diff --git a/docs/guides/authentication.mdx b/docs/guides/authentication.mdx
index 3a7120eb18..9236e6ebc1 100644
--- a/docs/guides/authentication.mdx
+++ b/docs/guides/authentication.mdx
@@ -37,7 +37,7 @@ Signing in is the same OAuth step as creating an account — new users land on t
   </Step>
 </Steps>
 
-The credential lives in `~/.heygen/credentials` (mode `0600`) — no per-repo `.env` to manage. Browser OAuth is a `hyperframes auth login` feature. The separate [`heygen` CLI](https://github.com/heygen-com/heygen-cli) (its own install — there's no `npx heygen`) is API-key-only, so `heygen auth login` just stores a key you paste. Both read the same `~/.heygen/credentials`, so signing in with one carries to the other.
+HyperFrames uses its own public OAuth client and stores credentials in `~/.hyperframes/credentials` (mode `0600`). Sign in again after upgrading from the shared HeyGen login. The separate [`heygen` CLI](https://github.com/heygen-com/heygen-cli) keeps its own login in `~/.heygen`; HyperFrames does not move or delete it. An expired HyperFrames OAuth session requires refresh or sign-in and never selects a saved API key instead. An explicit API-key login or environment key selects API-key billing.
 
 <Tip>
   No account is needed to try HyperFrames locally. With no credential, voice can
@@ -54,12 +54,11 @@ sound retrieval. It resolves first-match-wins:
 2. `HEYGEN_ACCESS_TOKEN` — an OAuth token a host app injects
 3. `HEYGEN_API_KEY` — environment variable
 4. `HYPERFRAMES_API_KEY` — alias, for parity with other tools
-5. `~/.heygen/credentials` — written by `hyperframes auth login` (or `heygen auth login`)
+5. `~/.hyperframes/credentials` — written by `hyperframes auth login`
 
 A nearby project `.env` can supply the keys, but never `HEYGEN_API_BASE`. Point at a different config directory
-with `HEYGEN_CONFIG_DIR`. The `hyperframes` CLI's own commands check the API keys before `HEYGEN_ACCESS_TOKEN`; see
-the [CLI reference](/packages/cli). `media-use resolve` searches through the separate `heygen` CLI, which resolves its
-own credential.
+with `HYPERFRAMES_CONFIG_DIR`. The `hyperframes` CLI's own commands check the API keys before `HEYGEN_ACCESS_TOKEN`; see
+the [CLI reference](/packages/cli). When `media-use` invokes the separate `heygen` executable, it supplies an isolated temporary credential containing the selected access token. That helper cannot refresh a HyperFrames grant or pick up another HeyGen login.
 
 ## Providers used by agent workflows
 
@@ -70,7 +69,7 @@ vision key is available.
 
 | Capability | Provider order | Key(s) — first match wins | Local dependency |
 |------------|----------------|---------------------------|------------------|
-| **Voice (TTS)** | HeyGen → ElevenLabs → Kokoro | `HEYGEN_API_KEY` → `HYPERFRAMES_API_KEY` → `~/.heygen` · then `ELEVENLABS_API_KEY` | Kokoro: `pip install kokoro-onnx soundfile` |
+| **Voice (TTS)** | HeyGen → ElevenLabs → Kokoro | `HEYGEN_API_KEY` → `HYPERFRAMES_API_KEY` → `~/.hyperframes` · then `ELEVENLABS_API_KEY` | Kokoro: `pip install kokoro-onnx soundfile` |
 | **Music (BGM)** | HeyGen library → Lyria → MusicGen | HeyGen credential (above) · then `GEMINI_API_KEY` → `GOOGLE_API_KEY` | MusicGen: `pip install transformers torch soundfile numpy` |
 | **Sound effects** | HeyGen library → bundled library | HeyGen credential (above) | bundled — no deps |
 | **Capture descriptions** | OpenRouter → Gemini | `OPENROUTER_API_KEY` → `GEMINI_API_KEY` | None; optional for [website capture](/guides/product-launch-video) |
@@ -145,7 +144,9 @@ to a shared space with `--space`.
 | `HEYGEN_ACCESS_TOKEN` | OAuth token a host app injects; never refreshed or saved. |
 | `HEYGEN_API_BASE` | A host app's gateway for media workflows; never read from a project `.env`. |
 | `HEYGEN_API_URL` | API base URL for `hyperframes` CLI commands (default `https://api.heygen.com`). |
-| `HEYGEN_CONFIG_DIR` | Credentials directory (default `~/.heygen`). |
+| `HYPERFRAMES_CONFIG_DIR` | HyperFrames credentials root (default `~/.hyperframes`). |
+| `HYPERFRAMES_ENV` | `prod` (default) or `dev`; switches OAuth and API defaults together. Dev credentials live under the root’s `dev/` directory. |
+| `HYPERFRAMES_OAUTH_CLIENT_ID` | Override the public client ID for a controlled OAuth environment. |
 | `ELEVENLABS_API_KEY` | ElevenLabs TTS, used when no HeyGen credential is present. |
 | `GEMINI_API_KEY` / `GOOGLE_API_KEY` | Explicit Gemini TTS selection and Lyria music generation; capture descriptions use `GEMINI_API_KEY`. |
 | `GOOGLE_APPLICATION_CREDENTIALS` / `GCS_CREDS` | Gemini TTS service-account JSON file path / injected JSON. Used when neither API key is set. |
diff --git a/docs/packages/cli.mdx b/docs/packages/cli.mdx
index f21de16913..1fef7f09b6 100644
--- a/docs/packages/cli.mdx
+++ b/docs/packages/cli.mdx
@@ -682,10 +682,11 @@ and are copied to `~/.media/` so other projects can reuse them. Sound effects
 under CC BY get their credit written to `.media/audio/sfx/CREDITS.md`.
 
 **What needs an account, and what can cost money.** The HeyGen sources run
-through the separate `heygen` CLI, signed in with `heygen auth login --oauth`.
-Searching the music, image, and icon catalogs is free. Text to speech and avatar
-video draw on a free allowance when you are signed in with OAuth, then on your
-HeyGen billing, so an agent should ask before generating them. When a
+through the separate `heygen` executable using the login selected by
+`hyperframes auth login`. It receives a temporary access-token credential and
+cannot read the separate HeyGen login or refresh a HyperFrames grant.
+The server decides feature eligibility and charges. An explicit API-key credential
+uses API-key billing. When a
 host app sets `HEYGEN_API_BASE` and `HEYGEN_API_KEY`, HeyGen calls go through that
 host instead and are charged to its key. The `codex` image fallback uses your
 ChatGPT subscription. Openverse, theSVG, GitHub, favicons, color grades, and the
@@ -2152,16 +2153,16 @@ usage event (`--skill`, `--event`, `--outcome`). Nothing calls it by hand.
 
 ## hyperframes auth
 
-Sign in to HeyGen and manage credentials. They live in `~/.heygen/credentials`
-(mode `0600`) and are **shared with the `heygen` CLI** — sign in with one and
-the other picks up the session.
+Sign into your HeyGen account through the dedicated HyperFrames OAuth client.
+Credentials live in `~/.hyperframes/credentials` (mode `0600`), independently
+of the `heygen` CLI. A previous shared login requires a fresh HyperFrames sign-in.
 
 First match wins:
 
 1. `HEYGEN_API_KEY`
 2. `HYPERFRAMES_API_KEY` (a HyperFrames alias for the same thing)
 3. `HEYGEN_ACCESS_TOKEN` (an OAuth token a host app injects; never refreshed or saved)
-4. `~/.heygen/credentials`
+4. `~/.hyperframes/credentials`
 
 ### `auth login`
 
@@ -2221,7 +2222,9 @@ hyperframes auth logout --yes            # no prompt
 | `HYPERFRAMES_API_KEY` | Alias for `HEYGEN_API_KEY`.                      |
 | `HEYGEN_ACCESS_TOKEN` | OAuth token from a host app; never refreshed.    |
 | `HEYGEN_API_URL`      | API base URL (default `https://api.heygen.com`). |
-| `HEYGEN_CONFIG_DIR`   | Credentials directory (default `~/.heygen`).     |
+| `HYPERFRAMES_CONFIG_DIR` | Credentials root (default `~/.hyperframes`). |
+| `HYPERFRAMES_ENV` | `prod` (default) or `dev`; selects matching OAuth/API hosts and a separate dev credential directory. |
+| `HYPERFRAMES_OAUTH_CLIENT_ID` | Override the selected public OAuth client. |
 
 For the keys other capabilities use — ElevenLabs and Gemini for voice and music
 fallback, OpenRouter and Gemini for capture — and how the skills prioritize
diff --git a/packages/cli/scripts/test-home.mjs b/packages/cli/scripts/test-home.mjs
index 708c7ac013..07feafbfc6 100644
--- a/packages/cli/scripts/test-home.mjs
+++ b/packages/cli/scripts/test-home.mjs
@@ -18,6 +18,7 @@ for (const name of [
   "CODEX_HOME",
   "CLAUDE_CONFIG_DIR",
   "HEYGEN_CONFIG_DIR",
+  "HYPERFRAMES_CONFIG_DIR",
   "HYPERFRAMES_CATALOG_ARTIFACT_DIR",
   "HYPERFRAMES_MEDIA_HOME",
   "HF_HOME",
diff --git a/packages/cli/src/auth/_test-utils.ts b/packages/cli/src/auth/_test-utils.ts
index 4afd6cd224..bbaceb14e2 100644
--- a/packages/cli/src/auth/_test-utils.ts
+++ b/packages/cli/src/auth/_test-utils.ts
@@ -14,9 +14,16 @@ const ENV_KEYS = [
   "HEYGEN_API_KEY",
   "HEYGEN_ACCESS_TOKEN",
   "HYPERFRAMES_API_KEY",
+  "HYPERFRAMES_CONFIG_DIR",
   "HEYGEN_CONFIG_DIR",
+  "HEYGEN_API_BASE",
   "HEYGEN_API_URL",
   "HYPERFRAMES_OAUTH_CLIENT_ID",
+  "HYPERFRAMES_ENV",
+  "HYPERFRAMES_OAUTH_TOKEN_URL",
+  "HYPERFRAMES_OAUTH_AUTHORIZE_URL",
+  "HYPERFRAMES_OAUTH_REVOKE_URL",
+  "HYPERFRAMES_OAUTH_DEVICE_URL",
 ] as const;
 
 type EnvKey = (typeof ENV_KEYS)[number];
@@ -30,7 +37,7 @@ export interface EnvFixture {
 
 /**
  * Take a snapshot of the auth-related env, clear them, make a tmp
- * `HEYGEN_CONFIG_DIR`, and return a `restore()` that undoes all of
+ * `HYPERFRAMES_CONFIG_DIR`, and return a `restore()` that undoes all of
  * the above.
  */
 export async function setupTempAuthEnv(prefix = "hf-auth-test-"): Promise<EnvFixture> {
@@ -40,7 +47,7 @@ export async function setupTempAuthEnv(prefix = "hf-auth-test-"): Promise<EnvFix
     saved[k] = process.env[k];
     delete process.env[k];
   }
-  process.env["HEYGEN_CONFIG_DIR"] = dir;
+  process.env["HYPERFRAMES_CONFIG_DIR"] = dir;
 
   const restore = async (): Promise<void> => {
     for (const k of ENV_KEYS) {
diff --git a/packages/cli/src/auth/client.ts b/packages/cli/src/auth/client.ts
index 0bb3f92bb4..a485f1b278 100644
--- a/packages/cli/src/auth/client.ts
+++ b/packages/cli/src/auth/client.ts
@@ -19,8 +19,8 @@ import { ErrApi, ErrUnauthenticated, isAuthError } from "./errors.js";
 import type { ResolvedCredential } from "./resolver.js";
 import { scrubCredentials } from "./scrub.js";
 import type { OAuthTokens } from "./store.js";
+import { oauthEnvironment } from "./config.js";
 
-const DEFAULT_BASE_URL = "https://api.heygen.com";
 export const HEYGEN_CLI_SOURCE_HEADER = "X-HeyGen-Source";
 export const HEYGEN_CLI_SOURCE = "cli";
 // Tool-attribution header identifying this CLI as the request origin. Sent on
@@ -32,7 +32,9 @@ export const HEYGEN_CLIENT_SOURCE = "hyperframes";
 
 export function apiBaseUrl(): string {
   const override = process.env["HEYGEN_API_URL"];
-  return override && override.length > 0 ? override.replace(/\/+$/, "") : DEFAULT_BASE_URL;
+  return override && override.length > 0
+    ? override.replace(/\/+$/, "")
+    : `https://api.${oauthEnvironment() === "dev" ? "dev." : ""}heygen.com`;
 }
 
 export type BillingType = "wallet" | "subscription" | "usage_based" | string;
diff --git a/packages/cli/src/auth/config.test.ts b/packages/cli/src/auth/config.test.ts
new file mode 100644
index 0000000000..9e50b53fa3
--- /dev/null
+++ b/packages/cli/src/auth/config.test.ts
@@ -0,0 +1,51 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { setupTempAuthEnv } from "./_test-utils.js";
+import {
+  assertOAuthIdentity,
+  authorizeEndpoint,
+  deviceAuthorizationEndpoint,
+  oauthIdentity,
+  resolveClientId,
+  revokeEndpoint,
+  tokenEndpoint,
+} from "./config.js";
+import { apiBaseUrl } from "./client.js";
+
+describe("HyperFrames OAuth configuration", () => {
+  let fixture: Awaited<ReturnType<typeof setupTempAuthEnv>>;
+  beforeEach(async () => {
+    fixture = await setupTempAuthEnv();
+  });
+  afterEach(async () => {
+    await fixture.restore();
+  });
+
+  it("uses the dedicated public production client", () => {
+    expect(resolveClientId()).toBe("Zg3LF4FCLoeJoGs2YqMtZ17g");
+    expect(authorizeEndpoint()).toBe("https://app.heygen.com/oauth/authorize");
+    expect(tokenEndpoint()).toBe("https://api2.heygen.com/v1/oauth/token");
+    expect(apiBaseUrl()).toBe("https://api.heygen.com");
+  });
+
+  it("switches every default host together for development", () => {
+    process.env["HYPERFRAMES_ENV"] = "dev";
+    expect(resolveClientId()).toBe("9QoaiwCZov9O0cAkC4OZbR4p");
+    expect(authorizeEndpoint()).toBe("https://api2.dev.heygen.com/v1/oauth/authorize");
+    expect(tokenEndpoint()).toBe("https://api2.dev.heygen.com/v1/oauth/token");
+    expect(revokeEndpoint()).toBe("https://api2.dev.heygen.com/v1/oauth/revoke");
+    expect(deviceAuthorizationEndpoint()).toBe(
+      "https://api2.dev.heygen.com/v1/oauth/device_authorization",
+    );
+    expect(apiBaseUrl()).toBe("https://api.dev.heygen.com");
+  });
+
+  it("rejects a session after either its client or token server changes", () => {
+    const identity = oauthIdentity();
+    expect(() => assertOAuthIdentity(identity)).not.toThrow();
+    process.env["HYPERFRAMES_OAUTH_CLIENT_ID"] = "another-client";
+    expect(() => assertOAuthIdentity(identity)).toThrow("different OAuth client or environment");
+    delete process.env["HYPERFRAMES_OAUTH_CLIENT_ID"];
+    process.env["HYPERFRAMES_OAUTH_TOKEN_URL"] = "https://other.example/token";
+    expect(() => assertOAuthIdentity(identity)).toThrow("different OAuth client or environment");
+  });
+});
diff --git a/packages/cli/src/auth/config.ts b/packages/cli/src/auth/config.ts
new file mode 100644
index 0000000000..b76ca60f17
--- /dev/null
+++ b/packages/cli/src/auth/config.ts
@@ -0,0 +1,65 @@
+import { AuthError, ErrOAuthNotConfigured } from "./errors.js";
+
+const PROD_CLIENT_ID = "Zg3LF4FCLoeJoGs2YqMtZ17g";
+
+export function oauthEnvironment(): "prod" | "dev" {
+  const value = process.env["HYPERFRAMES_ENV"] || "prod";
+  if (value === "prod" || value === "dev") return value;
+  throw new AuthError("OAUTH_NOT_CONFIGURED", "HYPERFRAMES_ENV must be prod or dev");
+}
+
+export function resolveClientId(): string {
+  const id =
+    process.env["HYPERFRAMES_OAUTH_CLIENT_ID"] ||
+    (oauthEnvironment() === "prod" ? PROD_CLIENT_ID : "9QoaiwCZov9O0cAkC4OZbR4p");
+  if (!id) throw ErrOAuthNotConfigured();
+  return id;
+}
+
+export function tokenEndpoint(): string {
+  return (
+    process.env["HYPERFRAMES_OAUTH_TOKEN_URL"] ||
+    `https://api2.${oauthEnvironment() === "dev" ? "dev." : ""}heygen.com/v1/oauth/token`
+  );
+}
+
+export function authorizeEndpoint(): string {
+  return (
+    process.env["HYPERFRAMES_OAUTH_AUTHORIZE_URL"] ||
+    (oauthEnvironment() === "dev"
+      ? "https://api2.dev.heygen.com/v1/oauth/authorize"
+      : "https://app.heygen.com/oauth/authorize")
+  );
+}
+
+export function revokeEndpoint(): string {
+  return (
+    process.env["HYPERFRAMES_OAUTH_REVOKE_URL"] ||
+    `https://api2.${oauthEnvironment() === "dev" ? "dev." : ""}heygen.com/v1/oauth/revoke`
+  );
+}
+
+export function deviceAuthorizationEndpoint(): string {
+  return (
+    process.env["HYPERFRAMES_OAUTH_DEVICE_URL"] ||
+    `https://api2.${oauthEnvironment() === "dev" ? "dev." : ""}heygen.com/v1/oauth/device_authorization`
+  );
+}
+
+export function oauthIdentity(): { client_id: string; token_endpoint: string } {
+  return { client_id: resolveClientId(), token_endpoint: tokenEndpoint() };
+}
+
+export function assertOAuthIdentity(tokens: { client_id?: string; token_endpoint?: string }): void {
+  const identity = oauthIdentity();
+  if (
+    tokens.client_id !== identity.client_id ||
+    tokens.token_endpoint !== identity.token_endpoint
+  ) {
+    throw new AuthError(
+      "LOGIN_EXPIRED",
+      "This login belongs to a different OAuth client or environment",
+      "Run `hyperframes auth login` to sign into the selected HyperFrames environment.",
+    );
+  }
+}
diff --git a/packages/cli/src/auth/errors.ts b/packages/cli/src/auth/errors.ts
index bb307c9d3c..365afbc952 100644
--- a/packages/cli/src/auth/errors.ts
+++ b/packages/cli/src/auth/errors.ts
@@ -37,7 +37,7 @@ export const ErrInvalidStore = (detail: string) =>
   new AuthError(
     "INVALID_STORE",
     `Credential file is unreadable: ${detail}`,
-    "Delete ~/.heygen/credentials and run `hyperframes auth login` to re-create it.",
+    "Delete ~/.hyperframes/credentials and run `hyperframes auth login` to re-create it.",
   );
 
 export const ErrUnauthenticated = (detail?: string) =>
diff --git a/packages/cli/src/auth/media-environment.test.ts b/packages/cli/src/auth/media-environment.test.ts
new file mode 100644
index 0000000000..c49abd56b2
--- /dev/null
+++ b/packages/cli/src/auth/media-environment.test.ts
@@ -0,0 +1,78 @@
+import { promises as fs } from "node:fs";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { setupTempAuthEnv } from "./_test-utils.js";
+import { persistFreshOAuth } from "./oauth.js";
+import { withMediaAuthEnvironment } from "./media-environment.js";
+
+describe("media-use authentication", () => {
+  let fixture: Awaited<ReturnType<typeof setupTempAuthEnv>>;
+  beforeEach(async () => {
+    fixture = await setupTempAuthEnv();
+  });
+  afterEach(async () => {
+    await fixture.restore();
+  });
+
+  it("passes a fresh access token through a private, temporary Go credential file", async () => {
+    await persistFreshOAuth({ access_token: "hf-access", refresh_token: "hf-refresh" });
+    let path = "";
+    await withMediaAuthEnvironment(async (env) => {
+      path = join(env.HEYGEN_CONFIG_DIR!, "credentials");
+      expect(env.HEYGEN_ACCESS_TOKEN).toBe("hf-access");
+      expect(env.HEYGEN_API_BASE).toBe("https://api.heygen.com");
+      expect(env.HEYGEN_API_KEY).toBeUndefined();
+      const copied = JSON.parse(await fs.readFile(path, "utf8"));
+      expect(copied.oauth.access_token).toBe("hf-access");
+      expect(copied.oauth.refresh_token).toBeUndefined();
+      expect((await fs.stat(path)).mode & 0o777).toBe(0o600);
+      expect((await fs.stat(env.HEYGEN_CONFIG_DIR!)).mode & 0o777).toBe(0o700);
+    });
+    await expect(fs.stat(path)).rejects.toMatchObject({ code: "ENOENT" });
+    expect(await fs.readFile(join(fixture.dir, "credentials"), "utf8")).toContain("hf-refresh");
+  });
+
+  it("refuses to send OAuth to a non-HeyGen media gateway", async () => {
+    await persistFreshOAuth({ access_token: "hf-access", refresh_token: "hf-refresh" });
+    process.env["HEYGEN_API_BASE"] = "https://gateway.example";
+    try {
+      await expect(withMediaAuthEnvironment(() => undefined)).rejects.toThrow(
+        "requires its own API credential",
+      );
+    } finally {
+      delete process.env["HEYGEN_API_BASE"];
+    }
+  });
+
+  it("isolates an anonymous operation from an existing HeyGen login", async () => {
+    process.env["HEYGEN_CONFIG_DIR"] = join(fixture.dir, "heygen");
+    await fs.mkdir(process.env["HEYGEN_CONFIG_DIR"]);
+    const legacyPath = join(process.env["HEYGEN_CONFIG_DIR"], "credentials");
+    await fs.writeFile(legacyPath, "hg_other_wallet");
+    await withMediaAuthEnvironment(async (env) => {
+      expect(env.HEYGEN_CONFIG_DIR).not.toBe(process.env["HEYGEN_CONFIG_DIR"]);
+      expect(await fs.readdir(env.HEYGEN_CONFIG_DIR!)).toEqual([]);
+      expect(env.HEYGEN_API_KEY).toBeUndefined();
+    });
+    expect(await fs.readFile(legacyPath, "utf8")).toBe("hg_other_wallet");
+  });
+
+  it("preserves an explicit host gateway and cleans up after a subprocess error", async () => {
+    process.env["HEYGEN_API_BASE"] = "https://gateway.example";
+    process.env["HEYGEN_API_KEY"] = "gateway-key";
+    let dir = "";
+    try {
+      await expect(
+        withMediaAuthEnvironment((env) => {
+          dir = env.HEYGEN_CONFIG_DIR!;
+          expect(env.HEYGEN_API_BASE).toBe("https://gateway.example");
+          expect(env.HEYGEN_API_KEY).toBe("gateway-key");
+          throw new Error("subprocess failed");
+        }),
+      ).rejects.toThrow("subprocess failed");
+      await expect(fs.stat(dir)).rejects.toMatchObject({ code: "ENOENT" });
+    } finally {
+      delete process.env["HEYGEN_API_BASE"];
+    }
+  });
+});
diff --git a/packages/cli/src/auth/media-environment.ts b/packages/cli/src/auth/media-environment.ts
new file mode 100644
index 0000000000..531124572d
--- /dev/null
+++ b/packages/cli/src/auth/media-environment.ts
@@ -0,0 +1,62 @@
+import { promises as fs } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { apiBaseUrl } from "./client.js";
+import { refreshTokens } from "./oauth.js";
+import { AuthError, isAuthError } from "./errors.js";
+import { resolveCredential, tryResolveCredential } from "./resolver.js";
+import { writeStore } from "./store.js";
+
+/** The Go CLI accepts OAuth through a credential file, but cannot refresh a HyperFrames grant. */
+export async function withMediaAuthEnvironment<T>(run: (env: NodeJS.ProcessEnv) => T): Promise<T> {
+  let credential;
+  try {
+    credential = await tryResolveCredential();
+  } catch (error) {
+    // An expired login must not stop anonymous/local providers or select another wallet.
+    if (!isAuthError(error) || error.code !== "LOGIN_EXPIRED") throw error;
+  }
+  if (credential?.type === "oauth" && credential.refreshable && credential.refresh_token) {
+    await refreshTokens(credential.refresh_token);
+    credential = await resolveCredential();
+  }
+
+  const dir = await fs.mkdtemp(join(tmpdir(), "hyperframes-media-auth-"));
+  try {
+    await fs.chmod(dir, 0o700);
+    const env: NodeJS.ProcessEnv = { ...process.env, HEYGEN_CONFIG_DIR: dir };
+    env.HEYGEN_API_BASE ||= apiBaseUrl();
+    if (credential?.type === "oauth") {
+      const host = new URL(env.HEYGEN_API_BASE).hostname;
+      if (host !== "heygen.com" && !host.endsWith(".heygen.com")) {
+        throw new AuthError(
+          "OAUTH_NOT_CONFIGURED",
+          "A media gateway requires its own API credential",
+        );
+      }
+      delete env.HEYGEN_API_KEY;
+      delete env.HYPERFRAMES_API_KEY;
+      env.HEYGEN_ACCESS_TOKEN = credential.access_token;
+      await writeStore(
+        {
+          oauth: {
+            access_token: credential.access_token,
+            expires_at: credential.expires_at?.toISOString(),
+            token_type: "Bearer",
+          },
+        },
+        join(dir, "credentials"),
+      );
+    } else if (credential?.type === "api_key") {
+      env.HEYGEN_API_KEY = credential.key;
+      delete env.HEYGEN_ACCESS_TOKEN;
+    } else {
+      delete env.HEYGEN_ACCESS_TOKEN;
+      delete env.HEYGEN_API_KEY;
+      delete env.HYPERFRAMES_API_KEY;
+    }
+    return await run(env);
+  } finally {
+    await fs.rm(dir, { recursive: true, force: true });
+  }
+}
diff --git a/packages/cli/src/auth/oauth.test.ts b/packages/cli/src/auth/oauth.test.ts
index a391ef7f7d..d5d76a2740 100644
--- a/packages/cli/src/auth/oauth.test.ts
+++ b/packages/cli/src/auth/oauth.test.ts
@@ -1,3 +1,4 @@
+import { oauthIdentity } from "./config.js";
 import { promises as fs } from "node:fs";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { setupTempAuthEnv } from "./_test-utils.js";
@@ -12,7 +13,7 @@ import {
   startAuthorizationCodeFlow,
   startDeviceAuthorizationFlow,
 } from "./oauth.js";
-import { readStore, writeStore } from "./store.js";
+import { readStore, writeStore as writeUnboundStore, type Credentials } from "./store.js";
 
 // Mock the interactive bits so startAuthorizationCodeFlow runs headless.
 vi.mock("./loopback.js", () => ({
@@ -68,6 +69,13 @@ async function loginWithTokens(body: Record<string, unknown>) {
   return (await readStore()).credentials;
 }
 
+async function writeStore(credentials: Credentials): Promise<void> {
+  await writeUnboundStore({
+    ...credentials,
+    ...(credentials.oauth ? { oauth: { ...oauthIdentity(), ...credentials.oauth } } : {}),
+  });
+}
+
 describe("auth/oauth", () => {
   let fixture: Awaited<ReturnType<typeof setupTempAuthEnv>>;
 
@@ -170,6 +178,26 @@ describe("auth/oauth", () => {
   });
 
   describe("refreshTokens", () => {
+    it.each([undefined, "foreign-client"])(
+      "does not send a refresh token with client binding %s",
+      async (client_id) => {
+        await writeUnboundStore({
+          oauth: {
+            access_token: "at",
+            refresh_token: "rt",
+            client_id,
+            token_endpoint: oauthIdentity().token_endpoint,
+          },
+        });
+        const fetchImpl = vi.fn<typeof fetch>();
+        await expect(refreshTokens("rt", { fetchImpl })).rejects.toMatchObject({
+          code: "LOGIN_EXPIRED",
+        });
+        expect(fetchImpl).not.toHaveBeenCalled();
+        expect((await readStore()).credentials.oauth?.refresh_token).toBe("rt");
+      },
+    );
+
     it("posts grant_type=refresh_token and persists the response", async () => {
       process.env["HEYGEN_API_URL"] = "https://api.test.example";
       await writeStore({ oauth: { access_token: "old_at", refresh_token: "old_rt" } });
@@ -196,7 +224,7 @@ describe("auth/oauth", () => {
 
       // Should have persisted.
       const { credentials } = await readStore();
-      expect(credentials.oauth?.access_token).toBe("new_at");
+      expect(credentials.oauth).toMatchObject({ ...oauthIdentity(), access_token: "new_at" });
     });
 
     it("preserves the prior refresh_token when the server omits it (no rotation)", async () => {
@@ -264,6 +292,7 @@ describe("auth/oauth", () => {
         path,
         JSON.stringify({
           oauth: {
+            ...oauthIdentity(),
             access_token: "old_at",
             refresh_token: "keep_me_rt",
             id_token: "future_id_token_value",
@@ -281,6 +310,7 @@ describe("auth/oauth", () => {
     });
 
     it("throws REFRESH_FAILED on 400/401", async () => {
+      await writeStore({ oauth: { access_token: "at", refresh_token: "bad_rt" } });
       const fetchImpl = (async () =>
         new Response("invalid_grant", {
           status: 400,
@@ -291,6 +321,7 @@ describe("auth/oauth", () => {
     });
 
     it("throws API_ERROR on 5xx", async () => {
+      await writeStore({ oauth: { access_token: "at", refresh_token: "rt" } });
       const fetchImpl = (async () =>
         new Response("upstream", { status: 503 })) as unknown as typeof fetch;
       await expect(refreshTokens("rt", { fetchImpl })).rejects.toSatisfy((err) => {
@@ -300,6 +331,20 @@ describe("auth/oauth", () => {
   });
 
   describe("revokeTokens", () => {
+    it("does not revoke another client's stored grant", async () => {
+      await writeUnboundStore({
+        oauth: {
+          access_token: "foreign-at",
+          refresh_token: "foreign-rt",
+          client_id: "another-client",
+          token_endpoint: oauthIdentity().token_endpoint,
+        },
+      });
+      const fetchImpl = vi.fn<typeof fetch>();
+      await revokeTokens("foreign-rt", { fetchImpl });
+      expect(fetchImpl).not.toHaveBeenCalled();
+    });
+
     it("never throws on network failure (best-effort)", async () => {
       const fetchImpl = (async () => {
         throw new Error("connection refused");
@@ -348,6 +393,7 @@ describe("auth/oauth", () => {
 
   describe("error scrubbing", () => {
     it("refreshTokens does not leak token-shaped secrets from the error body", async () => {
+      await writeStore({ oauth: { access_token: "at", refresh_token: "rt_leak_secret" } });
       const fetchImpl = (async () =>
         new Response(
           '{"error":"invalid_grant","echoed":"refresh_token=rt_leak_secret&code_verifier=cv_leak"}',
diff --git a/packages/cli/src/auth/oauth.ts b/packages/cli/src/auth/oauth.ts
index 4ef646beb8..e37fceef2e 100644
--- a/packages/cli/src/auth/oauth.ts
+++ b/packages/cli/src/auth/oauth.ts
@@ -38,7 +38,6 @@ import {
   ErrApi,
   ErrDeviceAuthFailed,
   ErrLoginChanged,
-  ErrOAuthNotConfigured,
   ErrRefreshFailed,
   isAuthError,
 } from "./errors.js";
@@ -55,25 +54,25 @@ import {
   type StoredUserInfo,
 } from "./store.js";
 import { c } from "../ui/colors.js";
+import {
+  assertOAuthIdentity,
+  authorizeEndpoint,
+  deviceAuthorizationEndpoint,
+  oauthIdentity,
+  resolveClientId,
+  revokeEndpoint,
+  tokenEndpoint,
+} from "./config.js";
+
+export { resolveClientId } from "./config.js";
 
 const REVOKE_TIMEOUT_MS = 5_000;
 const MIN_EXPIRES_IN_SECONDS = 30;
 
-/**
- * Default OAuth client_id baked at build time. Override with the
- * `HYPERFRAMES_OAUTH_CLIENT_ID` env var. Empty string means "not
- * configured" — `resolveClientId()` errors cleanly with a pointer
- * at `--api-key`.
- */
-const DEFAULT_CLIENT_ID = "q2A2QRSke2LrFTPJhoDbHtXh";
 const DEFAULT_SCOPES = "openid profile email";
 
 // Endpoint defaults — see file-header comment for why these straddle two
 // hosts. Each is independently overridable.
-const DEFAULT_AUTHORIZE_URL = "https://app.heygen.com/oauth/authorize";
-const DEFAULT_TOKEN_URL = "https://api2.heygen.com/v1/oauth/token";
-const DEFAULT_REVOKE_URL = "https://api2.heygen.com/v1/oauth/revoke";
-const DEFAULT_DEVICE_AUTHORIZATION_URL = "https://api2.heygen.com/v1/oauth/device_authorization";
 const DEVICE_CODE_GRANT_TYPE = "urn:ietf:params:oauth:grant-type:device_code";
 const MAX_DEVICE_FLOW_SECONDS = 30 * 60;
 const MIN_DEVICE_POLL_SECONDS = 5;
@@ -81,19 +80,6 @@ const MAX_DEVICE_POLL_SECONDS = 60;
 const MAX_DEVICE_RESPONSE_BYTES = 64 * 1024;
 const DEVICE_REQUEST_TIMEOUT_MS = 15_000;
 
-function authorizeEndpoint(): string {
-  return process.env["HYPERFRAMES_OAUTH_AUTHORIZE_URL"] || DEFAULT_AUTHORIZE_URL;
-}
-function tokenEndpoint(): string {
-  return process.env["HYPERFRAMES_OAUTH_TOKEN_URL"] || DEFAULT_TOKEN_URL;
-}
-function revokeEndpoint(): string {
-  return process.env["HYPERFRAMES_OAUTH_REVOKE_URL"] || DEFAULT_REVOKE_URL;
-}
-function deviceAuthorizationEndpoint(): string {
-  return process.env["HYPERFRAMES_OAUTH_DEVICE_URL"] || DEFAULT_DEVICE_AUTHORIZATION_URL;
-}
-
 export interface AuthorizeFlowOptions {
   /** Override scopes (default `openid profile email`). */
   scope?: string;
@@ -134,14 +120,6 @@ export interface DeviceAuthorizationFlowOptions {
   onChallenge?: (challenge: DeviceAuthorizationChallenge) => void | Promise<void>;
 }
 
-/** Read the client_id, throwing `ErrOAuthNotConfigured` when unset. */
-export function resolveClientId(): string {
-  const override = process.env["HYPERFRAMES_OAUTH_CLIENT_ID"];
-  const id = override && override.length > 0 ? override : DEFAULT_CLIENT_ID;
-  if (!id || id.length === 0) throw ErrOAuthNotConfigured();
-  return id;
-}
-
 /**
  * For command-entry points: throw the standard `ErrOAuthNotConfigured`
  * via `resolveClientId()`; on a real misconfig, print a friendly hint
@@ -385,6 +363,9 @@ export async function refreshTokens(
   refresh_token: string,
   opts: RefreshOptions = {},
 ): Promise<OAuthTokens> {
+  const { credentials } = await readStore();
+  if (credentials.oauth?.refresh_token !== refresh_token) throw ErrLoginChanged();
+  assertOAuthIdentity(credentials.oauth);
   const clientId = resolveClientId();
   const fetchImpl = opts.fetchImpl ?? fetch;
   const body = new URLSearchParams({
@@ -432,6 +413,13 @@ export async function revokeTokens(token: string, opts: RevokeOptions = {}): Pro
   let clientId: string;
   try {
     clientId = resolveClientId();
+    const { credentials } = await readStore();
+    if (
+      credentials.oauth &&
+      (credentials.oauth.access_token === token || credentials.oauth.refresh_token === token)
+    ) {
+      assertOAuthIdentity(credentials.oauth);
+    }
   } catch {
     // OAuth not configured — nothing to revoke server-side.
     return;
@@ -622,7 +610,9 @@ async function persistOAuth(tokens: OAuthTokens, opts: { refreshed?: string } =
     throw ErrLoginChanged();
   }
   const oauth: OAuthTokens =
-    opts.refreshed !== undefined ? { ...existing.oauth, ...tokens } : { ...tokens };
+    opts.refreshed !== undefined
+      ? { ...existing.oauth, ...tokens, ...oauthIdentity() }
+      : { ...tokens, ...oauthIdentity() };
   // Start from the existing record so co-located data survives: the
   // api_key, the friendly-display `user` block, AND any unknown/foreign
   // keys another CLI wrote (carried on a hidden symbol slot by spread).
@@ -656,7 +646,7 @@ export async function persistVerifiedOAuthSession(
   }
   const next: Credentials = {
     ...credentials,
-    oauth: { ...tokens },
+    oauth: { ...tokens, ...oauthIdentity() },
   };
   if (user.email || user.first_name || user.last_name || user.username) {
     // Preserve only unknown/foreign user fields from the existing record.
diff --git a/packages/cli/src/auth/paths.test.ts b/packages/cli/src/auth/paths.test.ts
index ec78ef4556..785543c46f 100644
--- a/packages/cli/src/auth/paths.test.ts
+++ b/packages/cli/src/auth/paths.test.ts
@@ -1,32 +1,40 @@
-import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { homedir } from "node:os";
 import { join } from "node:path";
 import { CREDENTIAL_FILENAME, configDir, credentialPath } from "./paths.js";
 
 describe("auth/paths", () => {
-  const original = process.env["HEYGEN_CONFIG_DIR"];
+  const original = process.env["HYPERFRAMES_CONFIG_DIR"];
 
   beforeEach(() => {
-    delete process.env["HEYGEN_CONFIG_DIR"];
+    delete process.env["HYPERFRAMES_CONFIG_DIR"];
   });
 
   afterEach(() => {
-    if (original !== undefined) process.env["HEYGEN_CONFIG_DIR"] = original;
-    else delete process.env["HEYGEN_CONFIG_DIR"];
+    vi.unstubAllEnvs();
+    if (original !== undefined) process.env["HYPERFRAMES_CONFIG_DIR"] = original;
+    else delete process.env["HYPERFRAMES_CONFIG_DIR"];
   });
 
-  it("defaults to ~/.heygen", () => {
-    expect(configDir()).toBe(join(homedir(), ".heygen"));
+  it("defaults to ~/.hyperframes", () => {
+    expect(configDir()).toBe(join(homedir(), ".hyperframes"));
   });
 
-  it("honors HEYGEN_CONFIG_DIR override", () => {
-    process.env["HEYGEN_CONFIG_DIR"] = "/tmp/some-test-dir";
+  it("honors HYPERFRAMES_CONFIG_DIR override", () => {
+    process.env["HYPERFRAMES_CONFIG_DIR"] = "/tmp/some-test-dir";
     expect(configDir()).toBe("/tmp/some-test-dir");
     expect(credentialPath()).toBe(join("/tmp/some-test-dir", CREDENTIAL_FILENAME));
   });
 
-  it("treats empty HEYGEN_CONFIG_DIR as unset", () => {
-    process.env["HEYGEN_CONFIG_DIR"] = "";
-    expect(configDir()).toBe(join(homedir(), ".heygen"));
+  it("treats empty HYPERFRAMES_CONFIG_DIR as unset", () => {
+    process.env["HYPERFRAMES_CONFIG_DIR"] = "";
+    expect(configDir()).toBe(join(homedir(), ".hyperframes"));
+  });
+
+  it("ignores the HeyGen CLI directory and isolates the dev environment", () => {
+    vi.stubEnv("HEYGEN_CONFIG_DIR", "/tmp/heygen-other-account");
+    expect(configDir()).toBe(join(homedir(), ".hyperframes"));
+    vi.stubEnv("HYPERFRAMES_ENV", "dev");
+    expect(configDir()).toBe(join(homedir(), ".hyperframes", "dev"));
   });
 });
diff --git a/packages/cli/src/auth/paths.ts b/packages/cli/src/auth/paths.ts
index 3df82f4fc2..c909b24650 100644
--- a/packages/cli/src/auth/paths.ts
+++ b/packages/cli/src/auth/paths.ts
@@ -1,23 +1,19 @@
 /**
- * Filesystem layout for the shared HeyGen credential store. Mirrors
- * `heygen-cli/internal/paths/paths.go` so both CLIs read the same file.
- * `HEYGEN_CONFIG_DIR` overrides the directory.
+ * HyperFrames credentials are isolated from the HeyGen CLI and between environments.
  */
 
 import { homedir } from "node:os";
 import { join } from "node:path";
+import { oauthEnvironment } from "./config.js";
 
 /**
- * Filename for the credential store. Matches heygen-cli (no `.json`
- * suffix) so a `~/.heygen/credentials` written by either CLI is
- * readable by the other — see `heygen-cli/internal/auth/file_resolver.go`.
+ * Filename for the HyperFrames credential store (JSON, no extension).
  */
 export const CREDENTIAL_FILENAME = "credentials";
 
 export function configDir(): string {
-  const override = process.env["HEYGEN_CONFIG_DIR"];
-  if (override && override.length > 0) return override;
-  return join(homedir(), ".heygen");
+  const root = process.env["HYPERFRAMES_CONFIG_DIR"] || join(homedir(), ".hyperframes");
+  return oauthEnvironment() === "dev" ? join(root, "dev") : root;
 }
 
 export function credentialPath(): string {
diff --git a/packages/cli/src/auth/resolver.test.ts b/packages/cli/src/auth/resolver.test.ts
index 6119879381..9450d74475 100644
--- a/packages/cli/src/auth/resolver.test.ts
+++ b/packages/cli/src/auth/resolver.test.ts
@@ -1,10 +1,18 @@
+import { oauthIdentity } from "./config.js";
 import { promises as fs } from "node:fs";
 import { join } from "node:path";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { setupTempAuthEnv } from "./_test-utils.js";
 import { isAuthError } from "./errors.js";
 import { resolveCredential, tryResolveCredential } from "./resolver.js";
-import { writeStore } from "./store.js";
+import { writeStore as writeUnboundStore, type Credentials } from "./store.js";
+
+async function writeStore(credentials: Credentials): Promise<void> {
+  await writeUnboundStore({
+    ...credentials,
+    ...(credentials.oauth ? { oauth: { ...oauthIdentity(), ...credentials.oauth } } : {}),
+  });
+}
 
 describe("auth/resolver", () => {
   let fixture: Awaited<ReturnType<typeof setupTempAuthEnv>>;
@@ -102,15 +110,20 @@ describe("auth/resolver", () => {
     if (r.type === "oauth") expect(r.refreshable).toBe(true);
   });
 
-  it("skips expired non-refreshable oauth and falls through to api_key", async () => {
+  it("refuses an expired OAuth login without switching to the stored API wallet", async () => {
     const past = new Date(Date.now() - 60 * 60 * 1000).toISOString();
     await writeStore({
       api_key: "fallback",
       oauth: { access_token: "stale-at", expires_at: past },
     });
-    const r = await resolveCredential();
-    expect(r.type).toBe("api_key");
-    if (r.type === "api_key") expect(r.key).toBe("fallback");
+    await expect(resolveCredential()).rejects.toMatchObject({ code: "LOGIN_EXPIRED" });
+  });
+
+  it("requires a new login for an unbound or foreign OAuth credential", async () => {
+    await writeUnboundStore({ api_key: "fallback", oauth: { access_token: "legacy" } });
+    await expect(resolveCredential()).rejects.toMatchObject({ code: "LOGIN_EXPIRED" });
+    await writeStore({ oauth: { access_token: "foreign", client_id: "shared-heygen-cli" } });
+    await expect(resolveCredential()).rejects.toMatchObject({ code: "LOGIN_EXPIRED" });
   });
 
   it("reports an expired login with no refresh token as expired, not as never signed in", async () => {
diff --git a/packages/cli/src/auth/resolver.ts b/packages/cli/src/auth/resolver.ts
index f2278ab730..f09559b28a 100644
--- a/packages/cli/src/auth/resolver.ts
+++ b/packages/cli/src/auth/resolver.ts
@@ -1,11 +1,11 @@
 /**
- * Chain resolver for HeyGen credentials.
+ * Chain resolver for HyperFrames credentials.
  *
  * Priority — first non-empty wins:
  *   1. `HEYGEN_API_KEY` env (matches heygen-cli)
  *   2. `HYPERFRAMES_API_KEY` env (alias for parity with other tools)
  *   3. `HEYGEN_ACCESS_TOKEN` env (host-managed OAuth)
- *   4. `~/.heygen/credentials` (JSON) — unexpired OAuth, else api_key
+ *   4. `~/.hyperframes/credentials` (JSON) — bound OAuth or an explicit API key
  *
  * Absent sources fall through. Broken files surface `ErrInvalidStore` immediately;
  * silently falling back would mask user configuration errors.
@@ -13,11 +13,12 @@
  * Expiry policy: an OAuth access_token whose `expires_at` is in the
  * past (60s skew) is considered expired. If a `refresh_token` is also
  * present, callers can still use it via `refreshable: true`. Otherwise
- * the api_key (if any) wins, else `ErrLoginExpired`, not `ErrNotConfigured`.
+ * session requires sign-in; a saved API key never replaces expired OAuth.
  */
 
 import { isHeaderSafe, readStore } from "./store.js";
 import { ErrInvalidStore, ErrLoginExpired, ErrNotConfigured, isAuthError } from "./errors.js";
+import { assertOAuthIdentity } from "./config.js";
 
 type EnvSource = "env" | "env_alias" | "env_oauth";
 type CredentialSource = EnvSource | "file_json" | "file_legacy";
@@ -79,12 +80,14 @@ export async function resolveCredential(opts: ResolveOptions = {}): Promise<Reso
 
   const fileSource: CredentialSource = source === "file_legacy" ? "file_legacy" : "file_json";
 
+  if (credentials.oauth) assertOAuthIdentity(credentials.oauth);
   const oauth = credentials.oauth ? pickOAuth(credentials.oauth, now, fileSource) : null;
   if (oauth) return oauth;
+  if (credentials.oauth) throw ErrLoginExpired();
   if (credentials.api_key) {
     return { type: "api_key", key: credentials.api_key, source: fileSource };
   }
-  throw credentials.oauth ? ErrLoginExpired() : ErrNotConfigured();
+  throw ErrNotConfigured();
 }
 
 function headerSafeEnv(name: string): string | undefined {
diff --git a/packages/cli/src/auth/store.ts b/packages/cli/src/auth/store.ts
index 6315591437..657e24f965 100644
--- a/packages/cli/src/auth/store.ts
+++ b/packages/cli/src/auth/store.ts
@@ -1,6 +1,6 @@
 /**
- * Read/write the shared `~/.heygen/credentials` file (JSON contents,
- * no `.json` extension — the path matches heygen-cli).
+ * Read/write the isolated `~/.hyperframes/credentials` file (JSON contents,
+ * no `.json` extension).
  *
  * Current format:
  *   {
@@ -26,10 +26,8 @@
  *
  * Writes go to a temp file + rename, 0600 mode, parent dir 0700.
  *
- * Cross-CLI forward compatibility: this file is SHARED with the Go
- * `heygen` CLI (and any future tool). Either CLI may write keys this
- * version doesn't model yet. To avoid one CLI silently clobbering the
- * other's data on round-trip, the reader stashes every unrecognized
+ * Forward compatibility: future HyperFrames versions may write keys this
+ * version does not model. To preserve them on round-trip, the reader stashes every unrecognized
  * top-level key (and every unrecognized key inside the `oauth` / `user`
  * sub-objects) into a hidden passthrough bag, and the writer re-emits
  * them verbatim. Known fields are still strictly validated; the
@@ -70,6 +68,8 @@ const KNOWN_OAUTH_KEYS = new Set([
   "expires_at",
   "scope",
   "token_type",
+  "client_id",
+  "token_endpoint",
 ]);
 /** Keys this CLI version models inside the `user` sub-object. */
 const KNOWN_USER_KEYS = new Set(["email", "first_name", "last_name", "username"]);
@@ -81,6 +81,8 @@ export interface OAuthTokens {
   expires_at?: string;
   scope?: string;
   token_type?: string;
+  client_id?: string;
+  token_endpoint?: string;
   /** Unknown/future keys captured for cross-CLI round-trip. */
   [UNKNOWN]?: Record<string, unknown>;
 }
@@ -284,6 +286,8 @@ function assignOptionalStrings(
 }
 
 const OAUTH_OPTIONAL: readonly [string, FieldPicker][] = [
+  ["client_id", "header_safe"],
+  ["token_endpoint", "non_empty"],
   ["refresh_token", "header_safe"],
   ["expires_at", "non_empty"],
   ["scope", "non_empty"],
@@ -433,6 +437,8 @@ function serializeOAuth(o: OAuthTokens): Record<string, unknown> {
   if (o.expires_at) oauth["expires_at"] = o.expires_at;
   if (o.scope) oauth["scope"] = o.scope;
   if (o.token_type) oauth["token_type"] = o.token_type;
+  if (o.client_id) oauth["client_id"] = o.client_id;
+  if (o.token_endpoint) oauth["token_endpoint"] = o.token_endpoint;
   return oauth;
 }
 
diff --git a/packages/cli/src/auth/user.ts b/packages/cli/src/auth/user.ts
index bb4146747a..f992a5f749 100644
--- a/packages/cli/src/auth/user.ts
+++ b/packages/cli/src/auth/user.ts
@@ -1,6 +1,6 @@
 /**
  * Persistence + display helpers for the friendly-display `user` block in
- * the shared `~/.heygen/credentials` file.
+ * the HyperFrames `~/.hyperframes/credentials` file.
  *
  * The `user` block is additive METADATA captured at login time from
  * `GET /v3/users/me` — NOT a credential. It lets `auth status` (and the
diff --git a/packages/cli/src/commands/auth.ts b/packages/cli/src/commands/auth.ts
index 9424eb5184..033e742d93 100644
--- a/packages/cli/src/commands/auth.ts
+++ b/packages/cli/src/commands/auth.ts
@@ -29,7 +29,7 @@ const HELP = `
 ${c.bold("hyperframes auth")} ${c.dim("<subcommand> [args]")}
 
 Manage HeyGen credentials. Credentials live in
-${c.accent("~/.heygen/credentials")} and are shared with heygen-cli.
+${c.accent("~/.hyperframes/credentials")} and are shared with heygen-cli.
 
 ${c.bold("SUBCOMMANDS:")}
   ${c.accent("login")}    ${c.dim("Sign in via browser, --device for SSH, or --api-key for a long-lived key.")}
@@ -42,7 +42,8 @@ ${c.bold("ENV VARS:")}
   ${c.accent("HYPERFRAMES_API_KEY")}         Alias for HEYGEN_API_KEY.
   ${c.accent("HEYGEN_ACCESS_TOKEN")}         OAuth token from a host app; used after the API keys, never refreshed or saved.
   ${c.accent("HEYGEN_API_URL")}              Override the API base URL (default https://api.heygen.com).
-  ${c.accent("HEYGEN_CONFIG_DIR")}           Override the credentials directory (default ~/.heygen).
+  ${c.accent("HYPERFRAMES_ENV")}           prod (default) or dev; selects OAuth/API hosts together.
+  ${c.accent("HYPERFRAMES_CONFIG_DIR")}           Override the credentials directory (default ~/.hyperframes).
   ${c.accent("HYPERFRAMES_OAUTH_CLIENT_ID")} Override the OAuth client_id (for dev/test).
   ${c.accent("HYPERFRAMES_OAUTH_DEVICE_URL")} Override the RFC 8628 device endpoint (for dev/test).
 `;
diff --git a/packages/cli/src/commands/auth/logout.ts b/packages/cli/src/commands/auth/logout.ts
index 0c0b3d711c..45b6041edd 100644
--- a/packages/cli/src/commands/auth/logout.ts
+++ b/packages/cli/src/commands/auth/logout.ts
@@ -69,8 +69,8 @@ function warnIfEnvCredentialActive(): void {
 async function ensureConfirmed(yes: boolean, keepApiKey: boolean): Promise<boolean> {
   if (yes) return true;
   const prompt = keepApiKey
-    ? `This will sign out of any active OAuth session on this machine (~/.heygen lives at ${configDir()}). Continue? [y/N] `
-    : `This will sign out of HeyGen on this machine (~/.heygen lives at ${configDir()}). Continue? [y/N] `;
+    ? `This will sign out of any active OAuth session on this machine (~/.hyperframes lives at ${configDir()}). Continue? [y/N] `
+    : `This will sign out of HeyGen on this machine (~/.hyperframes lives at ${configDir()}). Continue? [y/N] `;
   return confirmInteractive(prompt);
 }
 
diff --git a/packages/cli/src/commands/media-use.ts b/packages/cli/src/commands/media-use.ts
index 121dcc3bb3..cbb9e4f654 100644
--- a/packages/cli/src/commands/media-use.ts
+++ b/packages/cli/src/commands/media-use.ts
@@ -4,6 +4,7 @@ import { fileURLToPath } from "node:url";
 import { spawnSync } from "node:child_process";
 import { existsSync } from "node:fs";
 import { finishCommand } from "../utils/commandResult.js";
+import { withMediaAuthEnvironment } from "../auth/media-environment.js";
 
 const MEDIA_USE_ARGS = {
   type: { type: "string" },
@@ -68,18 +69,17 @@ export function mediaUseVerbFlags(verb: MediaUseVerb): string[] {
   return verb === "resolve" ? [] : [`--${verb}`];
 }
 
-type InvokeMediaUse = (verb: MediaUseVerb) => never;
+type InvokeMediaUse = (verb: MediaUseVerb) => never | Promise<never>;
 
-function invokeEngine(verb: MediaUseVerb): never {
+async function invokeEngine(verb: MediaUseVerb): Promise<never> {
   const here = dirname(fileURLToPath(import.meta.url));
   const passed = mediaUsePassthroughArgs(process.argv);
   const flag = mediaUseVerbFlags(verb);
-  const result = spawnSync(
-    process.execPath,
-    [resolveMediaUseEnginePath(here), ...flag, ...passed],
-    {
+  const result = await withMediaAuthEnvironment((env) =>
+    spawnSync(process.execPath, [resolveMediaUseEnginePath(here), ...flag, ...passed], {
       stdio: "inherit",
-    },
+      env,
+    }),
   );
   if (result.error) throw result.error;
   finishCommand(result.status ?? 1);
diff --git a/packages/cli/src/commands/publish.test.ts b/packages/cli/src/commands/publish.test.ts
index 552c4272fa..b5f8fac41c 100644
--- a/packages/cli/src/commands/publish.test.ts
+++ b/packages/cli/src/commands/publish.test.ts
@@ -12,9 +12,20 @@ vi.mock("../utils/publishProject.js", async (importOriginal) => ({
 
 import publishCommand, { examples, parseUpdateTarget } from "./publish.js";
 import { ensureProjectId } from "../utils/projectLink.js";
-import { writeStore } from "../auth/store.js";
+import { writeStore as writeUnboundStore, type Credentials } from "../auth/store.js";
+import { oauthIdentity } from "../auth/config.js";
 import { consumeCommandResult } from "../utils/commandResult.js";
 
+async function writeStore(credentials: Credentials, path?: string): Promise<void> {
+  await writeUnboundStore(
+    {
+      ...credentials,
+      ...(credentials.oauth ? { oauth: { ...oauthIdentity(), ...credentials.oauth } } : {}),
+    },
+    path,
+  );
+}
+
 const VISIBLE_INDEX = `<html><body><div data-composition-id="main" data-width="1920" data-height="1080" data-start="0" data-duration="5"><div class="clip" data-start="0" data-duration="5">Visible</div></div></body></html>`;
 
 function mockPublished(result: Record<string, unknown>): void {
@@ -193,7 +204,7 @@ describe("publish --update / --space ownership preflight", () => {
     const project = mkdtempSync(join(tmpdir(), "hf-publish-owner-"));
     const config = mkdtempSync(join(tmpdir(), "hf-publish-owner-config-"));
     writeFileSync(join(project, "index.html"), VISIBLE_INDEX);
-    vi.stubEnv("HEYGEN_CONFIG_DIR", config);
+    vi.stubEnv("HYPERFRAMES_CONFIG_DIR", config);
     vi.stubEnv("HEYGEN_API_KEY", credentials.env ?? "");
     vi.stubEnv("HYPERFRAMES_API_KEY", "");
     if (credentials.stored) await writeStore(credentials.stored, join(config, "credentials"));
@@ -352,7 +363,7 @@ describe("publish --update / --space ownership preflight", () => {
 
       expect(stored?.credentials.oauth).toMatchObject(loginB);
       expect(stored?.credentials.user?.email).toBe("b@example.com");
-      expect(fetchMock.mock.calls.map(([url]) => url)).toEqual(["https://auth.test/token"]);
+      expect(fetchMock).not.toHaveBeenCalled();
       expect(exitCode).toBe(1);
       expect(errors.join("\n")).toContain("Your login changed during publish. Run publish again.");
     } finally {
diff --git a/packages/cli/src/media-use/lib/heygen-cli.mjs b/packages/cli/src/media-use/lib/heygen-cli.mjs
index 214b93ae9e..3873b4c616 100644
--- a/packages/cli/src/media-use/lib/heygen-cli.mjs
+++ b/packages/cli/src/media-use/lib/heygen-cli.mjs
@@ -10,8 +10,8 @@ export const HEYGEN_MIN_VERSION = "0.3.0";
 // installer text out of the runtime module; the docs are the safer source of
 // truth for platform-specific setup.
 export const HEYGEN_INSTALL_COMMAND =
-  "Install the CLI from https://developers.heygen.com/cli, then run: heygen auth login --oauth";
-export const HEYGEN_AUTH_COMMAND = "heygen auth login --oauth";
+  "Install the CLI from https://developers.heygen.com/cli, then run: hyperframes auth login";
+export const HEYGEN_AUTH_COMMAND = "hyperframes auth login";
 export const HEYGEN_UPDATE_COMMAND = "heygen update";
 export const HEYGEN_CLIENT_SOURCE_ARGV = ["--headers", "X-HeyGen-Client-Source: media-use"];
 
diff --git a/packages/cli/src/utils/publishProject.test.ts b/packages/cli/src/utils/publishProject.test.ts
index a8779c29ec..a196b7992a 100644
--- a/packages/cli/src/utils/publishProject.test.ts
+++ b/packages/cli/src/utils/publishProject.test.ts
@@ -738,6 +738,7 @@ beforeEach(() => {
   linkMocks.writeProjectLink.mockReset();
   vi.stubEnv("HYPERFRAMES_PUBLISHED_PROJECTS_API_URL", "");
   vi.stubEnv("HEYGEN_API_URL", "");
+  vi.stubEnv("HYPERFRAMES_ENV", "prod");
 });
 
 afterEach(() => {
@@ -750,6 +751,11 @@ const signedStagedS3Url =
   "https://s3.example.com/upload?X-Amz-SignedHeaders=content-length;content-type;host;x-amz-server-side-encryption";
 
 describe("publishProjectArchive", () => {
+  it("uses the development publish service with the development login", () => {
+    vi.stubEnv("HYPERFRAMES_ENV", "dev");
+    expect(getPublishApiBaseUrl()).toBe("https://api2.dev.heygen.com");
+  });
+
   it("uploads through the staged publish flow and returns the stable project URL", async () => {
     const dir = makeProjectDir();
     const fetchMock = stagedFetch(
diff --git a/packages/cli/src/utils/publishProject.ts b/packages/cli/src/utils/publishProject.ts
index 72facfad6e..e7cf0c6758 100644
--- a/packages/cli/src/utils/publishProject.ts
+++ b/packages/cli/src/utils/publishProject.ts
@@ -15,6 +15,7 @@ import ignore, { type Ignore } from "ignore";
 import { CSS_URL_RE, isNonRelativeUrl, isPathInside, rewriteSrcsetUrls } from "@hyperframes/core";
 import { decodeUrlPathVariants, encodeUrlPath } from "@hyperframes/parsers";
 import { buildAuthHeaders } from "../auth/client.js";
+import { oauthEnvironment } from "../auth/config.js";
 import { tryResolveCredential } from "../auth/index.js";
 import { isAuthError } from "../auth/errors.js";
 import { envCredentialVar, isTokenExpired, type ResolvedCredential } from "../auth/resolver.js";
@@ -703,7 +704,7 @@ export function getPublishApiBaseUrl(): string {
   return (
     process.env["HYPERFRAMES_PUBLISHED_PROJECTS_API_URL"] ||
     process.env["HEYGEN_API_URL"] ||
-    "https://api2.heygen.com"
+    `https://api2.${oauthEnvironment() === "dev" ? "dev." : ""}heygen.com`
   ).replace(/\/$/, "");
 }
 
diff --git a/skills-manifest.json b/skills-manifest.json
index 587f7e8b11..92b142188f 100644
--- a/skills-manifest.json
+++ b/skills-manifest.json
@@ -18,7 +18,7 @@
       "files": 13
     },
     "media-use": {
-      "hash": "938c00af915a46b5",
+      "hash": "d6a12782a304ff15",
       "files": 116
     },
     "remotion-to-hyperframes": {
diff --git a/skills/media-use/audio/scripts/gemini-pipeline.test.mjs b/skills/media-use/audio/scripts/gemini-pipeline.test.mjs
index 842e5085e6..a277457d9d 100644
--- a/skills/media-use/audio/scripts/gemini-pipeline.test.mjs
+++ b/skills/media-use/audio/scripts/gemini-pipeline.test.mjs
@@ -90,7 +90,7 @@ fs.writeFileSync(path.join(args[args.indexOf('--dir')+1], 'transcript.json'), JS
           encoding: "utf8",
           env: {
             ...process.env,
-            HEYGEN_CONFIG_DIR: config,
+            HYPERFRAMES_CONFIG_DIR: config,
             HEYGEN_API_KEY: "",
             HYPERFRAMES_API_KEY: "",
             GEMINI_API_KEY: "fixture-key",
diff --git a/skills/media-use/audio/scripts/lib/audio-meta.test.mjs b/skills/media-use/audio/scripts/lib/audio-meta.test.mjs
index 2fa3a68807..3eb80dfee6 100644
--- a/skills/media-use/audio/scripts/lib/audio-meta.test.mjs
+++ b/skills/media-use/audio/scripts/lib/audio-meta.test.mjs
@@ -124,7 +124,7 @@ test("CLI partial run retains unselected voices, BGM and SFX", (t) => {
       encoding: "utf8",
       env: {
         ...process.env,
-        HEYGEN_CONFIG_DIR: dir,
+        HYPERFRAMES_CONFIG_DIR: dir,
         HEYGEN_API_KEY: "",
         HYPERFRAMES_API_KEY: "",
       },
diff --git a/skills/media-use/audio/scripts/lib/heygen.mjs b/skills/media-use/audio/scripts/lib/heygen.mjs
index 24ab9ed4b6..22e3b93863 100644
--- a/skills/media-use/audio/scripts/lib/heygen.mjs
+++ b/skills/media-use/audio/scripts/lib/heygen.mjs
@@ -3,8 +3,8 @@ import { fetchMedia } from "../../../scripts/lib/media-fetch.mjs";
 // pipeline. The credential resolver matches the hyperframes CLI auth: first
 // usable source wins — a host gateway ($HEYGEN_API_BASE with its own
 // $HEYGEN_API_KEY) → a host-injected OAuth $HEYGEN_ACCESS_TOKEN (Bearer) →
-// $HEYGEN_API_KEY / $HYPERFRAMES_API_KEY → a nearby .env → ~/.heygen/
-// credentials (oauth → Bearer, else api_key → X-Api-Key; $HEYGEN_CONFIG_DIR
+// $HEYGEN_API_KEY / $HYPERFRAMES_API_KEY → a nearby .env → ~/.hyperframes/
+// credentials (OAuth never falls back to an API key; $HYPERFRAMES_CONFIG_DIR
 // overrides the dir). $HEYGEN_API_BASE moves every request to that host, as it
 // does for the heygen CLI; plain HTTP needs $HEYGEN_ALLOW_HTTP=1, as there.
 // Vendored so the skill ships standalone. Pure node.
@@ -20,7 +20,8 @@ export const HEYGEN_BASE = "https://api.heygen.com/v3";
 // in the clear, so it needs $HEYGEN_ALLOW_HTTP=1, the heygen CLI's own rule.
 export function heygenBase() {
   const host = process.env.HEYGEN_API_BASE?.trim().replace(/\/+$/, "");
-  if (!host) return HEYGEN_BASE;
+  if (!host)
+    return process.env.HYPERFRAMES_ENV === "dev" ? "https://api.dev.heygen.com/v3" : HEYGEN_BASE;
   if (host.startsWith("http://") && process.env.HEYGEN_ALLOW_HTTP !== "1")
     throw new Error(
       `HEYGEN_API_BASE (${host}) uses HTTP, which sends the key in plaintext. Set HEYGEN_ALLOW_HTTP=1 to allow it.`,
@@ -104,7 +105,7 @@ export function heygenCredential() {
 }
 
 // heygenCredential's answer, or { unreadable: { file, code } } when the credentials path exists but cannot be read
-// (a folder, a locked ~/.heygen), so heygenAuthHeaders can say to fix that path: logging in again would fail there too.
+// (a folder, a locked ~/.hyperframes), so heygenAuthHeaders can say to fix that path: logging in again would fail there too.
 // Read without checking first, so the file cannot change between a check and the read.
 function resolveCredential() {
   const gatewayKey = hostGatewayKey();
@@ -116,7 +117,8 @@ function resolveCredential() {
   const envKey = process.env.HEYGEN_API_KEY || process.env.HYPERFRAMES_API_KEY;
   if (envKey) return { headers: { "X-Api-Key": envKey } };
 
-  const file = join(process.env.HEYGEN_CONFIG_DIR || join(homedir(), ".heygen"), "credentials");
+  const root = process.env.HYPERFRAMES_CONFIG_DIR || join(homedir(), ".hyperframes");
+  const file = join(root, ...(process.env.HYPERFRAMES_ENV === "dev" ? ["dev"] : []), "credentials");
   let raw;
   try {
     raw = readFileSync(file, "utf8").trim();
@@ -136,9 +138,23 @@ function resolveCredential() {
   }
   const oauth = cred.oauth;
   if (oauth?.access_token) {
+    const expectedClient =
+      process.env.HYPERFRAMES_OAUTH_CLIENT_ID ||
+      (process.env.HYPERFRAMES_ENV === "dev"
+        ? "9QoaiwCZov9O0cAkC4OZbR4p"
+        : "Zg3LF4FCLoeJoGs2YqMtZ17g");
+    const expectedTokenEndpoint =
+      process.env.HYPERFRAMES_OAUTH_TOKEN_URL ||
+      `https://api2.${process.env.HYPERFRAMES_ENV === "dev" ? "dev." : ""}heygen.com/v1/oauth/token`;
+    if (
+      !expectedClient ||
+      oauth.client_id !== expectedClient ||
+      oauth.token_endpoint !== expectedTokenEndpoint
+    )
+      return { expired: true };
     const expired = oauth.expires_at && new Date(oauth.expires_at).getTime() - 60_000 < Date.now();
     if (!expired) return { headers: { Authorization: `Bearer ${oauth.access_token}` } };
-    if (!cred.api_key) return { expired: true };
+    return { expired: true };
   }
   if (cred.api_key) return { headers: { "X-Api-Key": cred.api_key } };
   return null;
@@ -176,7 +192,7 @@ export function heygenAuthHeaders() {
       "HeyGen OAuth token expired — run `npx hyperframes auth refresh` (or `npx hyperframes auth login`)",
     );
   throw new Error(
-    "no HeyGen credentials — set $HEYGEN_API_KEY, or run `npx hyperframes auth login` (writes ~/.heygen/credentials)",
+    "no HyperFrames credentials — set $HEYGEN_API_KEY, or run `npx hyperframes auth login` (writes ~/.hyperframes/credentials)",
   );
 }
 
diff --git a/skills/media-use/audio/scripts/lib/heygen.test.mjs b/skills/media-use/audio/scripts/lib/heygen.test.mjs
index 8698feb027..39f894380f 100644
--- a/skills/media-use/audio/scripts/lib/heygen.test.mjs
+++ b/skills/media-use/audio/scripts/lib/heygen.test.mjs
@@ -17,7 +17,10 @@ const HEYGEN_ENV = [
   "HEYGEN_ACCESS_TOKEN",
   "HEYGEN_API_KEY",
   "HYPERFRAMES_API_KEY",
-  "HEYGEN_CONFIG_DIR",
+  "HYPERFRAMES_CONFIG_DIR",
+  "HYPERFRAMES_ENV",
+  "HYPERFRAMES_OAUTH_CLIENT_ID",
+  "HYPERFRAMES_OAUTH_TOKEN_URL",
   "HEYGEN_API_BASE",
   "HEYGEN_ALLOW_HTTP",
 ];
@@ -61,11 +64,13 @@ test("heygenAuthHeaders tags OAuth requests as CLI traffic and with the media-us
   withCleanHeygenEnv(() => {
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
-      process.env.HEYGEN_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
       writeFileSync(
         join(dir, "credentials"),
         JSON.stringify({
           oauth: {
+            client_id: "Zg3LF4FCLoeJoGs2YqMtZ17g",
+            token_endpoint: "https://api2.heygen.com/v1/oauth/token",
             access_token: "at_test",
             expires_at: "2099-01-01T00:00:00Z",
           },
@@ -82,6 +87,31 @@ test("heygenAuthHeaders tags OAuth requests as CLI traffic and with the media-us
   });
 });
 
+test("development audio uses the development client and isolated store", () => {
+  withCleanHeygenEnv(() => {
+    const dir = mkdtempSync(join(tmpdir(), "hf-dev-cred-"));
+    try {
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_ENV = "dev";
+      mkdirSync(join(dir, "dev"));
+      writeFileSync(
+        join(dir, "dev", "credentials"),
+        JSON.stringify({
+          oauth: {
+            access_token: "dev-at",
+            client_id: "9QoaiwCZov9O0cAkC4OZbR4p",
+            token_endpoint: "https://api2.dev.heygen.com/v1/oauth/token",
+          },
+        }),
+      );
+      assert.equal(heygenBase(), "https://api.dev.heygen.com/v3");
+      assert.equal(heygenAuthHeaders().Authorization, "Bearer dev-at");
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});
+
 test("a host-injected HEYGEN_ACCESS_TOKEN wins over an API key and is treated as OAuth", () => {
   withCleanHeygenEnv(() => {
     process.env.HEYGEN_ACCESS_TOKEN = "at_host";
@@ -106,11 +136,13 @@ test("heygenAuthMethod returns oauth for a live OAuth credential", () => {
   withCleanHeygenEnv(() => {
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
-      process.env.HEYGEN_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
       writeFileSync(
         join(dir, "credentials"),
         JSON.stringify({
           oauth: {
+            client_id: "Zg3LF4FCLoeJoGs2YqMtZ17g",
+            token_endpoint: "https://api2.heygen.com/v1/oauth/token",
             access_token: "at_test",
             expires_at: "2099-01-01T00:00:00Z",
           },
@@ -127,7 +159,7 @@ test("heygenAuthMethod returns null with no credential at all", () => {
   withCleanHeygenEnv(() => {
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
-      process.env.HEYGEN_CONFIG_DIR = dir; // no credentials file written
+      process.env.HYPERFRAMES_CONFIG_DIR = dir; // no credentials file written
       assert.equal(heygenAuthMethod(), null);
     } finally {
       rmSync(dir, { recursive: true, force: true });
@@ -135,6 +167,32 @@ test("heygenAuthMethod returns null with no credential at all", () => {
   });
 });
 
+test("an expired or foreign OAuth login never falls back to a saved API wallet", () => {
+  withCleanHeygenEnv(() => {
+    const dir = mkdtempSync(join(tmpdir(), "hf-auth-payer-"));
+    try {
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
+      const credential = {
+        api_key: "other-wallet",
+        oauth: {
+          client_id: "Zg3LF4FCLoeJoGs2YqMtZ17g",
+          token_endpoint: "https://api2.heygen.com/v1/oauth/token",
+          access_token: "expired",
+          expires_at: "2000-01-01T00:00:00Z",
+        },
+      };
+      writeFileSync(join(dir, "credentials"), JSON.stringify(credential));
+      assert.deepEqual(heygenCredential(), { expired: true });
+      credential.oauth.expires_at = "2099-01-01T00:00:00Z";
+      credential.oauth.client_id = "shared-heygen-client";
+      writeFileSync(join(dir, "credentials"), JSON.stringify(credential));
+      assert.deepEqual(heygenCredential(), { expired: true });
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});
+
 test("loadEnvFromDir skips a .env folder and loads the .env file above it", () => {
   const root = mkdtempSync(join(tmpdir(), "heygen-env-"));
   const project = join(root, "project");
@@ -175,7 +233,7 @@ test("heygenAuthMethod returns null when the credentials path is a folder", () =
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
       mkdirSync(join(dir, "credentials"));
-      process.env.HEYGEN_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
       assert.equal(heygenAuthMethod(), null);
     } finally {
       rmSync(dir, { recursive: true, force: true });
@@ -188,7 +246,7 @@ test("heygenAuthMethod returns null when the credentials path is a symlink loop"
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
       symlinkSync(join(dir, "credentials"), join(dir, "credentials"));
-      process.env.HEYGEN_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
       assert.equal(heygenAuthMethod(), null);
     } finally {
       rmSync(dir, { recursive: true, force: true });
@@ -200,8 +258,8 @@ test("heygenAuthHeaders says to fix an unreadable credentials path, and to log i
   withCleanHeygenEnv(() => {
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
-      process.env.HEYGEN_CONFIG_DIR = dir;
-      assert.throws(() => heygenAuthHeaders(), /no HeyGen credentials/);
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
+      assert.throws(() => heygenAuthHeaders(), /no HyperFrames credentials/);
       mkdirSync(join(dir, "credentials"));
       assert.equal(heygenCredential(), null);
       assert.throws(
@@ -276,12 +334,12 @@ test("a base that isn't HeyGen's gets no stored or host OAuth credential, only a
   withCleanHeygenEnv(() => {
     const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
     try {
-      process.env.HEYGEN_CONFIG_DIR = dir;
+      process.env.HYPERFRAMES_CONFIG_DIR = dir;
       writeFileSync(join(dir, "credentials"), JSON.stringify({ api_key: "hg_stored" }));
       process.env.HEYGEN_ACCESS_TOKEN = "at_host";
       process.env.HEYGEN_API_BASE = "https://proxy.example.com";
       assert.equal(heygenCredential(), null);
-      assert.throws(() => heygenAuthHeaders(), /no HeyGen credentials/);
+      assert.throws(() => heygenAuthHeaders(), /no HyperFrames credentials/);
       // HeyGen's own hosts keep every credential source.
       process.env.HEYGEN_API_BASE = "https://api-canary.heygen.com";
       assert.equal(heygenAuthMethod(), "oauth");
diff --git a/skills/media-use/audio/scripts/lib/tts.test.mjs b/skills/media-use/audio/scripts/lib/tts.test.mjs
index bf59c1eac4..025eb03ddc 100644
--- a/skills/media-use/audio/scripts/lib/tts.test.mjs
+++ b/skills/media-use/audio/scripts/lib/tts.test.mjs
@@ -209,7 +209,7 @@ test(
 );
 
 test("pickProvider heygen with an unreadable credentials path says to fix that path", () => {
-  const saved = ["HEYGEN_API_KEY", "HYPERFRAMES_API_KEY", "HEYGEN_CONFIG_DIR"].map((k) => [
+  const saved = ["HEYGEN_API_KEY", "HYPERFRAMES_API_KEY", "HYPERFRAMES_CONFIG_DIR"].map((k) => [
     k,
     process.env[k],
   ]);
@@ -217,7 +217,7 @@ test("pickProvider heygen with an unreadable credentials path says to fix that p
   try {
     delete process.env.HEYGEN_API_KEY;
     delete process.env.HYPERFRAMES_API_KEY;
-    process.env.HEYGEN_CONFIG_DIR = dir;
+    process.env.HYPERFRAMES_CONFIG_DIR = dir;
     mkdirSync(join(dir, "credentials"));
     assert.throws(() => pickProvider("heygen"), /fix or remove that path/);
   } finally {