chore: add installed langgraph version to js server (#1465)

Co-authored-by: Tat Dat Duong <david@duong.cz>

.changeset/slow-tigers-help.md

@@ -0,0 +1,5 @@
+---
+"@langchain/langgraph-api": patch
+---
+
+add installed langgraph version to info endpoint for js server

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

@@ -12,6 +12,7 @@ const packageJsonPath = path.resolve(
 );
 
 let version: string;
+let langgraph_js_version: string;
 try {
   const packageJson = JSON.parse(await fs.readFile(packageJsonPath, "utf-8"));
   version = packageJson.version;
@@ -19,6 +20,16 @@ try {
   console.warn("Could not determine version of langgraph-api");
 }
 
+// Get the installed version of @langchain/langgraph
+try {
+  const langgraphPkg = await import("@langchain/langgraph/package.json");
+  if (langgraphPkg?.default?.version) {
+    langgraph_js_version = langgraphPkg.default.version;
+  }
+} catch {
+  console.warn("Could not determine version of @langchain/langgraph");
+}
+
 // read env variable
 const env = process.env;
 
@@ -42,6 +53,7 @@ api.get("/info", (c) => {
   })();
   return c.json({
     version,
+    langgraph_js_version,
     context: "js",
     flags: {
       assistants: true,

libs/langgraph-api/src/server.mts

@@ -27,6 +27,7 @@ import { registerHttp } from "./http/custom.mjs";
 import { cors, ensureContentType } from "./http/middleware.mjs";
 import { bindLoopbackFetch } from "./loopback.mjs";
 import { checkLangGraphSemver } from "./semver/index.mjs";
+import { getConfig } from "@langchain/langgraph";
 
 export const StartServerSchema = z.object({
   port: z.number(),
@@ -99,9 +100,6 @@ export async function startServer(options: z.infer<typeof StartServerSchema>) {
   logger.info(`Registering graphs from ${options.cwd}`);
   await registerFromEnv(options.graphs, { cwd: options.cwd });
 
-  // Make sure to register the runtime formatter after we've loaded the graphs
-  // to ensure that we're not loading `@langchain/langgraph` from different path.
-  const { getConfig } = await import("@langchain/langgraph");
   registerRuntimeLogFormatter((info) => {
     const config = getConfig();
     if (config == null) return info;