# Materials Data Repository > Materials Data Repository (MDR) is a data repository that hosts materials research data and publications. MDR is operated by the [National Institute for Materials Science (NIMS), Japan](https://www.nims.go.jp/). ## Documents - [About MDR](https://mdr.nims.go.jp/page/about) - [MDR User's Manual](https://dice.nims.go.jp/services/MDR/manual/html/) ## API - [OpenAPI specification](https://mdr.nims.go.jp/openapi.yaml) - [API reference](https://dice.nims.go.jp/services/MDR/manual/html/api.html) ## Contact - [Contact form](https://dice.nims.go.jp/contact/form.html)