Diagnose a call

Give diagnose any call UUID and it explains what happened: whose side each step was on (your server, Plivo, the carrier), the timeline, and anything unusual. Use it on a failed call to find out why, and on a completed call that ended sooner than expected, had one-way audio, or dropped its stream. For a voice agent the usual culprits are three: Plivo could not reach your answer URL, the XML it returned was not valid, or the WebSocket bot did not answer: diagnose tells you which.

plivo voice calls list --limit 5                 # find the UUID
plivo voice calls diagnose <call_uuid>           # usually about a minute; allow 30 to 120 s

A typical answer:

What happened: This inbound call was terminated because Plivo could not fetch call instructions from your answer URL.
Likely cause: The answer URL https://api.example.com/plivo/answer returned 404. The call was hung up with
              cause 7011 (Error Reaching Answer URL).
Timeline: 07:48:40.600 call received · 07:48:40.630 answer URL responded 404 · 07:48:41.016 call hung up
Suggested next step: Make sure the answer URL is deployed and returns Plivo XML with HTTP 200; every inbound call will fail until it does.

The hangup causes you will see most often while building a voice agent:

Hangup cause	Meaning	Fix
`7011` Error reaching answer URL	Plivo could not fetch your answer URL (down, not public, tunnel closed, 4xx/5xx)	Check the URL is reachable from the internet; while developing, use Forward calls to your bot
`8011` Invalid answer XML	The answer URL returned something that is not Plivo XML (often JSON, or an HTML error page)	Return `<Response><Stream …>` with `Content-Type: application/xml`; check with `curl -X POST <answer-url>`
`4010` End of XML instructions	Normal end; the bot closed the WebSocket, or the XML finished	Only a problem if the call ended earlier than you expected: check your bot’s logs for why it closed
`USER_BUSY` (from your XML)	Your answer URL returned `<Hangup>` or an empty response	Fix the branch of your code that returned it

If the answer URL and XML are fine but the caller hears silence, the bot is the problem: reproduce without a phone with Test your WebSocket endpoint. For the raw record (hangup cause, source, duration) run plivo voice calls get <call_uuid> -o json.

The answer is written by Plivo’s AI assistant, so treat it as an explanation to read, not a stable schema to parse. diagnose and plivo ask share a limit of 5 requests per 10 minutes per account. Only calls on your own account can be diagnosed. For messages and general questions see Diagnose and ask.

Getting started

Voice agents with Audio Streaming

Plivo APIs

Diagnose a call