GMO Payment Gateway, the first PSP in Japan, has developed payment development documentation with LLM search and AI search
~Updating the Japan's payment development environment in line with the AI era~

GMO Internet Group's GMO Payment Gateway, Inc. (President & Chief Executive Officer: Issei Ainoura hereinafter referred to as GMO-PG) has developed a document platform for the payment development environment in the AI era for the first ^{time (*1)} in Japan.
Online Payment Service In "PG Multi-Payment Service", we will redesign the document structure so that the specifications that developers check are appropriately referenced, even when searching for information using large language models (LLMs). This will improve the accuracy of your answers.
This document will be released to some merchants and developers in advance from February 3, 2026 (Tuesday), and improvements will be made while reflecting feedback, leading to the main release in March 2026.

• *1 PSP (payment service provider) mainly targets the Japan market, and is the first case to combine the redesign of the document structure based on the premise of web search by LLM and the introduction of an AI search function. According to GMO-PG.

【Background】

Japan's online payment has a diverse range of payment method, including CVS Payment and QR code payment in addition to Credit card payment. As a result, the configuration of payment systems becomes more complex, requiring developers to make decisions during the design and implementation process, referencing across specifications that include different conditions and operational assumptions for each payment method.
In addition, the external environment, including security measures such as anti-fraud measures, legal systems, and threat trends, is changing every day, and the conditions to be considered during development are constantly updated. In these environments, misreadings, missed references, and a lack of understanding of prerequisites can directly impact quality and development timelines.
On the other hand, the way developers search for information is also changing. In addition to reading documents page by page, the search is expanding to ask LLMs questions and refer to relevant information across the board. At this time, whether the information is organized in a structure that is easy to interpret by both humans and LLMs determines the speed and accuracy of decisions in development.
GMO-PG organizes the actual operational knowledge gained while handling more than 21 trillion yen ^(*2) of payment processing per year into development documents, and provides a structure suitable for both LLM search and human reference.

• *2 Consolidated figures as of the end of September 2025.

Overview of the redesigned developer documentation

This document is structured around the following two points.

1. Redesign of document structure based on the premise of web search by LLM
In addition to expanding the business scenarios of developers and use cases for each payment method, we will provide basic information about "PG Multi-Payment Service" and a collection of links to documentation in a "llms.txt" format prepared for LLMs.
This makes it easier to refer to developers' questions based on specifications even when searching for information using LLMs, leading to improved answer accuracy.
Introducing the 2.AI Search Function
It provides a search function that allows you to cross-sectionally browse related information based on the content and questions you are considering, regardless of page structure or search terms. In the process from design consideration to implementation, the burden of information search is reduced and the reference efficiency is increased.

In addition, documents that were distributed by connection method are consolidated into a single document site, and the structure is designed to proceed as a series of flows from consideration to design and implementation.

【About PG Multi-Payment Service】

Online Payment Service supports more than 30 different payment method, including Credit card payment, CVS Payment, and QR code payment. Depending on the business type and growth phase of the business, we provide a flexible payment foundation.
In addition, in addition to adopting a development method that is easy to design and implement based on OpenAPI specifications, it is equipped with high security and fraud detection functions to support online payment in a wide range of fields such as e-commerce, digital services, and BtoB transactions. At the same time, we are continuously developing documentation and reference environments to help developers get to the exact information they need.