The MSU Open API provides read access to MapleStory Universe data — including accounts, characters, items, game metadata, and marketplace listings. Builders can use it to create tools, dashboards, and Synergy Apps that connect with the MSU ecosystem.Documentation Index
Fetch the complete documentation index at: https://docs.msu.io/llms.txt
Use this file to discover all available pages before exploring further.
- Base URL: https://openapi.msu.io
1. Authentication
All requests require an API key passed as a request header.| Header | Type | Required | Value |
|---|---|---|---|
| x-nxopen-api-key | string | Yes | Your MSU Open API key |
- Example: x-nxopen-api-key: gw_xxxxxxxxxxxxxxxxxx
For instructions on how to obtain an API key, refer to the Getting Started with MSU Builder guide.
2. Rate Limits
Rate limits are applied per API key. Higher limits are available upon request.| Level | Rate Limit (RPS) | Quota (RPD) |
|---|---|---|
| Default | 2 RPS | 3,000 RPD |
| Level 1 | 10 RPS | 50,000 RPD |
| Level 2 | 30 RPS | 200,000 RPD |
To request a limit increase, contact the MSU Builder Team at contact_builder@nexpace.io.
RPS = Requests Per Second, RPD = Requests Per Day. Quota resets daily at 00:00 UTC.
3. Response Format
All responses use a common structure:- Success:
- Error (4xx / 5xx):

