diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 72a383a608..e1b0dbd576 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -885,6 +885,7 @@ export type CompactionPart = {
   type: "compaction"
   auto: boolean
   overflow?: boolean
+  tail_start_id?: string
 }
 
 export type Part =
@@ -1642,6 +1643,14 @@ export type Config = {
      * Enable pruning of old tool outputs (default: true)
      */
     prune?: boolean
+    /**
+     * Number of recent user turns, including their following assistant/tool responses, to keep verbatim during compaction (default: 2)
+     */
+    tail_turns?: number
+    /**
+     * Token budget for retained recent turn spans during compaction
+     */
+    tail_tokens?: number
     /**
      * Token buffer for compaction. Leaves enough window to avoid overflow during compaction.
      */
diff --git a/packages/sdk/openapi.json b/packages/sdk/openapi.json
index b97d596b93..3ecb725d6d 100644
--- a/packages/sdk/openapi.json
+++ b/packages/sdk/openapi.json
@@ -9945,6 +9945,10 @@
           },
           "overflow": {
             "type": "boolean"
+          },
+          "tail_start_id": {
+            "type": "string",
+            "pattern": "^msg.*"
           }
         },
         "required": ["id", "sessionID", "messageID", "type", "auto"]
@@ -11868,6 +11872,18 @@
                 "description": "Enable pruning of old tool outputs (default: true)",
                 "type": "boolean"
               },
+              "tail_turns": {
+                "description": "Number of recent user turns, including their following assistant/tool responses, to keep verbatim during compaction (default: 2)",
+                "type": "integer",
+                "minimum": 0,
+                "maximum": 9007199254740991
+              },
+              "tail_tokens": {
+                "description": "Token budget for retained recent turn spans during compaction",
+                "type": "integer",
+                "minimum": 0,
+                "maximum": 9007199254740991
+              },
               "reserved": {
                 "description": "Token buffer for compaction. Leaves enough window to avoid overflow during compaction.",
                 "type": "integer",