--- /dev/null
+[[!meta title="Monkeysphere Validation Agent"]]
+
+# Monkeysphere Validation Agent #
+
+The Monkeysphere Validation Agent offers a local service for systems
+to validate certificates (both X.509 and OpenPGP) and other public
+keys in their proper contexts.
+
+Among other reasons, having a validation agent is a good thing
+because:
+
+* Multiple tools can rely on the same PKI (e.g. the user's web browser
+ and the user's ssh client).
+* A single validation agent can present a consistent UI to the user
+ (when used in an end-user context), or provide a unified trust model
+ to various services (when used in a server-side context).
+* Authentication/certificate validation code can potentially be
+ isolated to a protected environment.
+
+## Implementations ##
+
+There are currently two implementations of the validation agent:
+
+ * msva-perl
+ * msva-ruby
+
+## Protocol ##
+
+The Monkeysphere Validation Agent protocol (MSVA) is defined as a
+minimal HTTP server with JSON-encapsulated requests and responses.
+You may want to read [more protocol details](protocol).
+