diff --git a/cmd/mavend/actions_query.go b/cmd/mavend/actions_query.go
index 9ce9972..173a456 100644
--- a/cmd/mavend/actions_query.go
+++ b/cmd/mavend/actions_query.go
@@ -102,12 +102,15 @@ func (h *reactiveHandler) queryCalendar(ctx context.Context, t *queryTurn) (stri
 		log.Printf("voice: calendar events: %v", err)
 		return "не получилось проверить календарь.", true
 	}
-	values := make([]string, len(events))
+	// Provenance travels with each event. A work meeting relayed off a phone
+	// notification (source ambient:notif, #126) is stored below full confidence
+	// and gets hedged; a CalDAV read is recited plainly.
+	entries := make([]router.CalendarEntry, len(events))
 	for i, e := range events {
-		values[i] = e.Value
+		entries[i] = router.CalendarEntry{Text: e.Value, Uncertain: e.Confidence < 1.0}
 	}
 	var f router.CalendarEventFormatter
-	return f.Format(values, date), true
+	return f.FormatEntries(entries, date), true
 }
 
 func (h *reactiveHandler) queryWeather(ctx context.Context, t *queryTurn) (string, bool) {
diff --git a/cmd/mavweb/ambient.go b/cmd/mavweb/ambient.go
new file mode 100644
index 0000000..c6a57af
--- /dev/null
+++ b/cmd/mavweb/ambient.go
@@ -0,0 +1,135 @@
+package main
+
+import (
+	"crypto/subtle"
+	"encoding/json"
+	"errors"
+	"io"
+	"log"
+	"net/http"
+	"strings"
+
+	"github.com/kami/maven/internal/calendar"
+	"github.com/kami/maven/internal/ipc"
+)
+
+// POST /api/ambient — the work calendar read (Vikunja #126).
+//
+// Maven does not hold a work credential. A corp mail or calendar session on the
+// homelab ties the box's blast radius to the employer's data, so the work
+// calendar is read as a SIGNAL instead: an Android notification-listener on the
+// owner's phone posts meeting notifications here over wg/LAN, and the ones that
+// clearly describe a meeting become calendar events at source=ambient:notif,
+// confidence below 1.0. Mail as a notification signal, not a mailbox.
+//
+// Off unless configured: no -ambient-token, no route. The token is a shared
+// secret because the poster is a phone service, not a browser — WebAuthn has no
+// answer for a background Android service. The endpoint is write-only and
+// accepts exactly one shape of write; it cannot read anything back out.
+//
+// A notification with no recognisable clock reading stores NOTHING. Maven is
+// not a guesser-of-truth, and a mailbox of noise rendered as invented meetings
+// is worse than a gap.
+
+// ambientMaxBody bounds the request. A notification is two short lines.
+const ambientMaxBody = 8 << 10
+
+type ambientResp struct {
+	Stored bool   `json:"stored"`
+	Key    string `json:"key,omitempty"`
+	Reason string `json:"reason,omitempty"`
+}
+
+// handleAmbient ingests one relayed notification. token is the configured
+// shared secret; an empty token means the capability is off and the handler is
+// never registered, so it is treated as a hard failure here too.
+func handleAmbient(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI, token string) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+	if token == "" {
+		http.Error(w, "ambient ingest disabled (no -ambient-token)", http.StatusServiceUnavailable)
+		return
+	}
+	if !ambientAuthorized(r, token) {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	if core == nil {
+		http.Error(w, "ambient ingest disabled (no -core)", http.StatusServiceUnavailable)
+		return
+	}
+
+	var n calendar.Notification
+	body, err := io.ReadAll(io.LimitReader(r.Body, ambientMaxBody))
+	if err != nil {
+		http.Error(w, "read failed", http.StatusBadRequest)
+		return
+	}
+	if err := json.Unmarshal(body, &n); err != nil {
+		http.Error(w, "bad json", http.StatusBadRequest)
+		return
+	}
+	if n.Posted.IsZero() {
+		writeAmbient(w, http.StatusBadRequest, ambientResp{Reason: "posted_at is required"})
+		return
+	}
+
+	ev, ok := calendar.EventFromNotification(n)
+	if !ok {
+		// Not an event. 202: the relay did its job, there is just nothing here
+		// worth remembering, and it must not retry.
+		writeAmbient(w, http.StatusAccepted, ambientResp{Reason: "no meeting time in notification"})
+		return
+	}
+
+	key := calendar.FactKey(ev)
+	val := calendar.FactValue(ev)
+
+	// Append-only discipline, same as cmd/mavcaldav: a phone reposts the same
+	// notification many times, and each repost is the same event.
+	if prev, err := core.LatestFactBySource(r.Context(), key, calendar.SourceAmbient); err == nil && prev.Value == val {
+		writeAmbient(w, http.StatusOK, ambientResp{Stored: false, Key: key, Reason: "unchanged"})
+		return
+	} else if err != nil && !errors.Is(err, ipc.ErrNoFact) {
+		log.Printf("ambient: read %s: %v", key, err)
+		http.Error(w, "read failed", http.StatusBadGateway)
+		return
+	}
+
+	// kind=env: an observation about the world, never a self-fact — a passive
+	// signal does not write truth about the owner. Confidence below 1.0 is the
+	// honest part: this is a notification about a meeting, not a reading of a
+	// calendar, and the query path hedges when it recites one.
+	if _, err := core.WriteFact(r.Context(), ipc.WriteFactReq{
+		Ts:         ev.Start,
+		Kind:       "env",
+		Key:        key,
+		Value:      val,
+		Source:     calendar.SourceAmbient,
+		Confidence: calendar.AmbientConfidence,
+	}); err != nil {
+		log.Printf("ambient: write %s: %v", key, err)
+		http.Error(w, "write failed", http.StatusBadGateway)
+		return
+	}
+	log.Printf("ambient: %s=%s (%s, pkg=%s)", key, val, calendar.SourceAmbient, n.Package)
+	writeAmbient(w, http.StatusCreated, ambientResp{Stored: true, Key: key})
+}
+
+// ambientAuthorized accepts the token as a bearer header or as an X-Maven-Token
+// header, compared in constant time.
+func ambientAuthorized(r *http.Request, token string) bool {
+	got := strings.TrimSpace(strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer"))
+	if got == "" {
+		got = strings.TrimSpace(r.Header.Get("X-Maven-Token"))
+	}
+	return subtle.ConstantTimeCompare([]byte(got), []byte(token)) == 1
+}
+
+func writeAmbient(w http.ResponseWriter, code int, resp ambientResp) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	json.NewEncoder(w).Encode(resp)
+}
diff --git a/cmd/mavweb/ambient_test.go b/cmd/mavweb/ambient_test.go
new file mode 100644
index 0000000..f6870ac
--- /dev/null
+++ b/cmd/mavweb/ambient_test.go
@@ -0,0 +1,223 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/kami/maven/internal/calendar"
+	"github.com/kami/maven/internal/ipc"
+)
+
+const ambientTestToken = "s3cret"
+
+// ambientCore adds provenance-scoped reads to fakeCore, which the dedupe path
+// needs.
+type ambientCore struct {
+	fakeCore
+	latest  map[string]ipc.Fact // "key|source" → fact
+	readErr error
+}
+
+func (c *ambientCore) LatestFactBySource(_ context.Context, key, source string) (ipc.Fact, error) {
+	if c.readErr != nil {
+		return ipc.Fact{}, c.readErr
+	}
+	f, ok := c.latest[key+"|"+source]
+	if !ok {
+		return ipc.Fact{}, ipc.ErrNoFact
+	}
+	return f, nil
+}
+
+func postAmbient(t *testing.T, core ipc.CoreAPI, token string, n calendar.Notification) (*httptest.ResponseRecorder, ambientResp) {
+	t.Helper()
+	body, err := json.Marshal(n)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req := httptest.NewRequest(http.MethodPost, "/api/ambient", strings.NewReader(string(body)))
+	req.Header.Set("Authorization", "Bearer "+ambientTestToken)
+	rr := httptest.NewRecorder()
+	handleAmbient(rr, req, core, token)
+	var resp ambientResp
+	json.Unmarshal(rr.Body.Bytes(), &resp)
+	return rr, resp
+}
+
+func meetingNotification() calendar.Notification {
+	return calendar.Notification{
+		Package: "com.google.android.gm",
+		Title:   "Планёрка",
+		Text:    "10:00-10:30",
+		Posted:  time.Date(2026, 8, 3, 9, 40, 0, 0, time.UTC),
+	}
+}
+
+func TestHandleAmbientStoresMeeting(t *testing.T) {
+	core := &ambientCore{}
+	rr, resp := postAmbient(t, core, ambientTestToken, meetingNotification())
+
+	if rr.Code != http.StatusCreated {
+		t.Fatalf("status = %d, want 201: %s", rr.Code, rr.Body)
+	}
+	if !resp.Stored {
+		t.Errorf("resp = %+v, want stored", resp)
+	}
+	if len(core.writeLog) != 1 {
+		t.Fatalf("expected 1 fact write, got %d", len(core.writeLog))
+	}
+	got := core.writeLog[0]
+	if got.Source != calendar.SourceAmbient {
+		t.Errorf("source = %q, want %q", got.Source, calendar.SourceAmbient)
+	}
+	if got.Confidence >= 1.0 {
+		t.Errorf("confidence = %v — a notification is not a calendar read", got.Confidence)
+	}
+	if got.Confidence != calendar.AmbientConfidence {
+		t.Errorf("confidence = %v, want %v", got.Confidence, calendar.AmbientConfidence)
+	}
+	if got.Kind != "env" {
+		t.Errorf("kind = %q — a passive signal never writes a self-fact", got.Kind)
+	}
+	if want := "calendar_event_20260803_"; !strings.HasPrefix(got.Key, want) {
+		t.Errorf("key = %q, want prefix %q", got.Key, want)
+	}
+	if got.Value != "Планёрка @ 10:00-10:30" {
+		t.Errorf("value = %q", got.Value)
+	}
+}
+
+// A phone reposts the same notification many times. Each repost is the same
+// event, and the append-only log must not fill with duplicates.
+func TestHandleAmbientDedupesReposts(t *testing.T) {
+	core := &ambientCore{}
+	postAmbient(t, core, ambientTestToken, meetingNotification())
+	if len(core.writeLog) != 1 {
+		t.Fatalf("first post did not write")
+	}
+	w := core.writeLog[0]
+	core.latest = map[string]ipc.Fact{w.Key + "|" + w.Source: {Value: w.Value}}
+
+	rr, resp := postAmbient(t, core, ambientTestToken, meetingNotification())
+	if rr.Code != http.StatusOK {
+		t.Errorf("status = %d, want 200 for an unchanged repost", rr.Code)
+	}
+	if resp.Stored {
+		t.Error("a repost must not be stored again")
+	}
+	if len(core.writeLog) != 1 {
+		t.Errorf("wrote %d facts, want 1", len(core.writeLog))
+	}
+}
+
+// The conservative half: noise stores nothing at all.
+func TestHandleAmbientIgnoresNonMeetings(t *testing.T) {
+	core := &ambientCore{}
+	rr, resp := postAmbient(t, core, ambientTestToken, calendar.Notification{
+		Package: "com.google.android.gm",
+		Title:   "3 новых письма",
+		Posted:  time.Now(),
+	})
+	if rr.Code != http.StatusAccepted {
+		t.Errorf("status = %d, want 202 (accepted, nothing to store — the relay must not retry)", rr.Code)
+	}
+	if resp.Stored {
+		t.Error("a notification with no meeting time must store nothing")
+	}
+	if len(core.writeLog) != 0 {
+		t.Fatalf("wrote %d facts for a non-meeting", len(core.writeLog))
+	}
+}
+
+func TestHandleAmbientAuth(t *testing.T) {
+	body := `{"title":"Планёрка 10:00","posted_at":"2026-08-03T09:40:00Z"}`
+
+	newReq := func(hdr, val string) *http.Request {
+		r := httptest.NewRequest(http.MethodPost, "/api/ambient", strings.NewReader(body))
+		if hdr != "" {
+			r.Header.Set(hdr, val)
+		}
+		return r
+	}
+
+	t.Run("no token rejected", func(t *testing.T) {
+		core := &ambientCore{}
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, newReq("", ""), core, ambientTestToken)
+		if rr.Code != http.StatusUnauthorized {
+			t.Errorf("status = %d, want 401", rr.Code)
+		}
+		if len(core.writeLog) != 0 {
+			t.Error("an unauthorized post must not write")
+		}
+	})
+
+	t.Run("wrong token rejected", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, newReq("Authorization", "Bearer nope"), &ambientCore{}, ambientTestToken)
+		if rr.Code != http.StatusUnauthorized {
+			t.Errorf("status = %d, want 401", rr.Code)
+		}
+	})
+
+	t.Run("X-Maven-Token accepted", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, newReq("X-Maven-Token", ambientTestToken), &ambientCore{}, ambientTestToken)
+		if rr.Code != http.StatusCreated {
+			t.Errorf("status = %d, want 201: %s", rr.Code, rr.Body)
+		}
+	})
+
+	t.Run("capability off", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, newReq("Authorization", "Bearer "+ambientTestToken), &ambientCore{}, "")
+		if rr.Code != http.StatusServiceUnavailable {
+			t.Errorf("status = %d, want 503 when no token is configured", rr.Code)
+		}
+	})
+
+	t.Run("GET rejected", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		r := httptest.NewRequest(http.MethodGet, "/api/ambient", nil)
+		handleAmbient(rr, r, &ambientCore{}, ambientTestToken)
+		if rr.Code != http.StatusMethodNotAllowed {
+			t.Errorf("status = %d, want 405 — the ingest is write-only", rr.Code)
+		}
+	})
+}
+
+func TestHandleAmbientBadInput(t *testing.T) {
+	t.Run("bad json", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodPost, "/api/ambient", strings.NewReader("{nope"))
+		req.Header.Set("X-Maven-Token", ambientTestToken)
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, req, &ambientCore{}, ambientTestToken)
+		if rr.Code != http.StatusBadRequest {
+			t.Errorf("status = %d, want 400", rr.Code)
+		}
+	})
+
+	t.Run("missing posted_at", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodPost, "/api/ambient", strings.NewReader(`{"title":"Планёрка 10:00"}`))
+		req.Header.Set("X-Maven-Token", ambientTestToken)
+		rr := httptest.NewRecorder()
+		handleAmbient(rr, req, &ambientCore{}, ambientTestToken)
+		if rr.Code != http.StatusBadRequest {
+			t.Errorf("status = %d, want 400", rr.Code)
+		}
+	})
+
+	t.Run("read error surfaces", func(t *testing.T) {
+		core := &ambientCore{readErr: fmt.Errorf("socket closed")}
+		rr, _ := postAmbient(t, core, ambientTestToken, meetingNotification())
+		if rr.Code != http.StatusBadGateway {
+			t.Errorf("status = %d, want 502", rr.Code)
+		}
+	})
+}
diff --git a/cmd/mavweb/main.go b/cmd/mavweb/main.go
index a05fba5..3cf712b 100644
--- a/cmd/mavweb/main.go
+++ b/cmd/mavweb/main.go
@@ -334,6 +334,10 @@ func main() {
 	nexusURL := flag.String("nexus", "", "Nexus base URL for the /ecosystem panel (empty = not configured)")
 	praxisURL := flag.String("praxis", "", "Praxis base URL for the /ecosystem panel (empty = not configured)")
 	hexisURL := flag.String("hexis", "", "Hexis base URL for the /ecosystem panel (empty = not configured)")
+	// Shared secret for POST /api/ambient, the notification-relay ingest that
+	// reads the work calendar as a signal instead of holding a work credential
+	// (see ambient.go). Empty ⇒ the route is not registered at all.
+	ambientToken := flag.String("ambient-token", "", "shared secret for POST /api/ambient notification ingest (empty = ingest disabled, route not registered)")
 	flag.Parse()
 
 	var core ipc.CoreAPI
@@ -381,6 +385,14 @@ func main() {
 	mux.HandleFunc("/api/signal", func(w http.ResponseWriter, r *http.Request) {
 		handleSignal(w, r, core)
 	})
+	// Off unless configured: no token, no route — an unconfigured ingest is not
+	// a 503 waiting to be probed, it does not exist.
+	if *ambientToken != "" {
+		mux.HandleFunc("/api/ambient", func(w http.ResponseWriter, r *http.Request) {
+			handleAmbient(w, r, core, *ambientToken)
+		})
+		log.Printf("mavweb: ambient notification ingest enabled at POST /api/ambient")
+	}
 	mux.HandleFunc("/dash", func(w http.ResponseWriter, r *http.Request) {
 		handleDash(w, r, core)
 	})
diff --git a/internal/calendar/ambient.go b/internal/calendar/ambient.go
new file mode 100644
index 0000000..bc1272a
--- /dev/null
+++ b/internal/calendar/ambient.go
@@ -0,0 +1,221 @@
+package calendar
+
+import (
+	"strings"
+	"time"
+	"unicode"
+)
+
+// Ambient events — the work calendar read (Vikunja #126).
+//
+// The work calendar is not read by holding a work credential. A corp mail or
+// calendar session living on the homelab ties the box's blast radius to the
+// employer's data, which is the thing the task exists to refuse. What maven
+// reads instead is the SIGNAL: an Android notification-listener on the owner's
+// phone relays meeting notifications over wg/LAN, and maven turns the ones that
+// clearly describe a meeting into calendar events.
+//
+// That makes the provenance honest. A notification is evidence about an event,
+// not a reading of the calendar, so it is stored under SourceAmbient at
+// AmbientConfidence — never indistinguishable from a real CalDAV read, and the
+// query path hedges when it recites one.
+//
+// The parse is deliberately conservative. A notification with no recognisable
+// clock reading produces nothing at all: maven is not a guesser-of-truth, and a
+// mailbox full of noise turned into invented events is worse than a gap. Mail
+// as a notification signal, not a mailbox.
+
+// Notification — one relayed Android notification. Package is the posting app
+// (for the log and for the owner to see where a wrong event came from), Title
+// and Text are the notification's two text lines, Posted is when the phone
+// showed it. Nothing else off the notification is kept.
+type Notification struct {
+	Package string    `json:"package"`
+	Title   string    `json:"title"`
+	Text    string    `json:"text"`
+	Posted  time.Time `json:"posted_at"`
+}
+
+// EventFromNotification turns a notification into the event it describes, or
+// reports false when it does not clearly describe one.
+//
+// It needs two things: a clock reading, and a summary that is not just that
+// clock reading. Everything else is defaulted — the date is Posted's day (a
+// meeting notification is about today or it would not be firing now), and a
+// bare start time gets DefaultReminderDuration.
+func EventFromNotification(n Notification) (Event, bool) {
+	if n.Posted.IsZero() {
+		return Event{}, false
+	}
+	line := strings.TrimSpace(n.Title + " " + n.Text)
+	start, end, ok := parseTimeRange(line)
+	if !ok {
+		return Event{}, false
+	}
+	summary := notificationSummary(n)
+	if summary == "" {
+		return Event{}, false
+	}
+
+	y, m, d := n.Posted.Date()
+	loc := n.Posted.Location()
+	s := time.Date(y, m, d, start.hour, start.min, 0, 0, loc)
+	var e time.Time
+	if end != nil {
+		e = time.Date(y, m, d, end.hour, end.min, 0, 0, loc)
+		// A range that ends before it starts crossed midnight.
+		if !e.After(s) {
+			e = e.AddDate(0, 0, 1)
+		}
+	} else {
+		e = s.Add(DefaultReminderDuration)
+	}
+	return Event{Summary: summary, Start: s, End: e}, true
+}
+
+// notificationSummary picks the text that names the meeting: the title when it
+// carries words, otherwise the body. The clock reading is stripped out — it
+// already lives in the times, and FactValue renders it again.
+func notificationSummary(n Notification) string {
+	for _, cand := range []string{n.Title, n.Text} {
+		s := strings.TrimSpace(stripClock(cand))
+		s = strings.Trim(s, " \t-–—,;:@|·")
+		s = strings.Join(strings.Fields(s), " ")
+		if hasLetters(s) {
+			return s
+		}
+	}
+	return ""
+}
+
+type clock struct{ hour, min int }
+
+// parseTimeRange finds the first clock reading in s, and a second one if the
+// text spells a range. Accepted separators between hours and minutes are ":"
+// and "."; between the two ends of a range, "-", "–", "—" or "до".
+//
+// Bare hours ("в 14") are NOT accepted. Loose digits in a notification are far
+// more often a count, a date or an unread badge than a meeting time, and an
+// invented event is worse than no event.
+func parseTimeRange(s string) (start clock, end *clock, ok bool) {
+	first, _, firstEnd, ok := nextClock(s, 0)
+	if !ok {
+		return clock{}, nil, false
+	}
+	sep := strings.TrimLeft(s[firstEnd:], " \t")
+	for _, p := range []string{"-", "–", "—", "до "} {
+		if !strings.HasPrefix(sep, p) {
+			continue
+		}
+		if second, _, _, ok2 := nextClock(strings.TrimPrefix(sep, p), 0); ok2 {
+			return first, &second, true
+		}
+		break
+	}
+	return first, nil, true
+}
+
+// nextClock scans s from byte offset `from` for the first HH:MM (or HH.MM) and
+// returns it with the byte range it occupied. Digits and separators are ASCII,
+// so byte offsets are safe over Cyrillic text.
+func nextClock(s string, from int) (c clock, start, end int, ok bool) {
+	for i := from; i < len(s); i++ {
+		if !isDigit(s[i]) {
+			continue
+		}
+		j := i
+		for j < len(s) && isDigit(s[j]) {
+			j++
+		}
+		// A run longer than two digits is a year, an id or an unread count.
+		if j-i > 2 {
+			i = j
+			continue
+		}
+		if j >= len(s) || (s[j] != ':' && s[j] != '.') {
+			i = j
+			continue
+		}
+		k := j + 1
+		for k < len(s) && isDigit(s[k]) {
+			k++
+		}
+		if k-(j+1) != 2 {
+			i = j
+			continue
+		}
+		// Reject a group that is a link in a longer dotted or colon chain:
+		// "2026.08.15" would otherwise offer "08.15" as 08:15, and a deadline
+		// date invented as a meeting time is exactly the wrong kind of guess.
+		// A trailing ":ss" is fine — that is a time with seconds.
+		if i > 0 && (s[i-1] == '.' || s[i-1] == ':' || isDigit(s[i-1])) {
+			i = k
+			continue
+		}
+		if k < len(s) && s[k] == '.' && k+1 < len(s) && isDigit(s[k+1]) {
+			i = k
+			continue
+		}
+		hour, min := atoi(s[i:j]), atoi(s[j+1:k])
+		if hour > 23 || min > 59 {
+			i = k
+			continue
+		}
+		return clock{hour, min}, i, k, true
+	}
+	return clock{}, 0, 0, false
+}
+
+func isDigit(b byte) bool { return b >= '0' && b <= '9' }
+
+func atoi(s string) int {
+	n := 0
+	for i := 0; i < len(s); i++ {
+		n = n*10 + int(s[i]-'0')
+	}
+	return n
+}
+
+// stripClock removes every clock reading from a summary candidate, along with
+// the preposition or separator that introduced it.
+func stripClock(s string) string {
+	for {
+		_, start, end, ok := nextClock(s, 0)
+		if !ok {
+			return s
+		}
+		head := trimTrailingPreposition(strings.TrimRight(s[:start], "0123456789:.-–— \t"))
+		s = strings.TrimSpace(strings.TrimSpace(head) + " " + strings.TrimSpace(s[end:]))
+	}
+}
+
+// trimTrailingPreposition drops the word that introduced a clock reading, so
+// "Встреча в 14:00" becomes "Встреча" and "с 11:30 до 12:15 Созвон" does not
+// keep a dangling "с". It repeats, because a range has two of them.
+func trimTrailingPreposition(s string) string {
+	preps := []string{"в", "с", "до", "от", "at", "from", "to"}
+	for again := true; again; {
+		again = false
+		s = strings.TrimRight(s, " \t")
+		for _, p := range preps {
+			if s == p {
+				return ""
+			}
+			if strings.HasSuffix(s, " "+p) {
+				s = s[:len(s)-len(p)-1]
+				again = true
+				break
+			}
+		}
+	}
+	return s
+}
+
+func hasLetters(s string) bool {
+	for _, r := range s {
+		if unicode.IsLetter(r) {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/calendar/ambient_test.go b/internal/calendar/ambient_test.go
new file mode 100644
index 0000000..1dd4577
--- /dev/null
+++ b/internal/calendar/ambient_test.go
@@ -0,0 +1,148 @@
+package calendar
+
+import (
+	"testing"
+	"time"
+)
+
+func TestEventFromNotification(t *testing.T) {
+	posted := time.Date(2026, 8, 3, 9, 40, 0, 0, time.FixedZone("+04", 4*3600))
+
+	tests := []struct {
+		name        string
+		title, text string
+		wantOK      bool
+		wantSummary string
+		wantStart   string // "15:04"
+		wantEnd     string
+	}{
+		{
+			name:        "range in the body",
+			title:       "Планёрка",
+			text:        "10:00-10:30",
+			wantOK:      true,
+			wantSummary: "Планёрка",
+			wantStart:   "10:00", wantEnd: "10:30",
+		},
+		{
+			name:        "russian preposition and single time",
+			title:       "Встреча с подрядчиком в 14:00",
+			wantOK:      true,
+			wantSummary: "Встреча с подрядчиком",
+			wantStart:   "14:00", wantEnd: "14:30",
+		},
+		{
+			name:        "en dash range",
+			title:       "Sprint review",
+			text:        "Today 16:00 – 17:00, Meet",
+			wantOK:      true,
+			wantSummary: "Sprint review",
+			wantStart:   "16:00", wantEnd: "17:00",
+		},
+		{
+			name:        "до as a range separator",
+			title:       "Созвон",
+			text:        "с 11:30 до 12:15",
+			wantOK:      true,
+			wantSummary: "Созвон",
+			wantStart:   "11:30", wantEnd: "12:15",
+		},
+		{
+			name:        "dotted clock",
+			title:       "Обед 13.00",
+			wantOK:      true,
+			wantSummary: "Обед",
+			wantStart:   "13:00", wantEnd: "13:30",
+		},
+		{
+			name:        "range crossing midnight",
+			title:       "Ночной релиз",
+			text:        "23:30-00:30",
+			wantOK:      true,
+			wantSummary: "Ночной релиз",
+			wantStart:   "23:30", wantEnd: "00:30",
+		},
+		// The conservative half: no clock reading, no event.
+		{name: "no time at all", title: "3 новых письма", wantOK: false},
+		{name: "bare hour is not a time", title: "Планёрка в 14", wantOK: false},
+		{name: "unread count", title: "Входящие", text: "12 непрочитанных", wantOK: false},
+		{name: "a date is not a clock", title: "Отчёт", text: "срок 2026.08.15", wantOK: false},
+		{name: "time but nothing named", title: "10:00-10:30", wantOK: false},
+		{name: "impossible clock", title: "Смена 99:99", wantOK: false},
+		{name: "empty", wantOK: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ev, ok := EventFromNotification(Notification{
+				Package: "com.google.android.gm",
+				Title:   tt.title,
+				Text:    tt.text,
+				Posted:  posted,
+			})
+			if ok != tt.wantOK {
+				t.Fatalf("ok = %v, want %v (event %+v)", ok, tt.wantOK, ev)
+			}
+			if !ok {
+				return
+			}
+			if ev.Summary != tt.wantSummary {
+				t.Errorf("summary = %q, want %q", ev.Summary, tt.wantSummary)
+			}
+			if got := ev.Start.Format("15:04"); got != tt.wantStart {
+				t.Errorf("start = %s, want %s", got, tt.wantStart)
+			}
+			if got := ev.End.Format("15:04"); got != tt.wantEnd {
+				t.Errorf("end = %s, want %s", got, tt.wantEnd)
+			}
+			if !ev.End.After(ev.Start) {
+				t.Errorf("end %v must be after start %v", ev.End, ev.Start)
+			}
+			// The event lands on the day the phone showed it, in the phone's
+			// location — not shifted into UTC.
+			if ev.Start.Location() != posted.Location() {
+				t.Errorf("location = %v, want %v", ev.Start.Location(), posted.Location())
+			}
+			if y, m, d := ev.Start.Date(); y != 2026 || m != time.August || d != 3 {
+				t.Errorf("date = %d-%02d-%02d, want 2026-08-03", y, m, d)
+			}
+		})
+	}
+}
+
+func TestEventFromNotificationNeedsPostedAt(t *testing.T) {
+	if _, ok := EventFromNotification(Notification{Title: "Планёрка 10:00"}); ok {
+		t.Error("a notification with no posted_at has no date to sit on")
+	}
+}
+
+// An ambient event must never be indistinguishable from a calendar read.
+func TestAmbientEventsAreStoredAtReducedConfidence(t *testing.T) {
+	ev, ok := EventFromNotification(Notification{
+		Title:  "Планёрка 10:00-10:30",
+		Posted: time.Date(2026, 8, 3, 9, 0, 0, 0, time.UTC),
+	})
+	if !ok {
+		t.Fatal("expected an event")
+	}
+	if FactKey(ev) == "" || FactValue(ev) == "" {
+		t.Fatal("ambient events must use the shared fact encoding")
+	}
+	if AmbientConfidence >= 1.0 {
+		t.Fatal("ambient confidence must be below a calendar read's")
+	}
+}
+
+func TestStripClock(t *testing.T) {
+	tests := []struct{ in, want string }{
+		{"Встреча в 14:00", "Встреча"},
+		{"Планёрка 10:00-10:30", "Планёрка"},
+		{"с 11:30 до 12:15 Созвон", "Созвон"},
+		{"Ничего", "Ничего"},
+	}
+	for _, tt := range tests {
+		if got := stripClock(tt.in); got != tt.want {
+			t.Errorf("stripClock(%q) = %q, want %q", tt.in, got, tt.want)
+		}
+	}
+}
diff --git a/internal/router/calendar.go b/internal/router/calendar.go
index 72890ea..6188672 100644
--- a/internal/router/calendar.go
+++ b/internal/router/calendar.go
@@ -9,11 +9,41 @@ import (
 // CalendarEventFormatter formats calendar events into a Russian reply string.
 type CalendarEventFormatter struct{}
 
-// Format returns a Russian reply for the given calendar events on the given date.
-func (CalendarEventFormatter) Format(events []string, date time.Time) string {
+// CalendarEntry — one event to recite. Uncertain marks an event maven did not
+// read off a calendar server: the work calendar arrives as relayed phone
+// notifications (Vikunja #126), stored below full confidence, and she says so
+// rather than reciting a guess as fact.
+type CalendarEntry struct {
+	Text      string
+	Uncertain bool
+}
+
+// Format returns a Russian reply for the given calendar events on the given
+// date. Every event is treated as certain — use FormatEntries when provenance
+// differs between them.
+func (f CalendarEventFormatter) Format(events []string, date time.Time) string {
+	entries := make([]CalendarEntry, len(events))
+	for i, e := range events {
+		entries[i] = CalendarEntry{Text: e}
+	}
+	return f.FormatEntries(entries, date)
+}
+
+// FormatEntries returns a Russian reply, hedging the entries maven is not sure
+// about. "похоже" and not "возможно": the notification did arrive, what is
+// uncertain is whether it describes the meeting correctly.
+func (CalendarEventFormatter) FormatEntries(entries []CalendarEntry, date time.Time) string {
 	dateStr := date.Format("02.01.2006")
-	if len(events) == 0 {
+	if len(entries) == 0 {
 		return fmt.Sprintf("на %s ничего нет.", dateStr)
 	}
-	return fmt.Sprintf("на %s: %s", dateStr, strings.Join(events, "; "))
+	parts := make([]string, len(entries))
+	for i, e := range entries {
+		if e.Uncertain {
+			parts[i] = "похоже, " + e.Text
+			continue
+		}
+		parts[i] = e.Text
+	}
+	return fmt.Sprintf("на %s: %s", dateStr, strings.Join(parts, "; "))
 }
diff --git a/internal/router/calendar_test.go b/internal/router/calendar_test.go
index ba5867f..b955560 100644
--- a/internal/router/calendar_test.go
+++ b/internal/router/calendar_test.go
@@ -24,3 +24,24 @@ func TestCalendarEventFormatter(t *testing.T) {
 		t.Errorf("multiple: got %q", got)
 	}
 }
+
+func TestCalendarEventFormatterHedgesUncertainEntries(t *testing.T) {
+	f := CalendarEventFormatter{}
+	date := time.Date(2026, 7, 6, 0, 0, 0, 0, time.UTC)
+
+	// An event relayed off a phone notification is not a calendar read, and she
+	// says so instead of reciting a guess as fact.
+	got := f.FormatEntries([]CalendarEntry{
+		{Text: "Standup @ 10:00-10:30"},
+		{Text: "Планёрка @ 14:00-14:30", Uncertain: true},
+	}, date)
+	want := "на 06.07.2026: Standup @ 10:00-10:30; похоже, Планёрка @ 14:00-14:30"
+	if got != want {
+		t.Errorf("got  %q\nwant %q", got, want)
+	}
+
+	// Format is FormatEntries with everything certain.
+	if got := f.FormatEntries(nil, date); got != "на 06.07.2026 ничего нет." {
+		t.Errorf("empty: got %q", got)
+	}
+}
diff --git a/internal/store/facts.go b/internal/store/facts.go
index 5388eb2..d6590bf 100644
--- a/internal/store/facts.go
+++ b/internal/store/facts.go
@@ -6,7 +6,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
+
+	"github.com/kami/maven/internal/calendar"
 )
 
 // WriteFact appends a fact row. confidence must be 1.0 for taps and (0,1) for
@@ -79,17 +82,29 @@ func (s *Store) RecentFacts(ctx context.Context, n int) ([]Fact, error) {
 	return out, rows.Err()
 }
 
-// CalendarEvents returns caldav facts whose key date falls within [from, to).
+// CalendarEvents returns calendar facts whose key date falls within [from, to).
 // Calendar event keys have the format calendar_event_YYYYMMDD_<summary>.
+//
+// Every calendar source is included, not just the personal CalDAV poll: the work
+// calendar arrives as ambient:notif notifications (Vikunja #126) and belongs in
+// the same answer. The source stays on each Fact, along with its confidence, so
+// the caller can hedge a reading it did not get from a calendar server —
+// filtering by source here would have thrown that judgement away.
 func (s *Store) CalendarEvents(ctx context.Context, from, to time.Time) ([]Fact, error) {
-	prefixFrom := fmt.Sprintf("calendar_event_%s", from.Format("20060102"))
-	prefixTo := fmt.Sprintf("calendar_event_%s", to.Format("20060102"))
+	prefixFrom := calendar.KeyPrefixForDay(from)
+	prefixTo := calendar.KeyPrefixForDay(to)
+	sources := calendar.Sources()
+	args := make([]any, 0, len(sources)+2)
+	for _, src := range sources {
+		args = append(args, src)
+	}
+	args = append(args, prefixFrom, prefixTo)
 	rows, err := s.db.QueryContext(ctx, `
         SELECT id, ts, kind, key, value, source, confidence, voids_id
           FROM facts
-         WHERE source = 'poll:caldav'
+         WHERE source IN (`+placeholders(len(sources))+`)
            AND key >= ? AND key < ?
-         ORDER BY key`, prefixFrom, prefixTo)
+         ORDER BY key`, args...)
 	if err != nil {
 		return nil, fmt.Errorf("calendar events: %w", err)
 	}
@@ -254,3 +269,8 @@ func scanFact(r rowScanner) (Fact, error) {
 	f.VoidsID = voids
 	return f, nil
 }
+
+// placeholders renders n comma-separated SQL bind markers.
+func placeholders(n int) string {
+	return strings.TrimSuffix(strings.Repeat("?,", n), ",")
+}
diff --git a/internal/store/store_test.go b/internal/store/store_test.go
index 3e915b2..3a46f99 100644
--- a/internal/store/store_test.go
+++ b/internal/store/store_test.go
@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"testing"
 	"time"
+
+	"github.com/kami/maven/internal/calendar"
 )
 
 func newTestStore(t *testing.T) *Store {
@@ -378,3 +380,47 @@ func TestCalendarEvents(t *testing.T) {
 		t.Fatalf("expected 0 events on July 8, got %d", len(events))
 	}
 }
+
+// The work calendar arrives as relayed phone notifications, not a CalDAV read
+// (Vikunja #126). Those events belong in the same day's answer, and their
+// provenance has to survive the query so the caller can hedge them.
+func TestCalendarEventsIncludesAmbientSource(t *testing.T) {
+	store := newTestStore(t)
+	defer store.Close()
+
+	ctx := context.Background()
+	day := time.Date(2026, 8, 3, 0, 0, 0, 0, time.UTC)
+
+	store.WriteFact(ctx, day.Add(10*time.Hour), KindEnv, "calendar_event_20260803_Aaa-personal",
+		`"Aaa personal @ 10:00-10:30"`, calendar.SourcePersonal, 1.0, sql.NullInt64{})
+	store.WriteFact(ctx, day.Add(14*time.Hour), KindEnv, "calendar_event_20260803_Bbb-work",
+		`"Bbb work @ 14:00-14:30"`, calendar.SourceAmbient, calendar.AmbientConfidence, sql.NullInt64{})
+	// A fact that merely looks like one must still be excluded by source.
+	store.WriteFact(ctx, day.Add(16*time.Hour), KindEnv, "calendar_event_20260803_Ccc-forged",
+		`"Ccc forged @ 16:00-16:30"`, "tap:voice", 1.0, sql.NullInt64{})
+
+	events, err := store.CalendarEvents(ctx, day, day.AddDate(0, 0, 1))
+	if err != nil {
+		t.Fatalf("CalendarEvents: %v", err)
+	}
+	if len(events) != 2 {
+		t.Fatalf("got %d events, want the personal and the ambient one: %+v", len(events), events)
+	}
+	bySource := map[string]Fact{}
+	for _, e := range events {
+		bySource[e.Source] = e
+	}
+	if _, ok := bySource[calendar.SourcePersonal]; !ok {
+		t.Error("the personal CalDAV event is missing")
+	}
+	amb, ok := bySource[calendar.SourceAmbient]
+	if !ok {
+		t.Fatal("the ambient work event is missing")
+	}
+	if amb.Confidence >= 1.0 {
+		t.Errorf("ambient confidence = %v, must stay below a calendar read's", amb.Confidence)
+	}
+	if _, ok := bySource["tap:voice"]; ok {
+		t.Error("a non-calendar source must not be read as a calendar event")
+	}
+}