diff --git a/modules/mesh-vault/cmd/mesh-vault/enrolment.go b/modules/mesh-vault/cmd/mesh-vault/enrolment.go
index c88187ea..b9c92d03 100644
--- a/modules/mesh-vault/cmd/mesh-vault/enrolment.go
+++ b/modules/mesh-vault/cmd/mesh-vault/enrolment.go
@@ -24,6 +24,7 @@ import (
 	"time"
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/seal"
 	"golang.org/x/crypto/bcrypt"
 )
@@ -31,9 +32,9 @@ import (
 // The names enrolment gives: the module that holds the seat mesh-enrolment, the prefix of a token's bus user, and the
 // vault's state of each node's logins.
 const (
-	EnrolmentModule = "mesh-enrolment"
-	EnrolUserPrefix = "enrol."
-	NodeLoginsState = "node-logins"
+	EnrolmentModule = delivery.EnrolmentModule
+	EnrolUserPrefix = delivery.EnrolmentUserPrefix
+	NodeLoginsState = delivery.NodeLoginsState
 	// MeshHostModule is the module a node's own login secret is kept under (`own/<node>/mesh-host/<login>`, ADR 0583 §3).
 	MeshHostModule = "mesh-host"
 )
@@ -130,41 +131,9 @@ func (v *Vault) fromEnrolment(caller, verb string) error {
 // TokenBase is what a token states beside its secret: where the bus is and the certificate to expect there, and the
 // machine's first tunnel when the token carries one.
 type TokenBase struct {
-	Broker      string       `json:"broker"`
-	Fingerprint string       `json:"fingerprint"`
-	Tunnel      *TokenTunnel `json:"tunnel,omitempty"`
-}
-
-// TokenTunnel is the joining machine's side of its first tunnel, in the wire format the node-engine parses.
-type TokenTunnel struct {
-	Key         string `json:"key"`
-	Address     string `json:"address"`
-	Range       string `json:"range"`
-	HubKey      string `json:"hub_key"`
-	HubEndpoint string `json:"hub_endpoint"`
-}
-
-// EnrolToken is the token a person carries to a joining machine, in the wire format of the node-engine's parser
-// (mesh-host internal/identity.Token): version, node, the bus's address and certificate fingerprint, the vault's public
-// signing key, the one-time secret, and the tunnel when there is one.
-type EnrolToken struct {
-	Version     int          `json:"v"`
-	Node        string       `json:"node,omitempty"`
-	Broker      string       `json:"broker,omitempty"`
-	Fingerprint string       `json:"fingerprint,omitempty"`
-	Signer      []byte       `json:"signer,omitempty"`
-	Secret      string       `json:"secret"`
-	Adopted     bool         `json:"adopted,omitempty"`
-	Tunnel      *TokenTunnel `json:"tunnel,omitempty"`
-}
-
-// Text is the token as a person types it: base64url of its JSON.
-func (t EnrolToken) Text() (string, error) {
-	raw, err := json.Marshal(t)
-	if err != nil {
-		return "", err
-	}
-	return base64.RawURLEncoding.EncodeToString(raw), nil
+	Broker      string                `json:"broker"`
+	Fingerprint string                `json:"fingerprint"`
+	Tunnel      *delivery.TokenTunnel `json:"tunnel,omitempty"`
 }
 
 // EnrolmentTokenArgs are `enrolment-token`'s arguments: the node, when it expires (the seat's word, echoed), and which
@@ -268,8 +237,8 @@ func (v *Vault) showEnrolmentToken(caller, node string) (EnrolmentTokenAnswer, e
 	if err != nil {
 		return EnrolmentTokenAnswer{}, fmt.Errorf("the token carries the vault's signing key, which is not held yet: %w", err)
 	}
-	text, err := EnrolToken{Version: 1, Node: node, Broker: base.Broker, Fingerprint: base.Fingerprint,
-		Signer: []byte(keys.key.Public().(ed25519.PublicKey)), Secret: secret, Tunnel: base.Tunnel}.Text()
+	text, err := delivery.Token{Version: 1, Node: node, Broker: base.Broker, Fingerprint: base.Fingerprint,
+		Signer: []byte(keys.key.Public().(ed25519.PublicKey)), Secret: secret, Tunnel: base.Tunnel}.Encode()
 	if err != nil {
 		return EnrolmentTokenAnswer{}, err
 	}
diff --git a/modules/mesh-vault/cmd/mesh-vault/enrolment_test.go b/modules/mesh-vault/cmd/mesh-vault/enrolment_test.go
index 16d32e5d..1f52a26e 100644
--- a/modules/mesh-vault/cmd/mesh-vault/enrolment_test.go
+++ b/modules/mesh-vault/cmd/mesh-vault/enrolment_test.go
@@ -35,7 +35,10 @@ func (l *loginsState) Get(node string) (*NodeLogin, error) {
 func (l *loginsState) Put(n NodeLogin) error {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	raw, _ := json.Marshal(n)
+	raw, err := delivery.EncodeNodeLogin(n)
+	if err != nil {
+		return err
+	}
 	if field := credentialField(raw); field != "" {
 		return fmt.Errorf("%s carries a field %q, which names a credential", n.Node, field)
 	}
@@ -152,7 +155,7 @@ func TestTheVaultMakesAnEnrolmentsTokenAccountAndSignature(t *testing.T) {
 		t.Fatalf("show answered %+v, %v", shown, err)
 	}
 	text := openOperator(t, e.operatorPublic, e.operatorPrivate, shown.Sealed)
-	var tok EnrolToken
+	var tok delivery.Token
 	body, _ := base64.RawURLEncoding.DecodeString(text)
 	signer, _ := e.keys()
 	if err := json.Unmarshal(body, &tok); err != nil || tok.Version != 1 || tok.Secret != secret || tok.Node != "new1" ||
diff --git a/modules/mesh-vault/cmd/mesh-vault/noderotation.go b/modules/mesh-vault/cmd/mesh-vault/noderotation.go
index 2c4ab333..8666ceb5 100644
--- a/modules/mesh-vault/cmd/mesh-vault/noderotation.go
+++ b/modules/mesh-vault/cmd/mesh-vault/noderotation.go
@@ -29,35 +29,28 @@ import (
 	"time"
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"golang.org/x/crypto/bcrypt"
 )
 
-// The events a rotation says, and the stages of a node's key.
+// The events a rotation says and the stages of a node's key are mesh-sdk's (delivery/node_logins.go); a rotation warranted
+// by a hand act is warranted for a day.
 const (
-	RotationBegunEvent    = "rotation-begun"
-	NodeAccountReadyEvent = "node-account-ready"
-	RotationDoneEvent     = "rotation-done"
+	RotationBegunEvent    = delivery.RotationBegunEvent
+	NodeAccountReadyEvent = delivery.NodeAccountReadyEvent
+	RotationDoneEvent     = delivery.RotationDoneEvent
 
-	StageBegun     = "begun"
-	StageReady     = "ready"
-	StageConfirmed = "confirmed"
+	StageBegun     = delivery.RotationBegun
+	StageReady     = delivery.RotationReady
+	StageConfirmed = delivery.RotationConfirmed
 
 	// HandActWithin is how recent a hand act is that warrants a rotation.
 	HandActWithin = 24 * time.Hour
 )
 
-// NodeLogin is one key of the vault's state `node-logins`: the login the node's node-engine dials as, and, while a
-// rotation runs, the other login and how far it has come. Never a value or a hash.
-type NodeLogin struct {
-	Node  string `json:"node"`
-	Login string `json:"login"`
-	// Rotating is the other login while a rotation runs; empty reads as none.
-	Rotating string    `json:"rotating,omitempty"`
-	Stage    string    `json:"stage,omitempty"`
-	Since    time.Time `json:"since,omitzero"`
-	// ListRevision is the revision of the loaded user list the rotation began at.
-	ListRevision uint64 `json:"list-revision,omitempty"`
-}
+// NodeLogin is one key of the vault's state node-logins (mesh-sdk's contract): the login the node's node-engine dials as,
+// and while a rotation runs the other login with its stage. Never a value or a hash.
+type NodeLogin = delivery.NodeLogin
 
 // NodeLoginStore is the vault's state `node-logins`, by node.
 type NodeLoginStore interface {
@@ -75,15 +68,19 @@ func (busNodeLogins) Get(node string) (*NodeLogin, error) {
 	if err != nil || e == nil {
 		return nil, err
 	}
-	var n NodeLogin
-	if err := json.Unmarshal(e.Value, &n); err != nil {
+	n, err := delivery.DecodeNodeLogin(e.Value)
+	if err != nil {
 		return nil, fmt.Errorf("%s %s is not a node's login: %w", NodeLoginsState, node, err)
 	}
 	return &n, nil
 }
 
 func (busNodeLogins) Put(n NodeLogin) error {
-	_, err := stdio.State(NodeLoginsState).Put(n.Node, n)
+	raw, err := delivery.EncodeNodeLogin(n)
+	if err != nil {
+		return err
+	}
+	_, err = stdio.State(NodeLoginsState).Put(n.Node, json.RawMessage(raw))
 	return err
 }