diff --git a/src/smart_records_internals.h b/src/smart_records_internals.h
new file mode 100644
index 0000000..a7753dd
--- /dev/null
+++ b/src/smart_records_internals.h
@@ -0,0 +1,17 @@
+#ifndef SMART_RECORDS_INTERNALS_H
+#define SMART_RECORDS_INTERNALS_H
+
+/*
+ * Small helper to populate char **error and jump to failed label.
+ */
+#define set_error_and_fails(x) { if (error) *error = strdup(x); goto failed; }
+
+typedef struct smart_records_ctx_t {
+    void *CTX;
+    int (*set_format) (struct smart_records_ctx_t *ctx, char **error, char *fmp);
+    int (*write_record) (struct smart_records_ctx_t *ctx, char **error, va_list ap);
+    int (*close_records_base) (struct smart_records_ctx_t *ctx);
+} smart_records_ctx_t ;   
+
+#endif
+