Thanks — I see the TwirpError:

code=unavailable, message="twirp error unknown: no response from servers, status=503"

. I’ll help you diagnose why the LiveKit server is unreachable and walk through the most likely fixes. What this means (brief) • A 503 “Service Unavailable” means the LiveKit backend did not respond to the API request. This is typically a server or network reachability problem rather than a JWT/auth signing issue. Quick checklist to run now 1. Verify the server is running ◦ Confirm your LiveKit server process (or container/service) is up. If you run LiveKit as a systemd service or in Docker/Kubernetes, check the service/container logs and restart if needed. 1. Confirm the API/host URL is correct ◦ Make sure the

url

used by your client matches your LiveKit public address (for example your-host or the correct

*.livekit.cloud

endpoint). An incorrect host will produce no response. 1. Test basic connectivity ◦ From the machine making the API call, run a simple connectivity test (curl or telnet) to the server host and port used by the API to confirm TCP reachability and TLS handshake: ▪︎ Example:

curl -v <https://your-livekit-host/>

(adjust host) ◦ If TLS fails or the connection times out, note the error. 1. Check firewall / network / proxy ◦ Ensure required ports are open (for typical setups check TCP 443 and any configured management ports). If you use a corporate proxy or DPI (e.g., Zscaler), verify it isn’t blocking or intercepting requests to your LiveKit domain. 1. Use the LiveKit Connection Tester / diagnostics ◦ Run the connection test utility to check WebSocket/WebRTC/TURN reachability if you suspect network-level blocking. 1. Inspect server logs for 503s ◦ Look at the LiveKit server logs around the time of the request to find service errors, crashes, or resource exhaustion (OOM, CPU spikes, etc.). If you want I can walk you through any of the above steps. To help further, please share: • Where this error happens (SDK/language and version, e.g., Python SDK) • How you’re hosting LiveKit (self-hosted Docker/K8s/AWS or livekit.cloud) • The exact

url

you’re attempting to reach (you can redact private tokens/keys) • Any relevant server logs or output around the failure (error lines or timestamps) • Whether this affects all clients/rooms or only a subset Next steps I can take once you provide the above • Suggest exact commands to verify service status and view logs for your hosting type • Help interpret server logs and recommend configuration fixes (ports, routing, proxies) • Narrow down if this is an intermittent outage vs. persistent misconfiguration I’m here to help — send the details above and we’ll dig in together. Sources: Python SDKs | livekit/livekit_composite | DeepWiki | Firewall Tips for LiveKit Connectivity | LiveKit | Running LiveKit on AWS | Diagnosing Connection Errors with Connection Test Utility | Diagnosing Connection Errors with the Connection Test Utility | LiveKit