diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..61394c3
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,17 @@
+ISC license
+
+Copyright (C) 2026 Dragons@Work
+
+Permission to use, copy, modify, and/or distribute this software 
+for any purpose with or without fee is hereby granted, provided 
+that the above copyright notice and this permission notice appear 
+in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL 
+WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED 
+WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE 
+AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA 
+OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
+PERFORMANCE OF THIS SOFTWARE.
diff --git a/README.md b/README.md
index b6339cb..c233d77 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,28 @@
-# daw-module-registry-index
+# DAW Module Registry Index
 
-DAW module registry index — authoritative source for module versions and compatibility
\ No newline at end of file
+Authoritative source for DAW module versions and compatibility ranges.
+Used by steurjan, kaupapi, and other DAW projects.
+
+## Usage
+
+    steurjan modules update-index
+
+Fetches and verifies the current index. Requires a local installation
+of steurjan or any other DAW project that supports modules.
+
+## Direct fetch
+
+    https://smida.dragons-at-work.de/DAW/daw-module-registry-index/raw/branch/main/registry-index.yaml
+    https://smida.dragons-at-work.de/DAW/daw-module-registry-index/raw/branch/main/registry-index.yaml.minisig
+
+The index is signed with the DAW release key. Signature is verified
+automatically by `modules update-index`.
+
+## Format
+
+See [DAW/steurjan#94](https://smida.dragons-at-work.de/DAW/steurjan/issues/94)
+for the index format specification.
+
+## License
+
+ISC License -- see LICENSE