diff --git a/libsql-sqlite3/src/test_walapi.c b/libsql-sqlite3/src/test_walapi.c
new file mode 100644
index 0000000000..f7bdd54628
--- /dev/null
+++ b/libsql-sqlite3/src/test_walapi.c
@@ -0,0 +1,154 @@
+#include <sqlite3.h>
+#include <stdio.h>
+#include <string.h>
+
+#if 0
+static void dump_frame(unsigned char *frame, size_t size){
+  for(int addr=0; addr<size; addr+=16){
+    int sum = 0;
+    for(int i=0; i<16 && addr+1<size; i++){
+      sum += frame[addr+i] != 0;
+    }
+    if( sum ){
+      printf("%08x: ", addr);
+      for(int i=0; i<16 && addr+i<size; i++){
+        printf("%02x ", frame[addr+i]);
+      }
+      printf("  |");
+      for(int i=0; i<16 && addr+i<size; i++){
+        printf("%c", frame[addr+i] ? frame[addr+i] : '.');
+      }
+      printf("|");
+      printf("\n");
+    }
+  }
+}
+#endif
+
+static int cmp_data(sqlite3 *db1, sqlite3 *db2){
+  sqlite3_stmt *stmt1, *stmt2;
+  int rc;
+
+  rc = sqlite3_prepare_v2(db1, "SELECT * FROM users", -1, &stmt1, 0);
+  if( rc!=SQLITE_OK ){
+    fprintf(stderr, "Can't prepare statement: %s\n", sqlite3_errmsg(db1));
+    return 1;
+  }
+
+  rc = sqlite3_prepare_v2(db2, "SELECT * FROM users", -1, &stmt2, 0);
+  if( rc!=SQLITE_OK ){
+    fprintf(stderr, "Can't prepare statement: %s\n", sqlite3_errmsg(db2));
+    return 1;
+  }
+
+  for(;;){
+    int step1 = sqlite3_step(stmt1);
+    int step2 = sqlite3_step(stmt2);
+    if( step1!=step2 ){
+      fprintf(stderr, "Step mismatch: %d != %d\n", step1, step2);
+      return 1;
+    }
+    if( step1!=SQLITE_ROW ){
+      break;
+    }
+    const unsigned char *name1 = sqlite3_column_text(stmt1, 1);
+    const unsigned char *name2 = sqlite3_column_text(stmt2, 1);
+    if( strcmp((const char *)name1, (const char *)name2)!=0 ){
+      fprintf(stderr, "Data mismatch: %s != %s\n", name1, name2);
+      return 1;
+    }
+  }
+  return 0;
+}
+
+static int sync_db(sqlite3 *db_primary, sqlite3 *db_backup){
+  unsigned int max_frame;
+  int rc;
+
+  rc = libsql_wal_frame_count(db_primary, &max_frame);
+  if( rc!=SQLITE_OK ){
+    fprintf(stderr, "Can't get frame count: %s\n", sqlite3_errmsg(db_primary));
+    return 1;
+  }
+  rc = libsql_wal_insert_begin(db_backup);
+  if( rc!=SQLITE_OK ){
+    fprintf(stderr, "Can't begin commit: %s\n", sqlite3_errmsg(db_backup));
+    return 1;
+  }
+  for(int i=1; i<=max_frame; i++){
+    char frame[4096+24];
+    rc = libsql_wal_get_frame(db_primary, i, frame, sizeof(frame));
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "Can't get frame: %s\n", sqlite3_errmsg(db_primary));
+      return 1;
+    }
+    rc = libsql_wal_insert_frame(db_backup, i, frame, sizeof(frame));
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "Can't inject frame %d: %s\n", rc, sqlite3_errmsg(db_backup));
+      return 1;
+    }
+  }
+  rc = libsql_wal_insert_end(db_backup);
+  if( rc!=SQLITE_OK ){
+    fprintf(stderr, "Can't end commit: %s\n", sqlite3_errmsg(db_backup));
+    return 1;
+  }
+  return 0;
+}
+
+static void gen_data(sqlite3 *db){
+  sqlite3_exec(db, "CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)", 0, 0, 0);
+  sqlite3_exec(db, "INSERT INTO users (id, name) VALUES (1, 'John Doe')", 0, 0, 0);
+  sqlite3_exec(db, "INSERT INTO users (id, name) VALUES (2, 'Jane Doe')", 0, 0, 0);
+  sqlite3_exec(db, "INSERT INTO users (id, name) VALUES (3, 'Jim Beam')", 0, 0, 0);
+}
+
+int main(int argc, char *argv[])
+{
+    sqlite3 *db_primary, *db_backup;
+    int rc;
+
+    rc = sqlite3_open("primary.db", &db_primary);
+    if (rc != SQLITE_OK) {
+        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db_primary));
+        return 1;
+    }
+    rc = sqlite3_wal_autocheckpoint(db_primary, 0);
+    if (rc != SQLITE_OK) {
+        fprintf(stderr, "Can't disable checkpointing: %s\n", sqlite3_errmsg(db_primary));
+        return 1;
+    }
+    sqlite3_exec(db_primary, "PRAGMA journal_mode=WAL", NULL, NULL, NULL);
+
+    gen_data(db_primary);
+
+    rc = sqlite3_open("backup.db", &db_backup); 
+    if (rc != SQLITE_OK) {
+        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db_backup));
+        return 1;
+    }
+    rc = sqlite3_wal_autocheckpoint(db_backup, 0);
+    if (rc != SQLITE_OK) {
+        fprintf(stderr, "Can't disable checkpointing: %s\n", sqlite3_errmsg(db_backup));
+        return 1;
+    }
+    rc = sqlite3_exec(db_backup, "PRAGMA journal_mode=WAL", NULL, NULL, NULL);
+    if (rc != SQLITE_OK) {
+        fprintf(stderr, "Can't set journal mode: %s\n", sqlite3_errmsg(db_backup));
+        return 1;
+    }
+
+    sync_db(db_primary, db_backup);
+    if (cmp_data(db_primary, db_backup)) {
+        return 1;
+    }
+
+    sync_db(db_primary, db_backup);
+    if (cmp_data(db_primary, db_backup)) {
+        return 1;
+    }
+
+    printf("OK\n");
+
+    return 0;
+}