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

# Sotto API

> Programmatic access to manage users, send messages, and sync data with Sotto.

The Sotto API lets you manage users, send messages, upload media, subscribe to event webhooks, and read the segments and custom data fields configured for your brand. For high-volume data movement, Sotto also supports flat-file [bulk imports and exports](/guides/overview).

<CardGroup cols={2}>
  <Card title="Authenticate" icon="key" href="/authentication">
    Sign every request with HMAC-SHA256.
  </Card>

  <Card title="API Reference" icon="code" href="/api-reference/users/get-user-by-phone-number">
    Explore every endpoint, schema, and example.
  </Card>

  <Card title="Webhooks" icon="webhook" href="/webhooks">
    Receive callbacks when events happen in Sotto.
  </Card>

  <Card title="Bulk data" icon="file-csv" href="/guides/overview">
    Import and export users, purchases, and click data.
  </Card>
</CardGroup>

## Base URL

All API requests are made to:

```text theme={"dark"}
https://api.bigco.ai/api/v1
```

Requests must be made over HTTPS. All request and response bodies are JSON unless otherwise noted (the [Files](/api-reference/files/upload-a-file) endpoint accepts `multipart/form-data`).

## Conventions

<ResponseField name="Dates and times" type="string">
  Timestamps are ISO 8601 in UTC, e.g. `2024-05-15T10:30:00Z`. Dates of birth use `MM/DD/YYYY`.
</ResponseField>

<ResponseField name="Phone numbers" type="string">
  Phone numbers use E.164 format, e.g. `+15551234567`.
</ResponseField>

<ResponseField name="Identifiers" type="integer | string">
  Users and messages are identified by integer IDs. Files and webhooks are identified by UUIDs.
</ResponseField>

## Getting access

API credentials are provisioned by Sotto. You will receive a **username** and a **secret** that are used to sign requests. Reach out to [support@withsotto.com](mailto:support@withsotto.com) to request credentials or ask a question.

<Note>
  Keep your API secret confidential. It is used to generate request signatures and should never be exposed in client-side code.
</Note>