# ADR-007: Product versioning and releases

- **Status:** ACCEPTED
- **Date:** 2026-07-10
- **Deciders:** cproudlock
- **Supersedes:** none

## Context

ADR-002 established semantic versioning for the plugin contract via
`__contract_version__` in `shopdb/__init__.py`. That number answers one
question only: is a given plugin compatible with this platform build. It
says nothing about the state of the product as a whole. A sister site
standing up its own instance needs a different answer: which release am I
running, and what changed since the last one.

Until now the product had no version, no tags, no changelog, and no CI.
ADR-002's pinning model implicitly assumes that a downstream site can
pin a known-good build, but there were no tags to pin to. Adopters had no
release record to read before upgrading, and no automated gate confirming
that a given commit builds and passes tests.

## Decision

The product carries its own release version, separate from the plugin
contract version.

1. **Product version** (`shopdb/__init__.py`): a single `__version__`
   constant. This is the version of the shopdb-flask product as a whole.
   It follows semantic versioning of the product's user-visible and
   operator-visible behavior. It is deliberately NOT part of the
   `shopdb.api` contract surface, so it is never re-exported through
   `shopdb.api`; exporting it would itself be a contract change under
   ADR-002.

2. **Plugin contract version** (`__contract_version__`): unchanged from
   ADR-002. It moves only when the plugin contract surface changes, per
   the major/minor/patch rules in ADR-002.

The two are distinct series with independent bump rules. They happen to
coincide at `0.5.0` for this release; that is a coincidence of timing,
not a coupling. A product release that changes no contract surface bumps
`__version__` while leaving `__contract_version__` fixed, and vice versa.

3. **Release record** (`CHANGELOG.md`, repo root): the canonical,
   human-readable record of what changed in each release, in
   Keep-a-Changelog format. Every release has an entry; work in flight
   accumulates under `## [Unreleased]`.

4. **Git tags**: each product release is tagged `vX.Y.Z`, where `X.Y.Z`
   matches `__version__` at the tagged commit. Tags are what ADR-002's
   downstream-pinning model pins to.

5. **Frontend version** (`frontend/package.json`): kept in lock-step with
   `__version__` so the shipped single-page app reports the same product
   version as the backend that serves it.

### Release procedure

To cut release `X.Y.Z`:

1. Bump `__version__` in `shopdb/__init__.py` to `X.Y.Z`.
2. Bump `version` in `frontend/package.json` to the same `X.Y.Z`.
3. Move the accumulated `## [Unreleased]` notes in `CHANGELOG.md` into a
   new `## [X.Y.Z] - YYYY-MM-DD` section, leaving a fresh empty
   `## [Unreleased]` above it.
4. If the plugin contract surface changed this release, bump
   `__contract_version__` per ADR-002 (independently of `__version__`).
5. Commit, then tag: `git tag -a vX.Y.Z -m "shopdb-flask X.Y.Z"`.
6. Push the commit and the tag.

## Consequences

### Positive

- Adopters have a real release to name in bug reports and a changelog to
  read before upgrading.
- ADR-002's pinning story finally has tags to pin to.
- Product and contract can evolve at their own pace without one dragging
  the other into a misleading bump.

### Negative / cost

- Two version numbers to keep straight. The comment in
  `shopdb/__init__.py` and this ADR exist to keep the distinction clear.
- Release discipline: the changelog and both version constants must be
  updated together, or the tagged build misreports itself.

### Neutral

- The internal CI workflow runs the backend tests, the naming/style
  gate, and the frontend build on push and PR. It is best-effort: the internal CI
  Actions availability on the host is unverified, so the workflow is
  config-only until a runner is confirmed.

## Alternatives considered

1. **Reuse `__contract_version__` as the product version.** Conflates two
   independent concerns; a docs-only or UI-only release would either
   falsely bump the contract or leave the product looking unchanged.
   Rejected.
2. **Calendar versioning for the product** (e.g. `2026.07.0`). Easy to
   bump but poor at signaling breaking operator-facing changes. Rejected
   for the same reasons ADR-002 rejected it for the contract.
3. **No product version, rely on git SHAs.** Opaque to adopters and
   unpinnable in any human-meaningful way. Rejected.

## References

- ADR-001 (defines the contract surface)
- ADR-002 (plugin contract versioning; `__contract_version__` bump rules)
- `shopdb/__init__.py` (`__version__`, `__contract_version__`)
- `CHANGELOG.md` (release record)
- `frontend/package.json` (frontend version, kept in lock-step)
- the internal CI workflow (CI gate)
