diff --git a/knotmirror/db/db.go b/knotmirror/db/db.go
--- a/knotmirror/db/db.go
+++ b/knotmirror/db/db.go
@@ -10,6 +10,12 @@ _ "github.com/jackc/pgx/v5/stdlib"
 	"tangled.org/core/log"
 )
 
+type DBTX interface {
+	ExecContext(ctx context.Context, query string, args ...any) (sql.Result, error)
+	QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...any) *sql.Row
+}
+
 func Make(ctx context.Context, dbUrl string, maxConns int) (*sql.DB, error) {
 	db, err := sql.Open("pgx", dbUrl)
 	if err != nil {
diff --git a/knotmirror/db/hosts.go b/knotmirror/db/hosts.go
--- a/knotmirror/db/hosts.go
+++ b/knotmirror/db/hosts.go
@@ -10,7 +10,7 @@
 	"tangled.org/core/knotmirror/models"
 )
 
-func UpsertHost(ctx context.Context, e *sql.DB, host *models.Host) error {
+func UpsertHost(ctx context.Context, e DBTX, host *models.Host) error {
 	if _, err := e.ExecContext(ctx,
 		`insert into hosts (hostname, no_ssl, status, last_seq)
 		values ($1, $2, $3, $4)
@@ -29,7 +29,7 @@ }
 	return nil
 }
 
-func GetHost(ctx context.Context, e *sql.DB, hostname string) (*models.Host, error) {
+func GetHost(ctx context.Context, e DBTX, hostname string) (*models.Host, error) {
 	var host models.Host
 	if err := e.QueryRowContext(ctx,
 		`select hostname, no_ssl, status, last_seq
@@ -70,7 +70,7 @@ }
 	return tx.Commit()
 }
 
-func ListHosts(ctx context.Context, e *sql.DB, status models.HostStatus) ([]models.Host, error) {
+func ListHosts(ctx context.Context, e DBTX, status models.HostStatus) ([]models.Host, error) {
 	rows, err := e.QueryContext(ctx,
 		`select hostname, no_ssl, status, last_seq
 		from hosts
diff --git a/knotmirror/db/repos.go b/knotmirror/db/repos.go
--- a/knotmirror/db/repos.go
+++ b/knotmirror/db/repos.go
@@ -11,7 +11,7 @@ "tangled.org/core/appview/pagination"
 	"tangled.org/core/knotmirror/models"
 )
 
-func UpsertRepo(ctx context.Context, e *sql.DB, repo *models.Repo) error {
+func UpsertRepo(ctx context.Context, e DBTX, repo *models.Repo) error {
 	if repo.RepoDid == "" {
 		return fmt.Errorf("upsert repo: repo_did is required")
 	}
@@ -48,7 +48,7 @@ }
 	return nil
 }
 
-func UpdateRepoState(ctx context.Context, e *sql.DB, repoDid syntax.DID, state models.RepoState) error {
+func UpdateRepoState(ctx context.Context, e DBTX, repoDid syntax.DID, state models.RepoState) error {
 	if _, err := e.ExecContext(ctx,
 		`update repos
 		set state = $1
@@ -61,7 +61,7 @@ }
 	return nil
 }
 
-func DeleteRepo(ctx context.Context, e *sql.DB, did syntax.DID, rkey syntax.RecordKey) error {
+func DeleteRepo(ctx context.Context, e DBTX, did syntax.DID, rkey syntax.RecordKey) error {
 	if _, err := e.ExecContext(ctx,
 		`delete from repos where did = $1 and rkey = $2`,
 		did,
@@ -107,7 +107,7 @@ }
 	return &repo, nil
 }
 
-func GetRepoByRepoDid(ctx context.Context, e *sql.DB, repoDid syntax.DID) (*models.Repo, error) {
+func GetRepoByRepoDid(ctx context.Context, e DBTX, repoDid syntax.DID) (*models.Repo, error) {
 	row := e.QueryRowContext(ctx,
 		`select`+repoColumns+`
 		from repos
@@ -124,7 +124,7 @@ }
 	return repo, nil
 }
 
-func GetRepoByAtUri(ctx context.Context, e *sql.DB, aturi syntax.ATURI) (*models.Repo, error) {
+func GetRepoByAtUri(ctx context.Context, e DBTX, aturi syntax.ATURI) (*models.Repo, error) {
 	row := e.QueryRowContext(ctx,
 		`select`+repoColumns+`
 		from repos
@@ -141,7 +141,7 @@ }
 	return repo, nil
 }
 
-func ListRepos(ctx context.Context, e *sql.DB, page pagination.Page, did, knot, state, name string) ([]models.Repo, error) {
+func ListRepos(ctx context.Context, e DBTX, page pagination.Page, did, knot, state, name string) ([]models.Repo, error) {
 	var conditions []string
 	var args []any
 
@@ -200,7 +200,7 @@
 	return repos, nil
 }
 
-func GetRepoCountsByState(ctx context.Context, e *sql.DB) (map[models.RepoState]int64, error) {
+func GetRepoCountsByState(ctx context.Context, e DBTX) (map[models.RepoState]int64, error) {
 	const q = `
 		SELECT state, COUNT(*)
 		FROM repos