Welcome to the OSL API reference documentation. Here you will find a single, consolidated library for all application programming interfaces (API) offered by OSL’s platform.

This document provides the details required to use OSL's REST, WebSocket and FIX protocols which are organized into our key business functions.

Please direct any questions or feedback to [email protected].

Business Functions

OSL operates a brokerage platform, an exchange venue and a custody solution.

Through our digital asset markets business, we deliver a world-class digital asset offering for professional clients which includes brokerage, exchange and custody, all of which are supported by industry-leading customer service.


Through OSL's brokerage offering, clients can access institutional-size liquidity with tight spreads on principal basis. Trades can be executed over-the-counter with our global sales trading team, or electronically through our E-Trade (Electronic Trade) or RFQ (Request for Quote) capabilities.


OSL's exchange provides institutional-grade access to spot markets using an aggregated Central Limit Order Book (CLOB) model which provides shared liquidity access with OSL’s global SaaS partners. The OSL exchange has an ultra-low latency matching engine and is accessible directly via API (FIX, REST & WebSocket), native browser GUI and other OMS/EMS vendor partners. Finally, participants are protected by the integration of a full suite of compliance tools including market surveillance and transaction monitoring.


OSL provides industry leading insured custody for digital assets, including comprehensive protection of customer assets for cold wallets and insurance for loss, damage, destruction, or theft of private keys.