tests/integration/incr-edge-gap.test.js b/tests/integration/incr-edge-gap.test.ts
similarity index 100%
rename from tests/integration/incr-edge-gap.test.js
rename to tests/integration/incr-edge-gap.test.ts
diff --git a/tests/integration/incremental-edge-parity.test.js b/tests/integration/incremental-edge-parity.test.ts
similarity index 99%
rename from tests/integration/incremental-edge-parity.test.js
rename to tests/integration/incremental-edge-parity.test.ts
index 0d87dbea..06e097f4 100644
--- a/tests/integration/incremental-edge-parity.test.js
+++ b/tests/integration/incremental-edge-parity.test.ts
@@ -102,7 +102,7 @@ async function buildAndCompare(fixtureDir, mutate) {
 describe('Incremental edge parity (CI gate)', () => {
   // Scenario 1: Comment-only touch — edges must be identical
   describe('comment-only touch', () => {
-    let result;
+    let result: any;
 
     beforeAll(async () => {
       result = await buildAndCompare(FIXTURE_DIR, (dir) => {
@@ -122,7 +122,7 @@ describe('Incremental edge parity (CI gate)', () => {
 
   // Scenario 2: Body edit — change function implementation, keep exports
   describe('body edit (same exports)', () => {
-    let result;
+    let result: any;
 
     beforeAll(async () => {
       result = await buildAndCompare(FIXTURE_DIR, (dir) => {
@@ -147,7 +147,7 @@ describe('Incremental edge parity (CI gate)', () => {
 
   // Scenario 3: New export added — edges from consumers should resolve
   describe('new export added', () => {
-    let result;
+    let result: any;
 
     beforeAll(async () => {
       result = await buildAndCompare(FIXTURE_DIR, (dir) => {
@@ -206,7 +206,7 @@ describe('Incremental edge parity (CI gate)', () => {
 
   // Scenario 4: File deletion — stale edges must be purged
   describe('file deletion', () => {
-    let result;
+    let result: any;
 
     beforeAll(async () => {
       result = await buildAndCompare(FIXTURE_DIR, (dir) => {
diff --git a/tests/integration/incremental-parity.test.js b/tests/integration/incremental-parity.test.ts
similarity index 98%
rename from tests/integration/incremental-parity.test.js
rename to tests/integration/incremental-parity.test.ts
index 21a2a56c..d632503e 100644
--- a/tests/integration/incremental-parity.test.js
+++ b/tests/integration/incremental-parity.test.ts
@@ -87,9 +87,9 @@ function readAnalysisTables(dbPath) {
 }
 
 describe('Incremental build parity: full vs incremental', () => {
-  let fullDir;
-  let incrDir;
-  let tmpBase;
+  let fullDir: string;
+  let incrDir: string;
+  let tmpBase: string;
 
   beforeAll(async () => {
     tmpBase = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-incr-parity-'));
diff --git a/tests/integration/manifesto.test.js b/tests/integration/manifesto.test.ts
similarity index 99%
rename from tests/integration/manifesto.test.js
rename to tests/integration/manifesto.test.ts
index d9b5d93f..73691e9a 100644
--- a/tests/integration/manifesto.test.js
+++ b/tests/integration/manifesto.test.ts
@@ -52,7 +52,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-manifesto-'));
diff --git a/tests/integration/owners.test.js b/tests/integration/owners.test.ts
similarity index 99%
rename from tests/integration/owners.test.js
rename to tests/integration/owners.test.ts
index 7d26f958..025e1e1c 100644
--- a/tests/integration/owners.test.js
+++ b/tests/integration/owners.test.ts
@@ -22,7 +22,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-owners-'));
diff --git a/tests/integration/pagination.test.js b/tests/integration/pagination.test.ts
similarity index 99%
rename from tests/integration/pagination.test.js
rename to tests/integration/pagination.test.ts
index ecf31c5d..4bf5d0b0 100644
--- a/tests/integration/pagination.test.js
+++ b/tests/integration/pagination.test.ts
@@ -59,7 +59,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath, dbForExport;
+let tmpDir: string, dbPath: string, dbForExport: any;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-pagination-'));
diff --git a/tests/integration/qualified-names.test.js b/tests/integration/qualified-names.test.ts
similarity index 99%
rename from tests/integration/qualified-names.test.js
rename to tests/integration/qualified-names.test.ts
index 3fc1beae..61b5eeb9 100644
--- a/tests/integration/qualified-names.test.js
+++ b/tests/integration/qualified-names.test.ts
@@ -49,8 +49,8 @@ export class MathUtils {
 `,
 };
 
-let tmpDir;
-let dbPath;
+let tmpDir: string;
+let dbPath: string;
 
 beforeAll(async () => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cg-qualified-'));
diff --git a/tests/integration/queries.test.js b/tests/integration/queries.test.ts
similarity index 99%
rename from tests/integration/queries.test.js
rename to tests/integration/queries.test.ts
index d4f7f2b2..6381cdb2 100644
--- a/tests/integration/queries.test.js
+++ b/tests/integration/queries.test.ts
@@ -58,7 +58,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-queries-'));
diff --git a/tests/integration/roles.test.js b/tests/integration/roles.test.ts
similarity index 99%
rename from tests/integration/roles.test.js
rename to tests/integration/roles.test.ts
index 9fce5e84..9a6f29da 100644
--- a/tests/integration/roles.test.js
+++ b/tests/integration/roles.test.ts
@@ -38,7 +38,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── Fixture DB ────────────────────────────────────────────────────────
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-roles-'));
diff --git a/tests/integration/scoped-rebuild.test.js b/tests/integration/scoped-rebuild.test.ts
similarity index 99%
rename from tests/integration/scoped-rebuild.test.js
rename to tests/integration/scoped-rebuild.test.ts
index 5f6eaa9a..b3ff350d 100644
--- a/tests/integration/scoped-rebuild.test.js
+++ b/tests/integration/scoped-rebuild.test.ts
@@ -14,7 +14,7 @@ import { buildGraph } from '../../src/domain/graph/builder.js';
 
 const FIXTURE_DIR = path.join(import.meta.dirname, '..', 'fixtures', 'sample-project');
 
-let tmpDir;
+let tmpDir: string;
 
 function copyFixture() {
   const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-scoped-'));
diff --git a/tests/integration/sequence.test.js b/tests/integration/sequence.test.ts
similarity index 99%
rename from tests/integration/sequence.test.js
rename to tests/integration/sequence.test.ts
index e8705820..e4f01338 100644
--- a/tests/integration/sequence.test.js
+++ b/tests/integration/sequence.test.ts
@@ -41,7 +41,7 @@ function insertEdge(db, sourceId, targetId, kind, confidence = 1.0) {
 
 // ─── InMemory Fixture ─────────────────────────────────────────────────
 
-let repo;
+let repo: any;
 
 beforeAll(() => {
   ({ repo } = createTestRepo()
@@ -199,7 +199,7 @@ describe('sequenceToMermaid', () => {
 // ─── Dataflow annotations (SQLite — requires dataflow table) ──────────
 
 describe('dataflow annotations', () => {
-  let dfTmpDir, dfDbPath;
+  let dfTmpDir: string, dfDbPath: string;
 
   beforeAll(() => {
     dfTmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-seq-df-'));
diff --git a/tests/integration/structure.test.js b/tests/integration/structure.test.ts
similarity index 99%
rename from tests/integration/structure.test.js
rename to tests/integration/structure.test.ts
index fe97a118..762918e4 100644
--- a/tests/integration/structure.test.js
+++ b/tests/integration/structure.test.ts
@@ -36,7 +36,7 @@ export function main() { printSum(1, double(2)); }
 `.trimStart(),
 };
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(async () => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-structure-'));
diff --git a/tests/integration/triage.test.js b/tests/integration/triage.test.ts
similarity index 99%
rename from tests/integration/triage.test.js
rename to tests/integration/triage.test.ts
index 32a2b692..e7bdcb86 100644
--- a/tests/integration/triage.test.js
+++ b/tests/integration/triage.test.ts
@@ -10,7 +10,7 @@ import { createTestRepo } from '../helpers/fixtures.js';
 
 // ─── Fixture ──────────────────────────────────────────────────────────
 
-let repo;
+let repo: any;
 
 beforeAll(() => {
   const builder = createTestRepo()
diff --git a/tests/integration/watcher-rebuild.test.js b/tests/integration/watcher-rebuild.test.ts
similarity index 98%
rename from tests/integration/watcher-rebuild.test.js
rename to tests/integration/watcher-rebuild.test.ts
index b2f03142..be394f71 100644
--- a/tests/integration/watcher-rebuild.test.js
+++ b/tests/integration/watcher-rebuild.test.ts
@@ -92,9 +92,9 @@ function makeStmts(db) {
 }
 
 describe('Watcher rebuildFile parity (#533)', () => {
-  let fullDir;
-  let watcherDir;
-  let tmpBase;
+  let fullDir: string;
+  let watcherDir: string;
+  let tmpBase: string;
 
   beforeAll(async () => {
     tmpBase = fs.mkdtempSync(path.join(os.tmpdir(), 'cg-watcher-533-'));
diff --git a/tests/parsers/ast-all-langs.test.js b/tests/parsers/ast-all-langs.test.ts
similarity index 99%
rename from tests/parsers/ast-all-langs.test.js
rename to tests/parsers/ast-all-langs.test.ts
index b4130a18..28e2d2b7 100644
--- a/tests/parsers/ast-all-langs.test.js
+++ b/tests/parsers/ast-all-langs.test.ts
@@ -40,7 +40,7 @@ function queryAll(db) {
 // ─── JS-side: buildAstNodes accepts astNodes for non-JS files ────────
 
 describe('buildAstNodes — non-JS language astNodes', () => {
-  let tmpDir, db;
+  let tmpDir: string, db: any;
 
   beforeAll(() => {
     ({ tmpDir, db } = createTempDb());
@@ -266,7 +266,7 @@ function nativeSupportsMultiLangAst() {
 const canTestMultiLang = nativeSupportsMultiLangAst();
 
 describe.skipIf(!canTestMultiLang)('native AST nodes — multi-language', () => {
-  let tmpDir, db;
+  let tmpDir: string, db: any;
 
   beforeAll(async () => {
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ast-multilang-'));
diff --git a/tests/parsers/ast-nodes.test.js b/tests/parsers/ast-nodes.test.ts
similarity index 99%
rename from tests/parsers/ast-nodes.test.js
rename to tests/parsers/ast-nodes.test.ts
index 3d3c3de7..5f3e9179 100644
--- a/tests/parsers/ast-nodes.test.js
+++ b/tests/parsers/ast-nodes.test.ts
@@ -47,7 +47,7 @@ function helper() {
 
 // ─── Setup ────────────────────────────────────────────────────────────
 
-let tmpDir, dbPath, db;
+let tmpDir: string, dbPath: string, db: any;
 
 beforeAll(async () => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ast-extract-'));
@@ -210,7 +210,7 @@ function nativeSupportsAstNodes() {
 const canTestNative = nativeSupportsAstNodes();
 
 describe.skipIf(!canTestNative)('buildAstNodes — native engine', () => {
-  let nativeTmpDir, nativeDbPath, nativeDb;
+  let nativeTmpDir: string, nativeDbPath: string, nativeDb: any;
 
   function queryNativeAstNodes(kind) {
     return nativeDb.prepare('SELECT * FROM ast_nodes WHERE kind = ? ORDER BY line').all(kind);
diff --git a/tests/parsers/cfg-all-langs.test.js b/tests/parsers/cfg-all-langs.test.ts
similarity index 99%
rename from tests/parsers/cfg-all-langs.test.js
rename to tests/parsers/cfg-all-langs.test.ts
index f37c9a95..b13308c8 100644
--- a/tests/parsers/cfg-all-langs.test.js
+++ b/tests/parsers/cfg-all-langs.test.ts
@@ -34,7 +34,7 @@ function createTempDb() {
 // ─── JS-side: buildCFGData accepts native def.cfg ─────────────────────
 
 describe('buildCFGData — native CFG path', () => {
-  let tmpDir, db;
+  let tmpDir: string, db: any;
 
   beforeAll(() => {
     ({ tmpDir, db } = createTempDb());
@@ -294,7 +294,7 @@ const hasFixedCfg = (() => {
 })();
 
 describe.skipIf(!canTestNativeCfg)('native CFG — multi-language', () => {
-  let tmpDir;
+  let tmpDir: string;
   const nativeResults = new Map();
 
   beforeAll(async () => {
@@ -389,9 +389,9 @@ describe.skipIf(!canTestNativeCfg)('native CFG — multi-language', () => {
 // ─── Parity: native vs WASM CFG ──────────────────────────────────────
 
 describe.skipIf(!canTestNativeCfg || !hasFixedCfg)('native vs WASM CFG parity', () => {
-  let tmpDir;
+  let tmpDir: string;
   const nativeResults = new Map();
-  let parsers;
+  let parsers: any;
 
   const LANG_MAP = {
     '.js': 'javascript',
diff --git a/tests/parsers/csharp.test.js b/tests/parsers/csharp.test.ts
similarity index 99%
rename from tests/parsers/csharp.test.js
rename to tests/parsers/csharp.test.ts
index 46ccd25c..8f9f4e0c 100644
--- a/tests/parsers/csharp.test.js
+++ b/tests/parsers/csharp.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractCSharpSymbols } from '../../src/domain/parser.js';
 
 describe('C# parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-csharp.test.js b/tests/parsers/dataflow-csharp.test.ts
similarity index 99%
rename from tests/parsers/dataflow-csharp.test.js
rename to tests/parsers/dataflow-csharp.test.ts
index 30f91a2d..613438e1 100644
--- a/tests/parsers/dataflow-csharp.test.js
+++ b/tests/parsers/dataflow-csharp.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — C#', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-go.test.js b/tests/parsers/dataflow-go.test.ts
similarity index 99%
rename from tests/parsers/dataflow-go.test.js
rename to tests/parsers/dataflow-go.test.ts
index 2f73d294..bbc7f8ba 100644
--- a/tests/parsers/dataflow-go.test.js
+++ b/tests/parsers/dataflow-go.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — Go', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-java.test.js b/tests/parsers/dataflow-java.test.ts
similarity index 99%
rename from tests/parsers/dataflow-java.test.js
rename to tests/parsers/dataflow-java.test.ts
index 44481a4e..21d5947c 100644
--- a/tests/parsers/dataflow-java.test.js
+++ b/tests/parsers/dataflow-java.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — Java', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-javascript.test.js b/tests/parsers/dataflow-javascript.test.ts
similarity index 99%
rename from tests/parsers/dataflow-javascript.test.js
rename to tests/parsers/dataflow-javascript.test.ts
index bcbdf0c9..cb23eea8 100644
--- a/tests/parsers/dataflow-javascript.test.js
+++ b/tests/parsers/dataflow-javascript.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — JavaScript', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -329,7 +329,7 @@ describe('extractDataflow — JavaScript', () => {
     it('tracks x = foo() without const/let/var', () => {
       const data = parseAndExtract(`
         function update() {
-          let result;
+          let result: any;
           result = compute();
           return result;
         }
diff --git a/tests/parsers/dataflow-php.test.js b/tests/parsers/dataflow-php.test.ts
similarity index 99%
rename from tests/parsers/dataflow-php.test.js
rename to tests/parsers/dataflow-php.test.ts
index ef5ddcc9..b015e8e7 100644
--- a/tests/parsers/dataflow-php.test.js
+++ b/tests/parsers/dataflow-php.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — PHP', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-python.test.js b/tests/parsers/dataflow-python.test.ts
similarity index 99%
rename from tests/parsers/dataflow-python.test.js
rename to tests/parsers/dataflow-python.test.ts
index e97aeea9..be37839b 100644
--- a/tests/parsers/dataflow-python.test.js
+++ b/tests/parsers/dataflow-python.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — Python', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-ruby.test.js b/tests/parsers/dataflow-ruby.test.ts
similarity index 99%
rename from tests/parsers/dataflow-ruby.test.js
rename to tests/parsers/dataflow-ruby.test.ts
index 973c6bee..314f7739 100644
--- a/tests/parsers/dataflow-ruby.test.js
+++ b/tests/parsers/dataflow-ruby.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — Ruby', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/dataflow-rust.test.js b/tests/parsers/dataflow-rust.test.ts
similarity index 99%
rename from tests/parsers/dataflow-rust.test.js
rename to tests/parsers/dataflow-rust.test.ts
index f7200487..2520a79c 100644
--- a/tests/parsers/dataflow-rust.test.js
+++ b/tests/parsers/dataflow-rust.test.ts
@@ -6,7 +6,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { extractDataflow } from '../../src/features/dataflow.js';
 
 describe('extractDataflow — Rust', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/extended-kinds.test.js b/tests/parsers/extended-kinds.test.ts
similarity index 99%
rename from tests/parsers/extended-kinds.test.js
rename to tests/parsers/extended-kinds.test.ts
index ab1a8ccf..c10b1ea1 100644
--- a/tests/parsers/extended-kinds.test.js
+++ b/tests/parsers/extended-kinds.test.ts
@@ -20,7 +20,7 @@ import {
 // ── JavaScript ──────────────────────────────────────────────────────────────
 
 describe('JavaScript extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -97,7 +97,7 @@ describe('JavaScript extended kinds', () => {
 // ── Python ──────────────────────────────────────────────────────────────────
 
 describe('Python extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -155,7 +155,7 @@ describe('Python extended kinds', () => {
 // ── Go ──────────────────────────────────────────────────────────────────────
 
 describe('Go extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -209,7 +209,7 @@ describe('Go extended kinds', () => {
 // ── Rust ─────────────────────────────────────────────────────────────────────
 
 describe('Rust extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -276,7 +276,7 @@ describe('Rust extended kinds', () => {
 // ── Java ─────────────────────────────────────────────────────────────────────
 
 describe('Java extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -335,7 +335,7 @@ describe('Java extended kinds', () => {
 // ── C# ──────────────────────────────────────────────────────────────────────
 
 describe('C# extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -394,7 +394,7 @@ describe('C# extended kinds', () => {
 // ── Ruby ─────────────────────────────────────────────────────────────────────
 
 describe('Ruby extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
@@ -447,7 +447,7 @@ describe('Ruby extended kinds', () => {
 // ── PHP ──────────────────────────────────────────────────────────────────────
 
 describe('PHP extended kinds', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/go.test.js b/tests/parsers/go.test.ts
similarity index 99%
rename from tests/parsers/go.test.js
rename to tests/parsers/go.test.ts
index ddb1efdf..73e02b6d 100644
--- a/tests/parsers/go.test.js
+++ b/tests/parsers/go.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractGoSymbols } from '../../src/domain/parser.js';
 
 describe('Go parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/java.test.js b/tests/parsers/java.test.ts
similarity index 99%
rename from tests/parsers/java.test.js
rename to tests/parsers/java.test.ts
index 39bcf118..591bfa50 100644
--- a/tests/parsers/java.test.js
+++ b/tests/parsers/java.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractJavaSymbols } from '../../src/domain/parser.js';
 
 describe('Java parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/javascript.test.js b/tests/parsers/javascript.test.ts
similarity index 99%
rename from tests/parsers/javascript.test.js
rename to tests/parsers/javascript.test.ts
index 294ba39e..f68cffd8 100644
--- a/tests/parsers/javascript.test.js
+++ b/tests/parsers/javascript.test.ts
@@ -9,7 +9,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractSymbols } from '../../src/domain/parser.js';
 
 describe('JavaScript parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/php.test.js b/tests/parsers/php.test.ts
similarity index 99%
rename from tests/parsers/php.test.js
rename to tests/parsers/php.test.ts
index 106ba306..74a5436e 100644
--- a/tests/parsers/php.test.js
+++ b/tests/parsers/php.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractPHPSymbols } from '../../src/domain/parser.js';
 
 describe('PHP parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/ruby.test.js b/tests/parsers/ruby.test.ts
similarity index 99%
rename from tests/parsers/ruby.test.js
rename to tests/parsers/ruby.test.ts
index eff4a403..03f1d67c 100644
--- a/tests/parsers/ruby.test.js
+++ b/tests/parsers/ruby.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractRubySymbols } from '../../src/domain/parser.js';
 
 describe('Ruby parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/rust.test.js b/tests/parsers/rust.test.ts
similarity index 99%
rename from tests/parsers/rust.test.js
rename to tests/parsers/rust.test.ts
index e6ee7dae..0828fee4 100644
--- a/tests/parsers/rust.test.js
+++ b/tests/parsers/rust.test.ts
@@ -2,7 +2,7 @@ import { beforeAll, describe, expect, it } from 'vitest';
 import { createParsers, extractRustSymbols } from '../../src/domain/parser.js';
 
 describe('Rust parser', () => {
-  let parsers;
+  let parsers: any;
 
   beforeAll(async () => {
     parsers = await createParsers();
diff --git a/tests/parsers/unified.test.js b/tests/parsers/unified.test.ts
similarity index 100%
rename from tests/parsers/unified.test.js
rename to tests/parsers/unified.test.ts
diff --git a/tests/presentation/colors.test.js b/tests/presentation/colors.test.ts
similarity index 100%
rename from tests/presentation/colors.test.js
rename to tests/presentation/colors.test.ts
diff --git a/tests/presentation/queries-cli.test.js b/tests/presentation/queries-cli.test.ts
similarity index 99%
rename from tests/presentation/queries-cli.test.js
rename to tests/presentation/queries-cli.test.ts
index d5a41ae2..18fd76ea 100644
--- a/tests/presentation/queries-cli.test.js
+++ b/tests/presentation/queries-cli.test.ts
@@ -42,7 +42,7 @@ const { fileExports } = await import('../../src/presentation/queries-cli/exports
 const { moduleMap, roles } = await import('../../src/presentation/queries-cli/overview.js');
 
 // ── Helpers ────────────────────────────────────────────────────────
-let lines;
+let lines: any;
 
 beforeEach(() => {
   lines = [];
diff --git a/tests/presentation/result-formatter.test.js b/tests/presentation/result-formatter.test.ts
similarity index 99%
rename from tests/presentation/result-formatter.test.js
rename to tests/presentation/result-formatter.test.ts
index b524a297..88e4f432 100644
--- a/tests/presentation/result-formatter.test.js
+++ b/tests/presentation/result-formatter.test.ts
@@ -17,7 +17,7 @@ vi.mock('../../src/shared/paginate.js', () => ({
 const { outputResult } = await import('../../src/presentation/result-formatter.js');
 
 describe('outputResult', () => {
-  let logSpy;
+  let logSpy: any;
 
   beforeEach(() => {
     logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
diff --git a/tests/presentation/table.test.js b/tests/presentation/table.test.ts
similarity index 100%
rename from tests/presentation/table.test.js
rename to tests/presentation/table.test.ts
diff --git a/tests/resolution/parity.test.js b/tests/resolution/parity.test.ts
similarity index 100%
rename from tests/resolution/parity.test.js
rename to tests/resolution/parity.test.ts
diff --git a/tests/search/embedder-search.test.js b/tests/search/embedder-search.test.ts
similarity index 99%
rename from tests/search/embedder-search.test.js
rename to tests/search/embedder-search.test.ts
index 6216c986..38582fd3 100644
--- a/tests/search/embedder-search.test.js
+++ b/tests/search/embedder-search.test.ts
@@ -97,8 +97,8 @@ function captureLog(fn) {
 //   C: "function authMiddleware (auth Middleware) in src/middleware.js"
 //   D: "function formatDate (format Date) in src/utils.js"
 
-let tmpDir, dbPath;
-let noFtsDir, noFtsDbPath;
+let tmpDir: string, dbPath: string;
+let noFtsDir: string, noFtsDbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-test-'));
diff --git a/tests/search/embedding-regression.test.js b/tests/search/embedding-regression.test.ts
similarity index 99%
rename from tests/search/embedding-regression.test.js
rename to tests/search/embedding-regression.test.ts
index 8e618185..a0391b7e 100644
--- a/tests/search/embedding-regression.test.js
+++ b/tests/search/embedding-regression.test.ts
@@ -51,7 +51,7 @@ export function main() {
 `.trimStart(),
 };
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 describe.skipIf(!hasTransformers)('embedding regression (real model)', () => {
   beforeAll(async () => {
diff --git a/tests/search/embedding-strategy.test.js b/tests/search/embedding-strategy.test.ts
similarity index 99%
rename from tests/search/embedding-strategy.test.js
rename to tests/search/embedding-strategy.test.ts
index a8a50a2c..a8e58828 100644
--- a/tests/search/embedding-strategy.test.js
+++ b/tests/search/embedding-strategy.test.ts
@@ -70,7 +70,7 @@ const FIXTURE_FILES = {
   ].join('\n'),
 };
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-strategy-test-'));
@@ -290,7 +290,7 @@ describe('FTS5 index built alongside embeddings', () => {
 });
 
 describe('context window overflow detection', () => {
-  let bigDir, bigDbPath;
+  let bigDir: string, bigDbPath: string;
 
   beforeAll(() => {
     // Create a file with a very large function that will overflow minilm's 256-token window
diff --git a/tests/unit/boundaries.test.js b/tests/unit/boundaries.test.ts
similarity index 99%
rename from tests/unit/boundaries.test.js
rename to tests/unit/boundaries.test.ts
index 0f2642e7..d3f9b440 100644
--- a/tests/unit/boundaries.test.js
+++ b/tests/unit/boundaries.test.ts
@@ -202,7 +202,7 @@ describe('PRESETS', () => {
 // ─── evaluateBoundaries ──────────────────────────────────────────────
 
 describe('evaluateBoundaries', () => {
-  let tmpDir, dbPath, db;
+  let tmpDir: string, dbPath: string, db: any;
 
   function insertNode(database, name, kind, file, line) {
     return database
diff --git a/tests/unit/builder.test.js b/tests/unit/builder.test.ts
similarity index 99%
rename from tests/unit/builder.test.js
rename to tests/unit/builder.test.ts
index 7dc7d958..2d15c664 100644
--- a/tests/unit/builder.test.js
+++ b/tests/unit/builder.test.ts
@@ -11,7 +11,7 @@ import path from 'node:path';
 import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest';
 import { collectFiles, loadPathAliases, readFileSafe } from '../../src/domain/graph/builder.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-builder-'));
diff --git a/tests/unit/cfg.test.js b/tests/unit/cfg.test.ts
similarity index 99%
rename from tests/unit/cfg.test.js
rename to tests/unit/cfg.test.ts
index 50dc06dd..743ee7bd 100644
--- a/tests/unit/cfg.test.js
+++ b/tests/unit/cfg.test.ts
@@ -13,7 +13,7 @@ import { createParsers } from '../../src/domain/parser.js';
 import { buildFunctionCFG, makeCfgRules } from '../../src/features/cfg.js';
 import { COMPLEXITY_RULES } from '../../src/features/complexity.js';
 
-let jsParser;
+let jsParser: any;
 
 beforeAll(async () => {
   const parsers = await createParsers();
@@ -493,7 +493,7 @@ function makeLangHelpers(langId, parsers) {
 // ── Python ───────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — Python', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -589,7 +589,7 @@ def guard(x):
 // ── Go ───────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — Go', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -684,7 +684,7 @@ func sw(x int) {
 // ── Rust ─────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — Rust', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -790,7 +790,7 @@ fn match_fn(x: i32) {
 // ── Java ─────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — Java', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -913,7 +913,7 @@ class A {
 // ── C# ───────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — C#', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -1000,7 +1000,7 @@ class A {
 // ── Ruby ─────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — Ruby', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
@@ -1102,7 +1102,7 @@ end
 // ── PHP ──────────────────────────────────────────────────────────────────
 
 describe('buildFunctionCFG — PHP', () => {
-  let helpers;
+  let helpers: any;
 
   beforeAll(async () => {
     const parsers = await createParsers();
diff --git a/tests/unit/change-journal.test.js b/tests/unit/change-journal.test.ts
similarity index 99%
rename from tests/unit/change-journal.test.js
rename to tests/unit/change-journal.test.ts
index 3595c674..1812e3f2 100644
--- a/tests/unit/change-journal.test.js
+++ b/tests/unit/change-journal.test.ts
@@ -16,7 +16,7 @@ import {
   rotateIfNeeded,
 } from '../../src/domain/graph/change-journal.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-change-journal-'));
diff --git a/tests/unit/complexity.test.js b/tests/unit/complexity.test.ts
similarity index 99%
rename from tests/unit/complexity.test.js
rename to tests/unit/complexity.test.ts
index 776df84c..83bd87fe 100644
--- a/tests/unit/complexity.test.js
+++ b/tests/unit/complexity.test.ts
@@ -16,7 +16,7 @@ import {
   HALSTEAD_RULES,
 } from '../../src/features/complexity.js';
 
-let jsParser;
+let jsParser: any;
 
 beforeAll(async () => {
   const parsers = await createParsers();
@@ -458,7 +458,7 @@ describe('computeMaintainabilityIndex', () => {
 
 function makeHelpers(langId, parsersPromise) {
   const rules = COMPLEXITY_RULES.get(langId);
-  let parser;
+  let parser: any;
   let available = false;
   beforeAll(async () => {
     const parsers = await parsersPromise;
@@ -499,7 +499,7 @@ function makeHelpers(langId, parsersPromise) {
 }
 
 // Shared parsers promise to avoid re-initializing per suite
-let _parsersPromise;
+let _parsersPromise: any;
 function sharedParsers() {
   if (!_parsersPromise) _parsersPromise = createParsers();
   return _parsersPromise;
diff --git a/tests/unit/config.test.js b/tests/unit/config.test.ts
similarity index 99%
rename from tests/unit/config.test.js
rename to tests/unit/config.test.ts
index 401046da..bba8c190 100644
--- a/tests/unit/config.test.js
+++ b/tests/unit/config.test.ts
@@ -24,7 +24,7 @@ vi.mock('node:child_process', async (importOriginal) => {
   };
 });
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-config-'));
@@ -374,7 +374,7 @@ describe('applyEnvOverrides', () => {
 });
 
 describe('resolveSecrets', () => {
-  let mockExecFile;
+  let mockExecFile: any;
 
   beforeAll(async () => {
     const cp = await import('node:child_process');
@@ -486,7 +486,7 @@ describe('resolveSecrets', () => {
 
 describe('apiKeyCommand integration', () => {
   const ENV_KEYS = ['CODEGRAPH_LLM_PROVIDER', 'CODEGRAPH_LLM_API_KEY', 'CODEGRAPH_LLM_MODEL'];
-  let mockExecFile;
+  let mockExecFile: any;
 
   beforeAll(async () => {
     const cp = await import('node:child_process');
diff --git a/tests/unit/constants.test.js b/tests/unit/constants.test.ts
similarity index 100%
rename from tests/unit/constants.test.js
rename to tests/unit/constants.test.ts
diff --git a/tests/unit/db.test.js b/tests/unit/db.test.ts
similarity index 99%
rename from tests/unit/db.test.js
rename to tests/unit/db.test.ts
index fd0a595c..055afac9 100644
--- a/tests/unit/db.test.js
+++ b/tests/unit/db.test.ts
@@ -32,7 +32,7 @@ import {
   setBuildMeta,
 } from '../../src/db/index.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-db-'));
@@ -261,9 +261,9 @@ describe('findRepoRoot', () => {
 });
 
 describe('findDbPath with git ceiling', () => {
-  let outerDir;
-  let worktreeRoot;
-  let innerDir;
+  let outerDir: string;
+  let worktreeRoot: string;
+  let innerDir: string;
 
   beforeAll(() => {
     // Simulate a worktree-inside-repo layout:
diff --git a/tests/unit/errors.test.js b/tests/unit/errors.test.ts
similarity index 100%
rename from tests/unit/errors.test.js
rename to tests/unit/errors.test.ts
diff --git a/tests/unit/in-memory-repository.test.js b/tests/unit/in-memory-repository.test.ts
similarity index 100%
rename from tests/unit/in-memory-repository.test.js
rename to tests/unit/in-memory-repository.test.ts
diff --git a/tests/unit/index-exports.test.js b/tests/unit/index-exports.test.ts
similarity index 84%
rename from tests/unit/index-exports.test.js
rename to tests/unit/index-exports.test.ts
index caa5a5fa..ad636436 100644
--- a/tests/unit/index-exports.test.js
+++ b/tests/unit/index-exports.test.ts
@@ -1,12 +1,12 @@
 import { readFileSync } from 'node:fs';
-import { createRequire } from 'node:module';
+import { createRequire, register } from 'node:module';
 import { dirname, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { describe, expect, it } from 'vitest';
 
-// CJS require goes through Node's native loader — needs Node >= 22.6 for .ts
-const [_major, _minor] = process.versions.node.split('.').map(Number);
-const canStripTypes = _major > 22 || (_major === 22 && _minor >= 6);
+// Register .js → .ts resolve hook so CJS wrapper's import('./index.ts')
+// can resolve the .js import specifiers used throughout the source.
+register(new URL('../../scripts/ts-resolve-hooks.ts', import.meta.url));
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const pkg = JSON.parse(readFileSync(resolve(__dirname, '../../package.json'), 'utf8'));
@@ -26,7 +26,7 @@ describe('index.js re-exports', () => {
     expect(typeof mod).toBe('object');
   });
 
-  it.skipIf(!canStripTypes)('CJS wrapper resolves to the same exports', async () => {
+  it('CJS wrapper resolves to the same exports', async () => {
     const require = createRequire(import.meta.url);
     const cjs = await require('../../src/index.cjs');
     const esm = await import('../../src/index.js');
diff --git a/tests/unit/journal.test.js b/tests/unit/journal.test.ts
similarity index 99%
rename from tests/unit/journal.test.js
rename to tests/unit/journal.test.ts
index 27769f2a..8428e752 100644
--- a/tests/unit/journal.test.js
+++ b/tests/unit/journal.test.ts
@@ -13,7 +13,7 @@ import {
   writeJournalHeader,
 } from '../../src/domain/graph/journal.js';
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-journal-'));
diff --git a/tests/unit/logger.test.js b/tests/unit/logger.test.ts
similarity index 99%
rename from tests/unit/logger.test.js
rename to tests/unit/logger.test.ts
index fb54863d..22fbc1ab 100644
--- a/tests/unit/logger.test.js
+++ b/tests/unit/logger.test.ts
@@ -13,7 +13,7 @@ import {
 } from '../../src/infrastructure/logger.js';
 
 describe('logger', () => {
-  let stderrSpy;
+  let stderrSpy: any;
 
   afterEach(() => {
     setVerbose(false);
diff --git a/tests/unit/mcp.test.js b/tests/unit/mcp.test.ts
similarity index 100%
rename from tests/unit/mcp.test.js
rename to tests/unit/mcp.test.ts
diff --git a/tests/unit/normalize-symbol.test.js b/tests/unit/normalize-symbol.test.ts
similarity index 100%
rename from tests/unit/normalize-symbol.test.js
rename to tests/unit/normalize-symbol.test.ts
diff --git a/tests/unit/owners.test.js b/tests/unit/owners.test.ts
similarity index 99%
rename from tests/unit/owners.test.js
rename to tests/unit/owners.test.ts
index 52ed123c..f49a3939 100644
--- a/tests/unit/owners.test.js
+++ b/tests/unit/owners.test.ts
@@ -160,7 +160,7 @@ describe('matchOwners', () => {
 // ─── parseCodeowners ─────────────────────────────────────────────────
 
 describe('parseCodeowners', () => {
-  let tmpDir;
+  let tmpDir: string;
 
   beforeEach(() => {
     clearCodeownersCache();
diff --git a/tests/unit/parser.test.js b/tests/unit/parser.test.ts
similarity index 100%
rename from tests/unit/parser.test.js
rename to tests/unit/parser.test.ts
diff --git a/tests/unit/prompt-install.test.js b/tests/unit/prompt-install.test.ts
similarity index 98%
rename from tests/unit/prompt-install.test.js
rename to tests/unit/prompt-install.test.ts
index d7e09981..280620b1 100644
--- a/tests/unit/prompt-install.test.js
+++ b/tests/unit/prompt-install.test.ts
@@ -11,10 +11,10 @@
 import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
 
 describe('loadTransformers install prompt', () => {
-  let exitSpy;
-  let errorSpy;
-  let logSpy;
-  let origTTY;
+  let exitSpy: any;
+  let errorSpy: any;
+  let logSpy: any;
+  let origTTY: any;
 
   beforeEach(() => {
     vi.resetModules();
diff --git a/tests/unit/purge-files.test.js b/tests/unit/purge-files.test.ts
similarity index 100%
rename from tests/unit/purge-files.test.js
rename to tests/unit/purge-files.test.ts
diff --git a/tests/unit/queries-unit.test.js b/tests/unit/queries-unit.test.ts
similarity index 99%
rename from tests/unit/queries-unit.test.js
rename to tests/unit/queries-unit.test.ts
index 19a6b2aa..33ceafc4 100644
--- a/tests/unit/queries-unit.test.js
+++ b/tests/unit/queries-unit.test.ts
@@ -60,7 +60,7 @@ function insertEdge(db, sourceId, targetId, kind) {
 //     testHelper -> handleRequest
 //     ChildService.process -> BaseService.process  (intra-hierarchy)
 
-let tmpDir, dbPath;
+let tmpDir: string, dbPath: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-queries-unit-'));
diff --git a/tests/unit/query-builder.test.js b/tests/unit/query-builder.test.ts
similarity index 99%
rename from tests/unit/query-builder.test.js
rename to tests/unit/query-builder.test.ts
index a2a15e51..fa755a46 100644
--- a/tests/unit/query-builder.test.js
+++ b/tests/unit/query-builder.test.ts
@@ -158,7 +158,7 @@ describe('collectFile', () => {
 // ─── NodeQuery ───────────────────────────────────────────────────────
 
 describe('NodeQuery', () => {
-  let db;
+  let db: any;
 
   beforeEach(() => {
     db = new Database(':memory:');
diff --git a/tests/unit/registry.test.js b/tests/unit/registry.test.ts
similarity index 98%
rename from tests/unit/registry.test.js
rename to tests/unit/registry.test.ts
index c4456c1d..9a927804 100644
--- a/tests/unit/registry.test.js
+++ b/tests/unit/registry.test.ts
@@ -15,12 +15,8 @@ import {
   unregisterRepo,
 } from '../../src/infrastructure/registry.js';
 
-// Child processes load .ts files natively — requires Node >= 22.6 type stripping
-const [_major, _minor] = process.versions.node.split('.').map(Number);
-const canStripTypes = _major > 22 || (_major === 22 && _minor >= 6);
-
-let tmpDir;
-let registryPath;
+let tmpDir: string;
+let registryPath: string;
 
 beforeEach(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-registry-'));
@@ -38,11 +34,15 @@ describe('REGISTRY_PATH', () => {
     expect(REGISTRY_PATH).toBe(path.join(os.homedir(), '.codegraph', 'registry.json'));
   });
 
-  it.skipIf(!canStripTypes)('respects CODEGRAPH_REGISTRY_PATH env var', () => {
+  it('respects CODEGRAPH_REGISTRY_PATH env var', () => {
     const customPath = path.join(tmpDir, 'custom', 'registry.json');
+    const loaderUrl = new URL('../../scripts/ts-resolve-loader.ts', import.meta.url).href;
     const result = execFileSync(
       'node',
       [
+        '--experimental-strip-types',
+        '--import',
+        loaderUrl,
         '--input-type=module',
         '-e',
         `import { REGISTRY_PATH } from './src/infrastructure/registry.js'; process.stdout.write(REGISTRY_PATH);`,
diff --git a/tests/unit/repository-parity.test.js b/tests/unit/repository-parity.test.ts
similarity index 99%
rename from tests/unit/repository-parity.test.js
rename to tests/unit/repository-parity.test.ts
index 86d11610..a3bac79d 100644
--- a/tests/unit/repository-parity.test.js
+++ b/tests/unit/repository-parity.test.ts
@@ -149,9 +149,9 @@ describe.each([
   { label: 'SqliteRepository', seed: seedSqliteRepo },
   { label: 'InMemoryRepository', seed: seedInMemoryRepo },
 ])('Repository parity: $label', ({ seed }) => {
-  let repo;
-  let ids;
-  let dbToClose;
+  let repo: any;
+  let ids: any;
+  let dbToClose: any;
 
   beforeEach(() => {
     const result = seed();
diff --git a/tests/unit/repository.test.js b/tests/unit/repository.test.ts
similarity index 99%
rename from tests/unit/repository.test.js
rename to tests/unit/repository.test.ts
index 37d3defa..5966c2d8 100644
--- a/tests/unit/repository.test.js
+++ b/tests/unit/repository.test.ts
@@ -13,7 +13,7 @@ import {
 } from '../../src/db/repository/nodes.js';
 
 describe('repository', () => {
-  let db;
+  let db: any;
 
   beforeEach(() => {
     db = new Database(':memory:');
diff --git a/tests/unit/resolve.test.js b/tests/unit/resolve.test.ts
similarity index 99%
rename from tests/unit/resolve.test.js
rename to tests/unit/resolve.test.ts
index 8f6227f8..eaa8b5aa 100644
--- a/tests/unit/resolve.test.js
+++ b/tests/unit/resolve.test.ts
@@ -25,7 +25,7 @@ import {
 
 // ─── Temp project setup ──────────────────────────────────────────────
 
-let tmpDir;
+let tmpDir: string;
 
 beforeAll(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-resolve-'));
@@ -257,7 +257,7 @@ describe('parseBareSpecifier', () => {
 // ─── resolveViaExports ───────────────────────────────────────────────
 
 describe('resolveViaExports', () => {
-  let pkgRoot;
+  let pkgRoot: string;
 
   beforeAll(() => {
     clearExportsCache();
@@ -392,7 +392,7 @@ describe('resolveViaExports', () => {
 // ─── resolveImportPathJS with exports ────────────────────────────────
 
 describe('resolveImportPathJS with package.json exports', () => {
-  let pkgRoot;
+  let pkgRoot: string;
 
   beforeAll(() => {
     clearExportsCache();
@@ -428,7 +428,7 @@ describe('resolveImportPathJS with package.json exports', () => {
 // ─── resolveViaWorkspace ─────────────────────────────────────────────
 
 describe('resolveViaWorkspace', () => {
-  let wsRoot;
+  let wsRoot: string;
 
   beforeAll(() => {
     wsRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ws-'));
@@ -521,7 +521,7 @@ describe('resolveViaWorkspace', () => {
 // ─── resolveImportPathJS with workspaces ─────────────────────────────
 
 describe('resolveImportPathJS with workspace resolution', () => {
-  let wsRoot;
+  let wsRoot: string;
 
   beforeAll(() => {
     wsRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ws-resolve-'));
@@ -588,7 +588,7 @@ describe('resolveImportPathJS with workspace resolution', () => {
 // ─── computeConfidenceJS with workspace boost ────────────────────────
 
 describe('computeConfidenceJS workspace confidence', () => {
-  let wsRoot;
+  let wsRoot: string;
 
   beforeAll(() => {
     wsRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-ws-conf-'));
diff --git a/tests/unit/roles.test.js b/tests/unit/roles.test.ts
similarity index 99%
rename from tests/unit/roles.test.js
rename to tests/unit/roles.test.ts
index cf4fd5e6..d729f8e0 100644
--- a/tests/unit/roles.test.js
+++ b/tests/unit/roles.test.ts
@@ -18,7 +18,7 @@ import { beforeEach, describe, expect, it } from 'vitest';
 import { initSchema } from '../../src/db/index.js';
 import { classifyNodeRoles } from '../../src/features/structure.js';
 
-let db;
+let db: any;
 
 function setup() {
   db = new Database(':memory:');
diff --git a/tests/unit/snapshot.test.js b/tests/unit/snapshot.test.ts
similarity index 99%
rename from tests/unit/snapshot.test.js
rename to tests/unit/snapshot.test.ts
index b12b912a..ec149252 100644
--- a/tests/unit/snapshot.test.js
+++ b/tests/unit/snapshot.test.ts
@@ -12,8 +12,8 @@ import {
   validateSnapshotName,
 } from '../../src/features/snapshot.js';
 
-let tmpDir;
-let dbPath;
+let tmpDir: string;
+let dbPath: string;
 
 function createTestDb(filePath) {
   fs.mkdirSync(path.dirname(filePath), { recursive: true });
diff --git a/tests/unit/structure.test.js b/tests/unit/structure.test.ts
similarity index 99%
rename from tests/unit/structure.test.js
rename to tests/unit/structure.test.ts
index fd57e487..77aa3088 100644
--- a/tests/unit/structure.test.js
+++ b/tests/unit/structure.test.ts
@@ -10,7 +10,7 @@ import { beforeEach, describe, expect, it } from 'vitest';
 import { initSchema } from '../../src/db/index.js';
 import { buildStructure } from '../../src/features/structure.js';
 
-let db;
+let db: any;
 
 function setup() {
   db = new Database(':memory:');
diff --git a/tests/unit/update-check.test.js b/tests/unit/update-check.test.ts
similarity index 99%
rename from tests/unit/update-check.test.js
rename to tests/unit/update-check.test.ts
index 78bc204f..46621d8b 100644
--- a/tests/unit/update-check.test.js
+++ b/tests/unit/update-check.test.ts
@@ -8,8 +8,8 @@ import {
   semverCompare,
 } from '../../src/infrastructure/update-check.js';
 
-let tmpDir;
-let cachePath;
+let tmpDir: string;
+let cachePath: string;
 
 beforeEach(() => {
   tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-update-'));
diff --git a/tests/unit/visitor.test.js b/tests/unit/visitor.test.ts
similarity index 99%
rename from tests/unit/visitor.test.js
rename to tests/unit/visitor.test.ts
index e15571ec..62dc5b3e 100644
--- a/tests/unit/visitor.test.js
+++ b/tests/unit/visitor.test.ts
@@ -4,7 +4,7 @@
 import { describe, expect, it } from 'vitest';
 
 // We need a tree-sitter tree to test. Use the JS parser.
-let parse;
+let parse: any;
 
 async function ensureParser() {
   if (parse) return;
diff --git a/tsconfig.json b/tsconfig.json
index 613956a9..99220394 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -44,10 +44,6 @@
     "noPropertyAccessFromIndexSignature": true,
     "exactOptionalPropertyTypes": false,
 
-    /* Migration support */
-    "allowJs": true,
-    "checkJs": false,
-
     /* Misc */
     "skipLibCheck": true,
     "forceConsistentCasingInFileNames": true,
diff --git a/vitest.config.js b/vitest.config.js
deleted file mode 100644
index c3d7fc18..00000000
--- a/vitest.config.js
+++ /dev/null
@@ -1,61 +0,0 @@
-import { existsSync } from 'node:fs';
-import { dirname, resolve } from 'node:path';
-import { fileURLToPath, pathToFileURL } from 'node:url';
-import { defineConfig } from 'vitest/config';
-
-const __dirname = dirname(fileURLToPath(import.meta.url));
-const loaderPath = pathToFileURL(resolve(__dirname, 'scripts/ts-resolve-loader.js')).href;
-const [major, minor] = process.versions.node.split('.').map(Number);
-const supportsStripTypes = major > 22 || (major === 22 && minor >= 6);
-const supportsHooks = major > 20 || (major === 20 && minor >= 6);
-const existing = process.env.NODE_OPTIONS || '';
-
-/**
- * During the JS → TS migration, some .js files import from modules that have
- * already been renamed to .ts.  Vite only auto-resolves .js→.ts when the
- * *importer* is itself a .ts file.  This plugin fills the gap: when a .js
- * import target doesn't exist on disk, it tries the .ts counterpart.
- */
-function jsToTsResolver() {
-  return {
-    name: 'js-to-ts-resolver',
-    enforce: 'pre',
-    resolveId(source, importer) {
-      if (!importer || !source.endsWith('.js')) return null;
-      // Only handle relative/absolute paths, not bare specifiers
-      if (!source.startsWith('.') && !source.startsWith('/')) return null;
-      const importerPath = importer.startsWith('file://')
-        ? fileURLToPath(importer)
-        : importer;
-      const fsPath = resolve(dirname(importerPath), source);
-      if (!existsSync(fsPath)) {
-        const tsPath = fsPath.replace(/\.js$/, '.ts');
-        if (existsSync(tsPath)) return tsPath;
-      }
-      return null;
-    },
-  };
-}
-
-export default defineConfig({
-  plugins: [jsToTsResolver()],
-  test: {
-    globals: true,
-    testTimeout: 30000,
-    hookTimeout: 30000,
-    exclude: ['**/node_modules/**', '**/.git/**', '**/.claude/**'],
-    // Register the .js→.ts resolve loader for Node's native ESM resolver.
-    // This covers require() calls and child processes spawned by tests.
-    env: {
-      NODE_OPTIONS: [
-        existing,
-        supportsStripTypes &&
-        !existing.includes('--experimental-strip-types') &&
-        !existing.includes('--strip-types')
-          ? (major >= 23 ? '--strip-types' : '--experimental-strip-types')
-          : '',
-        existing.includes(loaderPath) ? '' : (supportsHooks ? `--import ${loaderPath}` : ''),
-      ].filter(Boolean).join(' '),
-    },
-  },
-});
diff --git a/vitest.config.ts b/vitest.config.ts
new file mode 100644
index 00000000..76d7f5e0
--- /dev/null
+++ b/vitest.config.ts
@@ -0,0 +1,25 @@
+import { defineConfig } from 'vitest/config';
+
+const [major, minor] = process.versions.node.split('.').map(Number);
+const existing = process.env.NODE_OPTIONS || '';
+const supportsStripTypes = major > 22 || (major === 22 && minor >= 6);
+const stripFlag = major >= 23 ? '--strip-types' : '--experimental-strip-types';
+
+export default defineConfig({
+  test: {
+    globals: true,
+    testTimeout: 30000,
+    hookTimeout: 30000,
+    exclude: ['**/node_modules/**', '**/.git/**', '**/.claude/**'],
+    // Ensure child processes spawned by tests (e.g. CLI integration tests)
+    // can load .ts files via Node's built-in type stripping.
+    env: {
+      NODE_OPTIONS: [
+        existing,
+        supportsStripTypes && !existing.includes('--experimental-strip-types') && !existing.includes('--strip-types')
+          ? stripFlag
+          : '',
+      ].filter(Boolean).join(' '),
+    },
+  },
+});