fix(ts-sdk): preserve user metadata keys across the case-conversion round-trip (#5515)

mem0-ts/src/client/utils.ts

@@ -14,9 +14,27 @@ function snakeToCamel(str: string): string {
   return str.replace(/_([a-z])/g, (_, letter) => letter.toUpperCase());
 }
 
+/**
+ * Keys whose values are user-controlled, opaque blobs. Their nested keys must
+ * be passed through verbatim — converting them would silently rewrite the
+ * user's own keys and break round-trips (see issue #5055).
+ *
+ * The check runs against the source key, so a multi-word key must be listed in
+ * both casings to be covered in both directions: the camelCase form for the
+ * outbound `camelToSnakeKeys` path and the snake_case form for the inbound
+ * `snakeToCamelKeys` path. `metadata` is spelled identically in both, so one
+ * entry suffices; `structuredDataSchema` needs both.
+ */
+const OPAQUE_VALUE_KEYS = new Set([
+  "metadata",
+  "structuredDataSchema",
+  "structured_data_schema",
+]);
+
 /**
  * Recursively converts all keys of an object from camelCase to snake_case.
  * Used for converting user-facing camelCase params to API snake_case payloads.
+ * Values under {@link OPAQUE_VALUE_KEYS} (e.g. `metadata`) are left untouched.
  */
 export function camelToSnakeKeys(obj: any): any {
   if (obj === null || obj === undefined || typeof obj !== "object") return obj;
@@ -26,7 +44,7 @@ export function camelToSnakeKeys(obj: any): any {
   return Object.fromEntries(
     Object.entries(obj).map(([key, value]) => [
       camelToSnake(key),
-      camelToSnakeKeys(value),
+      OPAQUE_VALUE_KEYS.has(key) ? value : camelToSnakeKeys(value),
     ]),
   );
 }
@@ -34,6 +52,7 @@ export function camelToSnakeKeys(obj: any): any {
 /**
  * Recursively converts all keys of an object from snake_case to camelCase.
  * Used for converting API snake_case responses to user-facing camelCase.
+ * Values under {@link OPAQUE_VALUE_KEYS} (e.g. `metadata`) are left untouched.
  */
 export function snakeToCamelKeys(obj: any): any {
   if (obj === null || obj === undefined || typeof obj !== "object") return obj;
@@ -43,7 +62,7 @@ export function snakeToCamelKeys(obj: any): any {
   return Object.fromEntries(
     Object.entries(obj).map(([key, value]) => [
       snakeToCamel(key),
-      snakeToCamelKeys(value),
+      OPAQUE_VALUE_KEYS.has(key) ? value : snakeToCamelKeys(value),
     ]),
   );
 }