diff --git a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
index aeaff44114..6a4c723bd9 100644
--- a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
+++ b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
@@ -17750,7 +17750,7 @@
             ]
           },
           "defaultPrompt": {
-            "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+            "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
             "items": {
               "type": "string"
             },
diff --git a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
index fbc7f8b5d4..26154496d2 100644
--- a/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
+++ b/codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
@@ -13711,7 +13711,7 @@
           ]
         },
         "defaultPrompt": {
-          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
           "items": {
             "type": "string"
           },
diff --git a/codex-rs/app-server-protocol/schema/json/v2/PluginInstalledResponse.json b/codex-rs/app-server-protocol/schema/json/v2/PluginInstalledResponse.json
index e258544028..322735c1b3 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/PluginInstalledResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/PluginInstalledResponse.json
@@ -118,7 +118,7 @@
           ]
         },
         "defaultPrompt": {
-          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
           "items": {
             "type": "string"
           },
diff --git a/codex-rs/app-server-protocol/schema/json/v2/PluginListResponse.json b/codex-rs/app-server-protocol/schema/json/v2/PluginListResponse.json
index 38207ac285..ce0bb10cdb 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/PluginListResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/PluginListResponse.json
@@ -118,7 +118,7 @@
           ]
         },
         "defaultPrompt": {
-          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
           "items": {
             "type": "string"
           },
diff --git a/codex-rs/app-server-protocol/schema/json/v2/PluginReadResponse.json b/codex-rs/app-server-protocol/schema/json/v2/PluginReadResponse.json
index 2123c0b8eb..62720874cc 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/PluginReadResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/PluginReadResponse.json
@@ -325,7 +325,7 @@
           ]
         },
         "defaultPrompt": {
-          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
           "items": {
             "type": "string"
           },
diff --git a/codex-rs/app-server-protocol/schema/json/v2/PluginShareListResponse.json b/codex-rs/app-server-protocol/schema/json/v2/PluginShareListResponse.json
index bcae24d57c..448a856439 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/PluginShareListResponse.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/PluginShareListResponse.json
@@ -92,7 +92,7 @@
           ]
         },
         "defaultPrompt": {
-          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+          "description": "Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
           "items": {
             "type": "string"
           },
diff --git a/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-experimental.json.zst b/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-experimental.json.zst
index 2317f2c209..a1d1ca3642 100644
Binary files a/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-experimental.json.zst and b/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-experimental.json.zst differ
diff --git a/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-stable.json.zst b/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-stable.json.zst
index c35c1e5ff0..47a33c0d68 100644
Binary files a/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-stable.json.zst and b/codex-rs/app-server-protocol/schema/precomputed/app-server-exports-stable.json.zst differ
diff --git a/codex-rs/app-server-protocol/schema/typescript/v2/PluginInterface.ts b/codex-rs/app-server-protocol/schema/typescript/v2/PluginInterface.ts
index 1e57d4974d..e32dcf10be 100644
--- a/codex-rs/app-server-protocol/schema/typescript/v2/PluginInterface.ts
+++ b/codex-rs/app-server-protocol/schema/typescript/v2/PluginInterface.ts
@@ -6,7 +6,7 @@ import type { AbsolutePathBuf } from "../AbsolutePathBuf";
 export type PluginInterface = { displayName: string | null, shortDescription: string | null, longDescription: string | null, developerName: string | null, category: string | null, capabilities: Array<string>, websiteUrl: string | null, privacyPolicyUrl: string | null, termsOfServiceUrl: string | null,
 /**
  * Starter prompts for the plugin. Capped at 3 entries with a maximum of
- * 128 characters per entry.
+ * 512 characters per entry.
  */
 defaultPrompt: Array<string> | null, brandColor: string | null,
 /**
diff --git a/codex-rs/app-server-protocol/src/protocol/v2/plugin.rs b/codex-rs/app-server-protocol/src/protocol/v2/plugin.rs
index ad368abead..05c1665af6 100644
--- a/codex-rs/app-server-protocol/src/protocol/v2/plugin.rs
+++ b/codex-rs/app-server-protocol/src/protocol/v2/plugin.rs
@@ -882,7 +882,7 @@ pub struct PluginInterface {
     pub privacy_policy_url: Option<String>,
     pub terms_of_service_url: Option<String>,
     /// Starter prompts for the plugin. Capped at 3 entries with a maximum of
-    /// 128 characters per entry.
+    /// 512 characters per entry.
     pub default_prompt: Option<Vec<String>>,
     pub brand_color: Option<String>,
     /// Local composer icon path, resolved from the installed plugin package.
diff --git a/codex-rs/core-plugins/src/discoverable_tests.rs b/codex-rs/core-plugins/src/discoverable_tests.rs
index 1821f6d823..5642ee211e 100644
--- a/codex-rs/core-plugins/src/discoverable_tests.rs
+++ b/codex-rs/core-plugins/src/discoverable_tests.rs
@@ -647,7 +647,7 @@ async fn discovery_warns_once_per_invalid_manifest() {
     write_openai_curated_marketplace(&curated_root, &["slack", "gmail", "openai-developers"]);
     install_marketplace_plugin(codex_home.path(), curated_root.as_path(), "slack").await;
 
-    let too_long_prompt = "x".repeat(129);
+    let too_long_prompt = "x".repeat(513);
     for plugin_name in ["gmail", "openai-developers"] {
         write_file(
             &curated_root.join(format!("plugins/{plugin_name}/.codex-plugin/plugin.json")),
diff --git a/codex-rs/core-plugins/src/manifest.rs b/codex-rs/core-plugins/src/manifest.rs
index a532660dde..854768f8ba 100644
--- a/codex-rs/core-plugins/src/manifest.rs
+++ b/codex-rs/core-plugins/src/manifest.rs
@@ -14,7 +14,7 @@ use std::path::PathBuf;
 mod manifest_cache;
 pub(crate) use manifest_cache::ManifestCache;
 const MAX_DEFAULT_PROMPT_COUNT: usize = 3;
-const MAX_DEFAULT_PROMPT_LEN: usize = 128;
+const MAX_DEFAULT_PROMPT_LEN: usize = 512;
 
 #[path = "agent_plugin_manifest.rs"]
 mod agent_plugin_manifest;
@@ -739,6 +739,7 @@ mod tests {
     fn plugin_interface_normalizes_default_prompt_array() {
         let tmp = tempdir().expect("tempdir");
         let plugin_root = tmp.path().join("demo-plugin");
+        let at_limit = "é".repeat(MAX_DEFAULT_PROMPT_LEN);
         let too_long = "x".repeat(MAX_DEFAULT_PROMPT_LEN + 1);
         write_manifest(
             &plugin_root,
@@ -747,7 +748,7 @@ mod tests {
                 r#"{{
     "displayName": "Demo Plugin",
     "defaultPrompt": [
-      " Summarize my inbox ",
+      " {at_limit} ",
       123,
       "{too_long}",
       "   ",
@@ -765,7 +766,7 @@ mod tests {
         assert_eq!(
             interface.default_prompt,
             Some(vec![
-                "Summarize my inbox".to_string(),
+                at_limit,
                 "Draft the reply".to_string(),
                 "Find my next action".to_string(),
             ])
diff --git a/sdk/python/src/openai_codex/generated/v2_all.py b/sdk/python/src/openai_codex/generated/v2_all.py
index 914cd5f063..5a839ab215 100644
--- a/sdk/python/src/openai_codex/generated/v2_all.py
+++ b/sdk/python/src/openai_codex/generated/v2_all.py
@@ -3376,7 +3376,7 @@ class PluginInterface(BaseModel):
         list[str] | None,
         Field(
             alias="defaultPrompt",
-            description="Starter prompts for the plugin. Capped at 3 entries with a maximum of 128 characters per entry.",
+            description="Starter prompts for the plugin. Capped at 3 entries with a maximum of 512 characters per entry.",
         ),
     ] = None
     developer_name: Annotated[str | None, Field(alias="developerName")] = None