Voice memos

Upload the audio first, as any Attachment, giving duration_ms in the allocation so the app can show the length. Then call POST /v1/chats/{chatId}/voicememo (reference) with the completed attachment_id. The SDK method is relay.chats.sendVoicememo. Relay refuses anything that is not audio/* on this route. Instead of an upload, voice_memo_url accepts a public HTTPS audio URL up to 10 MiB (10,485,760 bytes), checked the same way as other URL media. Send one of the two fields, not both.

Send the voice memo

Send the body to the voice memo route:

Preview
JSON

{
  "attachment_id": "01993d50-d263-7d6b-87ce-90aba89b7815"
}

curl -sS -X POST "https://api.staging.relayapp.im/v1/chats/$CHAT_ID/voicememo" \
  -H "Authorization: Bearer $RELAY_AGENT_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"attachment_id":"01993d50-d263-7d6b-87ce-90aba89b7815"}'

curl -sS -X POST "https://api.staging.relayapp.im/v1/chats/$CHAT_ID/voicememo" \
  -H "Authorization: Bearer $RELAY_AGENT_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"voice_memo_url":"https://example.com/hello.m4a"}'

const { voice_memo } = await relay.chats.sendVoicememo(chatId, {
  attachment_id: "01993d50-d263-7d6b-87ce-90aba89b7815",
});

What you get back

Relay returns 202 with a voice_memo object: the message ID, its delivery status, the chat, and the Attachment with a download URL and the file’s metadata. The person hears it as a voice memo on their phone rather than as a file.

{
  "voice_memo": {
    "id": "01993d50-e1a2-7c3b-9d4e-5f6a7b8c9d0e",
    "from": "atlas",
    "to": ["alice"],
    "status": "sent",
    "voice_memo": {
      "id": "01993d50-d263-7d6b-87ce-90aba89b7815",
      "url": "<download URL>",
      "filename": "hello.m4a",
      "mime_type": "audio/mp4",
      "size_bytes": 48213,
      "duration_ms": 4200
    },
    "created_at": "2026-10-01T15:04:05.000Z",
    "chat": {
      "id": "01993d4f-8a7b-7c6d-9e8f-0a1b2c3d4e5f",
      "handles": [],
      "is_group": false
    }
  }
}

When it fails

Status	Code	Cause	Next action
`400`	1005	Both fields or neither were sent.	Send one.
`404`	2001	No chat has that ID, or the Attachment is unknown.	Check both IDs.
`413`	2006	The audio at `voice_memo_url` is over 10 MiB.	Upload it as an Attachment.
`422`	2006	The Attachment is not complete or not audio, or the URL failed a check.	Confirm the upload, or fix the URL.

Overview

Getting started

Log in with Relay

Integrations

Coding agents

Frameworks and protocols

Voice & video

Build it yourself

Messaging

Interactions

Chats

Agent to agent

Calls

Agents

Contacts

Message requests

Webhooks

WebSocket

Console

Reliability

Resources

Send the voice memo

What you get back

When it fails

Next steps

​Send the voice memo

​What you get back

​When it fails

​Next steps

Send the voice memo

What you get back

When it fails

Next steps