diff --git a/.tangled/workflows/test.yml b/.tangled/workflows/test.yml
new file mode 100644
index 0000000..23b2c1a
--- /dev/null
+++ b/.tangled/workflows/test.yml
@@ -0,0 +1,25 @@
+when:
+  - event: ["push", "manual"]
+    # TODO: remove one-module when work finishes on that branch
+    branch: ["main", "one-module"]
+  - event: ["pull_request"]
+    branch: ["main"]
+
+engine: "microvm"
+image: "nixos"
+
+dependencies:
+  - gleam
+  - beam29Packages.erlang
+  - rebar3
+  - nodejs
+
+steps:
+  - name: "Download dependencies"
+    command: gleam deps download
+  - name: "Test (Erlang)"
+    command: gleam test --target erlang
+  - name: "Test (JavaScript)"
+    command: gleam test --target javascript
+  - name: "Verify formatting"
+    command: gleam format --check src test