diff --git a/.forgejo/workflows/buildAndTest.yml b/.forgejo/workflows/buildAndTest.yml
index c10b4439..9b3403db 100644
--- a/.forgejo/workflows/buildAndTest.yml
+++ b/.forgejo/workflows/buildAndTest.yml
@@ -37,17 +37,23 @@ jobs:
 
   build:
 
-    runs-on: debian-latest
+    runs-on: docker
 
     steps:
-    - uses: actions/checkout@v6
-    - name: Setup .NET
-      uses: actions/setup-dotnet@v5
-      with:
-        dotnet-version: 10.0.x
+    - name: Clone yavsc
+      run: |
+        cd /src
+        git clone https://forgejo.pschneider.fr/notazof/yavsc.git _src
+        cd _src
+        if [ -n "${GITHUB_REF:-}" ]; then
+          git fetch origin "$GITHUB_REF"
+          git checkout FETCH_HEAD
+        fi
+        git submodule update --init --recursive
+        echo "Checked out at $(git rev-parse HEAD) on $(git branch --show-current 2>/dev/null || echo detached HEAD)"
     - name: Restore dependencies
-      run: dotnet restore
+      run: cd /src/_src && dotnet restore
     - name: Build
-      run: dotnet build --no-restore
+      run: cd /src/_src && dotnet build --no-restore
     - name: Test
-      run: dotnet test --no-build --verbosity normal
+      run: cd /src/_src && dotnet test --no-build --verbosity normal
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..eadf3c7f
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "external/dotnet-android-build-image"]
+	path = external/dotnet-android-build-image
+	url = https://forgejo.pschneider.fr/notazof/dotnet-android-build-image.git
diff --git a/NuGet.config b/NuGet.config
new file mode 100644
index 00000000..c601d09b
--- /dev/null
+++ b/NuGet.config
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Project-level NuGet configuration.
+
+  The yavsc solution depends on HigginsSoft.IdentityServer8.* 8.1.0-alpha.*,
+  published only on the internal feed https://isn.pschneider.fr. The public
+  nuget.org feed has 8.0.4 as the nearest version, which causes NU1102 on
+  restore for every project that depends on it (Yavsc.Org, Yavsc.Api,
+  Yavsc.Blogs, Yavsc.Server, cli, tests).
+
+  Listing 'isn' before 'nuget.org' here ensures that restore finds the
+  alpha packages first, then falls back to nuget.org for everything else.
+  Both feeds are reachable anonymously; no credentials are stored here.
+
+  See AGENTS.md for the rationale.
+-->
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="isn" value="https://isn.pschneider.fr/api/v3/index.json" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+</configuration>
diff --git a/external/dotnet-android-build-image b/external/dotnet-android-build-image
new file mode 160000
index 00000000..0695a6c1
--- /dev/null
+++ b/external/dotnet-android-build-image
@@ -0,0 +1 @@
+Subproject commit 0695a6c1fea6508f1a88f7ad0ad9cb93733aa52d