diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe930ca..551d9e5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,11 @@ include the full version, for example `## 0.7.0-beta.1`.
 
 ## Unreleased
 
+### Documentation
+
+- Record OpenCode 2.0.15 as the last tested version in README, with the verified
+  compatibility scope and the distinction between devel and stable v0.6.6.
+
 ### Fixed
 
 - Prevent the runtime sidebar from crashing on OpenCode 2.0.10 after semantic
@@ -166,4 +171,4 @@ include the full version, for example `## 0.7.0-beta.1`.
 - Add detailed bot workflow diagrams and a documentation map in `AGENTS.md`.
 - Expand bundled bot instructions for planning, delegation, verification, and
   handing publication back to the dispatcher.
-- Add the README banner showing an OpenCode2 agent executing a task.
\ No newline at end of file
+- Add the README banner showing an OpenCode2 agent executing a task.
diff --git a/README.md b/README.md
index c0634dd..11e7423 100644
--- a/README.md
+++ b/README.md
@@ -11,13 +11,19 @@ titles, and can merge after an authorized approval. The TUI is optional.
 
 ## Requirements
 
-- OpenCode **2.0.6** with a working model; client/plugin SDK pinned to `2.0.6`.
+- OpenCode **2**, last tested with **2.0.15**; a working model is required.
+  Client/plugin SDK dependencies remain pinned to `2.0.6`.
 - Node.js 22+, npm, and Git on macOS/Linux.
 - GitHub authentication (`gh auth login` and `gh auth setup-git`, or a token in
   the service environment) and permission to comment, push, and create PRs.
 - When configuring a project: a primary Git checkout with a GitHub `origin`,
   a pushed commit, and issues enabled.
 
+Compatibility checks for the current `devel` build covered SDK type checking,
+native sidebar rendering with the 2.0.15 theme, and live session/status RPCs and
+GitHub polling. They did not include a new issue-to-PR execution. The sidebar fix
+required by newer themes is on `devel` and is not included in stable `v0.6.6`.
+
 Choose **one** installation method below. No target repository is needed yet.
 Nothing needs to be published to npm. `$HOME` expands to your home directory.