Feat: cxa-1833 update model/list (#12958)

### Summary
Update `model/list` in app server to include more upgrade information.

Author: shijie-oai

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

@@ -10271,6 +10271,16 @@
               "string",
               "null"
             ]
+          },
+          "upgradeInfo": {
+            "anyOf": [
+              {
+                "$ref": "#/definitions/v2/ModelUpgradeInfo"
+              },
+              {
+                "type": "null"
+              }
+            ]
           }
         },
         "required": [
@@ -10373,6 +10383,35 @@
         "title": "ModelReroutedNotification",
         "type": "object"
       },
+      "ModelUpgradeInfo": {
+        "properties": {
+          "migrationMarkdown": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "model": {
+            "type": "string"
+          },
+          "modelLink": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "upgradeCopy": {
+            "type": [
+              "string",
+              "null"
+            ]
+          }
+        },
+        "required": [
+          "model"
+        ],
+        "type": "object"
+      },
       "NetworkAccess": {
         "enum": [
           "restricted",

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

@@ -68,6 +68,16 @@
             "string",
             "null"
           ]
+        },
+        "upgradeInfo": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/ModelUpgradeInfo"
+            },
+            {
+              "type": "null"
+            }
+          ]
         }
       },
       "required": [
@@ -82,6 +92,35 @@
       ],
       "type": "object"
     },
+    "ModelUpgradeInfo": {
+      "properties": {
+        "migrationMarkdown": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "model": {
+          "type": "string"
+        },
+        "modelLink": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "upgradeCopy": {
+          "type": [
+            "string",
+            "null"
+          ]
+        }
+      },
+      "required": [
+        "model"
+      ],
+      "type": "object"
+    },
     "ReasoningEffort": {
       "description": "See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#get-started-with-reasoning",
       "enum": [

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

@@ -3,6 +3,7 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { InputModality } from "../InputModality";
 import type { ReasoningEffort } from "../ReasoningEffort";
+import type { ModelUpgradeInfo } from "./ModelUpgradeInfo";
 import type { ReasoningEffortOption } from "./ReasoningEffortOption";
 
-export type Model = { id: string, model: string, upgrade: string | null, displayName: string, description: string, hidden: boolean, supportedReasoningEfforts: Array<ReasoningEffortOption>, defaultReasoningEffort: ReasoningEffort, inputModalities: Array<InputModality>, supportsPersonality: boolean, isDefault: boolean, };
+export type Model = { id: string, model: string, upgrade: string | null, upgradeInfo: ModelUpgradeInfo | null, displayName: string, description: string, hidden: boolean, supportedReasoningEfforts: Array<ReasoningEffortOption>, defaultReasoningEffort: ReasoningEffort, inputModalities: Array<InputModality>, supportsPersonality: boolean, isDefault: boolean, };

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

@@ -0,0 +1,5 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export type ModelUpgradeInfo = { model: string, upgradeCopy: string | null, modelLink: string | null, migrationMarkdown: string | null, };

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

@@ -111,6 +111,7 @@ export type { ModelListParams } from "./ModelListParams";
 export type { ModelListResponse } from "./ModelListResponse";
 export type { ModelRerouteReason } from "./ModelRerouteReason";
 export type { ModelReroutedNotification } from "./ModelReroutedNotification";
+export type { ModelUpgradeInfo } from "./ModelUpgradeInfo";
 export type { NetworkAccess } from "./NetworkAccess";
 export type { NetworkApprovalContext } from "./NetworkApprovalContext";
 export type { NetworkApprovalProtocol } from "./NetworkApprovalProtocol";

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

@@ -1396,6 +1396,7 @@ pub struct Model {
     pub id: String,
     pub model: String,
     pub upgrade: Option<String>,
+    pub upgrade_info: Option<ModelUpgradeInfo>,
     pub display_name: String,
     pub description: String,
     pub hidden: bool,
@@ -1409,6 +1410,16 @@ pub struct Model {
     pub is_default: bool,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ModelUpgradeInfo {
+    pub model: String,
+    pub upgrade_copy: Option<String>,
+    pub model_link: Option<String>,
+    pub migration_markdown: Option<String>,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]

codex-rs/app-server/README.md

@@ -142,7 +142,7 @@ Example with notification opt-out:
 - `thread/realtime/stop` — stop the active realtime session for the thread (experimental); returns `{}`.
 - `review/start` — kick off Codex’s automated reviewer for a thread; responds like `turn/start` and emits `item/started`/`item/completed` notifications with `enteredReviewMode` and `exitedReviewMode` items, plus a final assistant `agentMessage` containing the review.
 - `command/exec` — run a single command under the server sandbox without starting a thread/turn (handy for utilities and validation).
-- `model/list` — list available models (set `includeHidden: true` to include entries with `hidden: true`), with reasoning effort options and optional `upgrade` model ids.
+- `model/list` — list available models (set `includeHidden: true` to include entries with `hidden: true`), with reasoning effort options, optional legacy `upgrade` model ids, and optional `upgradeInfo` metadata (`model`, `upgradeCopy`, `modelLink`, `migrationMarkdown`).
 - `experimentalFeature/list` — list feature flags with stage metadata (`beta`, `underDevelopment`, `stable`, etc.), enabled/default-enabled state, and cursor pagination. For non-beta flags, `displayName`/`description`/`announcement` are `null`.
 - `collaborationMode/list` — list available collaboration mode presets (experimental, no pagination). This response omits built-in developer instructions; clients should either pass `settings.developer_instructions: null` when setting a mode to use Codex's built-in instructions, or provide their own instructions explicitly.
 - `skills/list` — list skills for one or more `cwd` values (optional `forceReload`).

codex-rs/app-server/src/models.rs

@@ -1,6 +1,7 @@
 use std::sync::Arc;
 
 use codex_app_server_protocol::Model;
+use codex_app_server_protocol::ModelUpgradeInfo;
 use codex_app_server_protocol::ReasoningEffortOption;
 use codex_core::ThreadManager;
 use codex_core::models_manager::manager::RefreshStrategy;
@@ -24,7 +25,13 @@ fn model_from_preset(preset: ModelPreset) -> Model {
     Model {
         id: preset.id.to_string(),
         model: preset.model.to_string(),
-        upgrade: preset.upgrade.map(|upgrade| upgrade.id),
+        upgrade: preset.upgrade.as_ref().map(|upgrade| upgrade.id.clone()),
+        upgrade_info: preset.upgrade.as_ref().map(|upgrade| ModelUpgradeInfo {
+            model: upgrade.id.clone(),
+            upgrade_copy: upgrade.upgrade_copy.clone(),
+            model_link: upgrade.model_link.clone(),
+            migration_markdown: upgrade.migration_markdown.clone(),
+        }),
         display_name: preset.display_name.to_string(),
         description: preset.description.to_string(),
         hidden: !preset.show_in_picker,

codex-rs/app-server/tests/suite/v2/model_list.rs

@@ -9,6 +9,7 @@ use codex_app_server_protocol::JSONRPCResponse;
 use codex_app_server_protocol::Model;
 use codex_app_server_protocol::ModelListParams;
 use codex_app_server_protocol::ModelListResponse;
+use codex_app_server_protocol::ModelUpgradeInfo;
 use codex_app_server_protocol::ReasoningEffortOption;
 use codex_app_server_protocol::RequestId;
 use codex_protocol::openai_models::ModelPreset;
@@ -24,6 +25,12 @@ fn model_from_preset(preset: &ModelPreset) -> Model {
         id: preset.id.clone(),
         model: preset.model.clone(),
         upgrade: preset.upgrade.as_ref().map(|upgrade| upgrade.id.clone()),
+        upgrade_info: preset.upgrade.as_ref().map(|upgrade| ModelUpgradeInfo {
+            model: upgrade.id.clone(),
+            upgrade_copy: upgrade.upgrade_copy.clone(),
+            model_link: upgrade.model_link.clone(),
+            migration_markdown: upgrade.migration_markdown.clone(),
+        }),
         display_name: preset.display_name.clone(),
         description: preset.description.clone(),
         hidden: !preset.show_in_picker,
@@ -127,6 +134,50 @@ async fn list_models_includes_hidden_models() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn list_models_returns_upgrade_info_metadata() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    write_models_cache(codex_home.path())?;
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+
+    timeout(DEFAULT_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_list_models_request(ModelListParams {
+            limit: Some(100),
+            cursor: None,
+            include_hidden: Some(true),
+        })
+        .await?;
+
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+
+    let ModelListResponse { data: items, .. } = to_response::<ModelListResponse>(response)?;
+
+    let item = items
+        .iter()
+        .find(|item| item.upgrade_info.is_some())
+        .expect("expected at least one model with upgrade info");
+    let upgrade_info = item
+        .upgrade_info
+        .as_ref()
+        .expect("expected upgrade info to be populated");
+
+    assert_eq!(item.upgrade.as_ref(), Some(&upgrade_info.model));
+    assert!(!upgrade_info.model.is_empty());
+    assert!(
+        upgrade_info.upgrade_copy.is_some()
+            || upgrade_info.model_link.is_some()
+            || upgrade_info.migration_markdown.is_some()
+    );
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn list_models_pagination_works() -> Result<()> {
     let codex_home = TempDir::new()?;

codex-rs/docs/codex_mcp_interface.md

@@ -90,20 +90,26 @@ directory (it returns the restored thread summary).
 
 Fetch the catalog of models available in the current Codex build with `model/list`. The request accepts optional pagination inputs:
 
-- `pageSize` – number of models to return (defaults to a server-selected value)
+- `limit` – number of models to return (defaults to a server-selected value)
 - `cursor` – opaque string from the previous response’s `nextCursor`
 
 Each response yields:
 
-- `items` – ordered list of models. A model includes:
+- `data` – ordered list of models. A model includes:
   - `id`, `model`, `displayName`, `description`
   - `supportedReasoningEfforts` – array of objects with:
-    - `reasoningEffort` – one of `minimal|low|medium|high`
+    - `reasoningEffort` – one of `none|minimal|low|medium|high|xhigh`
     - `description` – human-friendly label for the effort
   - `defaultReasoningEffort` – suggested effort for the UI
+  - `inputModalities` – accepted input types for the model
   - `supportsPersonality` – whether the model supports personality-specific instructions
   - `isDefault` – whether the model is recommended for most users
   - `upgrade` – optional recommended upgrade model id
+  - `upgradeInfo` – optional upgrade metadata object with:
+    - `model` – recommended upgrade model id
+    - `upgradeCopy` – optional display copy for the upgrade recommendation
+    - `modelLink` – optional link for the upgrade recommendation
+    - `migrationMarkdown` – optional markdown shown when presenting the upgrade
 - `nextCursor` – pass into the next request to continue paging (optional)
 
 ## Collaboration modes (experimental)