diff --git a/templates/api-service/package.json b/templates/api-service/package.json
index e46db4f..fe3c993 100644
--- a/templates/api-service/package.json
+++ b/templates/api-service/package.json
@@ -4,9 +4,9 @@
   "private": true,
   "type": "module",
   "scripts": {
+    "start": "node src/start.js",
     "check": "node --check src/config.js && node --check src/stellar-client.js && node --check src/server.js && node --check src/start.js",
-    "test": "node --test test/*.test.js",
-    "start": "node src/start.js"
+    "test": "node --test test/*.test.js"
   },
   "engines": {
     "node": ">=22.13.0"
diff --git a/tests/api-service-package-metadata.test.ts b/tests/api-service-package-metadata.test.ts
new file mode 100644
index 0000000..4b01ad1
--- /dev/null
+++ b/tests/api-service-package-metadata.test.ts
@@ -0,0 +1,187 @@
+import { join } from 'node:path';
+import { spawnSync } from 'node:child_process';
+import { describe, expect, it } from 'vitest';
+import { createNewCommand } from '../src/commands/new.js';
+import { createNpmInvocation } from '../src/process/npm.js';
+import {
+  assertPackageMetadata,
+  createCapturedTerminalOutput,
+  withTempDirectory,
+} from './helpers/index.js';
+
+// Frozen template contract for API Service package.json (SW-043).
+// Update this object only when the template itself is intentionally changed.
+const FROZEN_SCRIPTS = {
+  start: 'node src/start.js',
+  check:
+    'node --check src/config.js && node --check src/stellar-client.js && node --check src/server.js && node --check src/start.js',
+  test: 'node --test test/*.test.js',
+} as const;
+
+const FROZEN_NODE_ENGINE = '>=22.13.0';
+
+function runNpmScript(projectRoot: string, script: string) {
+  const npm = createNpmInvocation(['run', script]);
+
+  return spawnSync(npm.command, [...npm.args], {
+    cwd: projectRoot,
+    encoding: 'utf8',
+    shell: false,
+  });
+}
+
+describe('API Service package metadata conformance (SW-043)', () => {
+  it('conforms to all frozen package.json metadata constraints', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('sets the package name to the generated project name', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('retains all frozen script entries without modification', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('retains only the frozen script keys and no extras', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('sets the engines.node constraint to the frozen minimum version', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('generates no dependencies field', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('generates no devDependencies field', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it('does not embed secret, seed, or private-key values in the generated package.json', () =>
+    withTempDirectory((root) => {
+      const command = createNewCommand({
+        cwd: () => root,
+        output: createCapturedTerminalOutput().output,
+      });
+
+      command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+      assertPackageMetadata(join(root, 'demo-api', 'package.json'), {
+        name: 'demo-api',
+        scripts: FROZEN_SCRIPTS,
+        nodeEngine: FROZEN_NODE_ENGINE,
+      });
+    }));
+
+  it(
+    'passes the repository check script after generation',
+    () =>
+      withTempDirectory((root) => {
+        const command = createNewCommand({
+          cwd: () => root,
+          output: createCapturedTerminalOutput().output,
+        });
+
+        command.parse(['node', 'new', 'demo-api', '--template', 'api-service']);
+
+        const projectRoot = join(root, 'demo-api');
+
+        assertPackageMetadata(join(projectRoot, 'package.json'), {
+          name: 'demo-api',
+          scripts: FROZEN_SCRIPTS,
+          nodeEngine: FROZEN_NODE_ENGINE,
+        });
+
+        const result = runNpmScript(projectRoot, 'check');
+
+        expect(result.status, result.stderr).toBe(0);
+      }),
+    15_000,
+  );
+});