Keep the builder's history as its own log that readers declare and follow, the memberships as the grants part's state, and refuse a module's own stream, so every module's data is in the bus's predefined forms and readable by its tools (issue 1955, ADR 0571 clauses 1, 4, 5, 7)

go/log_test.go

@@ -58,12 +58,13 @@ func (r *logRuntime) answer(m message) map[string]any {
 		From   uint64          `json:"from"`
 		Keys   string          `json:"keys"`
 		Limit  int             `json:"limit"`
+		Since  time.Time       `json:"since"`
 	}
 	_ = json.Unmarshal(m.Params, &p)
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	r.asked = append(r.asked, m)
-	if p.Log != "changes" {
+	if p.Log != "changes" && p.Log != "builder.build-log" {
 		return map[string]any{"error": map[string]any{"code": -32000, "message": "issues was issued no log " + p.Log}}
 	}
 	switch strings.TrimPrefix(m.Method, "mesh/log.") {
@@ -83,7 +84,7 @@ func (r *logRuntime) answer(m message) map[string]any {
 		page := map[string]any{"entries": []LogEntry{}, "next": 0, "last": len(r.entries)}
 		var got []LogEntry
 		for _, e := range r.entries {
-			if e.Sequence < p.From || !matches(p.Keys, e.Key) {
+			if e.Sequence < p.From || !matches(p.Keys, e.Key) || e.At.Before(p.Since) {
 				continue
 			}
 			if len(got) == limit {
@@ -96,6 +97,16 @@ func (r *logRuntime) answer(m message) map[string]any {
 			page["entries"] = got
 		}
 		return map[string]any{"result": page}
+	case "newest":
+		var out []LogEntry
+		for _, e := range r.entries {
+			if matches(p.Keys, e.Key) && r.last(e.Key) == e.Sequence {
+				out = append(out, e)
+			}
+		}
+		return map[string]any{"result": out}
+	case "watch":
+		return map[string]any{"result": map[string]any{}}
 	case "last":
 		seq := r.last(p.Key)
 		if seq == 0 {
@@ -148,6 +159,13 @@ func logging(t *testing.T, r *logRuntime, run func() (any, error)) map[string]an
 					a := r.answer(m)
 					a["id"] = m.ID
 					send(a)
+					// A watch's entries follow its answer, each named by the watch's id (ADR 0571 clause 1).
+					if m.Method == "mesh/log.watch" {
+						r.mu.Lock()
+						e := r.entries[len(r.entries)-1]
+						r.mu.Unlock()
+						send(map[string]any{"id": "entry-1", "method": "mesh/log", "params": map[string]any{"watch": m.ID, "entry": e}})
+					}
 				}(m)
 				continue
 			}
@@ -193,7 +211,9 @@ func TestABundleKeepsALogThroughTheRuntime(t *testing.T) {
 		pages                []*LogPage
 		last, none           *LogEntry
 		info                 *LogInfo
-		narrowed             *LogPage
+		narrowed, since      *LogPage
+		newest               []LogEntry
+		watched              *LogEntry
 	)
 	got := logging(t, r, func() (any, error) {
 		changes := Log("changes")
@@ -232,8 +252,27 @@ func TestABundleKeepsALogThroughTheRuntime(t *testing.T) {
 		if none, err = changes.Last("999"); err != nil {
 			return nil, err
 		}
-		info, err = changes.Info()
-		return "done", err
+		if info, err = changes.Info(); err != nil {
+			return nil, err
+		}
+		// ADR 0571 clause 1: another module's log, newest per key, from a time, and followed.
+		if newest, err = changes.Newest(""); err != nil {
+			return nil, err
+		}
+		if since, err = changes.Since(time.Date(2026, 10, 11, 18, 0, 5, 0, time.UTC), "", 0); err != nil {
+			return nil, err
+		}
+		heard := make(chan LogEntry, 1)
+		if err = Log("builder.build-log").Watch("letta", LogFromSince(time.Date(2026, 10, 11, 18, 0, 0, 0, time.UTC)),
+			func(e LogEntry) error { heard <- e; return nil }); err != nil {
+			return nil, err
+		}
+		select {
+		case e := <-heard:
+			watched = &e
+		case <-time.After(5 * time.Second):
+		}
+		return "done", nil
 	})
 	if out, isError := text(t, got); isError || out != `"done"` {
 		t.Fatalf("the tool answered %s", out)
@@ -296,6 +335,13 @@ func TestABundleKeepsALogThroughTheRuntime(t *testing.T) {
 	if none != nil {
 		t.Fatalf("a key with no entry has a last: %+v", none)
 	}
+	if len(newest) != 5 || newest[0].Key != "402" || newest[1].Sequence != 3 || len(since.Entries) != 2 || since.Entries[0].Sequence != 5 {
+		t.Fatalf("the newest per key are %+v, since a time %+v", newest, since)
+	}
+	if method, p = r.params(t, 15); method != "mesh/log.watch" || p["log"] != "builder.build-log" || p["keys"] != "letta" ||
+		p["from"] != "since" || p["since"] != "2026-10-11T18:00:00Z" || watched == nil || watched.Sequence != 6 {
+		t.Fatalf("a watch asked %s %v and heard %+v", method, p, watched)
+	}
 	if info == nil || info.Entries != 6 || info.MaxBytes != 1<<30 || info.First != 1 || info.Last != 6 || info.Bytes == 0 {
 		t.Fatalf("the log's info is %+v", info)
 	}