@@ -18,15 +18,17 @@ ObjectStack follows strict backward compatibility guarantees to ensure predictab
 **The 17.x minors ran under a launch-window override: a breaking change shipped as a MINOR release, not a MAJOR one.** Every published `@objectstack/*` package versions in lockstep, so the version number alone is not an upgrade-safety signal; read [Launch Window](#launch-window-minor-releases-can-contain-breaking-changes) at the end of this page before you upgrade across 17.x.
 
 **The v18 line has exited prerelease mode.** While Changesets was in pre mode with the tag `next`, every release cut from `main` was the next `18.0.0-next.N` on npm's `next` tag, and `scripts/check-changeset-no-major.mjs` stood aside in pre mode, so a pull request could declare a major bump. Changesets has exited pre mode, so the line's GA version is `18.0.0`, which publishes to npm's `latest` tag, and the guard again fails a pull request that declares a `major` bump. See [how a breaking stage lands on the v18 line](/docs/releases/v18#how-a-breaking-stage-lands-on-this-line).
+
+**After 18.0.0, a breaking change ships in a MINOR or a PATCH release.** The maintainer's 2026-10-21 ruling ([#25105](https://github.com/objectstack-ai/objectstack/issues/25105)) keeps the no-major guard and grades each change by the metadata protocol: a key, value or metadata type added, narrowed or given a new meaning takes MINOR, and every other change takes PATCH, breaking or not. A non-protocol breaking change (a REST response, a boot refusal, a CLI exit status, a removed runtime export) keeps its `**BREAKING**` banner and ships as a PATCH. 18.1.0, the first release under the rule, is a MINOR that carries 82 changesets declared breaking.
 </Callout>
 
 ObjectStack follows [Semantic Versioning 2.0.0](https://semver.org/) (`MAJOR.MINOR.PATCH`). The table below describes what each component means; which version a breaking change ships in depends on the line, as the callout above says.
 
 | Version Component | When Incremented | Guarantee |
 |:---|:---|:---|
 | **MAJOR** (X.0.0) | Incompatible API changes | May contain breaking changes |
-| **MINOR** (0.X.0) | New features — and, in the 17.x minors, breaking changes | Existing code may require migration; the [release notes](/docs/releases) lead with what broke |
-| **PATCH** (0.0.X) | Bug fixes, backward-compatible | No behavior changes, only fixes |
+| **MINOR** (0.X.0) | New features — and, in the 17.x minors, breaking changes; after 18.0.0, any change to the metadata protocol (added, narrowed or semantic) | Existing code may require migration; the [release notes](/docs/releases) lead with what broke |
+| **PATCH** (0.0.X) | Bug fixes — and, after 18.0.0, every change that is not to the metadata protocol, breaking ones included | Before 18.0.0, no behavior changes. After it, a PATCH can break a REST client, a boot or a script: read its release notes |
 
 ### SemVer Guarantees
 
@@ -201,14 +203,14 @@ The convention was enforced rather than informal — `scripts/check-changeset-no
 ### What this means for an upgrade
 
 - **Do not read a MINOR bump as safe to take unattended.** Read the [release notes](/docs/releases) for the version you are moving to: they lead with breaking changes and carry the migration steps.
-- **Pin exact versions** instead of caret ranges if you cannot review each MINOR before it lands.
+- **Pin exact versions** instead of caret ranges if you cannot review each MINOR before it lands, and after 18.0.0 each PATCH as well.
 - **Diff your own metadata** across the upgrade with `os diff <before> <after> --breaking-only`.
 
 MAJOR releases do still happen — 17.0.0 was cut precisely because its breaking density was too high to carry `^16.x` consumers across on a caret range, and the v18 line is the next one — but in the 17.x minors an individual breaking change did not, on its own, force one.
 
 ### When it stops applying
 
-The tables and deprecation timeline above state this rule for the 17.x minors directly, beside what the v18 prerelease did. Classic SemVer — where a breaking change once again requires a MAJOR — is the settled form the project returns to once the launch window closes: the window closes at GA, and strict SemVer resumes from that point. **For the 17.x minors, this section was the operative rule wherever any part of this page disagreed.** For the `18.0.0-next.N` prereleases, the operative rule is [how a breaking stage lands on the v18 line](/docs/releases/v18#how-a-breaking-stage-lands-on-this-line).
+The tables and deprecation timeline above state this rule for the 17.x minors directly, beside what the v18 prerelease did. Classic SemVer — where a breaking change once again requires a MAJOR — is the settled form the project returns to once the launch window closes. **It did not close at the 18.0.0 GA.** The 2026-10-21 ruling ([#25105](https://github.com/objectstack-ai/objectstack/issues/25105)) keeps the no-major guard on the v18 line and grades each change by the metadata protocol instead, so after 18.0.0 a breaking change ships in a MINOR when it narrows the metadata protocol and in a PATCH when it does not. **For the 17.x minors, this section was the operative rule wherever any part of this page disagreed.** For the `18.0.0-next.N` prereleases, the operative rule is [how a breaking stage lands on the v18 line](/docs/releases/v18#how-a-breaking-stage-lands-on-this-line). For the releases after 18.0.0, it is that ruling: read every release's notes, PATCH releases included, and pin exact versions.
 
 ---
 
 
@@ -64,6 +64,16 @@ publishes to npm's `latest` tag, and the guard again fails a pull request that
 declares a major bump. See
 [how a breaking stage lands on the v18 line](/docs/releases/v18#how-a-breaking-stage-lands-on-this-line).
 
+**After 18.0.0, the level follows the metadata protocol.** The maintainer's
+2026-10-21 ruling ([#25105](https://github.com/objectstack-ai/objectstack/issues/25105))
+keeps the no-major guard and grades every changeset by what it does to the
+metadata protocol: a key, value or metadata type added, narrowed or given a new
+meaning takes `minor`, and every other change takes `patch` — a REST door, a
+driver, a boot refusal, the CLI or the Console — breaking or not. A
+non-protocol breaking change keeps its `**BREAKING**` banner and its ADR-0087
+disposition. 18.1.0 is the first release cut under the rule: a minor carrying
+82 changesets declared breaking, 37 of them graded `patch`.
+
 What that means when you read a version number:
 
 - A **major** release may remove or change schemas in `@objectstack/spec`,
@@ -74,7 +84,9 @@ What that means when you read a version number:
   `sys_position.permissions`; `15.1.0` removed `tenancy.strategy` and
   `tenancy.crossTenantAccess` — all in minor releases. As the v17 notes put it,
   17.1.0 and 17.2.0 are minors by version number, not by blast radius.
-- A **patch** release fixes bugs.
+- A **patch** release fixes bugs. On the v18 line after 18.0.0 it may also
+  carry a breaking change to anything that is not the metadata protocol: a REST
+  response, a boot refusal, a CLI exit status, a removed runtime export.
 
 ⚠️ **The version number is not the upgrade-safety signal.** Read the release
 note for the version you are moving to — each one leads with breaking changes
 
@@ -59,7 +59,10 @@ Read with `npm view` and `npm pack` on 2026-10-20, after the publish:
 | Prereleases | `18.0.0-next.0` … `next.3` and `next.5`. `next.4` was never published, although the CHANGELOG carries a section for it |
 
 Install 18 by its exact version (`18.0.0`) or a caret range (`^18.0.0`); both
-resolve `latest`. Moving the stale `next` tag is a release act, outside these
+resolve `latest`. A caret range also takes every later 18.x release by itself,
+and under the v18 level rule a later minor or patch can break you: 18.1.0 does
+(see the [18.1.0 notes](/docs/releases/v18/18-1)). Pin the exact version when
+you cannot read each release's notes before it lands. Moving the stale `next` tag is a release act, outside these
 notes.
 
 ### How to read the 18.0.0 CHANGELOG
@@ -622,7 +625,8 @@ Every line here was answered by the walk's 18.0.0 server after the ceremony.
 The v18 line keeps landing on `main`, and the version commit did not take
 everything that landed before it. Read on `main` at `71696121a6`: 26 pending
 changesets, ten of them `minor`, so the release that publishes them is
-**18.1.0**. They fall in two sets.
+**18.1.0**. They fall in two sets. (By the 18.1.0 cut the pending set had grown
+to more than 220 changesets; the [18.1.0 notes](/docs/releases/v18/18-1) cover all of them.)
 
 **Shipped in 18.0.0, listed in no 18.0.0 CHANGELOG.** Eight of the 26 belong to
 commits that landed before the 18.0.0 version commit (`06cab4849a`), so their