diff --git a/src/modules/cards/application/useCases/queries/SearchCollectionsUseCase.ts b/src/modules/cards/application/useCases/queries/SearchCollectionsUseCase.ts
index 5045dfce..34e4431c 100644
--- a/src/modules/cards/application/useCases/queries/SearchCollectionsUseCase.ts
+++ b/src/modules/cards/application/useCases/queries/SearchCollectionsUseCase.ts
@@ -11,6 +11,9 @@ import {
   PaginationDTO,
   CollectionSortingDTO,
 } from '@semble/types';
+import { IIdentityResolutionService } from 'src/modules/atproto/domain/services/IIdentityResolutionService';
+import { DIDOrHandle } from 'src/modules/atproto/domain/DIDOrHandle';
+import { CollectionAccessType } from '../../../domain/Collection';
 
 export interface SearchCollectionsQuery {
   page?: number;
@@ -18,6 +21,8 @@ export interface SearchCollectionsQuery {
   sortBy?: CollectionSortField;
   sortOrder?: SortOrder;
   searchText?: string;
+  identifier?: string; // Can be DID or handle
+  accessType?: CollectionAccessType;
 }
 
 export interface SearchCollectionsResult {
@@ -32,6 +37,7 @@ export class SearchCollectionsUseCase
   constructor(
     private collectionQueryRepo: ICollectionQueryRepository,
     private profileService: IProfileService,
+    private identityResolutionService: IIdentityResolutionService,
   ) {}
 
   async execute(
@@ -44,6 +50,38 @@ export class SearchCollectionsUseCase
     const sortOrder = query.sortOrder || SortOrder.DESC;
 
     try {
+      // Resolve identifier to DID if provided
+      let authorId: string | undefined;
+      if (query.identifier) {
+        const identifierResult = DIDOrHandle.create(query.identifier);
+        if (identifierResult.isErr()) {
+          return err(
+            new Error(`Invalid identifier: ${identifierResult.error.message}`),
+          );
+        }
+
+        const didResult = await this.identityResolutionService.resolveToDID(
+          identifierResult.value,
+        );
+        if (didResult.isErr()) {
+          return err(
+            new Error(
+              `Failed to resolve identifier to DID: ${didResult.error.message}`,
+            ),
+          );
+        }
+
+        authorId = didResult.value.value;
+      }
+
+      // Validate accessType if provided
+      if (
+        query.accessType &&
+        !Object.values(CollectionAccessType).includes(query.accessType)
+      ) {
+        return err(new Error(`Invalid access type: ${query.accessType}`));
+      }
+
       // Execute query to get raw collection data
       const result = await this.collectionQueryRepo.searchCollections({
         page,
@@ -51,6 +89,8 @@ export class SearchCollectionsUseCase
         sortBy,
         sortOrder,
         searchText: query.searchText,
+        authorId,
+        accessType: query.accessType,
       });
 
       // Get unique author IDs from the results
diff --git a/src/modules/cards/domain/ICollectionQueryRepository.ts b/src/modules/cards/domain/ICollectionQueryRepository.ts
index 59a4e693..4b917599 100644
--- a/src/modules/cards/domain/ICollectionQueryRepository.ts
+++ b/src/modules/cards/domain/ICollectionQueryRepository.ts
@@ -78,6 +78,8 @@ export interface SearchCollectionsOptions {
   sortBy: CollectionSortField;
   sortOrder: SortOrder;
   searchText?: string;
+  authorId?: string; // Filter by author DID
+  accessType?: string; // Filter by access type (OPEN or CLOSED)
 }
 
 export interface ICollectionQueryRepository {
diff --git a/src/modules/cards/infrastructure/http/controllers/SearchCollectionsController.ts b/src/modules/cards/infrastructure/http/controllers/SearchCollectionsController.ts
index 3db93488..3e3762a3 100644
--- a/src/modules/cards/infrastructure/http/controllers/SearchCollectionsController.ts
+++ b/src/modules/cards/infrastructure/http/controllers/SearchCollectionsController.ts
@@ -5,6 +5,7 @@ import {
   CollectionSortField,
   SortOrder,
 } from '../../../domain/ICollectionQueryRepository';
+import { CollectionAccessType } from '../../../domain/Collection';
 
 export class SearchCollectionsController extends Controller {
   constructor(private searchCollectionsUseCase: SearchCollectionsUseCase) {
@@ -13,7 +14,15 @@ export class SearchCollectionsController extends Controller {
 
   async executeImpl(req: Request, res: Response): Promise<any> {
     try {
-      const { page, limit, sortBy, sortOrder, searchText } = req.query;
+      const {
+        page,
+        limit,
+        sortBy,
+        sortOrder,
+        searchText,
+        identifier,
+        accessType,
+      } = req.query;
 
       const result = await this.searchCollectionsUseCase.execute({
         page: page ? parseInt(page as string) : undefined,
@@ -21,6 +30,8 @@ export class SearchCollectionsController extends Controller {
         sortBy: sortBy as CollectionSortField,
         sortOrder: sortOrder as SortOrder,
         searchText: searchText as string,
+        identifier: identifier as string,
+        accessType: accessType as CollectionAccessType,
       });
 
       if (result.isErr()) {
diff --git a/src/modules/cards/infrastructure/repositories/DrizzleCollectionQueryRepository.ts b/src/modules/cards/infrastructure/repositories/DrizzleCollectionQueryRepository.ts
index 081ac1ae..6f42e38d 100644
--- a/src/modules/cards/infrastructure/repositories/DrizzleCollectionQueryRepository.ts
+++ b/src/modules/cards/infrastructure/repositories/DrizzleCollectionQueryRepository.ts
@@ -264,7 +264,15 @@ export class DrizzleCollectionQueryRepository
     options: SearchCollectionsOptions,
   ): Promise<PaginatedQueryResult<CollectionQueryResultDTO>> {
     try {
-      const { page, limit, sortBy, sortOrder, searchText } = options;
+      const {
+        page,
+        limit,
+        sortBy,
+        sortOrder,
+        searchText,
+        authorId,
+        accessType,
+      } = options;
       const offset = (page - 1) * limit;
 
       // Build the sort order
@@ -273,6 +281,16 @@ export class DrizzleCollectionQueryRepository
       // Build where conditions
       const whereConditions = [];
 
+      // Add author filter if provided
+      if (authorId) {
+        whereConditions.push(eq(collections.authorId, authorId));
+      }
+
+      // Add access type filter if provided
+      if (accessType) {
+        whereConditions.push(eq(collections.accessType, accessType));
+      }
+
       // Add tokenized search condition if searchText is provided
       if (searchText && searchText.trim()) {
         const searchWords = searchText.trim().split(/\s+/);
diff --git a/src/modules/cards/tests/utils/InMemoryCollectionQueryRepository.ts b/src/modules/cards/tests/utils/InMemoryCollectionQueryRepository.ts
index a1de39c9..d909101b 100644
--- a/src/modules/cards/tests/utils/InMemoryCollectionQueryRepository.ts
+++ b/src/modules/cards/tests/utils/InMemoryCollectionQueryRepository.ts
@@ -228,6 +228,20 @@ export class InMemoryCollectionQueryRepository
     try {
       let allCollections = this.collectionRepository.getAllCollections();
 
+      // Apply author filter if provided
+      if (options.authorId) {
+        allCollections = allCollections.filter(
+          (collection) => collection.authorId.value === options.authorId,
+        );
+      }
+
+      // Apply access type filter if provided
+      if (options.accessType) {
+        allCollections = allCollections.filter(
+          (collection) => collection.accessType === options.accessType,
+        );
+      }
+
       // Apply tokenized search if searchText is provided
       if (options.searchText && options.searchText.trim()) {
         const searchWords = options.searchText
diff --git a/src/shared/infrastructure/http/factories/UseCaseFactory.ts b/src/shared/infrastructure/http/factories/UseCaseFactory.ts
index 4c7f2ed5..306c7122 100644
--- a/src/shared/infrastructure/http/factories/UseCaseFactory.ts
+++ b/src/shared/infrastructure/http/factories/UseCaseFactory.ts
@@ -238,6 +238,7 @@ export class UseCaseFactory {
       searchCollectionsUseCase: new SearchCollectionsUseCase(
         repositories.collectionQueryRepository,
         services.profileService,
+        services.identityResolutionService,
       ),
       getUrlStatusForMyLibraryUseCase: new GetUrlStatusForMyLibraryUseCase(
         repositories.cardRepository,
diff --git a/src/types/src/api/requests.ts b/src/types/src/api/requests.ts
index d9c086aa..aed434a0 100644
--- a/src/types/src/api/requests.ts
+++ b/src/types/src/api/requests.ts
@@ -208,6 +208,8 @@ export interface GetGemActivityFeedParams extends PaginationParams {
 
 export interface SearchCollectionsParams extends PaginatedSortedParams {
   searchText?: string;
+  identifier?: string; // Can be DID or handle
+  accessType?: 'OPEN' | 'CLOSED';
 }
 
 // Notification request types
diff --git a/src/webapp/api-client/clients/CollectionClient.ts b/src/webapp/api-client/clients/CollectionClient.ts
index f5261fd5..7ee186f0 100644
--- a/src/webapp/api-client/clients/CollectionClient.ts
+++ b/src/webapp/api-client/clients/CollectionClient.ts
@@ -50,6 +50,8 @@ export class CollectionClient extends BaseClient {
     if (params?.sortBy) searchParams.set('sortBy', params.sortBy);
     if (params?.sortOrder) searchParams.set('sortOrder', params.sortOrder);
     if (params?.searchText) searchParams.set('searchText', params.searchText);
+    if (params?.identifier) searchParams.set('identifier', params.identifier);
+    if (params?.accessType) searchParams.set('accessType', params.accessType);
 
     const queryString = searchParams.toString();
     const endpoint = queryString