diff --git a/Justfile b/Justfile
index 39cb7898ff..6427c9660c 100644
--- a/Justfile
+++ b/Justfile
@@ -230,6 +230,11 @@ test-unit:
     #!/usr/bin/env bash
     if command -v cargo-nextest &>/dev/null; then
         cargo nextest run -p buzz-core -p buzz-auth --lib
+        # Multi-tenant conformance gate (buzz-conformance): the independent
+        # replay checker + golden fixtures. No infra — pure in-process trace
+        # replay — so it belongs in the unit job. Run all targets (lib + the
+        # tests/replay_fixtures.rs integration test), not just --lib.
+        cargo nextest run -p buzz-conformance
     else
         ./scripts/run-tests.sh unit
     fi
diff --git a/scripts/run-tests.sh b/scripts/run-tests.sh
index db27c42d64..525b430ffc 100755
--- a/scripts/run-tests.sh
+++ b/scripts/run-tests.sh
@@ -83,6 +83,11 @@ run_unit_tests() {
 
   run_test_step "buzz-auth unit tests" \
     cargo test -p buzz-auth --lib -- --nocapture
+
+  # Multi-tenant conformance gate: independent replay checker + golden
+  # fixtures (buzz-conformance). Pure in-process trace replay, no infra.
+  run_test_step "buzz-conformance tests" \
+    cargo test -p buzz-conformance -- --nocapture
 }
 
 # ---- DB / integration tests (infra required) --------------------------------