Toss Securities on Aug. 13 officially launched an open API service that links with large language models (LLMs) to allow users to place stock orders and make inquiries without separate coding knowledge.

An open API is an application programming interface that lets customers connect financial data and functions held by securities firms, such as prices, orders and account information, to programs they develop themselves or to external services.

Toss Securities said the service differs from existing open APIs in that it supports integration with external LLMs such as ChatGPT and Claude. It allows investors without development or coding knowledge to use related functions through an AI chat window.

After connecting an open API key issued to an investor to an external LLM, the investor enters the desired order details in natural language in the chat window. The AI interprets the request and connects it to an actual order.

For example, if the user types, "Buy 10 shares of Stock A at market price," the order can be executed based on that request.

Functions available through the Toss Securities open API include retrieving stock information, checking the user's account information, regular orders, conditional orders and real-time quotes.

Another feature is that it provides trading functions for domestic and overseas stocks through a single integrated API. Unlike approaches that provide separate APIs for domestic and overseas stocks, a single integration supports quote checks and orders in both markets.

Toss Securities has been providing a core-function open API in stages to customers who applied in advance since May. With the official launch, it expanded the service to all customers.

A Toss Securities official said, "With this official launch of the open API, general investors without development or coding knowledge can use AI and apply it to investment activities," adding, "We will continue to support investors so they can implement their own investment strategy systems."