Getting started

Make your first call to the Masttro API in a few minutes: get credentials, exchange them for a token, then read your data.

Before you begin

The Masttro API gives authorized users read-only access to the data they already see in Masttro: clients, holdings, transactions, performance, tax lots, closed-end funds, entity structures, published reports and Document AI extractions.

• Credentials. Each API user has an API key and an API secret. Users can generate their own api credentials in the Users module of the Masttro platform. Check the knowledge center within Masttro platform for more information.
• Data scope. Your credentials are tied to a Masttro user. The API returns exactly the clients and data that user can access. Nothing more.
• License. Different license types include access to different endpoints. See License types.

Base URL

All endpoints are relative to:

Requests and responses use JSON over HTTPS. Paths are shown with the casing used in this documentation, for example /Holdings/{id}. Use that exact casing.

Make your first call

1. Request an access token

   Send your API key and secret to POST /Auth/Token. The response contains a bearer token valid for 60 minutes (expires_in is in seconds).

2. List your clients

   Every data endpoint is scoped to a client. Call GET /Clients and keep the numeric id of the client you want.

3. Fetch holdings

   Request month-end holdings for a client. yearMonth is required and uses the YYYYMM format.

A reusable client

Production integrations should cache the token, refresh it before it expires, retry on 429, and normalize empty results. Here is a compact helper you can copy.

The rest of this documentation assumes a valid token in $MASTTRO_TOKEN (cURL), token (C#, Python, JavaScript), and http / headers configured as shown above.

Next steps