Expose multi-agent versions in model/list (#37433)

## What changed

- Add nullable `multiAgentVersion` metadata to v2 `model/list` responses.
- Represent supported values as `disabled`, `v1`, or `v2` in the Rust API and generated JSON Schema and TypeScript exports.
- Forward the value from model catalog presets through app-server responses.

## Testing

- Extend the remote model catalog test fixture with a `v2` multi-agent version.

GitOrigin-RevId: bd3b2bbe0a3b562b4d1f03df7da2a73a35713978

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

@@ -13590,6 +13590,17 @@
               "null"
             ]
           },
+          "multiAgentVersion": {
+            "anyOf": [
+              {
+                "$ref": "#/definitions/v2/MultiAgentVersion"
+              },
+              {
+                "type": "null"
+              }
+            ],
+            "description": "Multi-agent runtime declared by this model, when available."
+          },
           "serviceTiers": {
             "default": [],
             "items": {
@@ -13924,6 +13935,15 @@
           }
         ]
       },
+      "MultiAgentVersion": {
+        "description": "Multi-agent runtime supported by a model.",
+        "enum": [
+          "disabled",
+          "v1",
+          "v2"
+        ],
+        "type": "string"
+      },
       "NetworkAccess": {
         "enum": [
           "restricted",

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

@@ -9927,6 +9927,17 @@
             "null"
           ]
         },
+        "multiAgentVersion": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/MultiAgentVersion"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "description": "Multi-agent runtime declared by this model, when available."
+        },
         "serviceTiers": {
           "default": [],
           "items": {
@@ -10261,6 +10272,15 @@
         }
       ]
     },
+    "MultiAgentVersion": {
+      "description": "Multi-agent runtime supported by a model.",
+      "enum": [
+        "disabled",
+        "v1",
+        "v2"
+      ],
+      "type": "string"
+    },
     "NetworkAccess": {
       "enum": [
         "restricted",

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

@@ -93,6 +93,17 @@
             "null"
           ]
         },
+        "multiAgentVersion": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/MultiAgentVersion"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "description": "Multi-agent runtime declared by this model, when available."
+        },
         "serviceTiers": {
           "default": [],
           "items": {
@@ -198,6 +209,15 @@
       ],
       "type": "object"
     },
+    "MultiAgentVersion": {
+      "description": "Multi-agent runtime supported by a model.",
+      "enum": [
+        "disabled",
+        "v1",
+        "v2"
+      ],
+      "type": "string"
+    },
     "ReasoningEffort": {
       "description": "A non-empty reasoning effort value advertised by the model.",
       "minLength": 1,

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

@@ -6,9 +6,14 @@ import type { ReasoningEffort } from "../ReasoningEffort";
 import type { ModelAvailabilityNux } from "./ModelAvailabilityNux";
 import type { ModelServiceTier } from "./ModelServiceTier";
 import type { ModelUpgradeInfo } from "./ModelUpgradeInfo";
+import type { MultiAgentVersion } from "./MultiAgentVersion";
 import type { ReasoningEffortOption } from "./ReasoningEffortOption";
 
 export type Model = { id: string, model: string, upgrade: string | null, upgradeInfo: ModelUpgradeInfo | null, availabilityNux: ModelAvailabilityNux | null, displayName: string, description: string, modelSpecialty: string | null, hidden: boolean, supportedReasoningEfforts: Array<ReasoningEffortOption>, defaultReasoningEffort: ReasoningEffort, inputModalities: Array<InputModality>, supportsPersonality: boolean,
+/**
+ * Multi-agent runtime declared by this model, when available.
+ */
+multiAgentVersion: MultiAgentVersion | null,
 /**
  * Deprecated: use `serviceTiers` instead.
  */

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

@@ -0,0 +1,8 @@
+// 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.
+
+/**
+ * Multi-agent runtime supported by a model.
+ */
+export type MultiAgentVersion = "disabled" | "v1" | "v2";

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

@@ -288,6 +288,7 @@ export type { ModelUpgradeInfo } from "./ModelUpgradeInfo";
 export type { ModelVerification } from "./ModelVerification";
 export type { ModelVerificationNotification } from "./ModelVerificationNotification";
 export type { ModelsRequirements } from "./ModelsRequirements";
+export type { MultiAgentVersion } from "./MultiAgentVersion";
 export type { NetworkAccess } from "./NetworkAccess";
 export type { NetworkApprovalContext } from "./NetworkApprovalContext";
 export type { NetworkApprovalProtocol } from "./NetworkApprovalProtocol";

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

@@ -7,6 +7,7 @@ use codex_protocol::openai_models::ReasoningEffort;
 use codex_protocol::openai_models::default_input_modalities;
 use codex_protocol::protocol::ModelRerouteReason as CoreModelRerouteReason;
 use codex_protocol::protocol::ModelVerification as CoreModelVerification;
+use codex_protocol::protocol::MultiAgentVersion as CoreMultiAgentVersion;
 use serde::Deserialize;
 use serde::Serialize;
 use serde_json::Value as JsonValue;
@@ -23,6 +24,15 @@ v2_enum_from_core!(
     }
 );
 
+v2_enum_from_core!(
+    /// Multi-agent runtime supported by a model.
+    pub enum MultiAgentVersion from CoreMultiAgentVersion {
+        Disabled,
+        V1,
+        V2
+    }
+);
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Default, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
@@ -96,6 +106,8 @@ pub struct Model {
     pub input_modalities: Vec<InputModality>,
     #[serde(default)]
     pub supports_personality: bool,
+    /// Multi-agent runtime declared by this model, when available.
+    pub multi_agent_version: Option<MultiAgentVersion>,
     /// Deprecated: use `serviceTiers` instead.
     #[serde(default)]
     pub additional_speed_tiers: Vec<String>,

codex-rs/app-server/README.md

@@ -228,7 +228,7 @@ Example with notification opt-out:
 - `fs/watch` — subscribe this connection to filesystem change notifications for an absolute file or directory path and caller-provided `watchId`; returns the canonicalized `path`.
 - `fs/unwatch` — stop sending notifications for a prior `fs/watch`; returns `{}`.
 - `fs/changed` — notification emitted when watched paths change, including the `watchId` and `changedPaths`.
-- `model/list` — list available models (set `includeHidden: true` to include entries with `hidden: true`), with model-advertised string reasoning effort options in the catalog's intended progression order, optional `modelSpecialty`, `additionalSpeedTiers`, `serviceTiers`, optional `defaultServiceTier`, optional legacy `upgrade` model ids, optional `upgradeInfo` metadata (`model`, `upgradeCopy`, `modelLink`, `migrationMarkdown`), and optional `availabilityNux` metadata. Clients should preserve the `supportedReasoningEfforts` array order rather than deriving order from the effort names.
+- `model/list` — list available models (set `includeHidden: true` to include entries with `hidden: true`), with model-advertised string reasoning effort options in the catalog's intended progression order, optional `modelSpecialty`, nullable `multiAgentVersion` (`disabled`, `v1`, or `v2`), `additionalSpeedTiers`, `serviceTiers`, optional `defaultServiceTier`, optional legacy `upgrade` model ids, optional `upgradeInfo` metadata (`model`, `upgradeCopy`, `modelLink`, `migrationMarkdown`), and optional `availabilityNux` metadata. Clients should preserve the `supportedReasoningEfforts` array order rather than deriving order from the effort names.
 - `modelProvider/capabilities/read` — read provider-level capabilities for the currently configured model provider.
 - `experimentalFeature/list` — list feature flags with stage metadata (`beta`, `underDevelopment`, `stable`, etc.), enabled/default-enabled state, and cursor pagination. Pass `threadId` when showing feature state for an existing loaded thread so `enabled` is computed from that thread's refreshed config, including project-local config for the thread's cwd; if omitted, the server uses its default config resolution context. For non-beta flags, `displayName`/`description`/`announcement` are `null`.
 - `permissionProfile/list` — beta; list available permission profile ids with optional display `description` text and an `allowed` flag reflecting effective requirements, using cursor pagination. Pass `cwd` when the caller needs project-local `[permissions.<id>]` entries to be included in the current catalog view.

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

@@ -46,6 +46,7 @@ fn model_from_preset(preset: ModelPreset) -> Model {
         default_reasoning_effort: preset.default_reasoning_effort,
         input_modalities: preset.input_modalities,
         supports_personality: preset.supports_personality,
+        multi_agent_version: preset.multi_agent_version.map(Into::into),
         additional_speed_tiers: preset.additional_speed_tiers,
         service_tiers: preset
             .service_tiers

codex-rs/app-server/tests/common/models_cache.rs

@@ -68,7 +68,7 @@ fn preset_to_info(preset: &ModelPreset, priority: i32) -> ModelInfo {
         auto_review_model_override: None,
         model_specialty: None,
         tool_mode: None,
-        multi_agent_version: None,
+        multi_agent_version: preset.multi_agent_version,
     }
 }
 

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

@@ -61,6 +61,7 @@ fn model_from_preset(preset: &ModelPreset) -> Model {
         // cache report `supports_personality = false`.
         // todo(sayan): fix, maybe make roundtrip use ModelInfo only
         supports_personality: false,
+        multi_agent_version: preset.multi_agent_version.map(Into::into),
         additional_speed_tiers: preset.additional_speed_tiers.clone(),
         service_tiers: preset
             .service_tiers
@@ -177,6 +178,7 @@ async fn list_models_uses_chatgpt_remote_catalog_as_source_of_truth() -> Result<
         "truncation_policy": {"mode": "bytes", "limit": 10_000},
         "supports_parallel_tool_calls": false,
         "supports_image_detail_original": false,
+        "multi_agent_version": "v2",
         "context_window": 272_000,
         "max_context_window": 272_000,
         "experimental_supported_tools": [],