diff --git a/.github/workflows/pr-validation.yml b/.github/workflows/pr-validation.yml
index 5896660..889c08e 100644
--- a/.github/workflows/pr-validation.yml
+++ b/.github/workflows/pr-validation.yml
@@ -87,6 +87,8 @@ jobs:
             baseImage: mcr.microsoft.com/devcontainers/base:debian
           - features: github-dev
             baseImage: mcr.microsoft.com/devcontainers/base:ubuntu
+          - features: mistral-dev
+            baseImage: ubuntu:latest
 
     outputs:
       status: ${{ steps.status.outputs.status }}
@@ -104,6 +106,11 @@ jobs:
         # before the test runs (same pattern as dotfiles-sync below).
         run: mkdir -p ~/.claude
 
+      - name: Create mount sources for mistral-dev
+        if: matrix.features == 'mistral-dev'
+        # The bind mount source ~/.vibe must exist on the host or `docker run` aborts.
+        run: mkdir -p ~/.vibe
+
       - name: Create mount sources for dotfiles-sync
         if: matrix.features == 'dotfiles-sync'
         # All bind sources declared in src/dotfiles-sync/devcontainer-feature.json
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index da8fab7..4201e7c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -67,6 +67,10 @@ jobs:
           - features: claude-dev
             baseImage: ubuntu:latest
 
+          # mistral-dev — IDE-config-only feature
+          - features: mistral-dev
+            baseImage: ubuntu:latest
+
           # auto-header - requires jq (installed by helpers4-common)
           - features: auto-header
             baseImage: mcr.microsoft.com/devcontainers/base:ubuntu
@@ -102,6 +106,11 @@ jobs:
         # before the test runs (same pattern as dotfiles-sync below).
         run: mkdir -p ~/.claude
 
+      - name: Create mount sources for mistral-dev
+        if: matrix.features == 'mistral-dev'
+        # The bind mount source ~/.vibe must exist on the host or `docker run` aborts.
+        run: mkdir -p ~/.vibe
+
       - name: Create mount sources for dotfiles-sync
         if: matrix.features == 'dotfiles-sync'
         # All bind sources declared in src/dotfiles-sync/devcontainer-feature.json
diff --git a/src/claude-dev/devcontainer-feature.json b/src/claude-dev/devcontainer-feature.json
index 66342ef..fecffe5 100644
--- a/src/claude-dev/devcontainer-feature.json
+++ b/src/claude-dev/devcontainer-feature.json
@@ -1,6 +1,6 @@
 {
   "id": "claude-dev",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "name": "Claude Code Development Environment",
   "description": "Installs the Claude Code IDE extension (anthropic.claude-code) for VS Code and Cursor. Mounts ~/.claude from the host via a directory symlink — credentials and config persist across all rebuilds.",
   "documentationURL": "https://github.com/helpers4/devcontainer/tree/main/src/claude-dev",
@@ -19,6 +19,10 @@
       "description": "Username in the container that should receive the Claude credentials symlink."
     }
   },
+  // Creates ~/.claude on the host before Docker evaluates the bind mount.
+  // Without this, Docker refuses to start the container if the directory
+  // has never been created (e.g. fresh OS install, first Claude login).
+  "initializeCommand": "mkdir -p ~/.claude",
   "mounts": [
     {
       // Neutral staging path — install.sh resolves the correct target home at build
diff --git a/src/mistral-dev/devcontainer-feature.json b/src/mistral-dev/devcontainer-feature.json
index 753a66c..bda2179 100644
--- a/src/mistral-dev/devcontainer-feature.json
+++ b/src/mistral-dev/devcontainer-feature.json
@@ -1,6 +1,6 @@
 {
   "id": "mistral-dev",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "name": "Mistral Vibe Development Environment",
   "description": "Installs the Mistral Vibe IDE extension (mistralai.mistral-vibe-code) for VS Code and Cursor. Mounts ~/.vibe from the host via a directory symlink — credentials and config persist across all rebuilds.",
   "documentationURL": "https://github.com/helpers4/devcontainer/tree/main/src/mistral-dev",
@@ -24,6 +24,10 @@
       "description": "Also install the Mistral Vibe CLI (vibe command). Requires Python 3.12+ and pip in the container."
     }
   },
+  // Creates ~/.vibe on the host before Docker evaluates the bind mount.
+  // Without this, Docker refuses to start the container if the directory
+  // has never been created (e.g. fresh OS install, first Mistral login).
+  "initializeCommand": "mkdir -p ~/.vibe",
   "mounts": [
     {
       // Neutral staging path — install.sh resolves the correct target home at build
diff --git a/test/mistral-dev/test.sh b/test/mistral-dev/test.sh
new file mode 100755
index 0000000..1cbd23e
--- /dev/null
+++ b/test/mistral-dev/test.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+set -e
+
+SCRIPT="/usr/local/share/mistral-dev/setup-credentials.sh"
+
+if [ ! -f "${SCRIPT}" ]; then
+    echo "❌ FAIL: ${SCRIPT} is missing"
+    exit 1
+fi
+
+if [ ! -x "${SCRIPT}" ]; then
+    echo "❌ FAIL: ${SCRIPT} is not executable"
+    exit 1
+fi
+
+if ! grep -q '^TARGET_HOME=' "${SCRIPT}"; then
+    echo "❌ FAIL: TARGET_HOME not baked into ${SCRIPT}"
+    exit 1
+fi
+
+if ! grep -q 'STAGED="/mnt/h4vibe"' "${SCRIPT}"; then
+    echo "❌ FAIL: STAGED not baked into ${SCRIPT}"
+    exit 1
+fi
+
+if ! grep -q 'ln -sf' "${SCRIPT}"; then
+    echo "❌ FAIL: symlink creation not baked into ${SCRIPT}"
+    exit 1
+fi
+
+echo "✅ PASS: setup-credentials.sh installed, executable, and all required values baked in"
+echo "🎉 Test passed."