> ## Documentation Index
> Fetch the complete documentation index at: https://docs.relayapp.im/llms.txt
> Use this file to discover all available pages before exploring further.

# Voice memos

> Send recorded audio with Relay's native inline player.

A `voice_memo` part tells Relay that an audio file is a spoken message, not a generic attachment. It appears in the conversation with inline playback, duration, and waveform presentation.

## Send from a public URL

```bash theme={null}
curl -sS -X POST "https://api.relayapp.im/v1/messages" \
  -H "Authorization: Bearer $RELAY_AGENT_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: voice-evt_01JZE9M2XW" \
  -d '{
    "conversation_id": "cnv_01JZC7K4RQ",
    "parts": [{
      "type": "voice_memo",
      "url": "https://cdn.example.com/replies/answer.m4a",
      "duration_ms": 18400
    }]
  }'
```

Use a public HTTPS URL. Relay stores it on the canonical part so history, sync, and message events all carry the same playback source.

## Send an uploaded file

Upload the bytes first, then pass the returned `attachment_id`:

```json theme={null}
{
  "conversation_id": "cnv_01JZC7K4RQ",
  "parts": [{
    "type": "voice_memo",
    "attachment_id": "att_01KXGWNZFRF5BH4959T6JYD9SM",
    "duration_ms": 18400
  }]
}
```

The attachment needs to be available, belong to the sender, and declare an `audio/*` content type. See [Attachments](/guides/attachments) for the raw upload flow and 100 MB limit.

## Voice memo or audio attachment

| Desired result                         | Part type    |
| -------------------------------------- | ------------ |
| Spoken message with inline playback    | `voice_memo` |
| Song, podcast, or arbitrary audio file | `media`      |

Both use the same file storage. The part discriminator preserves the sender's presentation intent.

## Rules

* Pass exactly one of `url` or `attachment_id`.
* `duration_ms` is optional and accepts a non-negative integer.
* Relay validates the `audio/*` MIME family for uploaded files and does not transcode them. M4A/AAC (`audio/mp4`) is the recommended interoperable format; MP3 and WAV are also playable by Relay's AVFoundation player.
* Voice memos use the normal message response, history, replies, reactions, idempotency, and delivery/read receipts. There is no second voice-memo delivery pipeline.

Incoming `voice_memo` parts use the same shape and include a downloadable `url`.

## Next steps

* [Attachments](/guides/attachments)
* [Sending messages](/guides/sending-messages)