diff --git a/.github/workflows/scheduled.yml b/.github/workflows/scheduled.yml
index f9a48c9..48e699b 100644
--- a/.github/workflows/scheduled.yml
+++ b/.github/workflows/scheduled.yml
@@ -47,8 +47,36 @@ jobs:
       - uses: actions/checkout@v4
       - uses: jdx/mise-action@v2
       - run: just mutants-import
+      - run: just mutants-config
       - if: always()
         uses: actions/upload-artifact@v4
         with:
           name: mutants-import
-          path: mutants-import/mutants.out
+          path: |
+            mutants-import/mutants.out
+            mutants-config/mutants.out
+  mutants-mcp:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 350
+    steps:
+      - uses: actions/checkout@v4
+      - uses: jdx/mise-action@v2
+      - run: just mutants-mcp
+      - if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: mutants-mcp
+          path: mutants-mcp/mutants.out
+  mutants-gui:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 350
+    steps:
+      - uses: actions/checkout@v4
+      - uses: jdx/mise-action@v2
+      - run: sudo apt-get update && sudo apt-get install -y libxkbcommon-dev libgtk-3-dev
+      - run: just mutants-gui
+      - if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: mutants-gui
+          path: mutants-gui/mutants.out
diff --git a/.gitignore b/.gitignore
index 00a2377..d17ecbb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,6 @@ site/dist/
 /mutants.out*/
 /mutants-store/
 /mutants-import/
+/mutants-config/
+/mutants-mcp/
+/mutants-gui/
diff --git a/justfile b/justfile
index fd7570d..bc7136c 100644
--- a/justfile
+++ b/justfile
@@ -76,6 +76,19 @@ mutants-store:
 mutants-import:
     cargo mutants -p ledger-import --test-package ledger-import -j 4 --timeout 300 -o mutants-import
 
+# Mutation testing of the settings parser and the receipt policy.
+mutants-config:
+    cargo mutants -p ledger-config --test-package ledger-config -j 4 --timeout 120 -o mutants-config
+
+# Mutation testing of the MCP server (every mutant runs the stdio suites).
+mutants-mcp:
+    cargo mutants -p ledger-mcp --test-package ledger-mcp -j 4 --timeout 600 -o mutants-mcp
+
+# Mutation testing of the viewer's logic (formatting, file names, history,
+# search, ticks, the view model, the attention list; not the painting).
+mutants-gui:
+    cargo mutants -p ledger-gui --test-package ledger-gui -j 4 --timeout 300 -o mutants-gui -f crates/ledger-gui/src/fmt.rs -f crates/ledger-gui/src/export.rs -f crates/ledger-gui/src/nav.rs -f crates/ledger-gui/src/attention.rs -f crates/ledger-gui/src/books.rs -f crates/ledger-gui/src/palette.rs -f crates/ledger-gui/src/charts.rs
+
 # Benchmarks of the core's hot paths (no budget gates them yet)
 bench:
     cargo bench -p ledger-core --bench books