diff --git a/specification.md b/specification.md
index 78913f5..3931fc3 100644
--- a/specification.md
+++ b/specification.md
@@ -119,10 +119,11 @@ $ manager config get <key>
 
 List of registries which will be searched for packages. This allows brands/companies to each own a package list, but registries are combined for the user consuming the list.
 
-| Field | Type   | Description   | Example                                                          |
-| :---- | :----- | :------------ | :--------------------------------------------------------------- |
-| name  | string | Registry name | `"Open Audio Registry"`                                          |
-| url   | string | Registry url  | `"https://open-audio-stack.github.io/open-audio-stack-registry"` |
+| Field   | Type   | Description                                                         | Example                                                          |
+| :------ | :----- | :------------------------------------------------------------------ | :--------------------------------------------------------------- |
+| name    | string | Registry name                                                       | `"Open Audio Registry"`                                          |
+| url     | string | Registry url                                                        | `"https://open-audio-stack.github.io/open-audio-stack-registry"` |
+| version | string | Optional - see [Registry versioning](#registry-versioning-optional) | `"v1"`                                                           |
 
 #### Get registries
 
diff --git a/src/classes/Manager.ts b/src/classes/Manager.ts
index 7780fda..1cd41b2 100644
--- a/src/classes/Manager.ts
+++ b/src/classes/Manager.ts
@@ -6,6 +6,7 @@ import { ManagerReport, PackageVersion } from '../types/Package.js';
 import { RegistryInterface, RegistryPackages, RegistryType } from '../types/Registry.js';
 import { Base } from './Base.js';
 import { packageCompatibleFiles } from '../helpers/package.js';
+import { registryUrl } from '../helpers/registry.js';
 import { Architecture, SystemType } from '../index-browser.js';
 
 export class Manager extends Base {
@@ -137,7 +138,7 @@ export class Manager extends Base {
     for (const index in registries) {
       let json: RegistryInterface;
       try {
-        json = await apiJson(registries[index].url);
+        json = await apiJson(registryUrl(registries[index]));
       } catch (err) {
         // One unreachable/misconfigured registry shouldn't stop the others from being synced -
         // record the failure and move on, matching the spec's goal of combining packages from
diff --git a/src/helpers/registry.ts b/src/helpers/registry.ts
index a8a436d..bcc4986 100644
--- a/src/helpers/registry.ts
+++ b/src/helpers/registry.ts
@@ -1,3 +1,4 @@
+import { ConfigRegistry } from '../types/Config.js';
 import { RegistryInterface } from '../types/Registry.js';
 
 export function registryDefaults(): RegistryInterface {
@@ -10,3 +11,10 @@ export function registryDefaults(): RegistryInterface {
     version: '1.0.0',
   };
 }
+
+// See specification.md "Registry versioning (optional)" - appends the version segment to the
+// registry root when one is configured. Unversioned registries (the common case) are untouched,
+// resolving to whatever the registry serves as its latest version.
+export function registryUrl(registry: ConfigRegistry): string {
+  return registry.version ? `${registry.url.replace(/\/$/, '')}/${registry.version}` : registry.url;
+}
diff --git a/src/types/Config.ts b/src/types/Config.ts
index f327339..ee37488 100644
--- a/src/types/Config.ts
+++ b/src/types/Config.ts
@@ -22,4 +22,9 @@ export interface ConfigInterface {
 export interface ConfigRegistry {
   name: string;
   url: string;
+  // Optional versioned endpoint (see specification.md "Registry versioning (optional)") - when
+  // set, appended as a path segment onto `url` when requesting resources, so a registry can
+  // introduce breaking changes on a new version without affecting managers still pointed at the
+  // root (which always resolves to the latest version).
+  version?: string;
 }
diff --git a/tests/classes/Manager.test.ts b/tests/classes/Manager.test.ts
index 2d9b8d7..0e8af38 100644
--- a/tests/classes/Manager.test.ts
+++ b/tests/classes/Manager.test.ts
@@ -242,6 +242,24 @@ test('Manager sync isolates a malformed package version instead of throwing', as
   apiJsonSpy.mockRestore();
 });
 
+test('Manager sync appends a configured registry version to the request url', async () => {
+  const apiJsonSpy = vi.spyOn(apiHelpers, 'apiJson').mockResolvedValue({
+    name: 'Mock Registry',
+    url: 'https://example.invalid/registry',
+    version: '1.0.0',
+    [RegistryType.Plugins]: {},
+  });
+
+  const manager = new Manager(RegistryType.Plugins, {
+    registries: [{ name: 'Mock Registry', url: 'https://example.invalid/registry', version: 'v1' }],
+  });
+  await manager.sync();
+
+  expect(apiJsonSpy).toHaveBeenCalledWith('https://example.invalid/registry/v1');
+
+  apiJsonSpy.mockRestore();
+});
+
 test('Manager sync with existing package', async () => {
   const manager = new Manager(RegistryType.Plugins);
   const pkg = new Package(PLUGIN_PACKAGE.slug);
diff --git a/tests/helpers/registry.test.ts b/tests/helpers/registry.test.ts
new file mode 100644
index 0000000..41092f7
--- /dev/null
+++ b/tests/helpers/registry.test.ts
@@ -0,0 +1,34 @@
+import { expect, test } from 'vitest';
+import { registryDefaults, registryUrl } from '../../src/helpers/registry';
+import { RegistryInterface } from '../../src/types/Registry';
+
+const REGISTRY: RegistryInterface = {
+  name: 'Open Audio Registry',
+  plugins: {},
+  presets: {},
+  projects: {},
+  url: 'https://open-audio-stack.github.io/open-audio-stack-registry',
+  version: '1.0.0',
+};
+
+test('Get default value', () => {
+  expect(registryDefaults()).toEqual(REGISTRY);
+});
+
+test('Registry url without a version is unchanged', () => {
+  expect(registryUrl({ name: 'Open Audio Registry', url: 'https://example.com/registry' })).toEqual(
+    'https://example.com/registry',
+  );
+});
+
+test('Registry url with a version appends the version segment', () => {
+  expect(registryUrl({ name: 'Open Audio Registry', url: 'https://example.com/registry', version: 'v1' })).toEqual(
+    'https://example.com/registry/v1',
+  );
+});
+
+test('Registry url with a version strips a trailing slash from the root first', () => {
+  expect(registryUrl({ name: 'Open Audio Registry', url: 'https://example.com/registry/', version: 'v1' })).toEqual(
+    'https://example.com/registry/v1',
+  );
+});