# Design decisions

[Code standards](code-standards.md) are the rules every file follows; this folder is why the system is shaped the way it is.

One file per decision. Each states the decision, the reasoning, the alternatives
rejected, and the consequences — including the bad ones.

## Transport

- [0001 — Git lives at the root namespace, REST lives under `/api`](0001-namespace-split.md)
- [0019 — SSH is a second transport, not a second git](0019-ssh-is-a-second-transport-not-a-second-git.md)
- [0002 — The transport layer takes streams, not `Request`/`Response`](0002-streams-not-http-objects.md)
- [0013 — The request body is captured before anything else can await](0013-raw-body-is-captured-first.md)
- [0014 — A flush-only POST is a probe, not a malformed push](0014-the-pre-push-probe.md)
- [0003 — `git/` is not a REST resource](0003-git-is-not-a-resource.md)

## Storage and durability

- [0004 — Object storage is the source of truth, local disk is a cache](0004-object-storage-is-the-truth.md)
- [0005 — One commit point per push, and it is a compare-and-swap](0005-single-commit-point.md)
- [0006 — Entries carry no sequence number](0006-entries-carry-no-seq.md)
- [0007 — Optimistic concurrency, never locks](0007-optimistic-concurrency.md)
- [0008 — The log is a binary format](0008-binary-log-format.md)
- [0009 — The index holds a ref snapshot, not a diff](0009-index-holds-a-snapshot.md)
- [0010 — Orphaned entries are garbage, never corruption](0010-orphans-are-garbage.md)
- [0012 — Materialization is forward-only replay](0012-forward-only-materialization.md)
- [0015 — Nothing holds a packfile in memory](0015-nothing-holds-a-packfile.md)
- [0020 — Deleting a repository is a tombstone, then a purge](0020-deletion-is-a-tombstone-then-a-purge.md)

## Review

- [0016 — A pull request spans two logs, and lends objects rather than copying them](0016-a-pull-request-spans-two-logs.md)
- [0017 — Issues are rows, not branches](0017-issues-are-rows-not-branches.md)
- [0018 — Timestamps are `timestamptz`, never bare `timestamp`](0018-timestamps-are-timestamptz.md)
- [0021 — Repository access is a role ladder, and an invitation grants nothing](0021-access-is-a-role-ladder.md)
- [0022 — Users and organizations share one namespace](0022-owners-share-one-namespace.md)
- [0023 — Organization access is a base permission, raised per repository](0023-organization-access-is-a-base-permission.md)
- [0024 — Tags live in git, releases live in rows](0024-tags-live-in-git-releases-in-rows.md)
- [0025 — Stored files are billed to the owning account, and the quota is configuration](0025-storage-is-billed-to-the-owning-account.md)
- [0026 — A review is pinned to the head it read, and threads hang off its line comments](0026-a-review-is-pinned-to-the-head-it-read.md)
- [0027 — Squash and rebase carry the head along](0027-squash-and-rebase-carry-the-head-along.md)
- [0028 — Branch writes from the API are ref-only pushes](0028-branch-writes-are-ref-only-pushes.md)

## Open

- [0011 — Deferred decisions](0011-deferred.md)