Licence and notices

For anyone reusing the code or the data. Reference.

This page is a plain summary, not legal advice. The files in the repository are the source of truth.

Independence and trademark

Changeset Second Opinion is an independent open source tool for OpenStreetMap reviewers. It is not endorsed by, sponsored by or affiliated with the OpenStreetMap Foundation. OpenStreetMap is a trademark of the OpenStreetMap Foundation, used under its trademark policy. The project runs on a subdomain that contains the name, which the policy allows for a service based on OpenStreetMap that follows its notice and no-endorsement rules. The site uses no OpenStreetMap logo.

Code

The code is licensed under Apache-2.0. The full text is in LICENSE. The backend (backend/pyproject.toml) declares the same licence.

OpenStreetMap data

OpenStreetMap data and anything derived from it are © OpenStreetMap contributors and available under the Open Database License 1.0. See openstreetmap.org/copyright.

What	Licence
Recorded fixtures, including the fifteen demo changesets	ODbL 1.0, © OpenStreetMap contributors
Changeset ids and statistics in evaluation/	ODbL 1.0, © OpenStreetMap contributors
The optional map in the case screen	Shows its own attribution. Tiles come from OpenFreeMap, which carries its own attribution
Synthetic fixtures (changeset ids from 900000000000)	CC0 1.0

If you record a fixture, record only what you may redistribute under that licence, and do not use real mapper names. The recorder replaces names with placeholders and removes emails and links from changeset tags and comments, but it does not clean tags on map elements, so read the output. See CONTRIBUTING.md.

Models

Model	Licence
Strands Decider 2B, StrandsAgents/strands-decider-2B-qwen3.5-v1-2610	Apache-2.0 per its model card. The base model is Qwen/Qwen3.5-2B-Base, whose licence the project has not checked. Weights are downloaded at runtime and are not in the repository
Claude Haiku 4.5 on Amazon Bedrock	AWS service terms and the model provider’s terms

Fonts

The web app ships three variable fonts, each under the SIL Open Font Licence 1.1, with the licence text beside the file in web/src/fonts/.

Font	Licence text
Inter	Inter-OFL.txt
JetBrains Mono	JetBrainsMono-OFL.txt
Fraunces	Fraunces-OFL.txt

Third-party notices

THIRD_PARTY_NOTICES.md lists the Python and JavaScript packages the project depends on, with their declared licences. It was generated from the lockfiles on 17 October 2026. Licence names come from package metadata and have not been checked by a lawyer. Regenerate it after any lockfile change.

The file marks a few items for attention. At the time it was written:

• osmcha is declared GPL-3.0-or-later, while the project’s own code is Apache-2.0. The backend imports it for suspect-word and editor checks.
• psycopg is LGPL-3.0-only and is used unmodified for the optional Postgres path.
• certifi and lightningcss are MPL-2.0. The second is a build-time tool that is not in the shipped bundle.

The osmcha question was still open when the file was last changed on 20 October 2026, and the backend still depends on osmcha==0.9.2.

Documentation

This documentation lives in the same repository, in site/, and is under the repository’s licence, Apache-2.0. No separate licence applies to the text. The screenshots show the demo set, which comes from real changesets, so the map data in them is © OpenStreetMap contributors, under the Open Database Licence.

Next: roadmap.