diff --git a/libs/sdk-js/package.json b/libs/sdk-js/package.json
index 342b2c95a..71a0976bb 100644
--- a/libs/sdk-js/package.json
+++ b/libs/sdk-js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@langchain/langgraph-sdk",
-  "version": "0.0.19",
+  "version": "0.0.20",
   "description": "Client library for interacting with the LangGraph API",
   "type": "module",
   "packageManager": "yarn@1.22.19",
diff --git a/libs/sdk-js/src/client.ts b/libs/sdk-js/src/client.ts
index ae376fc70..32e75017b 100644
--- a/libs/sdk-js/src/client.ts
+++ b/libs/sdk-js/src/client.ts
@@ -160,6 +160,7 @@ export class CronsClient extends BaseClient {
       interrupt_after: payload?.interruptAfter,
       webhook: payload?.webhook,
       multitask_strategy: payload?.multitaskStrategy,
+      if_not_exists: payload?.ifNotExists,
     };
     return this.fetch<Run>(`/threads/${threadId}/runs/crons`, {
       method: "POST",
@@ -187,6 +188,7 @@ export class CronsClient extends BaseClient {
       interrupt_after: payload?.interruptAfter,
       webhook: payload?.webhook,
       multitask_strategy: payload?.multitaskStrategy,
+      if_not_exists: payload?.ifNotExists,
     };
     return this.fetch<Run>(`/runs/crons`, {
       method: "POST",
@@ -698,6 +700,7 @@ export class RunsClient extends BaseClient {
       on_completion: payload?.onCompletion,
       on_disconnect: payload?.onDisconnect,
       after_seconds: payload?.afterSeconds,
+      if_not_exists: payload?.ifNotExists,
     };
 
     const endpoint =
@@ -779,6 +782,7 @@ export class RunsClient extends BaseClient {
       checkpoint_id: payload?.checkpointId,
       multitask_strategy: payload?.multitaskStrategy,
       after_seconds: payload?.afterSeconds,
+      if_not_exists: payload?.ifNotExists,
     };
     return this.fetch<Run>(`/threads/${threadId}/runs`, {
       method: "POST",
@@ -849,6 +853,7 @@ export class RunsClient extends BaseClient {
       on_completion: payload?.onCompletion,
       on_disconnect: payload?.onDisconnect,
       after_seconds: payload?.afterSeconds,
+      if_not_exists: payload?.ifNotExists,
     };
     const endpoint =
       threadId == null ? `/runs/wait` : `/threads/${threadId}/runs/wait`;
diff --git a/libs/sdk-js/src/types.ts b/libs/sdk-js/src/types.ts
index 2ac87dba2..3f4e90764 100644
--- a/libs/sdk-js/src/types.ts
+++ b/libs/sdk-js/src/types.ts
@@ -95,6 +95,11 @@ interface RunsInvokePayload {
    * Use to schedule future runs.
    */
   afterSeconds?: number;
+
+  /**
+   * Behavior if the specified run doesn't exist. Defaults to "reject".
+   */
+  ifNotExists?: "create" | "reject";
 }
 
 export interface RunsStreamPayload extends RunsInvokePayload {