diff --git a/placement/go/clients/meshmoduleassignerclient/ops.go b/placement/go/clients/meshmoduleassignerclient/ops.go
new file mode 100644
index 0000000..0c85902
--- /dev/null
+++ b/placement/go/clients/meshmoduleassignerclient/ops.go
@@ -0,0 +1,39 @@
+package meshmoduleassignerclient
+
+// The operations a proposal's change names (novox/hq ADR 0567 §2), the words of a change's `op`. The seat's contract
+// carries the field; its callers (the enrolment builds OpAddNode and OpRemoveNode) and its holder share the words here.
+const (
+	// OpPlace places a module on a node, with its host ports and bindings.
+	OpPlace = "place"
+	// OpTakeOff takes a module off a node.
+	OpTakeOff = "take-off"
+	// OpPin pins the provider of a provision on a node; OpUnpin removes a pin.
+	OpPin   = "pin"
+	OpUnpin = "unpin"
+	// OpHold says a module placed on the node holds a seat; OpUnhold, that it holds it no more.
+	OpHold   = "hold"
+	OpUnhold = "unhold"
+	// OpDecide sets a decided field of the node (NodeDecided by its JSON name), its address among them.
+	OpDecide = "decide"
+	// OpConfig sets a module's config placement or values on the node.
+	OpConfig = "config"
+	// OpSeed is the node's whole placement: the take-over (adopt, §7), never given by a caller.
+	OpSeed = "seed"
+	// OpAddNode adds a joining node with its decided fields and the public halves of its keys, on the warrant of the
+	// enrolment that issued its token (novox/hq ADR 0587 §7): the enroller's alone, the proposal's one change.
+	OpAddNode = "add-node"
+	// OpRemoveNode takes a joining node off placement again when its enrolment ends unconfirmed, revoked or expired: the
+	// enroller's alone, on the same warrant, the proposal's one change, of a node with no module and no holding.
+	OpRemoveNode = "remove-node"
+)
+
+// The states of an open proposal (the field `state` of the state `proposals`).
+const (
+	// ProposalAnswering: its candidates are written and the nodes it must hear from have not all answered.
+	ProposalAnswering = "answering"
+	// ProposalFailed: its verdict failed; it stays open, for its proposer to read and withdraw, or for a node's later
+	// answer to judge it again.
+	ProposalFailed = "failed"
+	// ProposalAsked: its verdict passed and the operator is asked to approve it.
+	ProposalAsked = "asked"
+)
diff --git a/placement/go/clients/meshmoduleassignerclient/ops_test.go b/placement/go/clients/meshmoduleassignerclient/ops_test.go
new file mode 100644
index 0000000..d935baa
--- /dev/null
+++ b/placement/go/clients/meshmoduleassignerclient/ops_test.go
@@ -0,0 +1,14 @@
+package meshmoduleassignerclient
+
+import "testing"
+
+// The words are the wire's: a holder and a caller that spell one differently refuse each other's proposals.
+func TestOpsAndProposalStatesAreTheWire(t *testing.T) {
+	for got, want := range map[string]string{OpPlace: "place", OpTakeOff: "take-off", OpPin: "pin", OpUnpin: "unpin", OpHold: "hold",
+		OpUnhold: "unhold", OpDecide: "decide", OpConfig: "config", OpSeed: "seed", OpAddNode: "add-node", OpRemoveNode: "remove-node",
+		ProposalAnswering: "answering", ProposalFailed: "failed", ProposalAsked: "asked"} {
+		if got != want {
+			t.Errorf("%q, want %q", got, want)
+		}
+	}
+}