feat(voice): add ChatGPT OAuth auth option

.env.example

@@ -52,7 +52,10 @@ GOOGLE_MAPS_SERVER_API_KEY=
 # CLIENT-EXPOSED — use a public assets:read token with URL restrictions.
 CESIUM_ION_TOKEN=
 
-# Optional: OpenAI Realtime voice control. Do not prefix with VITE_.
+# Optional: OpenAI Realtime voice control. API key is the default cloud auth.
+# Provider Settings can instead opt voice into the signed-in local
+# ChatGPT/Codex OAuth session; the browser still receives only a short-lived
+# Realtime client secret. Do not prefix with VITE_.
 OPENAI_API_KEY=
 OPENAI_REALTIME_MODEL=gpt-realtime-2
 # Cheaper voice tier, used when the GEV MIC panel's MINI toggle is on.

README.md

@@ -231,7 +231,7 @@ _Why cockpit mode exists: you're riding a real aircraft over real terrain — an
 
 ## 🎙️ Talk to It
 
-> Voice needs an **OpenAI key**. Without one the entire app still runs — the mic button just reports voice is unavailable. The same key drives the **AI HUD summary**: a terse, five-word intelligence-style readout of the current view that regenerates as you move.
+> Voice can use an **OpenAI API key** or, on the same machine, an opt-in signed-in **ChatGPT/Codex OAuth** session. The API-key path remains the default. Selecting ChatGPT OAuth in Provider Settings reuses an existing local sign-in or starts the Codex browser sign-in flow and selects OAuth when it completes. The OpenAI key still drives the **AI HUD summary**: a terse, five-word intelligence-style readout of the current view that regenerates as you move.
 
 Click **GEV MIC**, grant the microphone, and just talk. This is more than a voice-controlled remote:
 
@@ -239,7 +239,7 @@ Click **GEV MIC**, grant the microphone, and just talk. This is more than a voic
 - **🎯 Entity Q&A.** Click any plane, ship, or datacenter and ask _"what's this?"_ It answers using the object's live telemetry.
 - **👁️ Visual grounding.** At street level, it reads a viewport screenshot to identify legible signage and building names, and is instructed never to hallucinate labels.
 - **🎬 Cinematic framing.** _"Show me the planes overhead"_ pulls the camera back, angles it, and frames the live traffic like a director.
-- **🔒 Honest and secure.** The agent only confirms actions that succeeded. Your `OPENAI_API_KEY` never touches the browser; the client only gets a short-lived session token.
+- **🔒 Honest and secure.** The agent only confirms actions that succeeded. Your `OPENAI_API_KEY` never touches the browser; the client only gets a short-lived session token. If you choose **USE CHATGPT OAUTH** in Provider Settings, the local server uses that sign-in only to mint the same kind of short-lived Realtime credential, and refuses the OAuth path for non-loopback clients.
 
 Twenty-nine tools, four jobs — the commands below come straight from the product's voice test suite and tool playbook:
 
@@ -412,7 +412,7 @@ Six keys. Four have a free tier, and the two 🔴 ones are metered:
 | --- | --------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | 🟡  | **Cesium ion**  | 🗺️ Google Photorealistic 3D, world terrain, and additional ion-hosted imagery stacks. The free Community plan is for eligible individual, personal/non-commercial use and has quotas | [cesium.com/ion](https://cesium.com/ion) — use a public `assets:read` token and check current [pricing/eligibility](https://cesium.com/platform/cesium-ion/pricing/) |
 | 🔴  | **Google Maps** | Direct Google Photorealistic 3D + Google place search ([Map Tiles API](https://developers.google.com/maps/documentation/tile))                                                       | [Google Cloud Console](https://console.cloud.google.com/) — URL-restrict it                                                                                          |
-| 🔴  | **OpenAI**      | 🎙️ The voice experience + AI HUD summary. The mini model works; the standard model is noticeably smarter. Want Gemini or another provider behind the mic? PRs welcome                | [platform.openai.com](https://platform.openai.com) — metered, see costs below                                                                                        |
+| 🔴  | **OpenAI**      | 🎙️ Voice + AI HUD summary through an API key. Provider Settings also offers **USE CHATGPT OAUTH** for cloud voice without removing the API-key option                              | [platform.openai.com](https://platform.openai.com) — API-key usage is metered, see costs below                                                                       |
 | 🟡  | **AISStream**   | 🚢 Live global ships                                                                                                                                                                 | [aisstream.io](https://aisstream.io) — free signup                                                                                                                   |
 | 🟡  | **NASA FIRMS**  | 🔥 Live active fires                                                                                                                                                                 | [firms.modaps.eosdis.nasa.gov](https://firms.modaps.eosdis.nasa.gov/api/map_key/) — free                                                                             |
 | 🟡  | **TomTom**      | 🚦 Live flow speeds and congestion colors for the simulated traffic layer                                                                                                            | [developer.tomtom.com](https://developer.tomtom.com) — free tier available                                                                                           |
@@ -490,7 +490,7 @@ Honest numbers, roughly, as of mid-2026 — always check the provider pricing pa
 | **🟢 Most layers**       | **$0, no signup.** OpenSky anon, USGS, CelesTrak, adsb.lol, city CCTV, Radio Browser, GBFS, Launch Library 2, transit feeds, OSRM routing, NOAA and ECMWF weather, OpenStreetMap ALPR mapping, bundled datasets.                                                                                                                                                            |
 | **🟡 The free-key tier** | **$0 with a signup.** AISStream, FIRMS, TomTom, OpenSky, plus Cesium ion for eligible personal/non-commercial use. Provider quotas and eligibility still apply.                                                                                                                                                                                                             |
 | **🗺️ Google 3D tiles**   | **Free through an eligible Cesium ion Community account within its quota; metered through a direct Google key.** Use the direct route for Google place search or commercial deployment, verify current provider terms, and set budget alerts where billing is enabled.                                                                                                      |
-| **🔴 OpenAI voice**      | **The one that costs real money — so the app meters it for you.** Realtime audio runs a few cents per active minute; an evening of heavy use is single-digit dollars. A live session-spend readout sits next to the mic, with an STD/MINI model toggle, a $2 warning, and a **$5 hard cap that ends the session**. The voice context window is kept deliberately short too. |
+| **🔴 OpenAI voice**      | API-key sessions keep the live spend readout, STD/MINI model toggle, $2 warning, and **$5 hard cap**. ChatGPT OAuth is an explicit choice in Provider Settings. Its usage is tracked without an API-dollar estimate or spend cap. The voice context window stays deliberately short. |
 
 Google's direct 3D route is surprisingly generous: the first 1,000 Photorealistic
 3D Tiles sessions each month are currently free, and one root request supports

docs/CURRENT-STATE.md

@@ -3607,7 +3607,7 @@ silently demoting every later lookup for the session.
 
 `GEV MIC` button (bottom UI) starts an OpenAI Realtime session over WebRTC:
 
-- **Token flow**: browser fetches a short-lived client secret from `/api/realtime/token`; the Vite middleware holds `OPENAI_API_KEY` and posts the full session config (instructions, tool schemas, VAD, truncation) to `api.openai.com/v1/realtime/client_secrets`. SDP exchange goes directly to `api.openai.com/v1/realtime/calls` with the ephemeral token.
+- **Token flow**: browser fetches a short-lived client secret from `/api/realtime/token`; the Vite middleware uses `OPENAI_API_KEY` by default, or the signed-in local ChatGPT/Codex OAuth access token when OAuth was explicitly selected in Provider Settings, and posts the full session config (instructions, tool schemas, VAD, truncation) to `api.openai.com/v1/realtime/client_secrets`. Both long-lived credentials stay server-side; OAuth minting is loopback-only. SDP exchange goes directly to `api.openai.com/v1/realtime/calls` with the ephemeral token.
 - **Session defaults** (env-tunable): model `gpt-realtime-2` (or `gpt-realtime-2.1-mini` when the MINI tier is selected — see the model-tier entry below), voice `marin`, reasoning effort `low`, semantic VAD with low eagerness, no response interruption, context window truncated to ~3,000 post-instruction tokens with 0.5 retention ratio — the conversational window stays short because map state is fetched live per turn.
 - **Twenty-nine tools** (argument schemas in `src/voice/actionSchemas.js`, served with their descriptions by `server/providers/openai/tools.js`, executed client-side in `src/voice/gevActions.js`): `fly_to_location`, `select_nearest_aircraft`, `adjust_camera_zoom`, `zoom_to_globe`, `set_layer_visibility`, `show_data_layers_menu`, `set_panel_open`, `set_visual_style`, `get_entity_context`, `get_current_view_state`, `set_hud`, `set_detection`, `set_map_stack`, `set_post_processing`, `control_scene`, `control_cctv`, `set_context_mode`, `control_cockpit`, `control_radio`, `track_entity`, `stop_tracking`, `frame_overhead`, `annotate_map`, `clear_annotations`, `move_camera`, `fly_route`, `analyst_query`, `next_iss_pass`, and `next_satellite_pass`.
 
@@ -3653,7 +3653,7 @@ silently demoting every later lookup for the session.
   2. **Contacts OFF** → "nearby" means **in view**; "near \<place\>" means a radius around that place. A radius query with Contacts active and no explicit centre is centred on the **active contact**, not the camera.
   3. **Every count names its scope in words** — "42 in your window", "8 in view", "about 30 within 250 km of Austin" — never a bare number. `analyst_query` returns `scopeLabel` so this is mechanical. Two different numbers with named scopes are not a contradiction.
   4. **The loaded-data caveat is stated once when relevant**: counts cover loaded data, and the flights layer loads where you look (appended to `coverage.note` for radius/view scopes over viewport-loaded layers).
-- **Degradation**: without `OPENAI_API_KEY`, `/api/realtime/token` returns 503 and the mic button surfaces the error; the rest of the app is unaffected.
+- **Degradation**: API-key mode without `OPENAI_API_KEY` returns 503 as before. Selecting OAuth without a usable local ChatGPT/Codex sign-in starts the local `codex login` browser flow, polls for the resulting local token, and selects OAuth when sign-in completes. If the Codex login flow cannot start or does not complete, the rest of the app is unaffected.
 
 ### AI HUD Summary (June 2026)
 
@@ -3835,7 +3835,7 @@ are omitted rather than framing the wrong part of the globe.
 - GBFS proxy refuses upstream redirects (`redirect: 'manual'`; any 3xx becomes a 502 and the redirect target is logged server-side only) and enforces its 5 MB response cap while the body streams, cancelling the upstream read past the cap; CCTV health map is bounded.
 - Proxy error payloads are sanitized (no internal error details returned to clients).
 - That holds for the OpenAI and CCTV media paths too: `/api/openai/hud-summary` never relays OpenAI's own `error.message`, `/api/realtime/token` passes successful ephemeral-token responses through but answers with a fixed error when minting fails or upstream rejects the request, and a failed CCTV media fetch stores a fixed camera health `message` — `GET /api/cctv/health` serializes that field and the CCTV panel renders it as a status label, so it is a client surface as much as the response body is.
-- `OPENAI_API_KEY` is server-side only; the browser receives ephemeral Realtime client secrets from `/api/realtime/token`.
+- `OPENAI_API_KEY` remains server-side only and remains the default voice credential. The optional OAuth mode reads the local ChatGPT/Codex access token server-side on loopback only; the browser receives only ephemeral Realtime client secrets from `/api/realtime/token`.
 - `AISSTREAM_API_KEY` is server-side only; the browser reads the same-origin `/api/ais-live` cache.
 - `/api/google/nearby-places` keeps the Google key out of Places requests issued for voice scene context.
 - `/api/google/text-search` keeps the Google key server-side for view-biased Places recovery used by annotation resolution.

scripts/dev-fresh.sh

@@ -347,7 +347,7 @@ case "${OPENSKY_AUTH_MODE}" in
     echo "OpenSky auth: disabled (anonymous mode)"
     ;;
 esac
-[[ -n "${OPENAI_API_KEY}" ]] && echo "OpenAI key (voice + HUD summary): configured" || echo "OpenAI key (voice + HUD summary): not set — GEV MIC disabled"
+[[ -n "${OPENAI_API_KEY}" ]] && echo "OpenAI key (voice + HUD summary): configured" || echo "OpenAI key: not set — GEV MIC can use ChatGPT OAuth from Provider Settings"
 [[ -n "${AISSTREAM_API_KEY}" ]] && echo "AISStream key (live vessels): configured" || echo "AISStream key (live vessels): not set — ships layer empty"
 if [[ -n "${GOOGLE_MAPS_API_KEY}" ]]; then
   echo "Startup map: Google Photorealistic 3D Tiles (direct)"

scripts/package-boundaries.json

@@ -262,6 +262,7 @@
       "server/providers/common/request.js",
       "server/providers/common/source-root.js",
       "server/providers/openai.js",
+      "server/providers/openai/codex-auth.js",
       "server/providers/openai/constants.js",
       "server/providers/openai/debug-log.js",
       "server/providers/openai/hud-summary.js",
@@ -1220,6 +1221,7 @@
     "modules": [
       "src/voice/realtimeController.js",
       "src/voice/realtimeBackend.js",
+      "src/voice/cloudVoiceAuth.js",
       "src/voice/control.js",
       "src/voice/layerSummary.js",
       "src/voice/voiceCost.js",
@@ -1795,6 +1797,7 @@
       "src/voice/gevActions.js",
       "src/voice/gevRealtime.js",
       "src/voice/layerSummary.js",
+      "src/voice/cloudVoiceAuth.js",
       "src/voice/realtimeBackend.js",
       "src/voice/realtimeController.js",
       "src/voice/voiceCost.js",

scripts/setup-doctor.mjs

@@ -175,7 +175,9 @@ export function buildCapabilitySummary(
         ? 'Google Photorealistic 3D Tiles through Cesium ion; Bing and world-terrain stacks available'
         : 'Esri World Imagery (keyless satellite basemap) with keyless terrain',
     flights,
-    voice: configured('OPENAI_API_KEY') ? 'available' : 'off until an OpenAI key is added',
+    voice: configured('OPENAI_API_KEY')
+      ? 'available'
+      : 'ChatGPT/Codex OAuth can be selected at runtime',
     vessels: configured('AISSTREAM_API_KEY') ? 'live AISStream feed' : 'off until an AISStream key is added',
     fires: configured('FIRMS_MAP_KEY') ? 'live NASA FIRMS feed' : 'off until a FIRMS key is added',
     traffic: configured('TOMTOM_API_KEY') ? 'live TomTom flow' : 'built-in traffic simulation',

server/providers/openai.js

@@ -1,13 +1,17 @@
 import { defaultSourceRoot } from './common/source-root.js';
 import { handleHudSummary } from './openai/hud-summary.js';
 import { createDebugLogHandler } from './openai/debug-log.js';
-import { createRealtimeTokenHandler } from './openai/realtime.js';
+import {
+  createRealtimeOAuthLoginHandler,
+  createRealtimeOAuthStatusHandler,
+  createRealtimeTokenHandler,
+} from './openai/realtime.js';
 
 /**
  * Vite plugin: OpenAI Realtime ephemeral client secret.
  *
- * Keeps OPENAI_API_KEY server-side while the browser connects to the
- * Realtime API over WebRTC with a short-lived secret.
+ * Keeps the selected cloud credential server-side while the browser connects
+ * to the Realtime API over WebRTC with a short-lived secret.
  */
 function openAiRealtimeProxy({
   sourceRoot = defaultSourceRoot,
@@ -26,6 +30,16 @@ function openAiRealtimeProxy({
       '/api/realtime/token',
       createRealtimeTokenHandler({ ...realtime, annotationGuidance }),
     );
+
+    middlewares.use(
+      '/api/realtime/oauth-status',
+      createRealtimeOAuthStatusHandler(realtime),
+    );
+
+    middlewares.use(
+      '/api/realtime/oauth-login',
+      createRealtimeOAuthLoginHandler(realtime),
+    );
   }
 
   return {

server/providers/openai/codex-auth.js

@@ -0,0 +1,100 @@
+import { spawn } from 'node:child_process';
+import { accessSync, constants as fsConstants, readFileSync } from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+
+export function codexAuthPath({
+  environment = process.env,
+  home = os.homedir(),
+} = {}) {
+  const explicit = String(environment.CODEX_AUTH_JSON || '').trim();
+  if (explicit) return path.resolve(explicit);
+  const codexHome = String(environment.CODEX_HOME || '').trim();
+  return path.join(
+    codexHome ? path.resolve(codexHome) : path.join(home, '.codex'),
+    'auth.json',
+  );
+}
+
+export function readCodexOAuthAccessToken({
+  authPath = codexAuthPath(),
+  readFile = readFileSync,
+} = {}) {
+  let parsed;
+  try {
+    parsed = JSON.parse(readFile(authPath, 'utf8'));
+  } catch {
+    throw new Error(
+      'ChatGPT sign-in is unavailable. Sign in to Codex or the ChatGPT desktop app and try again.',
+    );
+  }
+  const token = String(parsed?.tokens?.access_token || '').trim();
+  if (!token) {
+    throw new Error(
+      'ChatGPT sign-in is unavailable. Sign in to Codex or the ChatGPT desktop app and try again.',
+    );
+  }
+  return token;
+}
+
+export function resolveCodexExecutable({
+  environment = process.env,
+  home = os.homedir(),
+  access = accessSync,
+} = {}) {
+  const explicit = String(environment.CODEX_BIN || '').trim();
+  if (explicit) return explicit;
+
+  for (const candidate of [
+    path.join(home, '.local', 'bin', 'codex'),
+    path.join(
+      home,
+      '.codex',
+      'packages',
+      'standalone',
+      'current',
+      'bin',
+      'codex',
+    ),
+  ]) {
+    try {
+      access(candidate, fsConstants.X_OK);
+      return candidate;
+    } catch {
+      // Fall through to the next known location, then PATH.
+    }
+  }
+  return 'codex';
+}
+
+export function startCodexChatGptLogin({
+  spawnImpl = spawn,
+  environment = process.env,
+  home = os.homedir(),
+  executable = resolveCodexExecutable({ environment, home }),
+} = {}) {
+  return new Promise((resolve, reject) => {
+    let child;
+    try {
+      child = spawnImpl(executable, ['login'], {
+        cwd: home,
+        detached: true,
+        stdio: 'ignore',
+        env: environment,
+      });
+    } catch (error) {
+      reject(error);
+      return;
+    }
+
+    child.once('error', reject);
+    child.once('spawn', () => {
+      child.unref?.();
+      resolve({ executable });
+    });
+  }).catch((error) => {
+    throw new Error(
+      `Could not start ChatGPT sign-in with Codex: ${error?.message || error}`,
+    );
+  });
+}

server/providers/openai/realtime.js

@@ -13,12 +13,167 @@ import {
 } from './constants.js';
 import { realtimeInstructions } from './instructions.js';
 import { GEV_REALTIME_TOOLS } from './tools.js';
+import {
+  readCodexOAuthAccessToken,
+  startCodexChatGptLogin,
+} from './codex-auth.js';
+
+const LOOPBACK_ADDRESSES = new Set(['127.0.0.1', '::1', '::ffff:127.0.0.1']);
+
+function isLoopbackRequest(req) {
+  return LOOPBACK_ADDRESSES.has(String(req.socket?.remoteAddress || ''));
+}
+
+function isSameOriginRequest(req) {
+  const origin = String(req.headers?.origin || '').trim();
+  if (!origin) return true;
+  const host = String(req.headers?.host || '').trim();
+  if (!host) return false;
+  const protocol = req.socket?.encrypted ? 'https:' : 'http:';
+  try {
+    return new URL(origin).origin === new URL(`${protocol}//${host}`).origin;
+  } catch {
+    return false;
+  }
+}
+
+function requestQuery(req) {
+  try {
+    return new URL(req.url || '', 'http://localhost').searchParams;
+  } catch {
+    return new URLSearchParams();
+  }
+}
+
+function resolveRealtimeAuthMode(query) {
+  const requested = String(query.get('auth') || 'api-key').toLowerCase();
+  if (requested === 'api-key' || requested === 'oauth') return requested;
+  return null;
+}
+
+function createRealtimeOAuthStatusHandler({
+  resolveOAuthAccessToken = () => readCodexOAuthAccessToken(),
+} = {}) {
+  return (req, res) => {
+    res.setHeader('Cache-Control', 'no-store');
+    res.setHeader('Content-Type', 'application/json');
+    if (req.method !== 'GET') {
+      res.statusCode = 405;
+      res.end(JSON.stringify({ error: 'Method not allowed' }));
+      return;
+    }
+    if (!isLoopbackRequest(req)) {
+      res.statusCode = 403;
+      res.end(
+        JSON.stringify({
+          available: false,
+          error: 'ChatGPT OAuth is available only from this machine',
+        }),
+      );
+      return;
+    }
+    try {
+      const token = resolveOAuthAccessToken();
+      if (!token) throw new Error('ChatGPT sign-in is unavailable');
+      res.statusCode = 200;
+      res.end(JSON.stringify({ available: true }));
+    } catch (error) {
+      res.statusCode = 200;
+      res.end(
+        JSON.stringify({
+          available: false,
+          error: error?.message || 'ChatGPT sign-in is unavailable',
+        }),
+      );
+    }
+  };
+}
+
+function createRealtimeOAuthLoginHandler({
+  resolveOAuthAccessToken = () => readCodexOAuthAccessToken(),
+  startOAuthLogin = () => startCodexChatGptLogin(),
+  now = () => Date.now(),
+  restartCooldownMs = 30_000,
+} = {}) {
+  let lastStartedAt = 0;
+  return async (req, res) => {
+    res.setHeader('Cache-Control', 'no-store');
+    res.setHeader('Content-Type', 'application/json');
+    if (req.method !== 'POST') {
+      res.statusCode = 405;
+      res.end(JSON.stringify({ error: 'Method not allowed' }));
+      return;
+    }
+    if (!isLoopbackRequest(req)) {
+      res.statusCode = 403;
+      res.end(
+        JSON.stringify({
+          available: false,
+          error: 'ChatGPT OAuth sign-in is available only from this machine',
+        }),
+      );
+      return;
+    }
+    if (!isSameOriginRequest(req)) {
+      res.statusCode = 403;
+      res.end(
+        JSON.stringify({
+          available: false,
+          error: 'Cross-origin ChatGPT OAuth sign-in is not allowed',
+        }),
+      );
+      return;
+    }
+
+    try {
+      if (resolveOAuthAccessToken()) {
+        res.statusCode = 200;
+        res.end(
+          JSON.stringify({ available: true, started: false, pending: false }),
+        );
+        return;
+      }
+    } catch {
+      // No usable local token yet; launch the supported Codex sign-in flow.
+    }
+
+    const currentTime = now();
+    if (
+      lastStartedAt > 0 &&
+      currentTime - lastStartedAt < Math.max(0, restartCooldownMs)
+    ) {
+      res.statusCode = 202;
+      res.end(
+        JSON.stringify({ available: false, started: false, pending: true }),
+      );
+      return;
+    }
+
+    try {
+      await startOAuthLogin();
+      lastStartedAt = currentTime;
+      res.statusCode = 202;
+      res.end(
+        JSON.stringify({ available: false, started: true, pending: true }),
+      );
+    } catch (error) {
+      res.statusCode = 503;
+      res.end(
+        JSON.stringify({
+          available: false,
+          error: error?.message || 'Could not start ChatGPT sign-in',
+        }),
+      );
+    }
+  };
+}
 
 function createRealtimeTokenHandler({
   annotationGuidance,
   endpoint = 'https://api.openai.com/v1/realtime/client_secrets',
   fetchImpl = (...args) => fetch(...args),
   resolveApiKey = () => process.env.OPENAI_API_KEY,
+  resolveOAuthAccessToken = () => readCodexOAuthAccessToken(),
   models = {},
 } = {}) {
   return async (req, res) => {
@@ -30,15 +185,62 @@ function createRealtimeTokenHandler({
       return;
     }
 
+    const query = requestQuery(req);
+    const authMode = resolveRealtimeAuthMode(query);
+    if (!authMode) {
+      res.statusCode = 400;
+      res.setHeader('Content-Type', 'application/json');
+      res.end(JSON.stringify({ error: 'Unsupported cloud voice auth mode' }));
+      return;
+    }
+
     // Opt-in per-IP throttle (GEV_RATELIMIT_OPENAI_PER_MIN). No-op when unset.
     if (!enforceOptInRateLimit(openAiRateLimiter(), req, res)) return;
 
-    const apiKey = resolveApiKey();
-    if (!apiKey) {
-      res.statusCode = 503;
-      res.setHeader('Content-Type', 'application/json');
-      res.end(JSON.stringify({ error: 'OPENAI_API_KEY is not set' }));
-      return;
+    let bearer;
+    if (authMode === 'oauth') {
+      if (!isLoopbackRequest(req)) {
+        res.statusCode = 403;
+        res.setHeader('Content-Type', 'application/json');
+        res.end(
+          JSON.stringify({
+            error: 'ChatGPT OAuth voice is available only from this machine',
+          }),
+        );
+        return;
+      }
+      try {
+        bearer = resolveOAuthAccessToken();
+      } catch (error) {
+        res.statusCode = 503;
+        res.setHeader('Content-Type', 'application/json');
+        res.end(
+          JSON.stringify({
+            error: error?.message || 'ChatGPT sign-in is unavailable',
+            code: 'CODEX_OAUTH_UNAVAILABLE',
+          }),
+        );
+        return;
+      }
+      if (!bearer) {
+        res.statusCode = 503;
+        res.setHeader('Content-Type', 'application/json');
+        res.end(
+          JSON.stringify({
+            error: 'ChatGPT sign-in is unavailable',
+            code: 'CODEX_OAUTH_UNAVAILABLE',
+          }),
+        );
+        return;
+      }
+    } else {
+      bearer = resolveApiKey();
+      if (!bearer) {
+        res.statusCode = 503;
+        res.setHeader('Content-Type', 'application/json');
+        res.end(JSON.stringify({ error: 'OPENAI_API_KEY is not set' }));
+        return;
+      }
     }
 
     // Voice model tier, requested by the client as ?tier=standard|mini.
@@ -47,15 +249,7 @@ function createRealtimeTokenHandler({
     // bad querystring degrades to a normal session rather than a dead mic.
     // The env overrides stay authoritative per tier (see .env.example) —
     // a wrong upstream model id is then a config fix, not a code change.
-    const requestedTier = (() => {
-      try {
-        return new URL(req.url || '', 'http://localhost').searchParams.get(
-          'tier',
-        );
-      } catch {
-        return null;
-      }
-    })();
+    const requestedTier = query.get('tier');
     const tier = resolveVoiceModel(requestedTier).tier;
     const model =
       tier === 'mini'
@@ -124,7 +318,7 @@ function createRealtimeTokenHandler({
         redirect: 'error',
         signal: AbortSignal.timeout(30_000),
         headers: {
-          Authorization: `Bearer ${apiKey}`,
+          Authorization: `Bearer ${bearer}`,
           'Content-Type': 'application/json',
           'OpenAI-Safety-Identifier': 'gev-local-dev',
         },
@@ -167,4 +361,8 @@ function createRealtimeTokenHandler({
   };
 }
 
-export { createRealtimeTokenHandler };
+export {
+  createRealtimeOAuthLoginHandler,
+  createRealtimeOAuthStatusHandler,
+  createRealtimeTokenHandler,
+};

src/codexOauthRealtime.test.mjs

@@ -0,0 +1,93 @@
+import assert from 'node:assert/strict';
+import { EventEmitter } from 'node:events';
+import test from 'node:test';
+import path from 'node:path';
+import {
+  codexAuthPath,
+  readCodexOAuthAccessToken,
+  resolveCodexExecutable,
+  startCodexChatGptLogin,
+} from '../server/providers/openai/codex-auth.js';
+
+test('Codex auth path follows explicit auth file, CODEX_HOME, then home directory', () => {
+  assert.equal(
+    codexAuthPath({
+      environment: { CODEX_AUTH_JSON: '/tmp/custom-auth.json' },
+      home: '/home/fixture',
+    }),
+    path.resolve('/tmp/custom-auth.json'),
+  );
+  assert.equal(
+    codexAuthPath({
+      environment: { CODEX_HOME: '/tmp/codex-home' },
+      home: '/home/fixture',
+    }),
+    path.join(path.resolve('/tmp/codex-home'), 'auth.json'),
+  );
+  assert.equal(
+    codexAuthPath({ environment: {}, home: '/home/fixture' }),
+    path.join('/home/fixture', '.codex', 'auth.json'),
+  );
+});
+
+test('Codex OAuth token reader returns only the access token and fails closed', () => {
+  assert.equal(
+    readCodexOAuthAccessToken({
+      authPath: '/unused',
+      readFile: () => JSON.stringify({ tokens: { access_token: ' oauth-fixture ' } }),
+    }),
+    'oauth-fixture',
+  );
+  for (const readFile of [
+    () => '{bad json',
+    () => JSON.stringify({ tokens: {} }),
+    () => {
+      throw new Error('missing');
+    },
+  ]) {
+    assert.throws(
+      () => readCodexOAuthAccessToken({ authPath: '/unused', readFile }),
+      /ChatGPT sign-in is unavailable/,
+    );
+  }
+});
+
+test('Codex login resolves an installed executable before PATH and starts browser auth detached', async () => {
+  const checked = [];
+  assert.equal(
+    resolveCodexExecutable({
+      environment: {},
+      home: '/home/fixture',
+      access(candidate) {
+        checked.push(candidate);
+        if (candidate.endsWith('/.local/bin/codex')) return;
+        throw new Error('missing');
+      },
+    }),
+    path.join('/home/fixture', '.local', 'bin', 'codex'),
+  );
+  assert.equal(checked.length, 1);
+
+  const child = new EventEmitter();
+  let unref = 0;
+  child.unref = () => {
+    unref += 1;
+  };
+  const calls = [];
+  const pending = startCodexChatGptLogin({
+    executable: '/fixture/codex',
+    home: '/home/fixture',
+    environment: { PATH: '/fixture' },
+    spawnImpl(command, args, options) {
+      calls.push({ command, args, options });
+      queueMicrotask(() => child.emit('spawn'));
+      return child;
+    },
+  });
+  assert.deepEqual(await pending, { executable: '/fixture/codex' });
+  assert.equal(unref, 1);
+  assert.equal(calls[0].command, '/fixture/codex');
+  assert.deepEqual(calls[0].args, ['login']);
+  assert.equal(calls[0].options.detached, true);
+  assert.equal(calls[0].options.stdio, 'ignore');
+});

src/keySetup.js

@@ -1,4 +1,8 @@
 import { createSurfaceKeyboard } from './ui/surfaceKeyboard.js';
+import {
+  readStoredCloudVoiceAuthMode,
+  writeStoredCloudVoiceAuthMode,
+} from './voice/cloudVoiceAuth.js';
 
 /**
  * The POWER UP surface — paste a key, get a power.
@@ -38,6 +42,46 @@ export function collectKeyUpdates(fields) {
   return updates;
 }
 
+function sleepWithSignal(ms, signal) {
+  return new Promise((resolve, reject) => {
+    if (signal?.aborted) {
+      reject(signal.reason || new DOMException('Aborted', 'AbortError'));
+      return;
+    }
+    const onAbort = () => {
+      clearTimeout(timer);
+      reject(signal.reason || new DOMException('Aborted', 'AbortError'));
+    };
+    const timer = setTimeout(() => {
+      signal?.removeEventListener('abort', onAbort);
+      resolve();
+    }, ms);
+    signal?.addEventListener('abort', onAbort, { once: true });
+  });
+}
+
+export async function waitForChatGptOAuth({
+  fetchImpl,
+  signal,
+  timeoutMs = 120_000,
+  pollMs = 1_000,
+  now = () => Date.now(),
+  sleep = sleepWithSignal,
+} = {}) {
+  const deadline = now() + Math.max(0, timeoutMs);
+  while (!signal?.aborted && now() <= deadline) {
+    const response = await fetchImpl('/api/realtime/oauth-status', {
+      cache: 'no-store',
+      signal,
+    });
+    const payload = await response.json().catch(() => ({}));
+    if (response.ok && payload.available) return true;
+    if (now() >= deadline) break;
+    await sleep(Math.max(0, pollMs), signal);
+  }
+  return false;
+}
+
 /**
  * After the FIRST Google key lands, the restart's reload should boot the
  * photoreal default — not faithfully restore the auto-selected keyless OSM
@@ -144,6 +188,26 @@ function buildRow(documentRef, key) {
     }
     row.append(fields);
   }
+  if (key.id === 'openai') {
+    const auth = documentRef.createElement('div');
+    auth.className = 'key-setup-cloud-auth';
+    const mode = readStoredCloudVoiceAuthMode();
+    const state = documentRef.createElement('span');
+    state.className = 'key-setup-cloud-auth-state';
+    state.textContent =
+      mode === 'oauth' ? 'VOICE AUTH · CHATGPT OAUTH' : 'VOICE AUTH · API KEY';
+    const toggle = documentRef.createElement('button');
+    toggle.type = 'button';
+    toggle.className = 'key-setup-cloud-auth-toggle';
+    toggle.dataset.cloudVoiceAuthToggle = 'true';
+    toggle.textContent = mode === 'oauth' ? 'USE API KEY' : 'USE CHATGPT OAUTH';
+    toggle.title =
+      mode === 'oauth'
+        ? 'Use OPENAI_API_KEY for the next cloud voice session'
+        : 'Use the signed-in local ChatGPT/Codex OAuth session for the next cloud voice session';
+    auth.append(state, toggle);
+    row.append(auth);
+  }
   return row;
 }
 
@@ -363,6 +427,86 @@ export async function initKeySetup({
   applyButton?.addEventListener('click', onApply);
   // Remove buttons are rendered per row; delegate so re-renders stay wired.
   rowsHost?.addEventListener('click', (event) => {
+    const authButton = event.target?.closest?.(
+      '[data-cloud-voice-auth-toggle]',
+    );
+    if (authButton && !disposed) {
+      void (async () => {
+        const current = readStoredCloudVoiceAuthMode();
+        if (current === 'oauth') {
+          writeStoredCloudVoiceAuthMode('api-key');
+          render(status);
+          say('Cloud voice will use OPENAI_API_KEY on the next session.');
+          return;
+        }
+        authButton.disabled = true;
+        say('Checking local ChatGPT OAuth sign-in…');
+        try {
+          const response = await doFetch('/api/realtime/oauth-status', {
+            cache: 'no-store',
+            signal: lifetime.signal,
+          });
+          const payload = await response.json().catch(() => ({}));
+          if (response.ok && payload.available) {
+            writeStoredCloudVoiceAuthMode('oauth');
+            render(status);
+            say(
+              'ChatGPT OAuth selected for cloud voice. Your API key stays saved and available.',
+            );
+            return;
+          }
+
+          say('Opening ChatGPT sign-in in your browser…');
+          const loginResponse = await doFetch('/api/realtime/oauth-login', {
+            method: 'POST',
+            cache: 'no-store',
+            signal: lifetime.signal,
+          });
+          const loginPayload = await loginResponse.json().catch(() => ({}));
+          if (!loginResponse.ok && loginResponse.status !== 202) {
+            say(
+              loginPayload.error ||
+                payload.error ||
+                'Could not start ChatGPT sign-in on this machine.',
+            );
+            return;
+          }
+          if (loginPayload.available) {
+            writeStoredCloudVoiceAuthMode('oauth');
+            render(status);
+            say(
+              'ChatGPT OAuth selected for cloud voice. Your API key stays saved and available.',
+            );
+            return;
+          }
+
+          say(
+            'Finish ChatGPT sign-in in the browser. Waiting for it to complete…',
+          );
+          const available = await waitForChatGptOAuth({
+            fetchImpl: doFetch,
+            signal: lifetime.signal,
+          });
+          if (!available) {
+            say(
+              'ChatGPT sign-in is still pending. Finish it in the browser, then click USE CHATGPT OAUTH again.',
+            );
+            return;
+          }
+          writeStoredCloudVoiceAuthMode('oauth');
+          render(status);
+          say(
+            'ChatGPT sign-in complete. OAuth will be used for the next cloud voice session.',
+          );
+        } catch (error) {
+          if (lifetime.signal.aborted) return;
+          say(`OAuth check failed: ${error?.message || error}`);
+        } finally {
+          authButton.disabled = false;
+        }
+      })();
+      return;
+    }
     const button = event.target?.closest?.('[data-key-setup-remove]');
     if (disposed || !button || busy) return;
     let envVars = [];

src/keySetup.test.mjs

@@ -5,6 +5,7 @@ import {
   keySetupChipLabel,
   stripKeylessBasemapFromHash,
   bindKeySetupPlacement,
+  waitForChatGptOAuth,
 } from './keySetup.js';
 
 test('setup placement moves the same button only in Cyber and disconnects on teardown', () => {
@@ -61,6 +62,28 @@ test('collectKeyUpdates keeps only non-empty trimmed values', () => {
   assert.deepEqual(collectKeyUpdates(null), {});
 });
 
+test('OAuth login polling stops as soon as local ChatGPT auth becomes available', async () => {
+  let checks = 0;
+  let clock = 0;
+  const available = await waitForChatGptOAuth({
+    fetchImpl: async () => {
+      checks += 1;
+      return {
+        ok: true,
+        json: async () => ({ available: checks >= 3 }),
+      };
+    },
+    timeoutMs: 10_000,
+    pollMs: 100,
+    now: () => clock,
+    sleep: async (ms) => {
+      clock += ms;
+    },
+  });
+  assert.equal(available, true);
+  assert.equal(checks, 3);
+});
+
 test('the first Google key strips ONLY the keyless OSM basemap from the share hash', () => {
   const stripped = stripKeylessBasemapFromHash('lat=30.2&lon=-97.7&map=osm&style=normal');
   assert.ok(stripped !== null);

src/keySetupCore.mjs

@@ -52,7 +52,7 @@ export const KEY_SETUP_KEYS = Object.freeze([
   Object.freeze({
     id: 'openai',
     title: 'OPENAI',
-    unlocks: 'Voice control — talk to the planet',
+    unlocks: 'Voice control — API key or ChatGPT OAuth',
     getUrl: 'https://platform.openai.com/api-keys',
     envVars: Object.freeze(['OPENAI_API_KEY']),
     tier: 'metered',

src/setupDoctor.test.mjs

@@ -224,6 +224,13 @@ test('doctor describes the credential ladder without exposing values', () => {
   assert.match(capabilities.map, /Google Photorealistic 3D Tiles through Cesium ion/);
   assert.match(capabilities.map, /Bing and world-terrain stacks/);
   assert.equal(capabilities.voice, 'available');
+  assert.equal(
+    buildCapabilitySummary({
+      ...credentials,
+      OPENAI_API_KEY: { configured: false },
+    }).voice,
+    'ChatGPT/Codex OAuth can be selected at runtime',
+  );
   assert.match(capabilities.missions, /token allowance/);
   assert.equal(capabilities.flights, 'OpenSky keyless anonymous access (rate-limited)');
 

src/tooling/localServices.test.mjs

@@ -37,6 +37,7 @@ function request(
     url = '/',
     body = '',
     origin = 'http://localhost:4173',
+    remoteAddress = '127.0.0.1',
   } = {},
 ) {
   return new Promise((resolve, reject) => {
@@ -49,7 +50,7 @@ function request(
         origin,
         'content-type': 'application/json',
       },
-      socket: { remoteAddress: '127.0.0.1' },
+      socket: { remoteAddress },
     });
     const headers = {};
     const res = {
@@ -195,6 +196,147 @@ test('Realtime handler preserves tools and default instructions, isolates suppli
   assert.equal(sent[0].session.instructions, sent[2].session.instructions);
 });
 
+test('Realtime handler keeps API key as default and uses OAuth only when requested', async (t) => {
+  env(t, 'GEV_RATELIMIT_OPENAI_PER_MIN', undefined);
+  let oauthReads = 0;
+  const authorizations = [];
+  const routes = install(
+    openAiRealtimeProxy({
+      realtime: {
+        resolveApiKey: () => 'fixture-api-key',
+        resolveOAuthAccessToken: () => {
+          oauthReads += 1;
+          return 'fixture-oauth-token';
+        },
+        fetchImpl: async (_url, options) => {
+          authorizations.push(options.headers.Authorization);
+          return Response.json({ value: 'fixture-ephemeral' });
+        },
+      },
+    }),
+  );
+  const token = routes.get('/api/realtime/token');
+
+  assert.equal((await request(token)).status, 200);
+  assert.equal(oauthReads, 0, 'default cloud voice does not read OAuth');
+  assert.equal(authorizations.at(-1), 'Bearer fixture-api-key');
+
+  assert.equal((await request(token, { url: '/?auth=oauth' })).status, 200);
+  assert.equal(oauthReads, 1);
+  assert.equal(authorizations.at(-1), 'Bearer fixture-oauth-token');
+});
+
+test('OAuth status and token minting never expose local OAuth to remote clients', async () => {
+  let oauthReads = 0;
+  const routes = install(
+    openAiRealtimeProxy({
+      realtime: {
+        resolveOAuthAccessToken: () => {
+          oauthReads += 1;
+          return 'must-not-be-read-remotely';
+        },
+        fetchImpl: () =>
+          assert.fail('remote OAuth request must not reach OpenAI'),
+      },
+    }),
+  );
+  const remote = { remoteAddress: '192.168.1.20' };
+  assert.equal(
+    (await request(routes.get('/api/realtime/oauth-status'), remote)).status,
+    403,
+  );
+  assert.equal(
+    (
+      await request(routes.get('/api/realtime/token'), {
+        ...remote,
+        url: '/?auth=oauth',
+      })
+    ).status,
+    403,
+  );
+  assert.equal(oauthReads, 0);
+});
+
+test('OAuth status reports local sign-in availability without returning the token', async () => {
+  const routes = install(
+    openAiRealtimeProxy({
+      realtime: { resolveOAuthAccessToken: () => 'fixture-oauth-secret' },
+    }),
+  );
+  const response = await request(routes.get('/api/realtime/oauth-status'));
+  assert.equal(response.status, 200);
+  assert.deepEqual(response.json(), { available: true });
+  assert.equal(response.body.includes('fixture-oauth-secret'), false);
+});
+
+test('OAuth login endpoint launches local Codex sign-in once and never exposes credentials', async () => {
+  let starts = 0;
+  let clock = 1_000;
+  const routes = install(
+    openAiRealtimeProxy({
+      realtime: {
+        resolveOAuthAccessToken: () => {
+          throw new Error('not signed in');
+        },
+        startOAuthLogin: async () => {
+          starts += 1;
+        },
+        now: () => clock,
+      },
+    }),
+  );
+  const handler = routes.get('/api/realtime/oauth-login');
+
+  const started = await request(handler, { method: 'POST' });
+  assert.equal(started.status, 202);
+  assert.deepEqual(started.json(), {
+    available: false,
+    started: true,
+    pending: true,
+  });
+  assert.equal(starts, 1);
+
+  clock += 1_000;
+  const duplicate = await request(handler, { method: 'POST' });
+  assert.equal(duplicate.status, 202);
+  assert.equal(duplicate.json().pending, true);
+  assert.equal(starts, 1, 'rapid retries must not spawn another login');
+
+  const remote = await request(handler, {
+    method: 'POST',
+    remoteAddress: '192.168.1.20',
+  });
+  assert.equal(remote.status, 403);
+  assert.equal(starts, 1);
+
+  const crossOrigin = await request(handler, {
+    method: 'POST',
+    origin: 'https://example.com',
+  });
+  assert.equal(crossOrigin.status, 403);
+  assert.equal(starts, 1);
+});
+
+test('OAuth login endpoint selects an existing local sign-in without launching Codex', async () => {
+  const handler = install(
+    openAiRealtimeProxy({
+      realtime: {
+        resolveOAuthAccessToken: () => 'fixture-existing-secret',
+        startOAuthLogin: () =>
+          assert.fail('existing auth must not launch login'),
+      },
+    }),
+  ).get('/api/realtime/oauth-login');
+  const response = await request(handler, { method: 'POST' });
+  assert.equal(response.status, 200);
+  assert.deepEqual(response.json(), {
+    available: true,
+    started: false,
+    pending: false,
+  });
+  assert.equal(response.body.includes('fixture-existing-secret'), false);
+});
+
 test('debug logging resolves each supplied application directory independently', async (t) => {
   const first = root(t),
     second = root(t);

src/ui/styles/provider-settings.css

@@ -300,6 +300,43 @@
   color: rgba(148, 178, 188, 0.42);
 }
 
+.key-setup-cloud-auth {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+}
+
+.key-setup-cloud-auth-state {
+  color: rgba(190, 214, 222, 0.7);
+  font-family: var(--font-mono);
+  font-size: 0.56rem;
+  letter-spacing: 0.05rem;
+}
+
+.key-setup-cloud-auth-toggle {
+  margin-left: auto;
+  padding: 0.28rem 0.55rem;
+  color: rgba(54, 220, 255, 0.9);
+  font-family: var(--font-mono);
+  font-size: 0.55rem;
+  letter-spacing: 0.06rem;
+  background: rgba(54, 220, 255, 0.08);
+  border: 1px solid rgba(54, 220, 255, 0.28);
+  border-radius: 0.32rem;
+  cursor: pointer;
+}
+
+.key-setup-cloud-auth-toggle:hover,
+.key-setup-cloud-auth-toggle:focus-visible {
+  border-color: rgba(54, 220, 255, 0.65);
+  outline: none;
+}
+
+.key-setup-cloud-auth-toggle:disabled {
+  cursor: wait;
+  opacity: 0.5;
+}
+
 .key-setup-footer {
   margin-top: 0.85rem;
 }

src/voice/cloudVoiceAuth.js

@@ -0,0 +1,41 @@
+export const CLOUD_VOICE_AUTH_MODES = Object.freeze(['api-key', 'oauth']);
+export const DEFAULT_CLOUD_VOICE_AUTH_MODE = 'api-key';
+export const CLOUD_VOICE_AUTH_STORAGE_KEY = 'godsEyeView.voice.cloudAuth';
+
+function storageRef(storage) {
+  if (storage) return storage;
+  try {
+    return typeof localStorage === 'undefined' ? null : localStorage;
+  } catch {
+    return null;
+  }
+}
+
+export function normalizeCloudVoiceAuthMode(mode) {
+  const normalized = String(mode || '')
+    .trim()
+    .toLowerCase();
+  return CLOUD_VOICE_AUTH_MODES.includes(normalized)
+    ? normalized
+    : DEFAULT_CLOUD_VOICE_AUTH_MODE;
+}
+
+export function readStoredCloudVoiceAuthMode(storage) {
+  try {
+    return normalizeCloudVoiceAuthMode(
+      storageRef(storage)?.getItem(CLOUD_VOICE_AUTH_STORAGE_KEY),
+    );
+  } catch {
+    return DEFAULT_CLOUD_VOICE_AUTH_MODE;
+  }
+}
+
+export function writeStoredCloudVoiceAuthMode(mode, storage) {
+  const resolved = normalizeCloudVoiceAuthMode(mode);
+  try {
+    storageRef(storage)?.setItem(CLOUD_VOICE_AUTH_STORAGE_KEY, resolved);
+  } catch {
+    /* best effort */
+  }
+  return resolved;
+}

src/voice/cloudVoiceAuth.test.mjs

@@ -0,0 +1,29 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  CLOUD_VOICE_AUTH_STORAGE_KEY,
+  readStoredCloudVoiceAuthMode,
+  writeStoredCloudVoiceAuthMode,
+} from './cloudVoiceAuth.js';
+
+function memoryStorage(seed = {}) {
+  const values = new Map(Object.entries(seed));
+  return {
+    getItem: (key) => values.get(key) ?? null,
+    setItem: (key, value) => values.set(key, value),
+  };
+}
+
+test('cloud voice auth defaults to API key and persists OAuth independently', () => {
+  const storage = memoryStorage();
+  assert.equal(readStoredCloudVoiceAuthMode(storage), 'api-key');
+  assert.equal(writeStoredCloudVoiceAuthMode('oauth', storage), 'oauth');
+  assert.equal(readStoredCloudVoiceAuthMode(storage), 'oauth');
+  assert.equal(writeStoredCloudVoiceAuthMode('unknown', storage), 'api-key');
+  assert.equal(
+    readStoredCloudVoiceAuthMode(
+      memoryStorage({ [CLOUD_VOICE_AUTH_STORAGE_KEY]: 'oauth' }),
+    ),
+    'oauth',
+  );
+});

src/voice/gevRealtime.test.mjs

@@ -3194,6 +3194,20 @@ test('F1: the toggle still records the next-session preference while live', () =
   assert.match(ui.tierButton.title, /this session stays on/i);
 });
 
+test('OAuth cloud sessions hide API spend and do not trip the API spend guard', () => {
+  const { controller, ui } = costControllerHarness();
+  controller.status = 'listening';
+  controller._cost.cloudVoiceAuth = 'oauth';
+  controller._cost.sessionCloudVoiceAuth = 'oauth';
+  controller.syncCostUi();
+  const before = controller.costTracker.state();
+  assert.equal(ui.costValue.hidden, true);
+  assert.equal(controller.recordUsage(usdUsage(100)), null);
+  const after = controller.costTracker.state();
+  assert.equal(after.totalUsd, before.totalUsd);
+  assert.equal(controller.costCapStopped, false);
+});
+
 test('F1: when idle, toggling does re-price the preview meter', () => {
   const { controller } = costControllerHarness();
   controller.status = 'idle';

src/voice/realtimeBackend.js

@@ -15,11 +15,19 @@ export function createRealtimeBackend({
     );
   return Object.freeze({
     protocol: 'openai-realtime',
-    async requestToken({ tier = DEFAULT_VOICE_TIER, signal } = {}) {
+    async requestToken({
+      tier = DEFAULT_VOICE_TIER,
+      authMode = 'api-key',
+      signal,
+    } = {}) {
       signal = scoped(signal);
       signal.throwIfAborted();
       const separator = tokenEndpoint.includes('?') ? '&' : '?';
-      const url = `${tokenEndpoint}${separator}tier=${encodeURIComponent(resolveVoiceModel(tier).tier)}`;
+      const query = new URLSearchParams({
+        tier: resolveVoiceModel(tier).tier,
+      });
+      if (authMode === 'oauth') query.set('auth', 'oauth');
+      const url = `${tokenEndpoint}${separator}${query}`;
       const response = await tokenTransport(url, {
         signal,
         cache: 'no-store',

src/voice/realtimeBackend.test.mjs

@@ -41,6 +41,22 @@ test('separate configured token and SDP transports preserve model metadata and c
   ]);
 });
 
+test('OAuth is an additive token query while API key stays the default', async () => {
+  const calls = [];
+  const backend = createRealtimeBackend({
+    tokenTransport: async (input) => {
+      calls.push(input);
+      return tokenReply();
+    },
+  });
+  await backend.requestToken();
+  await backend.requestToken({ authMode: 'oauth' });
+  assert.deepEqual(calls, [
+    '/api/realtime/token?tier=standard',
+    '/api/realtime/token?tier=standard&auth=oauth',
+  ]);
+});
+
 test('denied tokens never negotiate or retry; reconnect requests a fresh token', async () => {
   let requests = 0;
   const backend = createRealtimeBackend({

src/voice/realtimeConnection.js

@@ -82,6 +82,7 @@ export class RealtimeConnection {
     this.debugLog('session.starting', {
       epoch,
       tier: this.cost.voiceTier,
+      authMode: this.cost.sessionCloudVoiceAuth,
       connection: this.connectionDiagnostics(),
     });
     let localStream = null;
@@ -89,6 +90,7 @@ export class RealtimeConnection {
     try {
       const minted = await this.backend.requestToken({
         tier: this.cost.voiceTier,
+        authMode: this.cost.sessionCloudVoiceAuth,
         signal,
       });
       const token = minted.token;

src/voice/realtimeCost.js

@@ -4,6 +4,7 @@ import {
   writeStoredVoiceTier,
   writeStoredVoiceLimits,
 } from './realtimePreferences.js';
+import { readStoredCloudVoiceAuthMode } from './cloudVoiceAuth.js';
 import {
   createVoiceCostTracker,
   resolveVoiceModel,
@@ -16,6 +17,8 @@ export class RealtimeCost {
     Object.assign(this, { readUi, readStatus }, operations);
     this.voiceTier = readStoredVoiceTier();
     this.voiceLimits = readStoredVoiceLimits();
+    this.cloudVoiceAuth = readStoredCloudVoiceAuthMode();
+    this.sessionCloudVoiceAuth = null;
     this.costTracker = createVoiceCostTracker({
       tier: this.voiceTier,
       limits: this.voiceLimits,
@@ -56,6 +59,8 @@ export class RealtimeCost {
             }; applies next session`;
     }
     if (this.ui?.costValue) {
+      const liveAuth = this.sessionCloudVoiceAuth || this.cloudVoiceAuth;
+      this.ui.costValue.hidden = liveAuth === 'oauth';
       this.ui.costValue.textContent = state.display;
       this.ui.costValue.dataset.level = state.level;
       this.ui.costValue.title =
@@ -136,6 +141,7 @@ export class RealtimeCost {
    */
   recordUsage(usage) {
     if (!usage) return null;
+    if (this.sessionCloudVoiceAuth === 'oauth') return null;
     const state = this.costTracker.record(usage);
     this.syncCostUi();
     if (state.warnCrossed) {
@@ -190,6 +196,8 @@ export class RealtimeCost {
   prepareSession() {
     this.voiceTier = readStoredVoiceTier();
     this.voiceLimits = readStoredVoiceLimits();
+    this.cloudVoiceAuth = readStoredCloudVoiceAuthMode();
+    this.sessionCloudVoiceAuth = this.cloudVoiceAuth;
     this.costCapStopped = false;
     // Provisional meter (tier-priced) so the readout shows $0.00 while
     // connecting. It is REPLACED below with one bound to the model the server