Introducing the new API for OSI Approved Licenses® – Open Source Initiative

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Learn more about OSI’s mission, history, people, and programs.
Explore the list of OSI-Approved licenses and learn more about the license review process.
Learn more about Open Source AI, how do we define it, and its benefits to society.
Advancing Open Source through policy, regulation, and standards.
Supporting research, education, and knowledge about Open Source.
Connecting the people and organizations that build and support Open Source.
Explore the latest news, blog posts, newsletters, press mentions, and events from the OSI.
The Open Source Initiative (OSI) is excited to announce the availability of a new API service providing access to the canonical list of OSI Approved Licenses®. This launch is part of our broader effort to modernize how we manage and share Open Source license data, making it easier for the community to identify and verify licenses that comply with the Open Source Definition.
The list of OSI Approved Licenses® is a critical reference point for developers, legal teams, companies, and communities around the world. The OSI Approved Licenses® database is a comprehensive, structured, and up-to-date database of approved licenses and their metadata. This new API service builds directly on that work.
The new API is served directly from our website and reflects the official source of truth for OSI license data. This service is fully public and free to use. You can now access the full list of OSI Approved Licenses® from:
https://opensource.org/api/license
You can fetch detailed metadata on individual licenses, including:
For example, you can access data from the GNU General Public License version 3 at:
https://opensource.org/api/license/gpl-3-0
It’s also possible to search licenses by name or spdx:
https://opensource.org/api/license?name=gpl
https://opensource.org/api/licenses?spdx=gpl
The new API is not backward compatible with the legacy API service. Users will need to migrate to the new endpoint. If you’re currently using api.opensource.org, please note that the old service is outdated and will be deprecated in the coming months. We recommend beginning your migration now to ensure uninterrupted access.
We’re still refining the API and exploring ways to expand its capabilities. If you have a use case, suggestion, or need help transitioning to the new service, please get in touch. We’re especially interested in hearing from developers, legal teams, and tooling providers who rely on accurate license data. We look forward to seeing what the community builds on top of this new API.
We would like to thank Automattic for sponsoring this work and our former intern Giulia Dellanoce for creating a systematic and well-ordered database of all the licenses that have been submitted to OSI for approval since the time of the organization’s founding.
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