diff --git a/packages/core/src/config/plugin/provider.ts b/packages/core/src/config/plugin/provider.ts
index 0d31b32d08..3c33131131 100644
--- a/packages/core/src/config/plugin/provider.ts
+++ b/packages/core/src/config/plugin/provider.ts
@@ -48,6 +48,9 @@ export const Plugin = PluginV2.define({
               if (config.capabilities !== undefined) {
                 model.capabilities = {
                   tools: config.capabilities.tools,
+                  reasoningOptions: config.capabilities.reasoningOptions?.map((option) =>
+                    option.type === "effort" ? { ...option, values: [...option.values] } : { ...option },
+                  ),
                   input: [...config.capabilities.input],
                   output: [...config.capabilities.output],
                 }
diff --git a/packages/core/src/model.ts b/packages/core/src/model.ts
index 3b0beece55..17a6e56ac1 100644
--- a/packages/core/src/model.ts
+++ b/packages/core/src/model.ts
@@ -2,6 +2,7 @@ import { DateTime, Schema } from "effect"
 import { DateTimeUtcFromMillis } from "effect/Schema"
 import { ProviderV2 } from "./provider"
 import { ModelRequest } from "./model-request"
+import { ModelsDev } from "./models-dev"
 
 export const ID = Schema.String.pipe(Schema.brand("ModelV2.ID"))
 export type ID = typeof ID.Type
@@ -15,6 +16,7 @@ export type Family = typeof Family.Type
 
 export const Capabilities = Schema.Struct({
   tools: Schema.Boolean,
+  reasoningOptions: Schema.Array(ModelsDev.ResolvedReasoningOption).pipe(Schema.optional),
   // mime patterns, image, audio, video/*, text/*
   input: Schema.String.pipe(Schema.Array),
   output: Schema.String.pipe(Schema.Array),
diff --git a/packages/core/src/models-dev.ts b/packages/core/src/models-dev.ts
index 3f9f670374..e0c248c7b3 100644
--- a/packages/core/src/models-dev.ts
+++ b/packages/core/src/models-dev.ts
@@ -43,6 +43,64 @@ const Cost = Schema.Struct({
   ),
 })
 
+const reasoningOption = <Fields extends Schema.Struct.Fields>(fields: Fields) =>
+  Schema.StructWithRest(Schema.Struct(fields), [Schema.Record(Schema.String, Schema.MutableJson)])
+
+export const ReasoningOption = Schema.Union([
+  reasoningOption({ type: Schema.Literal("toggle") }),
+  reasoningOption({
+    type: Schema.Literal("effort"),
+    values: Schema.Array(Schema.NullOr(Schema.String)),
+  }),
+  reasoningOption({
+    type: Schema.Literal("budget_tokens"),
+    min: Schema.optional(Schema.Finite),
+    max: Schema.optional(Schema.Finite),
+  }),
+  reasoningOption({ type: Schema.String }),
+])
+export type ReasoningOption = typeof ReasoningOption.Type
+
+export const ResolvedReasoningOption = Schema.Union([
+  Schema.Struct({ type: Schema.Literal("toggle") }),
+  Schema.Struct({
+    type: Schema.Literal("effort"),
+    values: Schema.Array(Schema.String),
+  }),
+  Schema.Struct({
+    type: Schema.Literal("budget_tokens"),
+    min: Schema.optional(Schema.Finite),
+    max: Schema.optional(Schema.Finite),
+  }),
+])
+export type ResolvedReasoningOption =
+  | { type: "toggle" }
+  | { type: "effort"; values: string[] }
+  | { type: "budget_tokens"; min?: number; max?: number }
+
+export function resolveReasoningOptions(
+  options: readonly ReasoningOption[] | undefined,
+): ResolvedReasoningOption[] | undefined {
+  if (!options) return
+  return options
+    .map((option): ResolvedReasoningOption | undefined => {
+      if (option.type === "toggle") return { type: "toggle" }
+      if (option.type === "effort" && Array.isArray(option.values)) {
+        return {
+          type: "effort",
+          values: option.values.filter((value): value is string => typeof value === "string"),
+        }
+      }
+      if (option.type !== "budget_tokens") return
+      return {
+        type: "budget_tokens",
+        ...(typeof option.min === "number" && Number.isFinite(option.min) ? { min: option.min } : {}),
+        ...(typeof option.max === "number" && Number.isFinite(option.max) ? { max: option.max } : {}),
+      }
+    })
+    .filter((option): option is ResolvedReasoningOption => option !== undefined)
+}
+
 export const Model = Schema.Struct({
   id: Schema.String,
   name: Schema.String,
@@ -50,6 +108,7 @@ export const Model = Schema.Struct({
   release_date: Schema.String,
   attachment: Schema.Boolean,
   reasoning: Schema.Boolean,
+  reasoning_options: Schema.optional(Schema.Array(ReasoningOption)),
   temperature: Schema.Boolean,
   tool_call: Schema.Boolean,
   interleaved: Schema.optional(
diff --git a/packages/core/src/plugin/models-dev.ts b/packages/core/src/plugin/models-dev.ts
index 6424c6b6ab..3da810a4a2 100644
--- a/packages/core/src/plugin/models-dev.ts
+++ b/packages/core/src/plugin/models-dev.ts
@@ -99,6 +99,7 @@ export const ModelsDevPlugin = PluginV2.define({
                   }
               draft.capabilities = {
                 tools: model.tool_call,
+                reasoningOptions: ModelsDev.resolveReasoningOptions(model.reasoning_options),
                 input: [...(model.modalities?.input ?? [])],
                 output: [...(model.modalities?.output ?? [])],
               }
diff --git a/packages/core/test/models.test.ts b/packages/core/test/models.test.ts
index 31a3e57c10..c7bba24e3d 100644
--- a/packages/core/test/models.test.ts
+++ b/packages/core/test/models.test.ts
@@ -1,5 +1,5 @@
-import { describe, expect, beforeAll, beforeEach, afterAll } from "bun:test"
-import { Effect, Layer, Ref } from "effect"
+import { describe, expect, beforeAll, beforeEach, afterAll, test } from "bun:test"
+import { Effect, Layer, Ref, Schema } from "effect"
 import { HttpClient, HttpClientResponse } from "effect/unstable/http"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Flag } from "@opencode-ai/core/flag/flag"
@@ -125,6 +125,19 @@ const initialState: MockState = {
   calls: [],
 }
 
+test("reasoning options preserve unknown types and fields", () => {
+  const options: ModelsDev.ReasoningOption[] = [
+    { type: "effort", values: [null, "low", "ultrathink"], default: "low" },
+    { type: "future_dynamic_budget", curve: { min: 1, max: 10 }, enabled: true },
+  ]
+  const model = Schema.decodeUnknownSync(ModelsDev.Model)({
+    ...fixture.acme.models["acme-1"],
+    reasoning_options: options,
+  })
+
+  expect(model.reasoning_options).toEqual(options)
+})
+
 describe("ModelsDev Service", () => {
   it.live("get() returns providers from disk when cache file exists", () =>
     Effect.gen(function* () {
diff --git a/packages/core/test/plugin/models-dev.test.ts b/packages/core/test/plugin/models-dev.test.ts
new file mode 100644
index 0000000000..81b7363384
--- /dev/null
+++ b/packages/core/test/plugin/models-dev.test.ts
@@ -0,0 +1,68 @@
+import { describe, expect } from "bun:test"
+import { Effect, Layer } from "effect"
+import { Catalog } from "@opencode-ai/core/catalog"
+import { EventV2 } from "@opencode-ai/core/event"
+import { Location } from "@opencode-ai/core/location"
+import { ModelV2 } from "@opencode-ai/core/model"
+import { ModelsDev } from "@opencode-ai/core/models-dev"
+import { ModelsDevPlugin } from "@opencode-ai/core/plugin/models-dev"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { AbsolutePath } from "@opencode-ai/core/schema"
+import { location } from "../fixture/location"
+import { testEffect } from "../lib/effect"
+
+const reasoningOptions: ModelsDev.ReasoningOption[] = [
+  { type: "toggle" },
+  { type: "effort", values: [null, "low", "ultrathink"], default: "low" },
+  { type: "budget_tokens", min: 1024, future: true },
+  { type: "future_dynamic_budget", curve: { min: 1, max: 10 }, enabled: true },
+]
+
+const modelsDev = Layer.succeed(
+  ModelsDev.Service,
+  ModelsDev.Service.of({
+    get: () =>
+      Effect.succeed({
+        acme: {
+          id: "acme",
+          name: "Acme",
+          env: [],
+          models: {
+            "acme-1": {
+              id: "acme-1",
+              name: "Acme One",
+              release_date: "2026-01-01",
+              attachment: false,
+              reasoning: true,
+              reasoning_options: reasoningOptions,
+              temperature: true,
+              tool_call: true,
+              limit: { context: 128_000, output: 8_192 },
+            },
+          },
+        },
+      }),
+    refresh: () => Effect.void,
+  }),
+)
+const locationLayer = Layer.succeed(
+  Location.Service,
+  Location.Service.of(location({ directory: AbsolutePath.make("test") })),
+)
+const catalog = Catalog.locationLayer.pipe(Layer.provideMerge(EventV2.defaultLayer), Layer.provideMerge(locationLayer))
+const it = testEffect(Layer.merge(catalog, modelsDev))
+
+describe("ModelsDevPlugin", () => {
+  it.effect("maps known reasoning options into typed V2 capabilities", () =>
+    Effect.gen(function* () {
+      yield* ModelsDevPlugin.effect
+      const model = yield* (yield* Catalog.Service).model.get(ProviderV2.ID.make("acme"), ModelV2.ID.make("acme-1"))
+
+      expect(model.capabilities.reasoningOptions).toEqual([
+        { type: "toggle" },
+        { type: "effort", values: ["low", "ultrathink"] },
+        { type: "budget_tokens", min: 1024 },
+      ])
+    }),
+  )
+})
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 86515068d4..a13c4e76d7 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -960,6 +960,7 @@ const ProviderInterleaved = Schema.Union([
 const ProviderCapabilities = Schema.Struct({
   temperature: Schema.Boolean,
   reasoning: Schema.Boolean,
+  reasoningOptions: optionalOmitUndefined(Schema.Array(ModelsDev.ResolvedReasoningOption)),
   attachment: Schema.Boolean,
   toolcall: Schema.Boolean,
   input: ProviderModalities,
@@ -1178,6 +1179,7 @@ function fromModelsDevModel(provider: ModelsDev.Provider, model: ModelsDev.Model
     capabilities: {
       temperature: model.temperature ?? false,
       reasoning: model.reasoning ?? false,
+      reasoningOptions: ModelsDev.resolveReasoningOptions(model.reasoning_options),
       attachment: model.attachment ?? false,
       toolcall: model.tool_call ?? true,
       input: {
@@ -1400,6 +1402,7 @@ export const layer = Layer.effect(
               capabilities: {
                 temperature: model.temperature ?? existingModel?.capabilities.temperature ?? false,
                 reasoning: model.reasoning ?? existingModel?.capabilities.reasoning ?? false,
+                reasoningOptions: existingModel?.capabilities.reasoningOptions,
                 attachment: model.attachment ?? existingModel?.capabilities.attachment ?? false,
                 toolcall: model.tool_call ?? existingModel?.capabilities.toolcall ?? true,
                 input: {
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index 6edfc97ca0..6f5a15cf70 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -1286,6 +1286,12 @@ test("mode cost preserves over-200k pricing from base model", () => {
 })
 
 test("models.dev normalization fills required response fields", () => {
+  const reasoningOptions: ModelsDev.ReasoningOption[] = [
+    { type: "toggle" },
+    { type: "effort", values: [null, "low", "ultrathink"], default: "low" },
+    { type: "budget_tokens", min: 1024, future: true },
+    { type: "future_dynamic_budget", curve: { min: 1, max: 10 } },
+  ]
   const provider = {
     id: "gateway",
     name: "Gateway",
@@ -1295,6 +1301,7 @@ test("models.dev normalization fills required response fields", () => {
         id: "gpt-5.4",
         name: "GPT-5.4",
         family: "gpt",
+        reasoning_options: reasoningOptions,
         cost: { input: 2.5, output: 15 },
         limit: { context: 1_050_000, input: 922_000, output: 128_000 },
       },
@@ -1305,6 +1312,11 @@ test("models.dev normalization fills required response fields", () => {
   expect(model.api.url).toBe("")
   expect(model.capabilities.temperature).toBe(false)
   expect(model.capabilities.reasoning).toBe(false)
+  expect(model.capabilities.reasoningOptions).toEqual([
+    { type: "toggle" },
+    { type: "effort", values: ["low", "ultrathink"] },
+    { type: "budget_tokens", min: 1024 },
+  ])
   expect(model.capabilities.attachment).toBe(false)
   expect(model.capabilities.toolcall).toBe(true)
   expect(model.release_date).toBe("")
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 2dce3f6f59..2bded90cca 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -2082,6 +2082,20 @@ export type Model = {
   capabilities: {
     temperature: boolean
     reasoning: boolean
+    reasoningOptions?: Array<
+      | {
+          type: "toggle"
+        }
+      | {
+          type: "effort"
+          values: Array<string>
+        }
+      | {
+          type: "budget_tokens"
+          min?: number
+          max?: number
+        }
+    >
     attachment: boolean
     toolcall: boolean
     input: {
@@ -2878,6 +2892,20 @@ export type ModelV2Info = {
       }
   capabilities: {
     tools: boolean
+    reasoningOptions?: Array<
+      | {
+          type: "toggle"
+        }
+      | {
+          type: "effort"
+          values: Array<string>
+        }
+      | {
+          type: "budget_tokens"
+          min?: number
+          max?: number
+        }
+    >
     input: Array<string>
     output: Array<string>
   }
@@ -4230,6 +4258,20 @@ export type ModelV2Info1 = {
       }
   capabilities: {
     tools: boolean
+    reasoningOptions?: Array<
+      | {
+          type: "toggle"
+        }
+      | {
+          type: "effort"
+          values: Array<string>
+        }
+      | {
+          type: "budget_tokens"
+          min?: number
+          max?: number
+        }
+    >
     input: Array<string>
     output: Array<string>
   }