diff --git a/.claude/skills/mendix/bootstrap-app/SKILL.md b/.claude/skills/mendix/bootstrap-app/SKILL.md
index b1b85e07b..97935b51e 100644
--- a/.claude/skills/mendix/bootstrap-app/SKILL.md
+++ b/.claude/skills/mendix/bootstrap-app/SKILL.md
@@ -55,7 +55,8 @@ it is building.
 6. **Look and feel.** One of the bundled themes: `signal` (light, high contrast),
    `ledger` (light, dense, data-heavy), `console` (dark), or `none` for stock Atlas.
    Default `signal`.
-7. **Mendix version.** Default `11.13.0`.
+7. **Mendix version.** Default to whatever the session environment already provides —
+   see below — and otherwise the newest version on the CDN (today `11.14.0`).
 8. **Do you have requirements to work from?** A specification document, a
    prototype, a wireframe, a long description — anything that is the source of
    truth but is not in this repo. **Default: yes, record them.** If they say yes,
@@ -71,20 +72,38 @@ it is building.
 If the user says "defaults" or ignores a question, choose something sensible for it,
 say what you chose in one line, and keep going — **do not block on them twice**.
 
-### Checking the Mendix version default
+### Choosing the Mendix version
 
-Everything mxcli does starts with downloading MxBuild, so "supported" means "on the
-CDN". If asked for a version newer than the default, verify both tarballs answer
-`200` before using it — `run --local` needs the runtime as well as MxBuild:
+**Prefer a version the environment already has.** A Claude Code session image may bake
+in an MxBuild, and using it turns a multi-hundred-MB download into no download at all.
+There is no environment variable for this — the cache directory is the signal:
 
 ```bash
-curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mxbuild-11.13.0.tar.gz
-curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mendix-11.13.0.tar.gz
+ls ~/.mxcli/mxbuild/ 2>/dev/null | sort -V | tail -1   # e.g. 11.13.0, or empty
 ```
 
+If that names a version, use it and say so in one line ("using 11.13.0, already cached
+in this environment"). If the user asked for a specific version, they win — check it on
+the CDN as below and accept the download.
+
+**Otherwise take the newest version on the CDN.** Everything mxcli does starts with
+downloading MxBuild, so "supported" means "on the CDN", and `run --local` needs the
+runtime tarball as well. At the time of writing the newest is **11.14.0** (11.15.0 is
+not published). Do not trust that number — it ages. Confirm the one you land on, and
+walk backwards a minor if it 404s:
+
+```bash
+V=11.14.0
+curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mxbuild-$V.tar.gz
+curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mendix-$V.tar.gz
+```
+
+Both have to answer `200`. Run the same check for any version the user names.
+
 In a solution, give every app the **same** version: they share the `~/.mxcli/mxbuild`
 cache, and a mismatch means a second multi-hundred-MB download and two runtimes to
-keep straight.
+keep straight — which also means the cached-version rule applies to the solution as a
+whole, not per app.
 
 ---
 
diff --git a/docs-site/src/tools/bootstrap-prompt.md b/docs-site/src/tools/bootstrap-prompt.md
index ff52d6c0c..d53788974 100644
--- a/docs-site/src/tools/bootstrap-prompt.md
+++ b/docs-site/src/tools/bootstrap-prompt.md
@@ -110,20 +110,33 @@ tag (latest is v0.16.0) **and** as a rolling `nightly` pre-release, with assets
 
 ## Which Mendix version to ask for
 
-The skill defaults to the newest version that has a published MxBuild — everything
-mxcli does starts with downloading it, so "supported" means "on the CDN". It runs this
-check itself when asked for a newer version, and it is the check to run before bumping
-the default:
+The skill prefers **whatever the session environment already provides**, and otherwise
+the newest version with a published MxBuild.
+
+The environment's contribution is a *cached* MxBuild, not a variable — a Claude Code
+session image may bake one in, and reusing it turns a multi-hundred-MB download into
+no download at all. The cache directory is the signal:
+
+```bash
+ls ~/.mxcli/mxbuild/ 2>/dev/null | sort -V | tail -1   # e.g. 11.13.0, or empty
+```
+
+With no cached version, the skill takes the newest on the CDN — everything mxcli does
+starts with downloading MxBuild, so "supported" means "on the CDN". At the time of
+writing that is **11.14.0**; treat the number as perishable and run the check rather
+than quoting it:
 
 ```bash
-curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mxbuild-11.13.0.tar.gz   # 200
-curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mendix-11.13.0.tar.gz    # 200 (runtime)
+V=11.14.0
+curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mxbuild-$V.tar.gz   # 200
+curl -sI -o /dev/null -w '%{http_code}\n' https://cdn.mendix.com/runtime/mendix-$V.tar.gz    # 200 (runtime)
 ```
 
 Both have to answer `200` — `run --local` needs the runtime tarball as well as
-MxBuild. In a solution, give every app the **same** version: they share the
-`~/.mxcli/mxbuild` cache, and a mismatch means a second multi-hundred-MB download and
-two runtimes to keep straight.
+MxBuild. This is also the check to run before bumping the version named in the skill.
+In a solution, give every app the **same** version: they share the `~/.mxcli/mxbuild`
+cache, and a mismatch means a second multi-hundred-MB download and two runtimes to
+keep straight.
 
 ## Two rules that make this robust