--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Fri Oct 07 20:06:32 2016 +0200
@@ -0,0 +1,1 @@
+.*swp$

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/types.go	Fri Oct 07 20:06:32 2016 +0200
@@ -0,0 +1,54 @@
+package clusterconsensus
+
+// A change that can be applied to a State and sent over the wire
+// Client-provided
+type Change interface {
+	Serialize() []byte
+	Deserialize([]byte) Change
+}
+
+// A state machine containing the overall state.
+// Client-provided
+type State interface {
+	Snapshot() []byte
+	Apply(Change)
+	Install([]byte)
+}
+
+// A channel that is connected to a peer and can roundtrip messages.
+type Transport interface {
+	Send([]byte) error
+	Recv() ([]byte, error)
+}
+
+// A remote member of the consensus
+type Member struct {
+	addr string
+}
+
+// One participant of the consensus
+// implements participating; implementation-provided
+type Participant struct {
+	members []Member
+	master  Member
+	self    Member
+
+	contacts map[Member]Transport
+
+	instance uint64 // nth round
+	serial   uint64 // nth submission in this round
+
+	state   State
+	staging map[uint64]Change // staging area for changes
+
+	// Used to deserialize changes
+	protoTypeDeserialize Change
+}
+
+// Implemented by Participant
+// Used by Server for asynchronous, external callbacks
+type Participating interface {
+	Prepare(instance uint64, m Member) bool
+	Accept(instance, serial uint64, changes []Change)
+	StartParticipation(instance, serial uint64, master Member, members []Member, snapshot []byte)
+}