diff --git a/api/server/README.md b/api/server/README.md
--- a/api/server/README.md
+++ b/api/server/README.md
@@ -1,4 +1,48 @@
-swh-graph
-=========
+Graph service - Server side
+===========================
 
-Server side REST API.
+Server side Java REST API.
+
+Build
+-----
+
+```bash
+$ mvn compile
+```
+
+Start REST API
+--------------
+
+```bash
+$ java -cp target/swh-graph-1.0.jar             \
+    org.softwareheritage.graph.App              \
+    <compressed_graph_path>
+```
+
+Default port is 5009.
+
+Tests
+-----
+
+```bash
+$ mvn test
+```
+
+Unit tests use a small example graph stored in
+`src/test/dataset/example.edges.csv`. The compressed version is already
+generated in `src/test/dataset/output/` using:
+
+```bash
+# Graph compression
+$ cd src/test/dataset
+$ ./generate_graph.sh
+$ cd ../../../
+
+# Compile with all dependencies into a single jar file
+$ mvn compile assembly:single
+# Dump mapping files
+$ java -cp target/swh-graph-1.0.jar             \
+    org.softwareheritage.graph.backend.Setup    \
+    src/test/dataset/example.nodes.csv.gz       \
+    src/test/dataset/output/example
+```