diff --git a/pkg/encoders/envelopes/messages/messages.go b/pkg/encoders/envelopes/messages/messages.go
new file mode 100644
index 0000000..4d87374
--- /dev/null
+++ b/pkg/encoders/envelopes/messages/messages.go
@@ -0,0 +1,54 @@
+// Package messages is a collection of example/common messages and
+// machine-readable prefixes to use with OK and CLOSED envelopes.
+package messages
+
+import (
+	"lukechampine.com/frand"
+)
+
+const (
+	// Duplicate is a machine readable prefix for OK envelopes indicating that the
+	// submitted event is already in the relay,s event store.
+	Duplicate = "duplicate"
+
+	// Pow is a machine readable prefix for OK envelopes indicating that the
+	// eventid.T lacks sufficient zeros at the front.
+	Pow = "pow"
+
+	// Blocked is a machine readable prefix for OK envelopes indicating the event
+	// submission or REQ has been rejected.
+	Blocked = "blocked"
+
+	// RateLimited is a machine readable prefix for CLOSED and OK envelopes
+	// indicating the relay is now slowing down processing of requests from the
+	// client.
+	RateLimited = "rate-limited"
+
+	// Invalid is a machine readable prefix for OK envelopes indicating
+	// that the submitted event or other request is not correctly formatted, and may
+	// mean a signature does not verify.
+	Invalid = "invalid"
+
+	// Error is a machine readable prefix for CLOSED and OK envelopes indicating
+	// there was some kind of error in processing the request.
+	Error = "error"
+)
+
+// Examples are some examples of the use of the prefixes above with appropriate
+// human-readable suffixes.
+var Examples = [][]byte{
+	[]byte("pow: difficulty 25>=24"),
+	[]byte("duplicate: already have this event"),
+	[]byte("blocked: you are banned from posting here"),
+	[]byte("blocked: please register your pubkey at " +
+		"https://my-expensive-relay.example.com"),
+	[]byte("rate-limited: slow down there chief"),
+	[]byte("invalid: event creation date is too far off from the current time"),
+	[]byte("pow: difficulty 26 is less than 30"),
+	[]byte("error: could not connect to the database"),
+}
+
+// RandomMessage generates a random message out of the above list of Examples.
+func RandomMessage() []byte {
+	return Examples[frand.Intn(len(Examples)-1)]
+}
diff --git a/pkg/encoders/envelopes/noticeenvelope/noticeenvelope.go b/pkg/encoders/envelopes/noticeenvelope/noticeenvelope.go
new file mode 100644
index 0000000..7e25f26
--- /dev/null
+++ b/pkg/encoders/envelopes/noticeenvelope/noticeenvelope.go
@@ -0,0 +1,84 @@
+// Package noticeenvelope is a codec for the NOTICE envelope, which is used to
+// serve (mostly ignored) messages that are supposed to be shown to a user in
+// the client.
+package noticeenvelope
+
+import (
+	"io"
+
+	"lol.mleku.dev/chk"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/text"
+	"next.orly.dev/pkg/interfaces/codec"
+)
+
+// L is the label associated with this type of codec.Envelope.
+const L = "NOTICE"
+
+// T is a NOTICE envelope, intended to convey information to the user about the
+// state of the relay connection. This thing is rarely displayed on clients
+// except sometimes in event logs.
+type T struct {
+	Message []byte
+}
+
+var _ codec.Envelope = (*T)(nil)
+
+// New creates a new empty NOTICE noticeenvelope.T.
+func New() *T { return &T{} }
+
+// NewFrom creates a new noticeenvelope.T with a provided message.
+func NewFrom[V string | []byte](msg V) *T { return &T{Message: []byte(msg)} }
+
+// Label returns the label of a NOTICE envelope.
+func (en *T) Label() string { return L }
+
+// Write the NOTICE T to a provided io.Writer.
+func (en *T) Write(w io.Writer) (err error) {
+	_, err = w.Write(en.Marshal(nil))
+	return
+}
+
+// Marshal a NOTICE envelope in minified JSON into an noticeenvelope.T,
+// appending to a provided destination slice. Note that this ensures correct
+// string escaping on the Reason field.
+func (en *T) Marshal(dst []byte) (b []byte) {
+	var err error
+	_ = err
+	b = dst
+	b = envelopes.Marshal(
+		b, L,
+		func(bst []byte) (o []byte) {
+			o = bst
+			o = append(o, '"')
+			o = text.NostrEscape(o, en.Message)
+			o = append(o, '"')
+			return
+		},
+	)
+	return
+}
+
+// Unmarshal a noticeenvelope.T from minified JSON, returning the remainder
+// after the end of the envelope. Note that this ensures the Reason string is
+// correctly unescaped by NIP-01 escaping rules.
+func (en *T) Unmarshal(b []byte) (r []byte, err error) {
+	r = b
+	if en.Message, r, err = text.UnmarshalQuoted(r); chk.E(err) {
+		return
+	}
+	if r, err = envelopes.SkipToTheEnd(r); chk.E(err) {
+		return
+	}
+	return
+}
+
+// Parse reads a NOTICE envelope in minified JSON into a newly allocated
+// noticeenvelope.T.
+func Parse(b []byte) (t *T, rem []byte, err error) {
+	t = New()
+	if rem, err = t.Unmarshal(b); chk.E(err) {
+		return
+	}
+	return
+}
diff --git a/pkg/encoders/envelopes/noticeenvelope/noticeenvelope_test.go b/pkg/encoders/envelopes/noticeenvelope/noticeenvelope_test.go
new file mode 100644
index 0000000..fb907e5
--- /dev/null
+++ b/pkg/encoders/envelopes/noticeenvelope/noticeenvelope_test.go
@@ -0,0 +1,66 @@
+package noticeenvelope
+
+import (
+	"testing"
+
+	"lol.mleku.dev/chk"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/envelopes/messages"
+	"next.orly.dev/pkg/utils"
+)
+
+func TestMarshalUnmarshal(t *testing.T) {
+	var err error
+	rb, rb1, rb2 := make([]byte, 0, 65535), make([]byte, 0, 65535), make(
+		[]byte, 0, 65535,
+	)
+	for _ = range 1000 {
+		req := NewFrom(messages.RandomMessage())
+		rb = req.Marshal(rb)
+		rb1 = rb1[:len(rb)]
+		copy(rb1, rb)
+		var rem []byte
+		var l string
+		if l, rb, err = envelopes.Identify(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if l != L {
+			t.Fatalf("invalid sentinel %s, expect %s", l, L)
+		}
+		req2 := New()
+		if rem, err = req2.Unmarshal(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		// log.I.Ln(req2.ID)
+		if len(rem) > 0 {
+			t.Fatalf(
+				"unmarshal failed, remainder\n%d %s",
+				len(rem), rem,
+			)
+		}
+		rb2 = req2.Marshal(rb2)
+		if !utils.FastEqual(rb1, rb2) {
+			if len(rb1) != len(rb2) {
+				t.Fatalf(
+					"unmarshal failed, different lengths\n%d %s\n%d %s\n",
+					len(rb1), rb1, len(rb2), rb2,
+				)
+			}
+			for i := range rb1 {
+				if rb1[i] != rb2[i] {
+					t.Fatalf(
+						"unmarshal failed, difference at position %d\n"+
+							"%d %s\n%s\n%d %s\n%s\n",
+						i, len(rb1), rb1[:i], rb1[i:], len(rb2), rb2[:i],
+						rb2[i:],
+					)
+				}
+			}
+			t.Fatalf(
+				"unmarshal failed\n%d %s\n%d %s\n",
+				len(rb1), rb1, len(rb2), rb2,
+			)
+		}
+		rb, rb1, rb2 = rb[:0], rb1[:0], rb2[:0]
+	}
+}
diff --git a/pkg/encoders/envelopes/okenvelope/okenvelope.go b/pkg/encoders/envelopes/okenvelope/okenvelope.go
new file mode 100644
index 0000000..d4f4a23
--- /dev/null
+++ b/pkg/encoders/envelopes/okenvelope/okenvelope.go
@@ -0,0 +1,133 @@
+// Package okenvelope is a codec for the OK message, which is an acknowledgement
+// for an EVENT eventenvelope.Submission, containing true/false and if false a
+// message with a machine readable error type as found in the messages package.
+package okenvelope
+
+import (
+	"io"
+
+	"lol.mleku.dev/chk"
+	"lol.mleku.dev/errorf"
+	"lol.mleku.dev/log"
+	"next.orly.dev/pkg/crypto/sha256"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/hex"
+	"next.orly.dev/pkg/encoders/text"
+	"next.orly.dev/pkg/interfaces/codec"
+)
+
+// L is the label associated with this type of codec.Envelope.
+const L = "OK"
+
+// T is an OK envelope, used to signal acceptance or rejection, with a reason,
+// to an eventenvelope.Submission.
+type T struct {
+	EventID []byte
+	OK      bool
+	Reason  []byte
+}
+
+var _ codec.Envelope = (*T)(nil)
+
+// New creates a new empty OK T.
+func New() *T { return &T{} }
+
+// NewFrom creates a new okenvelope.T with a string for the subscription.Id and
+// the optional reason.
+func NewFrom[V string | []byte](eid V, ok bool, msg ...V) *T {
+	var m []byte
+	if len(msg) > 0 {
+		m = []byte(msg[0])
+	}
+	if len(eid) != sha256.Size {
+		log.W.F(
+			"event ID unexpected length, expect %d got %d",
+			len(eid), sha256.Size,
+		)
+	}
+	return &T{EventID: []byte(eid), OK: ok, Reason: m}
+}
+
+// Label returns the label of an okenvelope.T.
+func (en *T) Label() string { return L }
+
+// ReasonString returns the Reason in the form of a string.
+func (en *T) ReasonString() string { return string(en.Reason) }
+
+// Write the okenvelope.T to a provided io.Writer.
+func (en *T) Write(w io.Writer) (err error) {
+	_, err = w.Write(en.Marshal(nil))
+	return
+}
+
+// Marshal a okenvelope.T from minified JSON, appending to a provided
+// destination slice. Note that this ensures correct string escaping on the
+// subscription.Id and Reason fields.
+func (en *T) Marshal(dst []byte) (b []byte) {
+	var err error
+	_ = err
+	b = dst
+	b = envelopes.Marshal(
+		b, L,
+		func(bst []byte) (o []byte) {
+			o = bst
+			o = append(o, '"')
+			o = hex.EncAppend(o, en.EventID)
+			o = append(o, '"')
+			o = append(o, ',')
+			o = text.MarshalBool(o, en.OK)
+			o = append(o, ',')
+			o = append(o, '"')
+			o = text.NostrEscape(o, en.Reason)
+			o = append(o, '"')
+			return
+		},
+	)
+	return
+}
+
+// Unmarshal a okenvelope.T from minified JSON, returning the remainder after
+// the end of the envelope. Note that this ensures the Reason and
+// subscription.Id strings are correctly unescaped by NIP-01 escaping rules.
+func (en *T) Unmarshal(b []byte) (r []byte, err error) {
+	r = b
+	var idBytes []byte
+	// Parse event id as quoted hex (NIP-20 compliant)
+	if idBytes, r, err = text.UnmarshalHex(r); err != nil {
+		return
+	}
+	if len(idBytes) != sha256.Size {
+		err = errorf.E(
+			"invalid size for ID, require %d got %d",
+			sha256.Size, len(idBytes),
+		)
+		return
+	}
+	en.EventID = idBytes
+	if r, err = text.Comma(r); chk.E(err) {
+		return
+	}
+	if r, en.OK, err = text.UnmarshalBool(r); chk.E(err) {
+		return
+	}
+	if r, err = text.Comma(r); chk.E(err) {
+		return
+	}
+	if en.Reason, r, err = text.UnmarshalQuoted(r); chk.E(err) {
+		return
+	}
+	if r, err = envelopes.SkipToTheEnd(r); chk.E(err) {
+		return
+	}
+	return
+}
+
+// Parse reads a OK envelope in minified JSON into a newly allocated
+// okenvelope.T.
+func Parse(b []byte) (t *T, rem []byte, err error) {
+	t = New()
+	if rem, err = t.Unmarshal(b); chk.E(err) {
+		return
+	}
+	return
+}
diff --git a/pkg/encoders/envelopes/okenvelope/okenvelope_test.go b/pkg/encoders/envelopes/okenvelope/okenvelope_test.go
new file mode 100644
index 0000000..276b4fb
--- /dev/null
+++ b/pkg/encoders/envelopes/okenvelope/okenvelope_test.go
@@ -0,0 +1,71 @@
+package okenvelope
+
+import (
+	"testing"
+
+	"lol.mleku.dev/chk"
+	"lukechampine.com/frand"
+	"next.orly.dev/pkg/crypto/sha256"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/envelopes/messages"
+	"next.orly.dev/pkg/utils"
+)
+
+func TestMarshalUnmarshal(t *testing.T) {
+	var err error
+	rb, rb1, rb2 := make([]byte, 0, 65535), make([]byte, 0, 65535), make(
+		[]byte, 0, 65535,
+	)
+	for i := range 1000 {
+		var randMsg []byte
+		ok := i%2 == 1
+		if !ok {
+			randMsg = messages.RandomMessage()
+		}
+		req := NewFrom(frand.Bytes(sha256.Size), ok, randMsg)
+		rb = req.Marshal(rb)
+		rb1 = rb1[:len(rb)]
+		copy(rb1, rb)
+		var rem []byte
+		var l string
+		if l, rb, err = envelopes.Identify(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if l != L {
+			t.Fatalf("invalid sentinel %s, expect %s", l, L)
+		}
+		req2 := New()
+		if rem, err = req2.Unmarshal(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if len(rem) > 0 {
+			t.Fatalf(
+				"unmarshal failed, remainder\n%d %s",
+				len(rem), rem,
+			)
+		}
+		rb2 = req2.Marshal(rb2)
+		if !utils.FastEqual(rb1, rb2) {
+			if len(rb1) != len(rb2) {
+				t.Fatalf(
+					"unmarshal failed, different lengths\n%d %s\n%d %s\n",
+					len(rb1), rb1, len(rb2), rb2,
+				)
+			}
+			for i := range rb1 {
+				if rb1[i] != rb2[i] {
+					t.Fatalf(
+						"unmarshal failed, difference at position %d\n%d %s\n%s\n%d %s\n%s\n",
+						i, len(rb1), rb1[:i], rb1[i:], len(rb2), rb2[:i],
+						rb2[i:],
+					)
+				}
+			}
+			t.Fatalf(
+				"unmarshal failed\n%d %s\n%d %s\n",
+				len(rb1), rb1, len(rb2), rb2,
+			)
+		}
+		rb, rb1, rb2 = rb[:0], rb1[:0], rb2[:0]
+	}
+}