diff --git a/src/DistroqueryAPI.cpp b/src/DistroqueryAPI.cpp
index c7465fc..bac2296 100644
--- a/src/DistroqueryAPI.cpp
+++ b/src/DistroqueryAPI.cpp
@@ -56,54 +56,6 @@ void DistroqueryAPI::sendErrorResponse(string message) {
     exit(0);
 }
 
-json DistroqueryAPI::getPackageSourceDetailsById(configTag* ct, long id) {
-    json j;
-    string sql;
-    sqlite3_stmt *stmt;
-
-    auto db = openRepositoryDatabase(ct);
-    if (!db) {
-        j["error"] = "error opening sources database for repository " + string(ct->tag);
-        return j;
-    }
-    sql = "SELECT * FROM sources,packagers WHERE sources.id=" + to_string(id) +
-        " AND sources.id_packager=packagers.id";
-    if (!sqlite3_prepare_v2(db, sql.c_str(), sql.length(), &stmt, NULL) == SQLITE_OK) {
-        j["error"] = "error preparing query '" + sql + "'";
-        return j;
-    }
-    if (sqlite3_step(stmt) == SQLITE_ROW) {
-        j["id"] = sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "id"));
-        j["name"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "name")));
-        j["summary"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "summary")));
-        j["epoch"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "epoch")));
-        j["version"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "version")));
-        j["release"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "release")));
-        j["description"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "description")));
-        j["group"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "groupdescr")));
-        j["license"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "license")));
-        j["url"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "url")));
-        //get_favicon_from_url((const char*)sqlite3_column_text(stmt1,sqlite3_find_column_id(stmt1, NULL, "url")),buffer,PATH_MAX);
-        j["size"] = sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "size"));
-        j["maintainer"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, "packagers", "name")));
-        // Convert buildtime to ISO-8601
-        auto itt = (time_t)sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "buildtime"));
-        ostringstream ss;
-        ss << std::put_time(gmtime(&itt), "%FT%TZ");
-        j["buildtime"] = ss.str();
-        // Download URL
-        j["download_url"] = string(ct->download_prefix) + ct->download_dir + "/SRPMS.base/" +
-            string(j["name"]) + "-" + string(j["version"]) + "-" + string(j["release"]) + ".src.rpm";
-        // Source URL
-        string name = string(j["name"]);
-        j["source_url"] = "https://src.openmamba.org/rpms/" + replaceAll(name, "+", "Plus");
-    } else {
-        j["error"] = "no results from query '" + sql + "'";
-        return j;
-    }
-    return j;
-}
-
 json DistroqueryAPI::getRepositoryPackages(string repository, int per_page, int page, string query) {
     json j;
     string sql;
@@ -196,11 +148,60 @@ json DistroqueryAPI::getRepositoryPackages(string repository, int per_page, int
     return j;
 }
 
-json DistroqueryAPI::getBuiltPackagesFromSourceID(configTag* ct, long id) {
-    json j = json::array();
+json DistroqueryAPI::getPackageSourceDetailsById(configTag* ct, long id) {
+    json j;
     string sql;
     sqlite3_stmt *stmt;
 
+    auto db = openRepositoryDatabase(ct);
+    if (!db) {
+        j["error"] = "error opening sources database for repository " + string(ct->tag);
+        return j;
+    }
+    sql = "SELECT * FROM sources,packagers WHERE sources.id=" + to_string(id) +
+        " AND sources.id_packager=packagers.id";
+    if (!sqlite3_prepare_v2(db, sql.c_str(), sql.length(), &stmt, NULL) == SQLITE_OK) {
+        j["error"] = "error preparing query '" + sql + "': " + sqlite3_errmsg(db);
+        return j;
+    }
+    if (sqlite3_step(stmt) == SQLITE_ROW) {
+        j["id"] = sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "id"));
+        j["name"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "name")));
+        j["summary"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "summary")));
+        j["epoch"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "epoch")));
+        j["version"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "version")));
+        j["release"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "release")));
+        j["description"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "description")));
+        j["group"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "groupdescr")));
+        j["license"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "license")));
+        j["url"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "url")));
+        //get_favicon_from_url((const char*)sqlite3_column_text(stmt1,sqlite3_find_column_id(stmt1, NULL, "url")),buffer,PATH_MAX);
+        j["size"] = sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "size"));
+        j["maintainer"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, "packagers", "name")));
+        // Convert buildtime to ISO-8601
+        auto itt = (time_t)sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "buildtime"));
+        ostringstream ss;
+        ss << std::put_time(gmtime(&itt), "%FT%TZ");
+        j["buildtime"] = ss.str();
+        // Download URL
+        j["download_url"] = string(ct->download_prefix) + ct->download_dir + "/SRPMS.base/" +
+            string(j["name"]) + "-" + string(j["version"]) + "-" + string(j["release"]) + ".src.rpm";
+        // Source URL
+        string name = string(j["name"]);
+        j["source_url"] = "https://src.openmamba.org/rpms/" + replaceAll(name, "+", "Plus");
+    } else {
+        j["error"] = "no results from query '" + sql + "'";
+        return j;
+    }
+    return j;
+}
+
+json DistroqueryAPI::getBuiltPackagesFromSourceID(configTag* ct, long id) {
+    json j = {};
+    string sql;
+    sqlite3_stmt *stmt;
+
+    json archs = {};
     for (auto arch: ct->arch) {
         if (arch == NULL) break;
         auto db = openRepositoryDatabase(ct, arch);
@@ -213,18 +214,91 @@ json DistroqueryAPI::getBuiltPackagesFromSourceID(configTag* ct, long id) {
         sql = "SELECT * FROM packages WHERE id_source = " + to_string(id) + " ORDER BY name";
         if (sqlite3_prepare_v2(db, sql.c_str(), sql.length(), &stmt, NULL) == SQLITE_OK) {
             while (sqlite3_step(stmt) == SQLITE_ROW) {
+                if (!archs.contains(arch)) {
+                    archs[arch] = json::array();
+                }
                 json package = {};
-                package["arch"] = arch;
                 package["name"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "name")));
-                j.push_back(package);
+                archs[arch].push_back(package);
             }
             sqlite3_finalize(stmt);
         } else {
             j = {};
-            j["error"] = "error preparing query '" + sql + "'";
+            j["error"] = "error preparing query '" + sql + "': " + sqlite3_errmsg(db);
             return j;
         }
     }
+    j["archs"] = archs;
+    return j;
+}
+
+json DistroqueryAPI::getProvidersForRequirement(string repository, string requirement, string flags, string version) {
+    json j;
+    sqlite3_stmt *stmt;
+
+    struct configTag* ct = findRepositoryByTag(repository.c_str());
+    if (ct == NULL) {
+        j["error"] = "repository with tag '" + repository + "' does not exist";
+        return j;
+    }
+
+    auto db = openRepositoryDatabase(ct);
+    if (!db) {
+        j["error"] = "error opening sources database for repository " + string(ct->tag);
+        return j;
+    }
+
+    string sql = "SELECT u.* FROM (";
+
+    int intflags = rpmSenseStringToFlags(flags);
+
+    int a = 0;
+    for (auto arch: ct->arch) {
+        if (arch == NULL) break;
+        attachCtDatabases(ct, db, arch);
+        int i = 0;
+        while (ct->repository[i]) {
+            if (a + i > 0) sql += " UNION ";
+            sql += "SELECT *,'" + string(ct->repository[i]->tag) + "' AS repository,'" +
+                arch + "' AS arch "
+                "FROM '" + string(ct->repository[i]->tag) + "_" + arch + "'.provides,'" +
+                string(ct->repository[i]->tag) + "_" + arch + "'.packages "
+                "WHERE providename='" + requirement + "' AND packages.id=provides.id_package";
+            if (flags != "") {
+                sql += " AND provideflags='" + to_string(intflags) + "' AND provideversion='" + version + "'";
+            }
+            i++;
+        }
+        a++;
+    }
+
+    sql += ") AS u ORDER BY providename COLLATE NOCASE ASC";
+
+    json archs = {};
+
+    if (sqlite3_prepare_v2(db, sql.c_str(), sql.length(), &stmt, NULL) == SQLITE_OK) {
+        json providers = json::array();
+        while (sqlite3_step(stmt) == SQLITE_ROW) {
+            string arch = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "arch")));
+            if (!archs.contains(arch)) {
+                archs[arch] = json::array();
+            }
+            json provider = {};
+            provider["repository"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "repository")));
+            provider["name"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "name")));
+            provider["flags"] = rpmSenseFlagsToString(sqlite3_column_int(stmt,sqlite3_find_column_id(stmt, NULL, "provideflags")));
+            provider["version"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt,sqlite3_find_column_id(stmt, NULL, "provideversion")));
+            archs[arch].push_back(provider);
+        }
+        //j["providers"] = providers;
+        sqlite3_finalize(stmt);
+    } else {
+        j = {};
+        j["error"] = "error preparing query '" + sql + "': " + sqlite3_errmsg(db);
+        return j;
+    }
+    j["providers"] = {};
+    j["providers"]["archs"] = archs;
     return j;
 }
 
@@ -267,6 +341,8 @@ json DistroqueryAPI::getPackageSourceDetails(string repository, string package)
                 buildrequire["name"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt2,sqlite3_find_column_id(stmt2, NULL, "buildrequirename")));
                 buildrequire["flags"] = rpmSenseFlagsToString(sqlite3_column_int(stmt2,sqlite3_find_column_id(stmt2, NULL, "buildrequireflags")));
                 buildrequire["version"] = reinterpret_cast<const char*>(sqlite3_column_text(stmt2,sqlite3_find_column_id(stmt2, NULL, "buildrequireversion")));
+                json jproviders = getProvidersForRequirement(repository, buildrequire["name"], buildrequire["flags"], buildrequire["version"]);
+                buildrequire["providers"] = jproviders["providers"];
                 j["buildrequires"].push_back(buildrequire);
             }
             sqlite3_finalize(stmt2);
@@ -504,6 +580,18 @@ void DistroqueryAPI::getApiResponse(string path_info) {
                 details = getPackageDetails(path_split[1], package, path_split[3]);
             }
             cout << details.dump();
+        } else if (path_split[0] == "providers") {
+            // API service: package
+            if (path_split.size() != 3 && path_split.size() != 5)
+                sendErrorResponse("expected 3 or 5 arguments for " + path_split[0]);
+            json providers;
+            if (path_split.size() == 3)
+                providers = getProvidersForRequirement(path_split[1], urlDecode(path_split[2]),
+                    "", "");
+            else if (path_split.size() == 5)
+                providers = getProvidersForRequirement(path_split[1], urlDecode(path_split[2]),
+                    urlDecode(path_split[3]), urlDecode(path_split[4]));
+            cout << providers.dump();
         } else {
             sendErrorResponse("invalid request for service '" + path_split[0]);
         }
diff --git a/src/DistroqueryAPI.hpp b/src/DistroqueryAPI.hpp
index 4edb947..41d146f 100644
--- a/src/DistroqueryAPI.hpp
+++ b/src/DistroqueryAPI.hpp
@@ -43,6 +43,7 @@ class DistroqueryAPI {
         void sendErrorResponse(string message);
         json getRepositoryPackages(string repository, int per_page, int page, string query);
         json getPackageSourceDetailsById(configTag* ct, long id);
+        json getProvidersForRequirement(string repository, string requirement, string flags, string version);
         json getPackageSourceDetails(string repository, string package);
         json getBuiltPackagesFromSourceID(configTag* ct, long id);
         json getPackageDetails(string repository, string package, string arch);
diff --git a/src/distroquery_functions.cpp b/src/distroquery_functions.cpp
index 9db5628..42ba21d 100644
--- a/src/distroquery_functions.cpp
+++ b/src/distroquery_functions.cpp
@@ -45,6 +45,15 @@ string rpmSenseFlagsToString(int flags) {
     return ret;
 }
 
+int rpmSenseStringToFlags(string flags) {
+    if (flags == "=") return RPMSENSE_EQUAL;
+    else if (flags == "<") return RPMSENSE_LESS;
+    else if (flags == ">") return RPMSENSE_GREATER;
+    else if (flags == "<=") return RPMSENSE_LESS | RPMSENSE_EQUAL;
+    else if (flags == ">=") return RPMSENSE_GREATER | RPMSENSE_EQUAL;
+    return RPMSENSE_ANY;
+}
+
 sqlite3* openRepositoryDatabase(struct configTag* ct, string arch, string append) {
     string dbname;
     sqlite3* db;
diff --git a/src/include/distroquery_functions.hpp b/src/include/distroquery_functions.hpp
index 8294ff5..f9f0a5f 100644
--- a/src/include/distroquery_functions.hpp
+++ b/src/include/distroquery_functions.hpp
@@ -27,6 +27,7 @@
 using namespace std;
 
 string rpmSenseFlagsToString(int flags);
+int rpmSenseStringToFlags(string flags);
 vector<string> split(string str, string token);
 sqlite3* openRepositoryDatabase(struct configTag* ct, string arch = "", string append = "");
 void attachCtDatabases(struct configTag* ct, sqlite3 *db, string arch = "");