Runway Mobile Proxies: Test Video Tools and API Clients From the US
Runway sells generative video to a global audience with the United States as its home market. Plans, feature flags and the web app's upload and render paths can differ by region, and the heavy asset traffic behaves differently on a cellular network than on office fibre. Teams integrating the Runway API into a product, or QA engineers checking the US mobile experience, get a faithful view from a Mobile Proxies US line: one carrier SIM in one US metro, HTTP(S) and SOCKS5 endpoints, exit IP and rotation in an API.
What a US mobile vantage point changes
Presentation: plan tiers, currency and promotional surfaces follow the market. Features: new models and modes often reach US accounts first. Access path: a hosting address is routed into extra verification on sign-in and sometimes on upload; a carrier address shared with real subscribers goes through the consumer path. Network: uploads of source clips and downloads of renders on a mobile link expose timeouts and retry logic that never fire on fibre.
That last point is the one developers underrate. If your product wraps Runway and your users are on phones, the mobile network is part of your test matrix.
Testing your Runway API integration end to end
Calls from your backend to the Runway API stay on your server's address; they are server to server. The line is for the client: your web or mobile app, used by a US mobile user, uploading a clip to your backend, which hands it to Runway and returns the result. Put a browser profile or an emulator behind the line and run that whole path.
Choose 5G for this work. Renders are large and a 5G line reads up to 50 Mbps download; data is not metered on any plan, so a day of pulling renders costs nothing extra. Log the line's exit IP from the API with each test case.
QA of the Runway web app on a cellular network
Chunked uploads, resumable transfers, WebSocket progress events and long-polling render status all behave differently when latency is mobile latency. Run the web app behind the line's HTTP endpoint in a browser profile and watch the network panel. Switch 4G and 5G lines to see both ends of the range. Move the line between metros for free when you want a different cell environment.
Keep the account signed in on one line and leave the address alone during a session. The carrier holds it by default.
Scheduling large clip uploads around the tower
Source clips and finished renders are the heaviest thing this suite moves, and a cell's capacity changes through the day. POST /proxy/speed-pattern returns hours, the median download per local hour on that tower, plus tz and the slow window. Schedule the large-upload cases for the quiet hours when you want to test Runway, and for the busy hours when you want to test your own retry logic.
Subscribe to the proxy.down webhook as well. An upload that dies because the modem went away is a different bug from one Runway rejected, and the webhook timestamp settles which it was. Keep the source clip identical between runs, so the only variable left in the comparison is the hour. Note the file size in the record too, and keep the clip's codec the same.
Rotation and terms
Rotate between test runs by API and wait for the new exit IP before the next run. Never rotate during an upload or a signed-in session; the connection resets and the session looks hijacked.
Use your own Runway account and API keys within Runway's terms. The line is a test connection on a US carrier network; it does not change plan limits or region settings.
Setting up a Runway proxy on Mobile Proxies US
- Buy a 5G line in the metro you want to test from.
- Read endpoints and credentials from the API and configure a browser profile or emulator with them.
- Verify the exit IP against ip from GET /proxy/status and the carrier ASN.
- Run upload, render and download flows through the line; record timings, failures and exit IP per case.
- Rotate by API between runs; try a 4G line or another metro to widen the network matrix.
Runway proxy questions
Should the backend call Runway through the line?
No. Server-to-server calls belong on your cloud address. The line is for the client half of the path.
Is 4G enough for video QA?
For interface and flow checks, yes. For repeated large renders a 5G line's higher download speed saves time. Neither plan meters data.
Does a rotation interrupt an upload?
Yes. The connection resets while the modem re-attaches. Rotate only between runs.