diff --git a/packages/client/src/promise/generated/types.ts b/packages/client/src/promise/generated/types.ts
index ce99934284b..da84380a25b 100644
--- a/packages/client/src/promise/generated/types.ts
+++ b/packages/client/src/promise/generated/types.ts
@@ -430,6 +430,8 @@ export type McpProtocol = "legacy" | "auto" | "2026-07-28"
 
 export type ConfigWorktree = { directory: string }
 
+export type ConfigModelCapabilities = { tools?: boolean; input?: Array<string>; output?: Array<string> }
+
 export type ConfigShellOption = { path: string; name: string; acceptable: boolean }
 
 export type SessionMessageLocationSwitched = {
@@ -2130,7 +2132,7 @@ export type ConfigEntry =
                 settings?: ConfigModelSettings
                 headers?: { [x: string]: string }
                 body?: { [x: string]: JsonValue }
-                capabilities?: { tools?: boolean; input?: Array<string>; output?: Array<string> }
+                capabilities?: ConfigModelCapabilities
                 variants?: Array<{
                   id: string
                   settings?: ConfigModelSettings
diff --git a/packages/schema/src/config/provider.ts b/packages/schema/src/config/provider.ts
index 166a4377b5c..d2e34abb2c6 100644
--- a/packages/schema/src/config/provider.ts
+++ b/packages/schema/src/config/provider.ts
@@ -2,7 +2,7 @@ export * as ConfigProvider from "./provider.js"
 
 import { Schema } from "effect"
 import { Money } from "../money.js"
-import { Compatibility, Family, ID, VariantID } from "../model.js"
+import { Capabilities, Compatibility, Family, ID, VariantID } from "../model.js"
 import { Provider } from "../provider.js"
 import { optional } from "../schema.js"
 
@@ -59,13 +59,6 @@ class Cost extends Schema.Class<Cost>("Config.Model.Cost")({
   cache: Cache.pipe(optional),
 }) {}
 
-// Partial: unset fields fall back to the existing/base model's capabilities or Model.Capabilities.default().
-class ModelCapabilities extends Schema.Class<ModelCapabilities>("Config.Model.Capabilities")({
-  tools: Schema.Boolean.pipe(optional),
-  input: Schema.Array(Schema.String).pipe(optional),
-  output: Schema.Array(Schema.String).pipe(optional),
-}) {}
-
 class Limit extends Schema.Class<Limit>("Config.Model.Limit")({
   context: Schema.Int.pipe(optional),
   input: Schema.Int.pipe(optional),
@@ -79,7 +72,14 @@ class Model extends Schema.Class<Model>("Config.Model")({
   compatibility: Compatibility.pipe(optional),
   package: Schema.String.pipe(optional),
   ...ModelOverlays,
-  capabilities: ModelCapabilities.pipe(optional),
+  // Partial: unset fields fall back to the base model's capabilities, then the defaults.
+  capabilities: Capabilities.mapFields((fields) => ({
+    tools: optional(fields.tools),
+    input: optional(fields.input),
+    output: optional(fields.output),
+  }))
+    .annotate({ identifier: "Config.Model.Capabilities" })
+    .pipe(optional),
   variants: Schema.Struct({
     id: VariantID,
     ...ModelOverlays,