diff --git a/config.dev.yaml b/config.dev.yaml
new file mode 100644
index 00000000..b6a9421a
--- /dev/null
+++ b/config.dev.yaml
@@ -0,0 +1,14 @@
+# Dev environment overlay
+# Merges with config.yaml — these keys override the base
+model:
+  default: qwen3:30b
+  provider: custom
+agent:
+  max_turns: 50
+  verbose: true
+display:
+  show_reasoning: true
+  streaming: true
+  show_cost: true
+terminal:
+  timeout: 300