The Crossref Grant Linking System (GLS) is a service for research funders to contribute to open science infrastructure. As members of Crossref, funders create unique links and open metadata about their support of all kinds, from financial grants to prizes to use of facilities. This metadata is distributed at scale openly and globally and the unique links are acknowledged in any outputs of the funding, such as publications, preprints, data and code - in order to streamline the reporting process. Background to the Grant Linking System In 2017, our board agreed that connecting more intentionally with research funding should be a key strategic priority for the Crossref infrastructure which already supported all kinds of research outputs like articles, preprints, standards, datasets, etc. Whilst the scholarly community has long been linking persistently between articles and other objects (Crossref), people (ORCID), and institutions (ROR), the record of the award was not captured in a consistent way across funders worldwide. Researchers and publishers have long been acknowledging funders in their publication metadata but the grants themselves were not easily and persistently linked up with the literature or with researchers or with institutions.