feat(api): add support for dynamically created graphs via runnable config

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

@@ -109,9 +109,10 @@ api.get(
     const assistant = await Assistants.get(assistantId);
     const { xray } = c.req.valid("query");
 
-    const graph = getGraph(assistant.graph_id);
+    const config = getRunnableConfig(assistant.config);
+    const graph = await getGraph(assistant.graph_id, config);
     const drawable = await graph.getGraphAsync({
-      ...getRunnableConfig(assistant.config),
+      ...config,
       xray: xray ?? undefined,
     });
     return c.json(drawable.toJSON());
@@ -152,7 +153,9 @@ api.get(
 
     const assistantId = getAssistantId(assistant_id);
     const assistant = await Assistants.get(assistantId);
-    const graph = getGraph(assistant.graph_id);
+
+    const config = getRunnableConfig(assistant.config);
+    const graph = await getGraph(assistant.graph_id, config);
 
     const graphSchema = await getGraphSchema(assistant.graph_id);
     const rootGraphId = Object.keys(graphSchema).find((i) => !i.includes("|"));

libs/langgraph-api/src/graph/load.mts

@@ -6,9 +6,11 @@ import type {
   BaseCheckpointSaver,
   BaseStore,
   CompiledGraph,
+  LangGraphRunnableConfig,
 } from "@langchain/langgraph";
 import { HTTPException } from "hono/http-exception";
 import {
+  type CompiledGraphFactory,
   type GraphSchema,
   type GraphSpec,
   resolveGraph,
@@ -18,7 +20,10 @@ import { checkpointer } from "../storage/checkpoint.mjs";
 import { store } from "../storage/store.mjs";
 import { logger } from "../logging.mjs";
 
-export const GRAPHS: Record<string, CompiledGraph<string>> = {};
+export const GRAPHS: Record<
+  string,
+  CompiledGraph<string> | CompiledGraphFactory<string>
+> = {};
 export const GRAPH_SPEC: Record<string, GraphSpec> = {};
 export const GRAPH_SCHEMA: Record<string, Record<string, GraphSchema>> = {};
 
@@ -69,8 +74,9 @@ export async function registerFromEnv(
   );
 }
 
-export function getGraph(
+export async function getGraph(
   graphId: string,
+  config: LangGraphRunnableConfig | undefined,
   options?: {
     checkpointer?: BaseCheckpointSaver | null;
     store?: BaseStore;
@@ -79,9 +85,11 @@ export function getGraph(
   if (!GRAPHS[graphId])
     throw new HTTPException(404, { message: `Graph "${graphId}" not found` });
 
-  // TODO: have a check for the type of graph
+  const compiled =
+    typeof GRAPHS[graphId] === "function"
+      ? await GRAPHS[graphId](config ?? { configurable: {} })
+      : GRAPHS[graphId];
 
-  const compiled = GRAPHS[graphId];
   if (typeof options?.checkpointer !== "undefined") {
     compiled.checkpointer = options?.checkpointer ?? undefined;
   } else {

libs/langgraph-api/src/graph/load.utils.mts

@@ -23,13 +23,17 @@ export interface GraphSpec {
   exportSymbol: string;
 }
 
+export type CompiledGraphFactory<T extends string> = (config: {
+  configurable?: Record<string, unknown>;
+}) => Promise<CompiledGraph<T>>;
+
 export async function resolveGraph(
   spec: string,
   options: { cwd: string; onlyFilePresence?: false },
 ): Promise<{
   sourceFile: string;
   exportSymbol: string;
-  resolved: CompiledGraph<string>;
+  resolved: CompiledGraph<string> | CompiledGraphFactory<string>;
 }>;
 
 export async function resolveGraph(
@@ -55,7 +59,9 @@ export async function resolveGraph(
   type GraphUnknown =
     | GraphLike
     | Promise<GraphLike>
-    | (() => GraphLike | Promise<GraphLike>)
+    | ((config: {
+        configurable?: Record<string, unknown>;
+      }) => GraphLike | Promise<GraphLike>)
     | undefined;
 
   const isGraph = (graph: GraphLike): graph is Graph<string> => {
@@ -68,13 +74,24 @@ export async function resolveGraph(
   ).then((module) => module[exportSymbol || "default"]);
 
   // obtain the graph, and if not compiled, compile it
-  const resolved: CompiledGraph<string> = await (async () => {
-    if (!graph) throw new Error("Failed to load graph: graph is nullush");
-    const graphLike = typeof graph === "function" ? await graph() : await graph;
+  const resolved: CompiledGraph<string> | CompiledGraphFactory<string> =
+    await (async () => {
+      if (!graph) throw new Error("Failed to load graph: graph is nullush");
 
-    if (isGraph(graphLike)) return graphLike.compile();
-    return graphLike;
-  })();
+      const afterResolve = (graphLike: GraphLike): CompiledGraph<string> => {
+        const graph = isGraph(graphLike) ? graphLike.compile() : graphLike;
+        return graph;
+      };
+
+      if (typeof graph === "function") {
+        return async (config: { configurable?: Record<string, unknown> }) => {
+          const graphLike = await graph(config);
+          return afterResolve(graphLike);
+        };
+      }
+
+      return afterResolve(await graph);
+    })();
 
   return { sourceFile, exportSymbol, resolved };
 }

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

@@ -803,7 +803,10 @@ export class Threads {
         };
       }
 
-      const graph = await getGraph(graphId, { checkpointer, store });
+      const graph = await getGraph(graphId, thread.config, {
+        checkpointer,
+        store,
+      });
       const result = await graph.getState(config, { subgraphs });
 
       if (
@@ -843,7 +846,10 @@ export class Threads {
       config.configurable ??= {};
       config.configurable.graph_id ??= graphId;
 
-      const graph = await getGraph(graphId, { checkpointer, store });
+      const graph = await getGraph(graphId, thread.config, {
+        checkpointer,
+        store,
+      });
 
       const updateConfig = structuredClone(config);
       updateConfig.configurable ??= {};
@@ -894,7 +900,10 @@ export class Threads {
       config.configurable ??= {};
       config.configurable.graph_id ??= graphId;
 
-      const graph = await getGraph(graphId, { checkpointer, store });
+      const graph = await getGraph(graphId, thread.config, {
+        checkpointer,
+        store,
+      });
 
       const updateConfig = structuredClone(config);
       updateConfig.configurable ??= {};
@@ -940,7 +949,10 @@ export class Threads {
       const graphId = thread.metadata?.graph_id as string | undefined | null;
       if (graphId == null) return [];
 
-      const graph = await getGraph(graphId, { checkpointer, store });
+      const graph = await getGraph(graphId, thread.config, {
+        checkpointer,
+        store,
+      });
       const before: RunnableConfig | undefined =
         typeof options?.before === "string"
           ? { configurable: { checkpoint_id: options.before } }

libs/langgraph-api/src/stream.mts

@@ -153,7 +153,7 @@ export async function* streamState(
     throw new Error("Invalid or missing graph_id");
   }
 
-  const graph = getGraph(graphId, {
+  const graph = await getGraph(graphId, kwargs.config, {
     checkpointer: kwargs.temporary ? null : undefined,
   });