diff --git a/js/src/client.ts b/js/src/client.ts
index 8c094e7fd..9fe068d5e 100644
--- a/js/src/client.ts
+++ b/js/src/client.ts
@@ -1234,10 +1234,22 @@ export class Client {
 
   public async readRun(
     runId: string,
-    { loadChildRuns }: { loadChildRuns: boolean } = { loadChildRuns: false }
+    {
+      loadChildRuns = false,
+      excludeS3StoredAttributes,
+    }: {
+      loadChildRuns?: boolean;
+      excludeS3StoredAttributes?: boolean;
+    } = {}
   ): Promise<Run> {
     assertUuid(runId);
-    let run = await this._get<Run>(`/runs/${runId}`);
+    const params =
+      excludeS3StoredAttributes !== undefined
+        ? new URLSearchParams({
+            exclude_s3_stored_attributes: excludeS3StoredAttributes.toString(),
+          })
+        : undefined;
+    let run = await this._get<Run>(`/runs/${runId}`, params);
     if (loadChildRuns && run.child_run_ids) {
       run = await this._loadChildRuns(run);
     }
diff --git a/js/src/schemas.ts b/js/src/schemas.ts
index 26afd7fc0..99df09799 100644
--- a/js/src/schemas.ts
+++ b/js/src/schemas.ts
@@ -193,11 +193,14 @@ export interface Run extends BaseRun {
   /** Whether the run is included in a dataset. */
   in_dataset?: boolean;
 
-  /** The output S3 URLs */
-  outputs_s3_urls?: S3URL;
+  /** Dictionary of presigned URLs for output data stored in blob storage, typically for multimedia in LLM runs. */
+  outputs_s3_urls?: Record<string, string>;
 
-  /** The input S3 URLs */
-  inputs_s3_urls?: S3URL;
+  /** Dictionary of presigned URLs for input data stored in blob storage, typically for multimedia in LLM runs. */
+  inputs_s3_urls?: Record<string, string>;
+
+  /** Dictionary of presigned URLs for attachments and oversized extra/error values stored in blob storage. */
+  s3_urls?: Record<string, string>;
 }
 
 export interface RunCreate extends BaseRun {
diff --git a/python/langsmith/client.py b/python/langsmith/client.py
index eb397b4c4..85ceadf5c 100644
--- a/python/langsmith/client.py
+++ b/python/langsmith/client.py
@@ -1740,7 +1740,11 @@ def _load_child_runs(self, run: ls_schemas.Run) -> ls_schemas.Run:
         return run
 
     def read_run(
-        self, run_id: ID_TYPE, load_child_runs: bool = False
+        self,
+        run_id: ID_TYPE,
+        load_child_runs: bool = False,
+        *,
+        exclude_s3_stored_attributes: Optional[bool] = None,
     ) -> ls_schemas.Run:
         """Read a run from the LangSmith API.
 
@@ -1756,8 +1760,13 @@ def read_run(
         Run
             The run.
         """
+        params = (
+            None
+            if exclude_s3_stored_attributes is None
+            else {"exclude_s3_stored_attributes": exclude_s3_stored_attributes}
+        )
         response = self.request_with_retries(
-            "GET", f"/runs/{_as_uuid(run_id, 'run_id')}"
+            "GET", f"/runs/{_as_uuid(run_id, 'run_id')}", params=params
         )
         run = ls_schemas.Run(**response.json(), _host_url=self._host_url)
         if load_child_runs and run.child_run_ids:
diff --git a/python/langsmith/schemas.py b/python/langsmith/schemas.py
index 80e112e46..1e4bf9902 100644
--- a/python/langsmith/schemas.py
+++ b/python/langsmith/schemas.py
@@ -333,6 +333,12 @@ class Run(RunBase):
 
     parent_run_ids: Optional[List[UUID]] = None
     """List of parent run IDs."""
+    inputs_s3_urls: Optional[dict] = None
+    """Dictionary of presigned URLs for input data stored in blob storage, typically for multimedia in LLM runs."""
+    outputs_s3_urls: Optional[dict] = None
+    """Dictionary of presigned URLs for output data stored in blob storage, typically for multimedia in LLM runs."""
+    s3_urls: Optional[dict] = None
+    """Dictionary of presigned URLs for attachments and oversized extra/error values stored in blob storage."""
     trace_id: UUID
     """Unique ID assigned to every run within this nested trace."""
     dotted_order: str = Field(default="")