Restore streaming read chunk limit

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

@@ -916,7 +916,7 @@
           "type": "string"
         },
         "maxBytes": {
-          "description": "Requested upper bound. Values above the server limit are capped.",
+          "description": "Requested upper bound. Values above `maxChunkBytes` are capped.",
           "format": "uint32",
           "minimum": 0.0,
           "type": [

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

@@ -9640,6 +9640,17 @@
       "FsReadFileOpenResponse": {
         "$schema": "http://json-schema.org/draft-07/schema#",
         "description": "Successful response for `fs/readFile/open`.",
+        "properties": {
+          "maxChunkBytes": {
+            "description": "Maximum decoded bytes returned by one read.\n\nClients may use this value to size reusable read buffers.",
+            "format": "uint32",
+            "minimum": 0.0,
+            "type": "integer"
+          }
+        },
+        "required": [
+          "maxChunkBytes"
+        ],
         "title": "FsReadFileOpenResponse",
         "type": "object"
       },
@@ -9670,7 +9681,7 @@
             "type": "string"
           },
           "maxBytes": {
-            "description": "Requested upper bound. Values above the server limit are capped.",
+            "description": "Requested upper bound. Values above `maxChunkBytes` are capped.",
             "format": "uint32",
             "minimum": 0.0,
             "type": [

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

@@ -5982,6 +5982,17 @@
     "FsReadFileOpenResponse": {
       "$schema": "http://json-schema.org/draft-07/schema#",
       "description": "Successful response for `fs/readFile/open`.",
+      "properties": {
+        "maxChunkBytes": {
+          "description": "Maximum decoded bytes returned by one read.\n\nClients may use this value to size reusable read buffers.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": "integer"
+        }
+      },
+      "required": [
+        "maxChunkBytes"
+      ],
       "title": "FsReadFileOpenResponse",
       "type": "object"
     },
@@ -6012,7 +6023,7 @@
           "type": "string"
         },
         "maxBytes": {
-          "description": "Requested upper bound. Values above the server limit are capped.",
+          "description": "Requested upper bound. Values above `maxChunkBytes` are capped.",
           "format": "uint32",
           "minimum": 0.0,
           "type": [

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

@@ -1,6 +1,17 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
   "description": "Successful response for `fs/readFile/open`.",
+  "properties": {
+    "maxChunkBytes": {
+      "description": "Maximum decoded bytes returned by one read.\n\nClients may use this value to size reusable read buffers.",
+      "format": "uint32",
+      "minimum": 0.0,
+      "type": "integer"
+    }
+  },
+  "required": [
+    "maxChunkBytes"
+  ],
   "title": "FsReadFileOpenResponse",
   "type": "object"
 }

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

@@ -6,7 +6,7 @@
       "type": "string"
     },
     "maxBytes": {
-      "description": "Requested upper bound. Values above the server limit are capped.",
+      "description": "Requested upper bound. Values above `maxChunkBytes` are capped.",
       "format": "uint32",
       "minimum": 0.0,
       "type": [

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

@@ -5,4 +5,10 @@
 /**
  * Successful response for `fs/readFile/open`.
  */
-export type FsReadFileOpenResponse = Record<string, never>;
+export type FsReadFileOpenResponse = {
+/**
+ * Maximum decoded bytes returned by one read.
+ *
+ * Clients may use this value to size reusable read buffers.
+ */
+maxChunkBytes: number, };

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

@@ -7,6 +7,6 @@
  */
 export type FsReadFileReadParams = { handleId: string, offset: number,
 /**
- * Requested upper bound. Values above the server limit are capped.
+ * Requested upper bound. Values above `maxChunkBytes` are capped.
  */
 maxBytes?: number | null, };

codex-rs/app-server-protocol/src/protocol/v2/fs.rs

@@ -54,7 +54,12 @@ pub struct FsReadFileOpenParams {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
-pub struct FsReadFileOpenResponse {}
+pub struct FsReadFileOpenResponse {
+    /// Maximum decoded bytes returned by one read.
+    ///
+    /// Clients may use this value to size reusable read buffers.
+    pub max_chunk_bytes: u32,
+}
 
 /// Read a bounded chunk from an open file at an absolute byte offset.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
@@ -64,7 +69,7 @@ pub struct FsReadFileReadParams {
     pub handle_id: String,
     #[ts(type = "number")]
     pub offset: u64,
-    /// Requested upper bound. Values above the server limit are capped.
+    /// Requested upper bound. Values above `maxChunkBytes` are capped.
     #[ts(optional = nullable)]
     pub max_bytes: Option<u32>,
 }