diff --git a/Taskfile.yml b/Taskfile.yml
index 152af12..0d610fa 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -20,3 +20,8 @@ tasks:
   ci:
     desc: Run full local CI sweep
     cmds: [task lint, task test, task audit]
+
+  coverage:
+    desc: Measure code coverage (SSOT: see grade.sh for the canonical command).
+    cmds:
+      - cargo llvm-cov --workspace --fail-under-lines 85
diff --git a/justfile b/justfile
index df61ca2..e53149d 100644
--- a/justfile
+++ b/justfile
@@ -24,3 +24,6 @@ grade-html:
     @echo "=== Running grade (HTML) ==="
     ./grade.sh --html
 
+# Measure code coverage (SSOT: see grade.sh for the canonical command)
+coverage:
+    cargo llvm-cov --workspace --fail-under-lines 85