REST API Overview

The Mostly REST API provides programmatic access to your creative intelligence database, brand monitoring pipelines, and video generation workflows.

Base URLs

All API requests should be made to:

Production: https://mostly.so/api/v1
Staging:    https://staging.mostly.so/api/v1
Local:      http://localhost:3000/api/v1

Authentication

Every request to the Mostly API must include your secret API key in the Authorization header as a Bearer token:

Authorization: Bearer mst_live_...

Alternatively, you can pass the key in the x-api-key header:

x-api-key: mst_live_...

Obtaining an API Key

1. Navigate to Settings → API & MCP.
2. Click Create API Key.
3. Provide a descriptive name (e.g. Zapier Integration, Cursor IDE) and optional expiration.
4. Copy the raw key immediately. For security, the key is hashed with SHA-256 and will never be shown again.

Response Formats

All API responses are returned in JSON format. Successful requests return standard 2xx HTTP status codes.

{
  "totalAvailable": 1500,
  "breakdown": {
    "SUBSCRIPTION": 1000,
    "GRANT": 500
  }
}

Error Handling

When an error occurs, the API returns standard HTTP error codes accompanied by an error response object:

{
  "error": "UNAUTHORIZED",
  "message": "Invalid, expired, or revoked API key."
}

Common HTTP Status Codes