diff --git a/api/rest.go b/api/rest.go
index 7b75fae..f5d571d 100644
--- a/api/rest.go
+++ b/api/rest.go
@@ -17,6 +17,7 @@ import (
 	"github.com/ClusterCockpit/cc-backend/graph/model"
 	"github.com/ClusterCockpit/cc-backend/log"
 	"github.com/ClusterCockpit/cc-backend/metricdata"
+	"github.com/ClusterCockpit/cc-backend/repository"
 	"github.com/ClusterCockpit/cc-backend/schema"
 	sq "github.com/Masterminds/squirrel"
 	"github.com/gorilla/mux"
@@ -24,6 +25,7 @@ import (
 )
 
 type RestApi struct {
+	r                 *repository.JobRepository
 	DB                *sqlx.DB
 	Resolver          *graph.Resolver
 	AsyncArchiving    bool
@@ -51,7 +53,7 @@ func (api *RestApi) MountRoutes(r *mux.Router) {
 	}
 }
 
-type StartJobApiRespone struct {
+type StartJobApiResponse struct {
 	DBID int64 `json:"id"`
 }
 
@@ -153,14 +155,14 @@ func (api *RestApi) tagJob(rw http.ResponseWriter, r *http.Request) {
 
 	for _, tag := range req {
 		var tagId int64
-		if err := sq.Select("id").From("tag").
-			Where("tag.tag_type = ?", tag.Type).Where("tag.tag_name = ?", tag.Name).
-			RunWith(api.DB).QueryRow().Scan(&tagId); err != nil {
+		exists := false
+
+		if exists, tagId = api.r.TagExists(tag.Type, tag.Name); exists {
 			http.Error(rw, fmt.Sprintf("the tag '%s:%s' does not exist", tag.Type, tag.Name), http.StatusNotFound)
 			return
 		}
 
-		if _, err := api.DB.Exec(`INSERT INTO jobtag (job_id, tag_id) VALUES (?, ?)`, job.ID, tagId); err != nil {
+		if err := api.r.AddTag(job.JobID, tagId); err != nil {
 			http.Error(rw, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -204,8 +206,7 @@ func (api *RestApi) startJob(rw http.ResponseWriter, r *http.Request) {
 	}
 
 	// Check if combination of (job_id, cluster_id, start_time) already exists:
-	rows, err := api.DB.Query(`SELECT job.id FROM job WHERE job.job_id = ? AND job.cluster = ? AND job.start_time = ?`,
-		req.JobID, req.Cluster, req.StartTime)
+	rows, err := api.r.JobExists(req.JobID, req.Cluster, req.StartTime)
 	if err != nil {
 		http.Error(rw, err.Error(), http.StatusInternalServerError)
 		return
@@ -250,7 +251,7 @@ func (api *RestApi) startJob(rw http.ResponseWriter, r *http.Request) {
 	log.Printf("new job (id: %d): cluster=%s, jobId=%d, user=%s, startTime=%d", id, req.Cluster, req.JobID, req.User, req.StartTime)
 	rw.Header().Add("Content-Type", "application/json")
 	rw.WriteHeader(http.StatusCreated)
-	json.NewEncoder(rw).Encode(StartJobApiRespone{
+	json.NewEncoder(rw).Encode(StartJobApiResponse{
 		DBID: id,
 	})
 }
diff --git a/repository/job.go b/repository/job.go
new file mode 100644
index 0000000..e053bc0
--- /dev/null
+++ b/repository/job.go
@@ -0,0 +1,40 @@
+package repository
+
+import (
+	"database/sql"
+
+	sq "github.com/Masterminds/squirrel"
+	"github.com/jmoiron/sqlx"
+)
+
+type JobRepository struct {
+	DB *sqlx.DB
+}
+
+func (r *JobRepository) JobExists(jobId int64, cluster string, startTime int64) (rows *sql.Rows, err error) {
+	rows, err = r.DB.Query(`SELECT job.id FROM job WHERE job.job_id = ? AND job.cluster = ? AND job.start_time = ?`,
+		jobId, cluster, startTime)
+	return
+}
+
+func (r *JobRepository) IdExists(jobId int64) bool {
+
+	return true
+}
+
+func (r *JobRepository) AddTag(jobId int64, tagId int64) error {
+	_, err := r.DB.Exec(`INSERT INTO jobtag (job_id, tag_id) VALUES (?, ?)`, jobId, tagId)
+	return err
+}
+
+func (r *JobRepository) TagExists(tagType string, tagName string) (exists bool, tagId int64) {
+	exists = true
+	if err := sq.Select("id").From("tag").
+		Where("tag.tag_type = ?", tagType).Where("tag.tag_name = ?", tagName).
+		RunWith(r.DB).QueryRow().Scan(&tagId); err != nil {
+		exists = false
+		return exists, tagId
+	} else {
+		return exists, tagId
+	}
+}
diff --git a/repository/user.go b/repository/user.go
new file mode 100644
index 0000000..50a4378
--- /dev/null
+++ b/repository/user.go
@@ -0,0 +1 @@
+package repository