Add a Sponsor button with a valid FUNDING.yml
GitHub shows a Sponsor button on a repository when it finds a .github/FUNDING.yml listing your funding platforms. The format is small but strict about keys and quoting, and one malformed line hides the button entirely. This builder produces a guaranteed-valid file from your handles.
How it works
The tool writes one line per platform using GitHub’s exact keys: github, patreon, open_collective, ko_fi, tidelift, buy_me_a_coffee, liberapay, and custom. The github field accepts up to four usernames — a single one is emitted as a plain value and several become a YAML inline list [a, b]. The custom field accepts up to four URLs, each JSON-quoted so colons and slashes never break parsing. Platforms left blank are omitted entirely, keeping the file minimal. Simple alphanumeric handles are left unquoted while anything unusual is quoted defensively.
Example and notes
A common setup lists a single GitHub Sponsors username plus an Open Collective slug and one custom donate link. Tidelift uses a platform-name/package form (for example npm/my-package), not a username, so enter it in that shape. After saving the file to .github/FUNDING.yml on your default branch and pushing, the Sponsor button appears on the repository header within a few minutes.