diff --git a/packages/service-core/test/src/sync/BucketChecksumState.test.ts b/packages/service-core/test/src/sync/BucketChecksumState.test.ts
index df43cc9bd..717c017d2 100644
--- a/packages/service-core/test/src/sync/BucketChecksumState.test.ts
+++ b/packages/service-core/test/src/sync/BucketChecksumState.test.ts
@@ -607,11 +607,20 @@ bucket_definitions:
   describe('streams', () => {
     let source: { -readonly [P in keyof BucketSource]: BucketSource[P] };
     let storage: MockBucketChecksumStateStorage;
-    let staticBucketIds = ['stream|0[]'];
 
-    function checksumState(options?: Partial<BucketChecksumStateOptions>) {
-      const rules = new SqlSyncRules('');
-      rules.bucketSources.push(source);
+    function checksumState(source: string | boolean, options?: Partial<BucketChecksumStateOptions>) {
+      if (typeof source == 'boolean') {
+        source = `
+streams:
+  stream:
+    auto_subscribe: ${source}
+    query: SELECT * FROM assets WHERE id IN ifnull(subscription.parameter('ids'), '["default"]');
+`;
+      }
+
+      const rules = SqlSyncRules.fromYaml(source, {
+        defaultSchema: 'public'
+      });
 
       return new BucketChecksumState({
         syncContext,
@@ -623,77 +632,15 @@ bucket_definitions:
       });
     }
 
-    function createQuerier(ids: string[], subscription: number | null): BucketParameterQuerier {
-      return {
-        staticBuckets: ids.map((bucket) => ({
-          definition: 'stream',
-          inclusion_reasons: subscription == null ? ['default'] : [{ subscription }],
-          bucket,
-          priority: 3
-        })),
-        hasDynamicBuckets: false,
-        parameterQueryLookups: [],
-        queryDynamicBucketDescriptions: function (): never {
-          throw new Error('no dynamic buckets.');
-        }
-      };
-    }
-
     beforeEach(() => {
-      // Currently using mocked streams before streams are actually implemented as parsable rules.
-      source = {
-        name: 'stream',
-        type: BucketSourceType.SYNC_STREAM,
-        subscribedToByDefault: false,
-        pushBucketParameterQueriers(result, options) {
-          // Create a fake querier that resolves the global stream["default"] bucket by default and allows extracting
-          // additional buckets from parameters.
-          const subscriptions = options.streams['stream'] ?? [];
-          if (!this.subscribedToByDefault && !subscriptions.length) {
-            return;
-          }
-
-          let hasExplicitDefaultSubscription = false;
-          for (const subscription of subscriptions) {
-            try {
-              let subscriptionParameters = [];
-
-              if (subscription.parameters != null) {
-                subscriptionParameters = JSON.parse(subscription.parameters['ids'] as string).map(
-                  (e: string) => `stream["${e}"]`
-                );
-              } else {
-                hasExplicitDefaultSubscription = true;
-              }
-
-              result.queriers.push(createQuerier([...subscriptionParameters], subscription.opaque_id));
-            } catch (e) {
-              result.errors.push({
-                descriptor: 'stream',
-                subscription,
-                message: `Error evaluating bucket ids: ${e.message}`
-              });
-            }
-          }
-
-          // If the stream is subscribed to by default and there is no explicit subscription that would match the default
-          // subscription, also include the default querier.
-          if (this.subscribedToByDefault && !hasExplicitDefaultSubscription) {
-            result.queriers.push(createQuerier(['stream["default"]'], null));
-          }
-        }
-      } satisfies Partial<BucketSource> as any;
-
       storage = new MockBucketChecksumStateStorage();
-      storage.updateTestChecksum({ bucket: 'stream["default"]', checksum: 1, count: 1 });
-      storage.updateTestChecksum({ bucket: 'stream["a"]', checksum: 1, count: 1 });
-      storage.updateTestChecksum({ bucket: 'stream["b"]', checksum: 1, count: 1 });
+      storage.updateTestChecksum({ bucket: 'stream|0["default"]', checksum: 1, count: 1 });
+      storage.updateTestChecksum({ bucket: 'stream|0["a"]', checksum: 1, count: 1 });
+      storage.updateTestChecksum({ bucket: 'stream|0["b"]', checksum: 1, count: 1 });
     });
 
     test('includes defaults', async () => {
-      source.subscribedToByDefault = true;
-      const state = checksumState();
-
+      const state = checksumState(true);
       const line = await state.buildNextCheckpointLine({
         base: storage.makeCheckpoint(1n),
         writeCheckpoint: null,
@@ -703,7 +650,7 @@ bucket_definitions:
       expect(line?.checkpointLine).toEqual({
         checkpoint: {
           buckets: [
-            { bucket: 'stream["default"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ default: 0 }] }
+            { bucket: 'stream|0["default"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ default: 0 }] }
           ],
           last_op_id: '1',
           write_checkpoint: undefined,
@@ -713,8 +660,7 @@ bucket_definitions:
     });
 
     test('can exclude defaults', async () => {
-      source.subscribedToByDefault = true;
-      const state = checksumState({ syncRequest: { streams: { include_defaults: false, subscriptions: [] } } });
+      const state = checksumState(true, { syncRequest: { streams: { include_defaults: false, subscriptions: [] } } });
 
       const line = await state.buildNextCheckpointLine({
         base: storage.makeCheckpoint(1n),
@@ -733,9 +679,7 @@ bucket_definitions:
     });
 
     test('custom subscriptions', async () => {
-      source.subscribedToByDefault = true;
-
-      const state = checksumState({
+      const state = checksumState(true, {
         syncRequest: {
           streams: {
             subscriptions: [
@@ -755,9 +699,9 @@ bucket_definitions:
       expect(line?.checkpointLine).toEqual({
         checkpoint: {
           buckets: [
-            { bucket: 'stream["a"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ sub: 0 }] },
-            { bucket: 'stream["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 1 }] },
-            { bucket: 'stream["default"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ default: 0 }] }
+            { bucket: 'stream|0["a"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ sub: 0 }] },
+            { bucket: 'stream|0["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 1 }] },
+            { bucket: 'stream|0["default"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ default: 0 }] }
           ],
           last_op_id: '1',
           write_checkpoint: undefined,
@@ -767,7 +711,7 @@ bucket_definitions:
     });
 
     test('overlap between custom subscriptions', async () => {
-      const state = checksumState({
+      const state = checksumState(false, {
         syncRequest: {
           streams: {
             subscriptions: [
@@ -787,8 +731,8 @@ bucket_definitions:
       expect(line?.checkpointLine).toEqual({
         checkpoint: {
           buckets: [
-            { bucket: 'stream["a"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ sub: 0 }] },
-            { bucket: 'stream["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }, { sub: 1 }] }
+            { bucket: 'stream|0["a"]', checksum: 1, count: 1, priority: 3, subscriptions: [{ sub: 0 }] },
+            { bucket: 'stream|0["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }, { sub: 1 }] }
           ],
           last_op_id: '1',
           write_checkpoint: undefined,
@@ -798,8 +742,7 @@ bucket_definitions:
     });
 
     test('overlap between default and custom subscription', async () => {
-      source.subscribedToByDefault = true;
-      const state = checksumState({
+      const state = checksumState(true, {
         syncRequest: {
           streams: {
             subscriptions: [{ stream: 'stream', parameters: { ids: '["a", "default"]' }, override_priority: 1 }]
@@ -816,9 +759,9 @@ bucket_definitions:
       expect(line?.checkpointLine).toEqual({
         checkpoint: {
           buckets: [
-            { bucket: 'stream["a"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
+            { bucket: 'stream|0["a"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
             {
-              bucket: 'stream["default"]',
+              bucket: 'stream|0["default"]',
               checksum: 1,
               count: 1,
               priority: 1,
@@ -833,9 +776,7 @@ bucket_definitions:
     });
 
     test('reports errors', async () => {
-      source.subscribedToByDefault = true;
-
-      const state = checksumState({
+      const state = checksumState(true, {
         syncRequest: {
           streams: {
             subscriptions: [
@@ -855,10 +796,10 @@ bucket_definitions:
       expect(line?.checkpointLine).toEqual({
         checkpoint: {
           buckets: [
-            { bucket: 'stream["a"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
-            { bucket: 'stream["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
+            { bucket: 'stream|0["a"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
+            { bucket: 'stream|0["b"]', checksum: 1, count: 1, priority: 1, subscriptions: [{ sub: 0 }] },
             {
-              bucket: 'stream["default"]',
+              bucket: 'stream|0["default"]',
               checksum: 1,
               count: 1,
               priority: 3,