diff --git a/quill_test.go b/quill_test.go
new file mode 100644
index 0000000..cbbb9a2
--- /dev/null
+++ b/quill_test.go
@@ -0,0 +1,97 @@
+package main
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+)
+
+type quillBrain struct {
+	mu    sync.Mutex
+	pairs [][2]string
+	reply string
+}
+
+func (b *quillBrain) Name() string { return "quill-rec" }
+func (b *quillBrain) Ask(ctx context.Context, system, prompt string) (string, int, error) {
+	b.mu.Lock()
+	b.pairs = append(b.pairs, [2]string{system, prompt})
+	b.mu.Unlock()
+	return b.reply, 10, nil
+}
+
+func newQuillServer(t *testing.T, reply string) (*httptest.Server, *Server, *quillBrain) {
+	t.Helper()
+	ts, s := newTestNestServer(t)
+	qb := &quillBrain{reply: reply}
+	s.p.Flock.brain = qb
+	return ts, s, qb
+}
+
+func TestQuillIsServiceRole(t *testing.T) {
+	ts, _, _ := newQuillServer(t, "hello back")
+	id := newNest(t, ts, "Lab", `"Hugin","Munin"`)
+	code, msg := post(t, ts.URL+"/api/nests/"+id+"/messages",
+		`{"author":"owner","to":"Quill","kind":"say","text":"hello"}`)
+	if code != http.StatusCreated {
+		t.Fatalf("Quill must be addressable like Elder: got %d %v", code, msg)
+	}
+}
+
+func TestQuillAnswersInCharacter(t *testing.T) {
+	ts, _, qb := newQuillServer(t, "Already on it, boss.")
+	id := newNest(t, ts, "Lab", `"Hugin","Munin"`)
+	code, _ := post(t, ts.URL+"/api/nests/"+id+"/messages",
+		`{"author":"owner","to":"Quill","kind":"request","text":"quiet the room"}`)
+	if code != http.StatusCreated {
+		t.Fatalf("post: %d", code)
+	}
+	msgs := awaitMessages(t, ts, id, 2)
+	var reply map[string]any
+	for _, m := range msgs {
+		if m["author"] == "Quill" {
+			reply = m
+		}
+	}
+	if reply == nil {
+		t.Fatalf("Quill never answered: %v", msgs)
+	}
+	if reply["kind"] != "deliver" || reply["to"] != "owner" {
+		t.Fatalf("want deliver to owner, got %v", reply)
+	}
+	if reply["text"] != "Already on it, boss." {
+		t.Fatalf("reply text: %v", reply["text"])
+	}
+	qb.mu.Lock()
+	defer qb.mu.Unlock()
+	if len(qb.pairs) != 1 {
+		t.Fatalf("want exactly one model call, got %d", len(qb.pairs))
+	}
+	if !strings.Contains(qb.pairs[0][0], "Quill") || !strings.Contains(qb.pairs[0][0], "The Hand") {
+		t.Fatalf("system prompt must carry the Quill persona: %q", qb.pairs[0][0])
+	}
+	if !strings.Contains(qb.pairs[0][1], "quiet the room") {
+		t.Fatalf("prompt must carry the request text: %q", qb.pairs[0][1])
+	}
+}
+
+func TestQuillNotInNestCrows(t *testing.T) {
+	ts, s, _ := newQuillServer(t, "noted")
+	id := newNest(t, ts, "Lab", `"Hugin"`)
+	post(t, ts.URL+"/api/nests/"+id+"/messages",
+		`{"author":"owner","to":"Quill","kind":"request","text":"status?"}`)
+	awaitMessages(t, ts, id, 2)
+	for _, c := range nestOf(s, id).Crows {
+		if c == "Quill" {
+			t.Fatal("Quill must never become a nest member")
+		}
+	}
+	// No trust promotion happened for Quill either: service roles act on
+	// address, not on trust (the test server ledger was never touched).
+	if _, ok := s.p.Ledger.Crows["Quill|other"]; ok {
+		t.Fatal("Quill must not need or earn a worker trust record")
+	}
+}