# How a landing happens

How a checked answer becomes the platform's own commit on main.

1. The platform checks the answer's merged tree: the ask's check and the project's lanes.
2. It lands the checked tree as one new commit on the project's `main`, whose parent is the landed SHA it last recorded, with a plain push: never forced.
3. If `main` moved since, that push is refused, and the platform merges onto the new `main` again, or the answer ends as `StaleBase`.
4. Only once `main` has moved does it write its bookkeeping, each in a push of its own: the ref that mirrors the landed SHA, then the verdict note. Either may trail `main` for a moment, and nothing decides by them.
5. A landing tried again finds its own commit on `main` by its `Request-Id` trailer and writes only what is missing, so it never makes a second commit.

Across every project, the MCP tool `recentLandings` lists the latest landings and the answers the gate refused, the latest first and at most 20: when, the project, the ask and its want, and of each refusal its tag and its area, never a held-back check's name.