Meeting SDK Web 6.2.0 — wc/info returns HTTP 503, join fails with -3000 on own-account live meeting

Meeting SDK Web
1

Hi,

We’ve integrated the Meeting SDK for Web 6.2.0 (Component View) into our own LMS at campus.academiaenlevo.com.br. Students join scheduled classes from inside our platform. No join has ever succeeded.

The visible error is:

{ “type”: “JOIN_MEETING_FAILED”, “reason”: “connection error”, “errorCode”: -3000 }

But the actual failure, captured in DevTools, is:

POST https://zoom.us/api/v1/wc/info → HTTP 503

init() completes fine. The SDK dies on that call, every time.

Our setup

  • App: General App, Admin-managed, published to our account (“Users within my account”, Live).
  • Meeting SDK is enabled under Features → Embed — confirmed in the downloaded Manifest File: embed.meeting_sdk.enable: true, platform Web.
  • Using the Production Client ID / Client Secret from that same app.
  • A separate Server-to-Server OAuth app on the same account creates the meetings, and works perfectly.

What we’ve already ruled out (please skip these — happy to show evidence for any):

  1. Signature format. HS256 JWT with appKey, sdkKey, mn, role: 0, iat, exp, tokenExp. exp - iat = 120 minutes.
  2. Credential pair. appKey matches the app’s production Client ID exactly; the secret is that same app’s Client Secret. Both were re-entered together to rule out a mismatched pair.
  3. Clock skew. Our server’s clock is identical to yours — compared against the date: header from api.zoom.us, zero seconds difference.
  4. Browser environment. HTTPS, cross-origin isolated (COOP same-origin + COEP require-corp), SDK bundle loaded from source.zoom.us with crossorigin=“anonymous”.
  5. Meeting settings. Created via our S2S app on the same account, with waiting_room: false, join_before_host: true, approval_type: 2.
  6. The meeting itself is healthy. It opens normally in the Zoom Web Client at app.zoom.us/wc//start.
  7. Live meeting, host present — still 503. We started the meeting as host and then joined via the SDK on a clean page load. Same result.
  8. Reproduced with three different meetings, both API-created and created manually in the web portal.

Questions

  1. What makes wc/info return 503 for an existing, live meeting owned by the same account as the app?
  2. Is there an account-level setting outside the app — something like allowing embedded Web SDK, or a domain allowlist — that must be enabled before Meeting SDK credentials are accepted?
  3. Does the March 2, 2026 OBF/ZAK requirement apply when joining meetings owned by the app’s own account? If so, what exactly is missing from our join flow?

Happy to share the app’s Client ID, account ID, and a failing timestamp privately via DM.

Thanks!