diff --git a/docs/grpc-api.rst b/docs/grpc-api.rst
index d4e2b8c..e487e51 100644
--- a/docs/grpc-api.rst
+++ b/docs/grpc-api.rst
@@ -1,11 +1,127 @@
 .. _swh-graph-grpc-api:
 
 Using the GRPC API
 ==================
 
-Protobuf API Specification
---------------------------
+The GRPC API is the core API used to query the graph remotely. It uses the
+`GRPC framework <https://grpc.io/>`_ to provide high-performance graph
+traversal methods with server streaming.
+
+It is more expressive than the :ref:`HTTP API <swh-graph-api>` (which itself
+uses the GRPC API under the hood to serve queries), however it can only be
+used internally or with a local setup, and is never exposed publicly.
+
+Its major features include: returning node and edge properties, performing BFS
+traversals, including traversals with more than one starting node, finding
+shortest paths, common ancestors, etc.
+
+Quickstart
+----------
+
+Starting the server
+~~~~~~~~~~~~~~~~~~~
+
+The GRPC server is automatically started on port 50091 when the HTTP server
+is started with ``swh graph rpc-serve``. It can also be started directly with
+Java, instead of going through the Python layer, by using the fat-jar shipped
+with swh-graph:
+
+.. code-block:: console
+
+    $ java -cp swh-graph-XXX.jar org.softwareheritage.graph.rpc.GraphServer <graph_basename>
+
+(See :ref:`swh-graph-java-api` and :ref:`swh-graph-memory` for more
+information on Java process options and JVM tuning.)
+
+Running queries
+~~~~~~~~~~~~~~~
+
+The `gRPC command line tool
+<https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md>`_
+can be an easy way to query the GRPC API from the command line. It is
+invoked with the ``grpc_cli`` command. Of course, it is also possible to use
+a generated RPC client in any programming language supported by GRPC.
+
+All RPC methods are defined in the service ``swh.graph.TraversalService``.
+The available endpoints can be listed with ``ls``:
+
+.. code-block:: console
+
+    $ grpc_cli ls localhost:50091 swh.graph.TraversalService
+    Traverse
+    FindPathTo
+    FindPathBetween
+    CountNodes
+    CountEdges
+    Stats
+    GetNode
+
+A RPC method can be called with ``call``:
+
+.. code-block:: console
+
+    % grpc_cli --json_output call localhost:50091 swh.graph.TraversalService.Stats ""
+    connecting to localhost:50091
+    {
+     "numNodes": "21",
+     "numEdges": "23",
+     [...]
+    }
+    Rpc succeeded with OK status
+
+
+Endpoints
+---------
+
+For a full documentation of all the endpoints, as well as the request and
+response messages, see :ref:`swh-graph-grpc-api-protobuf`.
+
+Stats
+~~~~~
+
+Stats returns overall statistics on the entire compressed graph.
+
+TODO
+
+GetNode
+~~~~~~~
+
+TODO
+
+Traverse
+~~~~~~~~
+
+TODO
+
+FindPathTo
+~~~~~~~~~~
+
+TODO
+
+FindPathBetween
+~~~~~~~~~~~~~~~
+
+TODO
+
+CountNodes
+~~~~~~~~~~
+
+TODO
+
+CountEdges
+~~~~~~~~~~
+
+TODO
+
+.. _swh-graph-grpc-api-protobuf:
+
+Protobuf API Reference
+----------------------
+
+The GRPC API is specified in a single self-documenting
+`protobuf <https://developers.google.com/protocol-buffers>`_ file, reproduced
+here verbatim.
 
 .. literalinclude:: ../proto/swhgraph.proto
    :language: protobuf
    :linenos: