diff --git a/packages/opencode/src/plugin/openai/codex.ts b/packages/opencode/src/plugin/openai/codex.ts
index a577e2a82a..b55fa3dda8 100644
--- a/packages/opencode/src/plugin/openai/codex.ts
+++ b/packages/opencode/src/plugin/openai/codex.ts
@@ -410,7 +410,7 @@ export async function CodexAuthPlugin(input: PluginInput, options: CodexAuthPlug
           websocketFetches.push(websocketFetch)
           websocketFetchInstalled = true
         }
-        if (auth.type !== "oauth") return websocketFetch ? { fetch: websocketFetch } : {}
+        if (auth.type !== "oauth") return websocketFetch ? { fetch: websocketFetch, headerTimeout: false } : {}
 
         let refreshPromise:
           | Promise<{
@@ -421,6 +421,7 @@ export async function CodexAuthPlugin(input: PluginInput, options: CodexAuthPlug
 
         return {
           apiKey: OAUTH_DUMMY_KEY,
+          ...(websocketFetch ? { headerTimeout: false } : {}),
           async fetch(requestInput: RequestInfo | URL, init?: RequestInit) {
             if (init?.headers) {
               if (init.headers instanceof Headers) {
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 2c50a9a60d..8a8ba63907 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -190,13 +190,13 @@ function custom(dep: CustomDep): Record<string, CustomLoader> {
         options: ok ? {} : { apiKey: "public" },
       }
     }),
-    openai: () =>
+    openai: (input) =>
       Effect.succeed({
         autoload: false,
         async getModel(sdk: any, modelID: string, _options?: Record<string, any>) {
           return sdk.responses(modelID)
         },
-        options: { headerTimeout: OPENAI_HEADER_TIMEOUT_DEFAULT },
+        options: { headerTimeout: input.options.headerTimeout ?? OPENAI_HEADER_TIMEOUT_DEFAULT },
       }),
     xai: () =>
       Effect.succeed({
@@ -1425,7 +1425,7 @@ export const layer = Layer.effect(
             log.error("Provider does not exist in model list " + providerID)
             continue
           }
-          const result = yield* fn(data)
+          const result = yield* fn(providers[providerID] ?? data)
           if (result && (result.autoload || providers[providerID])) {
             if (result.getModel) modelLoaders[providerID] = result.getModel
             if (result.vars) varsLoaders[providerID] = result.vars
diff --git a/packages/opencode/test/plugin/codex.test.ts b/packages/opencode/test/plugin/codex.test.ts
index a375fe4ee1..02a83e8107 100644
--- a/packages/opencode/test/plugin/codex.test.ts
+++ b/packages/opencode/test/plugin/codex.test.ts
@@ -137,9 +137,23 @@ describe("plugin.codex", () => {
 
     expect(disabledOptions.fetch).toBeUndefined()
     expect(enabledOptions.fetch).toBeFunction()
+    expect(disabledOptions.headerTimeout).toBeUndefined()
+    expect(enabledOptions.headerTimeout).toBe(false)
     await enabled.dispose?.()
   })
 
+  test("disables the HTTP header timeout for websocket OAuth transport", async () => {
+    const hooks = await CodexAuthPlugin({} as never, { experimentalWebSockets: true })
+    const options = await hooks.auth!.loader!(
+      async () => ({ type: "oauth", refresh: "refresh", access: "access", expires: Date.now() + 60_000 }) as never,
+      {} as never,
+    )
+
+    expect(options.fetch).toBeFunction()
+    expect(options.headerTimeout).toBe(false)
+    await hooks.dispose?.()
+  })
+
   test("deduplicates concurrent Codex token refreshes", async () => {
     let auth = {
       type: "oauth" as const,
diff --git a/packages/opencode/test/provider/header-timeout.test.ts b/packages/opencode/test/provider/header-timeout.test.ts
index a3caf4fd8a..90008aac24 100644
--- a/packages/opencode/test/provider/header-timeout.test.ts
+++ b/packages/opencode/test/provider/header-timeout.test.ts
@@ -11,6 +11,12 @@ import { Env } from "@/env"
 import { Plugin } from "@/plugin"
 import { Provider } from "@/provider/provider"
 import { ProviderError } from "@/provider/error"
+import { RuntimeFlags } from "@/effect/runtime-flags"
+import { FSUtil } from "@opencode-ai/core/fs-util"
+import { Config } from "@/config/config"
+import { Auth } from "@/auth"
+import { ModelsDev } from "@opencode-ai/core/models-dev"
+import { EventV2Bridge } from "@/event-v2-bridge"
 
 afterEach(async () => {
   await disposeAllInstances()
@@ -19,6 +25,8 @@ afterEach(async () => {
 const it = testEffect(
   Layer.mergeAll(Provider.defaultLayer, Env.defaultLayer, Plugin.defaultLayer, CrossSpawnSpawner.defaultLayer),
 )
+const httpOnly = testEffect(providerLayer({ disableDefaultPlugins: true }))
+const websockets = testEffect(providerLayer({ experimentalWebSockets: true }))
 
 it.live("headerTimeout does not abort delayed SSE body after headers arrive", () =>
   Effect.gen(function* () {
@@ -152,7 +160,7 @@ it.live("OpenAI Codex headerTimeout default can be disabled by config", () =>
   }),
 )
 
-it.live("OpenAI API auth gets default headerTimeout", () =>
+httpOnly.live("OpenAI API auth gets default headerTimeout", () =>
   Effect.gen(function* () {
     yield* withAuthContent(
       Effect.gen(function* () {
@@ -169,6 +177,65 @@ it.live("OpenAI API auth gets default headerTimeout", () =>
   }),
 )
 
+websockets.live("OpenAI Codex websocket transport disables default headerTimeout", () =>
+  Effect.gen(function* () {
+    yield* withAuthContent(
+      Effect.gen(function* () {
+        yield* provideTmpdirInstance(() =>
+          Effect.gen(function* () {
+            const provider = yield* Provider.Service
+            const openai = yield* provider.getProvider(ProviderV2.ID.openai)
+            expect(openai.options.headerTimeout).toBe(false)
+          }),
+        )
+      }),
+      { openai: { type: "api", key: "sk-test" } },
+    )
+  }),
+)
+
+websockets.live("OpenAI Codex websocket transport preserves configured headerTimeout", () =>
+  Effect.gen(function* () {
+    yield* withAuthContent(
+      Effect.gen(function* () {
+        yield* provideTmpdirInstance(
+          () =>
+            Effect.gen(function* () {
+              const provider = yield* Provider.Service
+              const openai = yield* provider.getProvider(ProviderV2.ID.openai)
+              expect(openai.options.headerTimeout).toBe(30_000)
+            }),
+          { config: { provider: { openai: { options: { headerTimeout: 30_000 } } } } },
+        )
+      }),
+      { openai: { type: "api", key: "sk-test" } },
+    )
+  }),
+)
+
+function providerLayer(flags: Partial<RuntimeFlags.Info>) {
+  const runtime = RuntimeFlags.layer(flags)
+  const plugin = Plugin.layer.pipe(
+    Layer.provide(EventV2Bridge.defaultLayer),
+    Layer.provide(Config.defaultLayer),
+    Layer.provide(runtime),
+  )
+  return Layer.mergeAll(
+    Provider.layer.pipe(
+      Layer.provide(FSUtil.defaultLayer),
+      Layer.provide(Env.defaultLayer),
+      Layer.provide(Config.defaultLayer),
+      Layer.provide(Auth.defaultLayer),
+      Layer.provide(plugin),
+      Layer.provide(ModelsDev.defaultLayer),
+      Layer.provide(runtime),
+    ),
+    Env.defaultLayer,
+    plugin,
+    CrossSpawnSpawner.defaultLayer,
+  )
+}
+
 function providerConfig(url: string, options: Record<string, unknown> = {}) {
   const config = testProviderConfig(url)
   return {