API overview

The Larynth REST API. JSON over HTTPS, bearer API keys, cursor pagination and problem+json errors.

The Larynth API lets you manage assistants, phone numbers, contacts, campaigns, calls and webhooks from your own code. Everything you can do in the dashboard with these objects is available here.

Base URL

https://api-us.larynth.com

All paths start with /v1. Requests and responses are JSON, except file uploads (multipart) and recording audio (WAV). Each region has its own API host; the US region is https://api-us.larynth.com.

Make a first request

Create an API key in the dashboard, then list your assistants.

curl https://api-us.larynth.com/v1/assistants \
  -H "Authorization: Bearer $LARYNTH_API_KEY"

{
  "data": [
    {
      "id": "3f1c6e0a-5b1d-4c3e-9a57-2d0f4c8d1e11",
      "name": "Front desk",
      "status": "active",
      "latest_version": 3,
      "published_version": 3,
      "created_at": "2026-10-20T14:02:11Z",
      "updated_at": "2026-10-28T09:41:03Z"
    }
  ],
  "next_cursor": null
}

Conventions

• Timestamps are RFC 3339 in UTC.
• Phone numbers are E.164, for example [phone].
• Money is in micro-USD (1,000,000 micro-USD is one dollar) unless a field says otherwise.
• Request bodies reject unknown fields. A typo in a field name returns a validation error instead of being ignored.

Next

Authentication

API keys and scopes.

Errors

Problem responses and error codes.

Pagination

Cursors and filters on list endpoints.

Idempotency

Retry requests that place calls safely.