diff --git a/internal/runtime/orchestration/comm/comm.go b/internal/runtime/orchestration/comm/comm.go
new file mode 100644
index 0000000..cfc02c4
--- /dev/null
+++ b/internal/runtime/orchestration/comm/comm.go
@@ -0,0 +1,178 @@
+// Package comm implements agent-to-agent communication for the Cyrene v2
+// orchestration layer (DevDocs/design/05-子代理.md §4). Subagents and the main
+// agent exchange messages over the in-process bus (internal/bus) using a
+// request/answer protocol built on three message kinds: ask, reply and event.
+//
+// # Protocol
+//
+// A Probe is bound to one agent id. It can ask another agent a question and
+// wait for its reply (ask/reply), or fire events at another agent or to anyone
+// listening (event). Messages are published to the bus with dot-separated
+// subjects so the bus's NATS-like wildcard matching routes them to the right
+// agent; see the "Subject convention" section below.
+//
+// # Subject convention
+//
+// Subjects are built from sanitized agent ids (any rune outside [A-Za-z0-9_-]
+// is replaced by "_", so an id never breaks a subject token):
+//
+//	ask:        cyrene.agent.<from>.<to>.ask
+//	reply:      cyrene.agent.<from>.<to>.reply.<askId>
+//	event (to): cyrene.agent.<from>.<to>.event
+//	event (bc): cyrene.agent.<from>.event
+//
+// The reply subject carries the ask id as its last token, giving each in-flight
+// ask a private reply address so concurrent asks from the same agent never
+// cross replies. To receive asks addressed to it, an agent subscribes to
+// cyrene.agent.*.<me>.ask. To receive events (both broadcasts and events
+// addressed to it) it subscribes to cyrene.agent.*.event and to
+// cyrene.agent.*.<me>.event.
+//
+// # Delivery semantics
+//
+// Ask blocks until a reply arrives, an ask-timeout elapses, or the passed
+// context is canceled; it returns ErrTimeout on the former and the wrapped
+// context error on the latter. Reply and the event senders are fire-and-forget
+// publishes that return the bus error (if any). Handler callbacks are invoked
+// on the bus's per-subscription worker goroutines, so an EventHandler may be
+// called concurrently from two subscriptions and must be safe for concurrent
+// use; an AskHandler for one agent is serialized by the bus.
+package comm
+
+import (
+	"errors"
+	"strings"
+	"time"
+)
+
+// Kind is the wire kind of an agent-to-agent message.
+type Kind string
+
+const (
+	// KindAsk is a question from one agent to another, answered by a reply.
+	KindAsk Kind = "ask"
+	// KindReply is the answer to a previously published ask.
+	KindReply Kind = "reply"
+	// KindEvent is a one-directional notification, broadcast or addressed.
+	KindEvent Kind = "event"
+)
+
+// subjectPrefix is the fixed first two tokens of every agent-to-agent subject.
+const subjectPrefix = "cyrene.agent"
+
+// DefaultAskTimeout caps how long Ask waits for a reply when the caller's
+// context carries no shorter deadline. It bounds a request/answer round so a
+// silent agent never hangs its caller.
+const DefaultAskTimeout = 30 * time.Second
+
+// Sentinel errors returned by the package. Use errors.Is to test for them; they
+// are returned directly or wrapped with %w so the underlying cause stays
+// available.
+var (
+	// ErrTimeout is returned by Ask when no reply arrives before the ask
+	// deadline (the caller's context deadline or DefaultAskTimeout) elapses.
+	ErrTimeout = errors.New("comm: reply timeout")
+
+	// ErrNoReply is returned by Ask when the ask cannot be delivered (the bus
+	// rejected the publish/reply subscription), so no reply is expected.
+	ErrNoReply = errors.New("comm: no reply")
+)
+
+// Ask is a question sent from one agent to another.
+type Ask struct {
+	// ID uniquely identifies this ask within the answering exchange.
+	ID string
+	// From is the id of the asking agent (the sender).
+	From string
+	// To is the id of the agent that should answer (the receiver).
+	To string
+	// Question is the human-readable question text.
+	Question string
+	// Data carries an optional structured payload alongside the question.
+	Data any
+}
+
+// Reply is the answer to a previously published ask.
+type Reply struct {
+	// AskID is the ID of the ask this reply answers.
+	AskID string
+	// From is the id of the replying agent (the sender).
+	From string
+	// To is the id of the asking agent (the receiver).
+	To string
+	// Text is the human-readable answer text.
+	Text string
+	// Data carries an optional structured payload alongside the answer.
+	Data any
+}
+
+// Event is a one-directional notification, either broadcast or addressed to one
+// agent. It has no reply.
+type Event struct {
+	// From is the id of the emitting agent.
+	From string
+	// Name is a short event name, e.g. "task.progress" or "tool.used".
+	Name string
+	// Data carries an optional structured payload.
+	Data any
+}
+
+// token sanitizes an agent id so it can be used as a single subject token: any
+// rune outside [A-Za-z0-9_-] is replaced with "_". This keeps the id useful for
+// routing while guaranteeing dots (and the other subject metacharacters) never
+// leak into a token.
+func token(s string) string {
+	var b strings.Builder
+	for _, r := range s {
+		switch {
+		case r >= 'a' && r <= 'z', r >= 'A' && r <= 'Z', r >= '0' && r <= '9', r == '-', r == '_':
+			b.WriteRune(r)
+		default:
+			b.WriteRune('_')
+		}
+	}
+	return b.String()
+}
+
+// subjectFor builds the base subject for a from/to message of the given kind.
+func subjectFor(from, to string, kind Kind) string {
+	return subjectPrefix + "." + token(from) + "." + token(to) + "." + string(kind)
+}
+
+// askSubject is the subject an ask from→to is published to.
+func askSubject(from, to string) string {
+	return subjectFor(from, to, KindAsk)
+}
+
+// replySubject is the private subject a reply from→to answering askID is
+// published to. The trailing askID token gives each in-flight ask its own
+// address so replies never cross between concurrent asks.
+func replySubject(from, to, askID string) string {
+	return subjectPrefix + "." + token(from) + "." + token(to) + "." + string(KindReply) + "." + token(askID)
+}
+
+// eventSubject is the subject of an event addressed from→to.
+func eventSubject(from, to string) string {
+	return subjectFor(from, to, KindEvent)
+}
+
+// broadcastEventSubject is the subject of a broadcast event emitted by from.
+func broadcastEventSubject(from string) string {
+	return subjectPrefix + "." + token(from) + "." + string(KindEvent)
+}
+
+// askReceivePattern is the subscription pattern an agent named me uses to
+// receive asks addressed to it from any sender.
+func askReceivePattern(me string) string {
+	return subjectPrefix + ".*." + token(me) + "." + string(KindAsk)
+}
+
+// eventReceivePatterns are the subscription patterns an agent named me uses to
+// receive every event it should see: broadcasts from any sender and events
+// addressed specifically to it.
+func eventReceivePatterns(me string) []string {
+	return []string{
+		subjectPrefix + ".*." + string(KindEvent),
+		subjectPrefix + ".*." + token(me) + "." + string(KindEvent),
+	}
+}
diff --git a/internal/runtime/orchestration/comm/comm_test.go b/internal/runtime/orchestration/comm/comm_test.go
new file mode 100644
index 0000000..26644ae
--- /dev/null
+++ b/internal/runtime/orchestration/comm/comm_test.go
@@ -0,0 +1,359 @@
+package comm
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/bus"
+)
+
+// recvEvent blocks until an event arrives on ch or d elapses, failing the test
+// on timeout. It makes delivery assertions deterministic instead of relying on a
+// bare sleep.
+func recvEvent(t *testing.T, ch <-chan Event, d time.Duration) Event {
+	t.Helper()
+	select {
+	case e := <-ch:
+		return e
+	case <-time.After(d):
+		t.Fatalf("timed out waiting for an event after %v", d)
+		return Event{}
+	}
+}
+
+func TestSubjectConvention(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name string
+		got  string
+		want string
+	}{
+		{"ask", askSubject("alice", "bob"), "cyrene.agent.alice.bob.ask"},
+		{"reply carries ask id", replySubject("bob", "alice", "alice-3"), "cyrene.agent.bob.alice.reply.alice-3"},
+		{"event addressed", eventSubject("alice", "bob"), "cyrene.agent.alice.bob.event"},
+		{"event broadcast", broadcastEventSubject("alice"), "cyrene.agent.alice.event"},
+		{"ask receive pattern", askReceivePattern("bob"), "cyrene.agent.*.bob.ask"},
+		{"agent ids sanitized", askSubject("a.b", "c d"), "cyrene.agent.a_b.c_d.ask"},
+	}
+	for _, c := range cases {
+		c := c
+		t.Run(c.name, func(t *testing.T) {
+			t.Parallel()
+			if c.got != c.want {
+				t.Fatalf("subject = %q, want %q", c.got, c.want)
+			}
+		})
+	}
+}
+
+func TestEventReceivePatterns(t *testing.T) {
+	t.Parallel()
+
+	got := eventReceivePatterns("bob")
+	want := []string{"cyrene.agent.*.event", "cyrene.agent.*.bob.event"}
+	if len(got) != len(want) {
+		t.Fatalf("patterns = %v, want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("patterns[%d] = %q, want %q", i, got[i], want[i])
+		}
+	}
+}
+
+func TestAskReply_RoundTrip(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+	bob := New(b, "bob")
+
+	unsub, err := bob.SubscribeAsk(context.Background(), func(ctx context.Context, a Ask) error {
+		return bob.Answer(ctx, a.From, a.ID, "pong:"+a.Question, a.Data)
+	})
+	if err != nil {
+		t.Fatalf("SubscribeAsk: %v", err)
+	}
+	defer unsub()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	reply, err := alice.Ask(ctx, "bob", "ping", "payload")
+	if err != nil {
+		t.Fatalf("Ask: %v", err)
+	}
+	if reply.Text != "pong:ping" {
+		t.Fatalf("reply.Text = %q, want pong:ping", reply.Text)
+	}
+	if reply.From != "bob" {
+		t.Fatalf("reply.From = %q, want bob", reply.From)
+	}
+	if reply.To != "alice" {
+		t.Fatalf("reply.To = %q, want alice", reply.To)
+	}
+	if reply.Data != "payload" {
+		t.Fatalf("reply.Data = %#v, want payload", reply.Data)
+	}
+}
+
+func TestAsk_TimeoutNoReply(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+	// bob has no ask handler, so nothing ever replies.
+
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+
+	_, err := alice.Ask(ctx, "bob", "hello", nil)
+	if !errors.Is(err, ErrTimeout) {
+		t.Fatalf("Ask err = %v, want ErrTimeout", err)
+	}
+}
+
+func TestAsk_ContextCanceled(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	got := make(chan error, 1)
+	go func() {
+		_, err := alice.Ask(ctx, "bob", "hello", nil)
+		got <- err
+	}()
+	time.Sleep(50 * time.Millisecond)
+	cancel()
+
+	select {
+	case err := <-got:
+		if !errors.Is(err, context.Canceled) {
+			t.Fatalf("Ask err = %v, want context.Canceled", err)
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("Ask did not return after ctx cancel")
+	}
+}
+
+func TestAsk_ContextPreCanceled(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	_, err := alice.Ask(ctx, "bob", "q", nil)
+	if !errors.Is(err, context.Canceled) {
+		t.Fatalf("Ask err = %v, want context.Canceled", err)
+	}
+}
+
+func TestEventBroadcast(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+	bob := New(b, "bob")
+
+	events := make(chan Event, 4)
+	unsub, err := bob.SubscribeEvent(context.Background(), func(ctx context.Context, e Event) error {
+		events <- e
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("SubscribeEvent: %v", err)
+	}
+	defer unsub()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	if err := alice.PublishEvent(ctx, Event{Name: "tick", Data: 7}); err != nil {
+		t.Fatalf("PublishEvent: %v", err)
+	}
+	e := recvEvent(t, events, 2*time.Second)
+	if e.Name != "tick" || e.Data != 7 || e.From != "alice" {
+		t.Fatalf("event = %+v, want name=tick data=7 from=alice", e)
+	}
+}
+
+func TestEventSend_AddressedAndIsolated(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+	bob := New(b, "bob")
+	carol := New(b, "carol")
+
+	bobEvents := make(chan Event, 4)
+	carolEvents := make(chan Event, 4)
+
+	unsubBob, err := bob.SubscribeEvent(context.Background(), func(ctx context.Context, e Event) error {
+		bobEvents <- e
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("SubscribeEvent bob: %v", err)
+	}
+	defer unsubBob()
+	unsubCarol, err := carol.SubscribeEvent(context.Background(), func(ctx context.Context, e Event) error {
+		carolEvents <- e
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("SubscribeEvent carol: %v", err)
+	}
+	defer unsubCarol()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	if err := alice.Send(ctx, "bob", Event{Name: "direct"}); err != nil {
+		t.Fatalf("Send: %v", err)
+	}
+	e := recvEvent(t, bobEvents, 2*time.Second)
+	if e.Name != "direct" || e.From != "alice" {
+		t.Fatalf("bob event = %+v, want name=direct from=alice", e)
+	}
+
+	// An event addressed to bob must not reach carol.
+	select {
+	case e := <-carolEvents:
+		t.Fatalf("carol unexpectedly received %+v", e)
+	case <-time.After(100 * time.Millisecond):
+	}
+}
+
+func TestEventHandler_Concurrent(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	emitter := New(b, "emit")
+	recv := New(b, "recv")
+
+	const n = 100
+	var got atomic.Int64
+	done := make(chan struct{})
+	unsub, err := recv.SubscribeEvent(context.Background(), func(ctx context.Context, e Event) error {
+		if got.Add(1) == n {
+			close(done)
+		}
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("SubscribeEvent: %v", err)
+	}
+	defer unsub()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	// Fire a mix of broadcasts and events addressed to recv so both event
+	// subscriptions (and their separate worker goroutines) invoke the handler
+	// concurrently.
+	var wg sync.WaitGroup
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			if i%2 == 0 {
+				_ = emitter.PublishEvent(ctx, Event{Name: "bc", Data: i})
+			} else {
+				_ = emitter.Send(ctx, "recv", Event{Name: "to", Data: i})
+			}
+		}(i)
+	}
+	wg.Wait()
+
+	select {
+	case <-done:
+	case <-time.After(3 * time.Second):
+		t.Fatalf("only %d of %d events delivered", got.Load(), n)
+	}
+}
+
+func TestAsk_ConcurrentDistinct(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+	bob := New(b, "bob")
+
+	unsub, err := bob.SubscribeAsk(context.Background(), func(ctx context.Context, a Ask) error {
+		return bob.Answer(ctx, a.From, a.ID, "ack:"+a.Question, a.Data)
+	})
+	if err != nil {
+		t.Fatalf("SubscribeAsk: %v", err)
+	}
+	defer unsub()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	const n = 20
+	var wg sync.WaitGroup
+	errs := make(chan error, n)
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			q := fmt.Sprintf("q%d", i)
+			reply, err := alice.Ask(ctx, "bob", q, i)
+			if err != nil {
+				errs <- fmt.Errorf("ask %d: %w", i, err)
+				return
+			}
+			if reply.Text != "ack:"+q {
+				errs <- fmt.Errorf("ask %d: reply.Text = %q, want %q", i, reply.Text, "ack:"+q)
+				return
+			}
+			if reply.Data != i {
+				errs <- fmt.Errorf("ask %d: reply.Data = %#v, want %d", i, reply.Data, i)
+				return
+			}
+		}(i)
+	}
+	wg.Wait()
+	close(errs)
+	for err := range errs {
+		t.Fatal(err)
+	}
+}
+
+func TestSend_NoErrorAndNoReceiver(t *testing.T) {
+	t.Parallel()
+
+	b := bus.New()
+	defer b.Close()
+	alice := New(b, "alice")
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	// Publishing to a subject with no subscriber is a no-op, not an error.
+	if err := alice.Send(ctx, "ghost", Event{Name: "nobody"}); err != nil {
+		t.Fatalf("Send to lost receiver: %v", err)
+	}
+	if err := alice.PublishEvent(ctx, Event{Name: "nobody"}); err != nil {
+		t.Fatalf("PublishEvent with no subscriber: %v", err)
+	}
+}
diff --git a/internal/runtime/orchestration/comm/probe.go b/internal/runtime/orchestration/comm/probe.go
new file mode 100644
index 0000000..62d2716
--- /dev/null
+++ b/internal/runtime/orchestration/comm/probe.go
@@ -0,0 +1,182 @@
+package comm
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"sync/atomic"
+	"time"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/bus"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
+)
+
+// Probe is an agent-to-agent communication endpoint bound to a single agent id.
+// It is safe for concurrent use: the only mutable field is an atomic sequence
+// counter used to mint unique ask ids, and every in-flight ask carries its own
+// reply subscription and channel.
+type Probe struct {
+	bus        bus.Bus
+	agentID    string
+	seq        atomic.Uint64
+	askTimeout time.Duration
+	log        *slog.Logger
+}
+
+// Option customizes a Probe built by New.
+type Option func(*Probe)
+
+// WithLogger replaces the probe's logger. The default is a discard logger so the
+// probe is quiet until configured.
+func WithLogger(l *slog.Logger) Option {
+	return func(p *Probe) { p.log = newLogger(l) }
+}
+
+// WithAskTimeout sets how long Ask waits for a reply when the caller's context
+// carries no shorter deadline. A non-positive value keeps DefaultAskTimeout.
+func WithAskTimeout(d time.Duration) Option {
+	return func(p *Probe) { p.askTimeout = d }
+}
+
+// New builds a Probe bound to agentID. The agentID is sanitized for use in bus
+// subjects (see token); an empty id panics because every probe must be routable.
+func New(b bus.Bus, agentID string, opts ...Option) *Probe {
+	if agentID == "" {
+		panic("comm: New: agentID must not be empty")
+	}
+	p := &Probe{
+		bus:        b,
+		agentID:    token(agentID),
+		askTimeout: DefaultAskTimeout,
+		log:        newLogger(nil),
+	}
+	for _, opt := range opts {
+		opt(p)
+	}
+	if p.askTimeout <= 0 {
+		p.askTimeout = DefaultAskTimeout
+	}
+	return p
+}
+
+// AgentID returns the sanitized id this Probe is bound to.
+func (p *Probe) AgentID() string { return p.agentID }
+
+// Ask sends a question to to and blocks until a matching Reply arrives, an ask
+// deadline elapses, or ctx is canceled. It returns the reply on success;
+// otherwise it returns ErrTimeout when the deadline elapsed without a reply,
+// ErrNoReply when the ask could not be delivered at all, or the wrapped context
+// error when ctx was canceled.
+//
+// The caller's context supplies a deadline if one is set; otherwise
+// p.askTimeout bounds the wait. The reply subscription is created before the
+// ask is published, so a fast answerer cannot be missed.
+func (p *Probe) Ask(ctx context.Context, to, question string, data any) (Reply, error) {
+	if err := ctx.Err(); err != nil {
+		return Reply{}, fmt.Errorf("comm: ask to %q: %w", to, err)
+	}
+	askID := p.nextAskID()
+	from := p.agentID
+
+	replyCh := make(chan Reply, 1)
+	replySub := replySubject(to, from, askID)
+	unsub, err := p.bus.Subscribe(ctx, replySub, func(bctx context.Context, e bus.Event) error {
+		r, ok := e.Payload.(Reply)
+		if !ok {
+			return fmt.Errorf("comm: reply payload type %T, want Reply", e.Payload)
+		}
+		if r.AskID != askID {
+			return fmt.Errorf("comm: reply ask id %q, want %q", r.AskID, askID)
+		}
+		select {
+		case replyCh <- r:
+		default:
+		}
+		return nil
+	})
+	if err != nil {
+		return Reply{}, fmt.Errorf("comm: ask to %q: subscribe reply: %w: %w", to, ErrNoReply, err)
+	}
+	defer unsub()
+
+	ask := Ask{ID: askID, From: from, To: to, Question: question, Data: data}
+	if err := p.bus.Publish(ctx, askSubject(from, to), ask); err != nil {
+		return Reply{}, fmt.Errorf("comm: ask to %q: publish ask: %w: %w", to, ErrNoReply, err)
+	}
+
+	waitCtx, cancel := context.WithTimeout(ctx, p.askTimeout)
+	defer cancel()
+
+	select {
+	case r := <-replyCh:
+		return r, nil
+	case <-waitCtx.Done():
+		if errors.Is(waitCtx.Err(), context.Canceled) {
+			return Reply{}, fmt.Errorf("comm: ask to %q: %w", to, ctx.Err())
+		}
+		return Reply{}, fmt.Errorf("comm: ask to %q: %w", to, ErrTimeout)
+	}
+}
+
+// Reply publishes an answer to the ask identified by r.AskID, addressed to to.
+// The answerer defaults to this Probe's agent id when r.From is empty, so an
+// answering handler can simply pass the reply text and payload.
+func (p *Probe) Reply(ctx context.Context, to string, r Reply) error {
+	if r.From == "" {
+		r.From = p.agentID
+	}
+	if r.To == "" {
+		r.To = to
+	}
+	if err := p.bus.Publish(ctx, replySubject(r.From, to, r.AskID), r); err != nil {
+		return fmt.Errorf("comm: reply to %q: %w", to, err)
+	}
+	return nil
+}
+
+// Answer is a convenience for replying with plain text. It publishes a Reply
+// for askID to the asking agent to.
+func (p *Probe) Answer(ctx context.Context, to, askID, text string, data any) error {
+	return p.Reply(ctx, to, Reply{AskID: askID, From: p.agentID, To: to, Text: text, Data: data})
+}
+
+// Send delivers an event addressed specifically to to. The emitter defaults to
+// this Probe's agent id when ev.From is empty.
+func (p *Probe) Send(ctx context.Context, to string, ev Event) error {
+	if ev.From == "" {
+		ev.From = p.agentID
+	}
+	if err := p.bus.Publish(ctx, eventSubject(ev.From, to), ev); err != nil {
+		return fmt.Errorf("comm: send event to %q: %w", to, err)
+	}
+	return nil
+}
+
+// PublishEvent broadcasts an event to every agent subscribed for events. The
+// emitter defaults to this Probe's agent id when ev.From is empty.
+func (p *Probe) PublishEvent(ctx context.Context, ev Event) error {
+	if ev.From == "" {
+		ev.From = p.agentID
+	}
+	if err := p.bus.Publish(ctx, broadcastEventSubject(ev.From), ev); err != nil {
+		return fmt.Errorf("comm: publish event: %w", err)
+	}
+	return nil
+}
+
+// nextAskID mints a unique ask id from the agent id and an atomic counter. It is
+// safe for concurrent calls.
+func (p *Probe) nextAskID() string {
+	return fmt.Sprintf("%s-%d", p.agentID, p.seq.Add(1))
+}
+
+// newLogger returns l tagged with the orchestrations/comm source, swapping a nil
+// logger for a discard one so the probe can always log safely.
+func newLogger(l *slog.Logger) *slog.Logger {
+	if l == nil {
+		l = slog.New(slog.NewTextHandler(io.Discard, nil))
+	}
+	return logger.WithSource(l, "orchestration/comm")
+}
diff --git a/internal/runtime/orchestration/comm/subscribe.go b/internal/runtime/orchestration/comm/subscribe.go
new file mode 100644
index 0000000..ab3c197
--- /dev/null
+++ b/internal/runtime/orchestration/comm/subscribe.go
@@ -0,0 +1,95 @@
+package comm
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/bus"
+)
+
+// AskHandler processes an Ask addressed to this agent. It runs on the bus's
+// per-subscription worker goroutine; for a single agent asks are serialized. A
+// handler should answer via (p *Probe).Reply or Answer; a non-nil returned
+// error is logged by the probe and discarded.
+type AskHandler func(ctx context.Context, a Ask) error
+
+// EventHandler processes an Event addressed to, or broadcast to, this agent.
+// Because an agent subscribes to two event patterns (broadcast and addressed),
+// the bus may invoke a handler concurrently from two worker goroutines, so an
+// EventHandler must be safe for concurrent use.
+type EventHandler func(ctx context.Context, e Event) error
+
+// SubscribeAsk registers h to receive every Ask addressed to this agent and
+// returns an unsubscribe function that removes the registration. When ctx is
+// canceled the registration is removed automatically; the returned function is
+// idempotent.
+func (p *Probe) SubscribeAsk(ctx context.Context, h AskHandler) (func(), error) {
+	if h == nil {
+		return nil, fmt.Errorf("comm: subscribe ask: handler must not be nil")
+	}
+	pattern := askReceivePattern(p.agentID)
+	unsub, err := p.bus.Subscribe(ctx, pattern, func(bctx context.Context, e bus.Event) error {
+		a, ok := e.Payload.(Ask)
+		if !ok {
+			return fmt.Errorf("comm: ask payload type %T, want Ask", e.Payload)
+		}
+		if err := h(bctx, a); err != nil {
+			p.log.Warn("ask handler failed", "from", a.From, "ask_id", a.ID, "err", err)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("comm: subscribe ask: %w", err)
+	}
+	return func() { unsub() }, nil
+}
+
+// SubscribeEvent registers h to receive both broadcast events and events
+// addressed to this agent. It returns an unsubscribe function that removes both
+// registrations; it is idempotent and safe to call more than once. When ctx is
+// canceled both registrations are removed automatically.
+//
+// The handler reaches the caller from two subscription worker goroutines and
+// may also run concurrently with a SubscribeAsk handler, so it must be safe for
+// concurrent use.
+func (p *Probe) SubscribeEvent(ctx context.Context, h EventHandler) (func(), error) {
+	if h == nil {
+		return nil, fmt.Errorf("comm: subscribe event: handler must not be nil")
+	}
+
+	wrap := func(bctx context.Context, e bus.Event) error {
+		ev, ok := e.Payload.(Event)
+		if !ok {
+			return fmt.Errorf("comm: event payload type %T, want Event", e.Payload)
+		}
+		if err := h(bctx, ev); err != nil {
+			p.log.Warn("event handler failed", "from", ev.From, "name", ev.Name, "err", err)
+		}
+		return nil
+	}
+
+	var (
+		mu     sync.Mutex
+		unsubs []func()
+	)
+	combined := func() {
+		mu.Lock()
+		defer mu.Unlock()
+		for _, u := range unsubs {
+			u()
+		}
+	}
+
+	for _, pattern := range eventReceivePatterns(p.agentID) {
+		u, err := p.bus.Subscribe(ctx, pattern, wrap)
+		if err != nil {
+			combined()
+			return nil, fmt.Errorf("comm: subscribe event %q: %w", pattern, err)
+		}
+		mu.Lock()
+		unsubs = append(unsubs, u)
+		mu.Unlock()
+	}
+	return combined, nil
+}