@@ -47,6 +47,7 @@ import { copyFileSync, mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'nod
 import { tmpdir } from 'node:os';
 import { dirname, join, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import Database from 'better-sqlite3';
 
 const HERE = dirname(fileURLToPath(import.meta.url));
 const CLI_ROOT = resolve(HERE, '..', '..', '..');
@@ -125,26 +126,14 @@ process.exit(0);
 `;
 
 /** The repro's off-shape value, written past the write path: a location keyed the retired way. */
-const OFF_SHAPE_CHILD = `
-const { SqlDriver } = await import('@objectstack/driver-sql');
-const raw = new SqlDriver({ client: 'better-sqlite3', connection: { filename: process.env.FIXTURE_DB }, useNullAsDefault: true });
-await raw.knex('os21644_site').where({ id: 's1' }).update({ geo: JSON.stringify({ latitude: 1, longitude: 2 }) });
-await raw.disconnect();
-process.exit(0);
-`;
-
-/** The flag rows and the app rows, read on a connection of our own. */
-const READ_STATE_CHILD = `
-const { SqlDriver } = await import('@objectstack/driver-sql');
-const raw = new SqlDriver({ client: 'better-sqlite3', connection: { filename: process.env.FIXTURE_DB }, useNullAsDefault: true });
-const k = raw.knex;
-const flags = await k('sys_migration').select('id', 'last_run_at', 'verified_at', 'blocking').orderBy('id');
-const site = await k('os21644_site').select('id', 'geo').orderBy('id');
-const product = await k('os21644_product').select('id', 'image').orderBy('id');
-await raw.disconnect();
-process.stdout.write(JSON.stringify({ flags, site, product }));
-process.exit(0);
-`;
+function writeOffShape(db: string): void {
+  const conn = new Database(db);
+  try {
+    conn.prepare('UPDATE os21644_site SET geo = ? WHERE id = ?').run(JSON.stringify({ latitude: 1, longitude: 2 }), 's1');
+  } finally {
+    conn.close();
+  }
+}
 
 interface Run {
   code: number | null;
@@ -186,10 +175,22 @@ function freshDb(): string {
   return db;
 }
 
+/**
+ * The flag rows and the app rows, read on a connection of our own, in this
+ * process: a child `node` per read cost ~0.5 s each, sixteen times a file.
+ */
 function readState(db: string): State {
-  const out = childNode(READ_STATE_CHILD, { FIXTURE_DB: db });
-  if (out.status !== 0) throw new Error(`could not read the fixture database (status ${out.status})\n${out.stderr}`);
-  return JSON.parse(out.stdout) as State;
+  // Opened as the child it replaces opened it (read-write, knex's default).
+  const conn = new Database(db);
+  try {
+    return {
+      flags: conn.prepare('SELECT id, last_run_at, verified_at, blocking FROM sys_migration ORDER BY id').all() as FlagRow[],
+      site: conn.prepare('SELECT id, geo FROM os21644_site ORDER BY id').all() as State['site'],
+      product: conn.prepare('SELECT id, image FROM os21644_product ORDER BY id').all() as State['product'],
+    };
+  } finally {
+    conn.close();
+  }
 }
 
 function flagRow(state: State, id: string): FlagRow | undefined {
@@ -296,8 +297,7 @@ beforeAll(async () => {
 
   // The measured repro: one off-shape value stored, then a misspelled --object --apply.
   const reproDb = freshDb();
-  const offShape = childNode(OFF_SHAPE_CHILD, { FIXTURE_DB: reproDb });
-  if (offShape.status !== 0) throw new Error(`the off-shape value was not written\n${offShape.stderr}`);
+  writeOffShape(reproDb);
   const reproRightDb = join(dir, 'data', 'repro-right.db');
   copyFileSync(reproDb, reproRightDb);
   reproFullDry = await runCommand('value-shapes', ['--json'], reproDb);
 
@@ -57,8 +57,14 @@ import Database from 'better-sqlite3';
 
 const HERE = dirname(fileURLToPath(import.meta.url));
 const CLI_ROOT = resolve(HERE, '..', '..', '..');
+/**
+ * The source entry, spawned by this process's own `node`, as the family's other spawners
+ * (`data-commands.absent-database`, `object-scope`, `unmapped-columns`) spawn it. Not through
+ * the `tsx` binary: the entry, its `src/` and its pinned `NODE_ENV=development` are the same
+ * either way, and the wrapper only adds a second process and its own transform, ~3.4 s of
+ * every spawn (#23181 slice 12: `tsx bin/run-dev.js --version` 8.28-8.44 s, `node` 4.93-4.99 s).
+ */
 const RUN_DEV = resolve(CLI_ROOT, 'bin', 'run-dev.js');
-const TSX = resolve(CLI_ROOT, '..', '..', 'node_modules', '.bin', 'tsx');
 const CASE_TIMEOUT_MS = 300_000;
 const NOT_AN_OBJECT = ['sys_packages'];
 
@@ -98,10 +104,10 @@ interface Reading {
 function bootThenPlan(dir: string): Reading {
   const dbFile = join(dir, 'boot.db');
   const env = childEnv(dir, dbFile);
-  const boot = spawnSync(TSX, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
+  const boot = spawnSync(process.execPath, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
     cwd: dir, env: { ...env, OS_MIGRATE_AND_EXIT: '1' }, encoding: 'utf8', timeout: 240_000,
   });
-  const plan = spawnSync(TSX, [RUN_DEV, 'migrate', 'plan', '--json'], {
+  const plan = spawnSync(process.execPath, [RUN_DEV, 'migrate', 'plan', '--json'], {
     cwd: dir, env, encoding: 'utf8', timeout: 240_000,
   });
   let payload: any;
 
@@ -55,8 +55,14 @@ import Database from 'better-sqlite3';
 
 const HERE = dirname(fileURLToPath(import.meta.url));
 const CLI_ROOT = resolve(HERE, '..', '..', '..');
+/**
+ * The source entry, spawned by this process's own `node`, as the family's other spawners
+ * (`data-commands.absent-database`, `object-scope`, `unmapped-columns`) spawn it. Not through
+ * the `tsx` binary: the entry, its `src/` and its pinned `NODE_ENV=development` are the same
+ * either way, and the wrapper only adds a second process and its own transform, ~3.4 s of
+ * every spawn (#23181 slice 12: `tsx bin/run-dev.js --version` 8.28-8.44 s, `node` 4.93-4.99 s).
+ */
 const RUN_DEV = resolve(CLI_ROOT, 'bin', 'run-dev.js');
-const TSX = resolve(CLI_ROOT, '..', '..', 'node_modules', '.bin', 'tsx');
 const CASE_TIMEOUT_MS = 600_000;
 const SPAWN_TIMEOUT_MS = 240_000;
 
@@ -134,7 +140,7 @@ async function freePort(): Promise<number> {
  */
 function devBootOnce(): string {
   const r = spawnSync(
-    TSX,
+    process.execPath,
     [RUN_DEV, 'dev', '--port', String(port), '--compile', '--no-watch', '--no-restart', '--no-seed-admin'],
     { cwd: dir, env: env({ OS_MIGRATE_AND_EXIT: '1' }), encoding: 'utf8', timeout: SPAWN_TIMEOUT_MS },
   );
@@ -145,7 +151,7 @@ function devBootOnce(): string {
 
 /** One read-only `os migrate` door's `--json` document. */
 function migrateJson(args: string[]): any {
-  const r = spawnSync(TSX, [RUN_DEV, 'migrate', ...args, '--json'], {
+  const r = spawnSync(process.execPath, [RUN_DEV, 'migrate', ...args, '--json'], {
     cwd: dir, env: env(), encoding: 'utf8', timeout: SPAWN_TIMEOUT_MS,
   });
   expect(r.status, `os migrate ${args.join(' ')} failed:\n${`${r.stdout}\n${r.stderr}`.slice(-1500)}`).toBe(0);
 
@@ -32,8 +32,14 @@ import Database from 'better-sqlite3';
 
 const HERE = dirname(fileURLToPath(import.meta.url));
 const CLI_ROOT = resolve(HERE, '..', '..', '..');
+/**
+ * The source entry, spawned by this process's own `node`, as the family's other spawners
+ * (`data-commands.absent-database`, `object-scope`, `unmapped-columns`) spawn it. Not through
+ * the `tsx` binary: the entry, its `src/` and its pinned `NODE_ENV=development` are the same
+ * either way, and the wrapper only adds a second process and its own transform, ~3.4 s of
+ * every spawn (#23181 slice 12: `tsx bin/run-dev.js --version` 8.28-8.44 s, `node` 4.93-4.99 s).
+ */
 const RUN_DEV = resolve(CLI_ROOT, 'bin', 'run-dev.js');
-const TSX = resolve(CLI_ROOT, '..', '..', 'node_modules', '.bin', 'tsx');
 const CASE_TIMEOUT_MS = 300_000;
 
 const APP_OBJECT = 'os25134_deal';
@@ -93,14 +99,14 @@ function childEnv(f: Fixture, extra: NodeJS.ProcessEnv = {}): NodeJS.ProcessEnv
 
 /** `os serve`'s own provision-and-exit: a fresh store, the full composition schema-synced into it. */
 function serveBoot(f: Fixture): void {
-  const boot = spawnSync(TSX, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
+  const boot = spawnSync(process.execPath, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
     cwd: f.dir, env: childEnv(f, { OS_MIGRATE_AND_EXIT: '1' }), encoding: 'utf8', timeout: 240_000,
   });
   expect(boot.status, `the serving boot did not provision the database:\n${(boot.stderr ?? '').slice(-6000)}`).toBe(0);
 }
 
 function plan(f: Fixture, json: boolean): { exit: number | null; payload: any; text: string } {
-  const run = spawnSync(TSX, [RUN_DEV, 'migrate', 'plan', ...(json ? ['--json'] : [])], {
+  const run = spawnSync(process.execPath, [RUN_DEV, 'migrate', 'plan', ...(json ? ['--json'] : [])], {
     cwd: f.dir, env: childEnv(f), encoding: 'utf8', timeout: 240_000,
   });
   let payload: any;
 
@@ -46,8 +46,14 @@ import Database from 'better-sqlite3';
 
 const HERE = dirname(fileURLToPath(import.meta.url));
 const CLI_ROOT = resolve(HERE, '..', '..', '..');
+/**
+ * The source entry, spawned by this process's own `node`, as the family's other spawners
+ * (`data-commands.absent-database`, `object-scope`, `unmapped-columns`) spawn it. Not through
+ * the `tsx` binary: the entry, its `src/` and its pinned `NODE_ENV=development` are the same
+ * either way, and the wrapper only adds a second process and its own transform, ~3.4 s of
+ * every spawn (#23181 slice 12: `tsx bin/run-dev.js --version` 8.28-8.44 s, `node` 4.93-4.99 s).
+ */
 const RUN_DEV = resolve(CLI_ROOT, 'bin', 'run-dev.js');
-const TSX = resolve(CLI_ROOT, '..', '..', 'node_modules', '.bin', 'tsx');
 const CASE_TIMEOUT_MS = 300_000;
 
 /** The one table outside the object set (`PackageServicePlugin.start()`'s raw DDL; see the boot-parity pin). */
@@ -116,7 +122,7 @@ const BOOT_STREAM_TAIL = 8_000;
  * there at `error`), and an assertion that failed without it left the CI log unable to confirm or refute one.
  */
 function serveBoot(f: Fixture, extra: NodeJS.ProcessEnv = {}): string {
-  const boot = spawnSync(TSX, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
+  const boot = spawnSync(process.execPath, [RUN_DEV, 'serve', '--no-server', '--no-ui', '--no-console', '--port', '0'], {
     cwd: f.dir, env: childEnv(f, { ...extra, OS_MIGRATE_AND_EXIT: '1' }), encoding: 'utf8', timeout: 240_000,
   });
   const output =
@@ -130,7 +136,7 @@ function serveBoot(f: Fixture, extra: NodeJS.ProcessEnv = {}): string {
 const afterBoot = (bootOutput: string, what: string): string => `${what}\n${bootOutput}`;
 
 function command(f: Fixture, argv: string[], extra: NodeJS.ProcessEnv = {}): { exit: number | null; payload: any } {
-  const run = spawnSync(TSX, [RUN_DEV, 'migrate', ...argv], { cwd: f.dir, env: childEnv(f, extra), encoding: 'utf8', timeout: 240_000 });
+  const run = spawnSync(process.execPath, [RUN_DEV, 'migrate', ...argv], { cwd: f.dir, env: childEnv(f, extra), encoding: 'utf8', timeout: 240_000 });
   let payload: any;
   try { payload = JSON.parse(run.stdout); } catch { payload = { unparsed: `${run.stdout}\n${run.stderr}`.slice(-800) }; }
   return { exit: run.status, payload };