diff --git a/apps/api/src/tenders/source-registry.spec.ts b/apps/api/src/tenders/source-registry.spec.ts
new file mode 100644
index 0000000..172a4a2
--- /dev/null
+++ b/apps/api/src/tenders/source-registry.spec.ts
@@ -0,0 +1,73 @@
+import { describe, expect, it } from 'vitest';
+import type { RawTenderRecord, SourceType } from './tender.types';
+import type { TenderSourceAdapter } from './adapters/tender-source-adapter.interface';
+import { DeniedPortalError, SourceRegistry } from './source-registry';
+
+/**
+ * Fake adapter stub — no real scraping/HTTP, just satisfies the
+ * TenderSourceAdapter contract for registry-behavior tests.
+ */
+function fakeAdapter(
+  sourceType: SourceType,
+  portals: readonly string[],
+): TenderSourceAdapter {
+  return {
+    sourceType,
+    portals,
+    async fetchTenders(_dayCursor: string): Promise<RawTenderRecord[]> {
+      return [];
+    },
+  };
+}
+
+describe('SourceRegistry', () => {
+  it('throws DeniedPortalError when registering an adapter serving vergabe24', () => {
+    const registry = new SourceRegistry();
+    const adapter = fakeAdapter('ai-netserver', ['vergabe24']);
+
+    expect(() => registry.register(adapter)).toThrow(DeniedPortalError);
+  });
+
+  it('throws DeniedPortalError when registering an adapter serving aumass', () => {
+    const registry = new SourceRegistry();
+    const adapter = fakeAdapter('cosinex-dtvp', ['aumass']);
+
+    expect(() => registry.register(adapter)).toThrow(DeniedPortalError);
+  });
+
+  it('rejects a mixed portals array wholesale when one entry is denylisted', () => {
+    const registry = new SourceRegistry();
+    const adapter = fakeAdapter('ai-netserver', ['tender24', 'aumass']);
+
+    expect(() => registry.register(adapter)).toThrow(DeniedPortalError);
+    expect(registry.get('ai-netserver')).toBeUndefined();
+  });
+
+  it('registers a legitimate adapter and returns it via get()', () => {
+    const registry = new SourceRegistry();
+    const adapter = fakeAdapter('ai-netserver', ['tender24']);
+
+    expect(() => registry.register(adapter)).not.toThrow();
+    expect(registry.get('ai-netserver')).toBe(adapter);
+  });
+
+  it('activeAdapters() returns all registered adapters', () => {
+    const registry = new SourceRegistry();
+    const doe = fakeAdapter('doe-opendata', ['doe-opendata']);
+    const netserver = fakeAdapter('ai-netserver', ['tender24']);
+
+    registry.register(doe);
+    registry.register(netserver);
+
+    expect(registry.activeAdapters()).toHaveLength(2);
+    expect(registry.activeAdapters()).toEqual(
+      expect.arrayContaining([doe, netserver]),
+    );
+  });
+
+  it('get() returns undefined for an unregistered sourceType (no throw)', () => {
+    const registry = new SourceRegistry();
+
+    expect(registry.get('cosinex-dtvp')).toBeUndefined();
+  });
+});