diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f6d4ec6
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,40 @@
+
+# ── GSD baseline (auto-generated) ──
+.gsd/activity/
+.gsd/forensics/
+.gsd/runtime/
+.gsd/worktrees/
+.gsd/parallel/
+.gsd/auto.lock
+.gsd/metrics.json
+.gsd/completed-units.json
+.gsd/STATE.md
+.gsd/gsd.db
+.gsd/DISCUSSION-MANIFEST.json
+.gsd/milestones/**/*-CONTINUE.md
+.gsd/milestones/**/continue.md
+.DS_Store
+Thumbs.db
+*.swp
+*.swo
+*~
+.idea/
+.vscode/
+*.code-workspace
+.env
+.env.*
+!.env.example
+node_modules/
+.next/
+dist/
+build/
+__pycache__/
+*.pyc
+.venv/
+venv/
+target/
+vendor/
+*.log
+coverage/
+.cache/
+tmp/