diff --git a/Build-Tools-Specs.md b/Build-Tools-Specs.md
index 755186d..c6f57c4 100644
--- a/Build-Tools-Specs.md
+++ b/Build-Tools-Specs.md
@@ -1 +1,22 @@
-# Build Tools Specs
\ No newline at end of file
+# Build Tools Specs
+
+This page is a draft for specs for OL3 Build Tools. OL3 will be a big library, so it is crucial to provide efficient and convenient tools for creating custom builds.
+
+## High-level Specs
+
+- We provide both a CLI and a BUI.
+- They are compatible, and complementary.
+
+## CLI Specs
+
+- CLI input is a "build profile".
+- CLI output is a "build".
+- A "build profile" is a file declaring the OL3 code to add to the "build".
+- A "build" is a file including compiled OL3 code.
+
+## BUI Specs
+
+- BUI is basically a form including checkboxes.  One checkbox per component.
+- BUI output is a build profile, or a zip including js file + css file + build profile.
+- Note: producing a build profile does not require a dynamic site. Producing a zip does.
+- BUI may also take a build profile on input (Drag & Drop). Only makes sense when a zip is to be created.
\ No newline at end of file