diff --git a/CHANGELOG.md b/CHANGELOG.md
index 767672d..ef87c23 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+The versioned surface is the module together with the container image published to
+`ghcr.io/channelfinder/reccaster`. It covers the databases in `db/`, the iocsh
+functions the module registers, the installed headers and the library soname, and
+the paths and entry point inside the image. A backwards incompatible change to any
+of these is a major release. The wire protocol is left out: it is shared with other
+implementations, and this repository cannot version it alone.
+
 > The reccaster client previously lived in the `client/` directory of the
 > [recsync](https://github.com/ChannelFinder/recsync) repository, where
 > releases 1.0 through 1.9.6 were tagged. See
@@ -16,6 +23,21 @@ and this project adheres to
 > repository, in which some releases contain no reccaster changes.
 
 ## [Unreleased]
+
+## [2.0.0] - 2026-08-07
+
+First release carrying changes made since reccaster left the recsync repository,
+and the first under Semantic Versioning. The releases up to 1.9.6 describe source
+from the combined repository.
+
+The build paths inside the container image moved from `/recsync` to `/reccaster`,
+which breaks anything addressing files in the image by absolute path. A startup
+script loading `/recsync/dbd/demo.dbd` has to load `/reccaster/dbd/demo.dbd`
+instead, and the binaries are now under `/reccaster/bin/$EPICS_HOST_ARCH`. Nothing
+in the module itself changed incompatibly; sites building from source are
+unaffected. The major version reflects that rename alone. Moving the repository is
+not a versioned change.
+
 ### Added
 - LICENSE file
 
@@ -124,7 +146,8 @@ No recCaster changes were included in this combined recsync release. This tag is
 - `SKIPDEMO=YES` build option
 - Default `RELEASE` configuration
 
-[Unreleased]: https://github.com/ChannelFinder/reccaster/compare/1.9.6...HEAD
+[Unreleased]: https://github.com/ChannelFinder/reccaster/compare/2.0.0...HEAD
+[2.0.0]: https://github.com/ChannelFinder/reccaster/compare/1.9.6...2.0.0
 [1.9.6]: https://github.com/ChannelFinder/reccaster/compare/1.9.5...1.9.6
 [1.9.5]: https://github.com/ChannelFinder/reccaster/compare/1.9.4...1.9.5
 [1.9.4]: https://github.com/ChannelFinder/reccaster/compare/1.9.3...1.9.4