chore: update oss API spec to match python (#1726)

Co-authored-by: Hunter Lovell <40191806+hntrl@users.noreply.github.com>

.changeset/tough-hounds-hope.md

@@ -0,0 +1,5 @@
+---
+"@langchain/langgraph-api": patch
+---
+
+Update API spec to match python api

libs/langgraph-api/src/api/threads.mts

@@ -68,7 +68,13 @@ api.post(
         total = item.total;
       }
     }
-    c.res.headers.set("X-Pagination-Total", total.toString());
+    const nextOffset = (payload.offset ?? 0) + total;
+    if (total === payload.limit) {
+      c.res.headers.set("X-Pagination-Next", nextOffset.toString());
+      c.res.headers.set("X-Pagination-Total", (nextOffset + 1).toString());
+    } else {
+      c.res.headers.set("X-Pagination-Total", nextOffset.toString());
+    }
     return jsonExtra(c, result);
   }
 );

libs/langgraph-api/src/storage/ops.mts

@@ -367,7 +367,7 @@ export class FileSystemAssistants implements AssistantsRepo {
         graph_id: options.graph_id,
         metadata: mutable.metadata ?? ({} as Metadata),
         name: options.name || options.graph_id,
-        description: options.description,
+        description: options.description ?? null,
       };
 
       STORE.assistant_versions.push({
@@ -379,7 +379,7 @@ export class FileSystemAssistants implements AssistantsRepo {
         metadata: mutable.metadata ?? ({} as Metadata),
         created_at: now,
         name: options.name || options.graph_id,
-        description: options.description,
+        description: options.description ?? null,
       });
 
       return STORE.assistants[assistant_id];

libs/langgraph-api/src/storage/types.mts

@@ -82,8 +82,8 @@ export interface RunnableConfig {
 }
 
 export interface Assistant {
-  name: string | undefined;
-  description: string | undefined;
+  name: string;
+  description: string | null;
   assistant_id: string;
   graph_id: string;
   created_at: Date;
@@ -102,8 +102,8 @@ export interface AssistantVersion {
   context: unknown;
   metadata: Metadata;
   created_at: Date;
-  name: string | undefined;
-  description: string | undefined;
+  name: string;
+  description: string | null;
 }
 
 export interface RunKwargs {