Add excludeTurns parameter to thread/resume and thread/fork (#19014)

For callers who expect to be paginating the results for the UI, they can
now call thread/resume or thread/fork with excludeturns:true so it will
not fetch any pages of turns, and instead only set up the subscription.
That call can be immediately followed by pagination requests to
thread/turns/list to fetch pages of turns according to the UI's current
interactions.

codex-rs/app-server-protocol/schema/json/ClientRequest.json

@@ -3312,6 +3312,10 @@
         "ephemeral": {
           "type": "boolean"
         },
+        "excludeTurns": {
+          "description": "When true, return only thread metadata and live fork state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after forking.",
+          "type": "boolean"
+        },
         "model": {
           "description": "Configuration overrides for the forked thread, if any.",
           "type": [
@@ -3715,6 +3719,10 @@
             "null"
           ]
         },
+        "excludeTurns": {
+          "description": "When true, return only thread metadata and live-resume state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after resuming.",
+          "type": "boolean"
+        },
         "model": {
           "description": "Configuration overrides for the resumed thread, if any.",
           "type": [

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -14356,6 +14356,10 @@
           "ephemeral": {
             "type": "boolean"
           },
+          "excludeTurns": {
+            "description": "When true, return only thread metadata and live fork state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after forking.",
+            "type": "boolean"
+          },
           "model": {
             "description": "Configuration overrides for the forked thread, if any.",
             "type": [
@@ -15785,6 +15789,10 @@
               "null"
             ]
           },
+          "excludeTurns": {
+            "description": "When true, return only thread metadata and live-resume state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after resuming.",
+            "type": "boolean"
+          },
           "model": {
             "description": "Configuration overrides for the resumed thread, if any.",
             "type": [

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -12243,6 +12243,10 @@
         "ephemeral": {
           "type": "boolean"
         },
+        "excludeTurns": {
+          "description": "When true, return only thread metadata and live fork state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after forking.",
+          "type": "boolean"
+        },
         "model": {
           "description": "Configuration overrides for the forked thread, if any.",
           "type": [
@@ -13672,6 +13676,10 @@
             "null"
           ]
         },
+        "excludeTurns": {
+          "description": "When true, return only thread metadata and live-resume state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after resuming.",
+          "type": "boolean"
+        },
         "model": {
           "description": "Configuration overrides for the resumed thread, if any.",
           "type": [

codex-rs/app-server-protocol/schema/json/v2/ThreadForkParams.json

@@ -400,6 +400,10 @@
     "ephemeral": {
       "type": "boolean"
     },
+    "excludeTurns": {
+      "description": "When true, return only thread metadata and live fork state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after forking.",
+      "type": "boolean"
+    },
     "model": {
       "description": "Configuration overrides for the forked thread, if any.",
       "type": [

codex-rs/app-server-protocol/schema/json/v2/ThreadResumeParams.json

@@ -1313,6 +1313,10 @@
         "null"
       ]
     },
+    "excludeTurns": {
+      "description": "When true, return only thread metadata and live-resume state without populating `thread.turns`. This is useful when the client plans to call `thread/turns/list` immediately after resuming.",
+      "type": "boolean"
+    },
     "model": {
       "description": "Configuration overrides for the resumed thread, if any.",
       "type": [

codex-rs/app-server-protocol/schema/typescript/v2/ThreadForkParams.ts

@@ -33,6 +33,11 @@ approvalsReviewer?: ApprovalsReviewer | null, sandbox?: SandboxMode | null, /**
  * with `sandbox`.
  */
 permissionProfile?: PermissionProfile | null, config?: { [key in string]?: JsonValue } | null, baseInstructions?: string | null, developerInstructions?: string | null, ephemeral?: boolean, /**
+ * When true, return only thread metadata and live fork state without
+ * populating `thread.turns`. This is useful when the client plans to call
+ * `thread/turns/list` immediately after forking.
+ */
+excludeTurns?: boolean, /**
  * If true, persist additional rollout EventMsg variants required to
  * reconstruct a richer thread history on subsequent resume/fork/read.
  */

codex-rs/app-server-protocol/schema/typescript/v2/ThreadResumeParams.ts

@@ -42,6 +42,11 @@ approvalsReviewer?: ApprovalsReviewer | null, sandbox?: SandboxMode | null, /**
  * with `sandbox`.
  */
 permissionProfile?: PermissionProfile | null, config?: { [key in string]?: JsonValue } | null, baseInstructions?: string | null, developerInstructions?: string | null, personality?: Personality | null, /**
+ * When true, return only thread metadata and live-resume state without
+ * populating `thread.turns`. This is useful when the client plans to call
+ * `thread/turns/list` immediately after resuming.
+ */
+excludeTurns?: boolean, /**
  * If true, persist additional rollout EventMsg variants required to
  * reconstruct a richer thread history on subsequent resume/fork/read.
  */