Voice Agent API abrupt websocket closure

[joshgIPS]

I am utilizing the voice agent API via Twilio and have run into a snag. I am able to establish the websocket connection and successfully apply settings, as well as receive audio from DG and send it successfully to Twilio. However immediately after I begin sending Twilio audio to DG the websocket connection closes with the error:

{"type":"Error","description":"Listen connection closed unexpectedly.","code":"ASR_CONNECTION_CLOSED"}

Here is a request_id that received the above error: e3552a80-1477-46e6-b283-46eabe5aa1d3

Any help here would be greatly appreciated.

[deepgram-community[bot]]

Thanks for asking your question. Please be sure to reply with as much detail as possible so the community can assist you efficiently.
_{Consider joining our Discord community for more opportunity to engage with your fellow Deepgram users. You can earn points which can be redeemed for cool stuff by being active in our communities!}

[deepgram-community[bot]]

Hey there! It looks like you haven't connected your GitHub account to your Deepgram account. You can do this at https://community.deepgram.com - being verified through this process will allow our team to help you in a much more streamlined fashion.

[deepgram-community[bot]]

It looks like we're missing some important information to help debug your issue. Would you mind providing us with the following details in a reply?

• The programming language you are working in (e.g. JavaScript, Python).

[joshgIPS]

PHP.

Also here is the 'Settings' I am sending if that is helpful:

        // Construct session update payload following Deepgram Voice Agent v1 spec
        $sessionUpdate = [
            'type'  => 'Settings',
            'audio' => [
                'input'  => [
                    // Twilio sends mu-law 8 kHz audio; configure Deepgram to expect the same
                    'encoding'    => 'mulaw',
                    'sample_rate' => 8000,
                ],
                'output' => [
                    // Return mu-law 8 kHz so Twilio can play back without transcoding (per Deepgram Twilio guide)
                    'encoding'    => 'mulaw',
                    'sample_rate' => 8000,
                    'container'   => 'none'
                ],
            ],
            'agent' => [
                'language' => 'en',
                'listen'   => [
                    'provider' => [
                        'type'  => 'deepgram',
                        'model' => 'nova-2-general',
                    ],
                ],
                'think'    => [
                    'provider' => [
                        'type'        => 'open_ai',
                        'model'       => 'gpt-4o-mini',
                        'temperature' => 0.7,
                    ],
                    'prompt'    => "Today is " . date('l jS \of F Y h:i:s A') . ". " .
                        str_replace('{agent_name}', $agentName, $this->aiInstructions->ai_instructions) .
                        $instructionsPrompt,
                ],
                'speak'    => [
                    'provider' => [
                        'type'  => 'deepgram',
                        'model' => 'aura-2-' . $randomVoice . '-en',
                    ],
                ],
                'greeting' => "Hello! How can I help you today?",
            ],
        ];

[deepgram-community[bot]]

I looked at the logs for e3552a80-1477-46e6-b283-46eabe5aa1d3 and nothing stands out to me at first glance.

I'm curious why you've opted to do this: 'model' => 'aura-2-' . $randomVoice . '-en',

instead of just picking an actual model for the speak provider? it's the only thing that stands out to me in your Agent Settings as potentially problematic, depending on what is getting sent in your actual API Request.

Also, double check input / output encoding and sample rates values as it might be causing this error.

This message was sent by John Vajda from Deepgram, via our community automation.