praxis: an empty attention list is not always an all-clear (V-540)

ECOSYSTEM-SPEC §2.6 requires list_attention to distinguish "nothing needs
attention" from "I cannot currently tell", and to say so when a source is
failed or stale. Maven said the first one unconditionally: ListAttention
decoded into []map[string]any, the word degraded appeared nowhere, and an empty
list answered "ничего не требует внимания". A Praxis with every source dead
read as calm.

Two halves, because the spec's mechanism does not exist server-side yet. The
deployed Praxis answers /api/v1/tools/attention with a bare array and no
envelope, so praxisAttention now decodes either shape and believes a degraded
array when one arrives. Until one does, an empty list triggers one read of
/api/v1/sources, and anything that is not reporting health "ok" is named
instead of the all-clear. Zero sources is the same answer: a Praxis that polls
nothing knows nothing, which is the state of this box today.

A sources read that fails is deliberately not a hedge. The attention call
succeeded, and not being able to ask about health is not evidence of a fault.

Both hedges also cover the entity-scoped digest, where a per-entity all-clear
is the more convincing of the two. New keys attention_degraded and
attention_no_sources, in acts_ru_v1.json and the floor. The fake Praxis serves
one healthy source by default, so the existing attention tests still assert an
all-clear on purpose rather than by omission.

cmd/mavend/attention_degraded_test.go

@@ -0,0 +1,125 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+// An empty attention list used to be answered "ничего не требует внимания"
+// unconditionally, which is an all-clear Maven had no way to know was true
+// (ECOSYSTEM-SPEC §2.6, Vikunja #540).
+func TestAttentionEmptyWithHealthySourcesIsAllClear(t *testing.T) {
+	praxis := newFakePraxisWithSources(t, `[]`, `[{"source_id":"src_ntfy","health":"ok"}]`)
+	h := newPraxisTestHandler(t, praxis)
+
+	reply := h.handlePraxisAct(context.Background(), praxisActDec("list_attention"))
+	if !strings.Contains(reply, "ничего не требует внимания") {
+		t.Fatalf("healthy and quiet should be an all-clear, got %q", reply)
+	}
+}
+
+func TestAttentionEmptyWithAFailedSourceHedges(t *testing.T) {
+	praxis := newFakePraxisWithSources(t, `[]`, `[
+		{"source_id":"src_ntfy","health":"ok"},
+		{"source_id":"src_llamacpp","health":"failed"},
+		{"source_id":"src_imap","health":"stale"}
+	]`)
+	h := newPraxisTestHandler(t, praxis)
+
+	reply := h.handlePraxisAct(context.Background(), praxisActDec("list_attention"))
+	if strings.Contains(reply, "ничего не требует внимания") {
+		t.Fatalf("a failed source must not read as all-clear, got %q", reply)
+	}
+	for _, want := range []string{"src_llamacpp", "src_imap"} {
+		if !strings.Contains(reply, want) {
+			t.Errorf("reply names no %s: %q", want, reply)
+		}
+	}
+	if strings.Contains(reply, "src_ntfy") {
+		t.Errorf("the healthy source is named as a problem: %q", reply)
+	}
+}
+
+// A Praxis that polls nothing knows nothing, which is the state the box is in.
+func TestAttentionEmptyWithNoSourcesHedges(t *testing.T) {
+	praxis := newFakePraxisWithSources(t, `[]`, `[]`)
+	h := newPraxisTestHandler(t, praxis)
+
+	reply := h.handlePraxisAct(context.Background(), praxisActDec("list_attention"))
+	if strings.Contains(reply, "ничего не требует внимания") {
+		t.Fatalf("a Praxis with no sources must not answer all-clear, got %q", reply)
+	}
+	if !strings.Contains(reply, "источник") {
+		t.Errorf("reply does not say why she cannot tell: %q", reply)
+	}
+}
+
+// The spec's own mechanism, which the deployed Praxis does not send yet: the
+// envelope's degraded array is believed without a second call.
+func TestAttentionDegradedEnvelopeIsReadWithoutASourcesCall(t *testing.T) {
+	praxis := newFakePraxisWithSources(t,
+		`{"items":[],"degraded":["src_metrics"]}`,
+		`[{"source_id":"src_ntfy","health":"ok"}]`)
+	h := newPraxisTestHandler(t, praxis)
+
+	reply := h.handlePraxisAct(context.Background(), praxisActDec("list_attention"))
+	if !strings.Contains(reply, "src_metrics") {
+		t.Fatalf("the envelope's degraded source is not named: %q", reply)
+	}
+	for _, r := range praxis.Requests() {
+		if r.Path == "/api/v1/sources" {
+			t.Error("sources was read even though the response carried degraded")
+		}
+	}
+}
+
+// A sources endpoint that errors is not evidence of a fault: the attention call
+// itself succeeded, and hedging on it would make her permanently uncertain.
+func TestAttentionKeepsAllClearWhenSourcesCannotBeRead(t *testing.T) {
+	praxis := newFakePraxisWithSources(t, `[]`, `[]`)
+	praxis.SetRouteFault("/api/v1/sources", 500)
+	h := newPraxisTestHandler(t, praxis)
+
+	reply := h.handlePraxisAct(context.Background(), praxisActDec("list_attention"))
+	if !strings.Contains(reply, "ничего не требует внимания") {
+		t.Fatalf("an unreadable sources list should leave the answer alone, got %q", reply)
+	}
+}
+
+// Both response shapes decode, because the spec says one and the box sends the
+// other.
+func TestPraxisAttentionDecodesBothShapes(t *testing.T) {
+	var bare praxisAttention
+	if err := json.Unmarshal([]byte(`[{"id":"item_1"}]`), &bare); err != nil {
+		t.Fatalf("bare array: %v", err)
+	}
+	if len(bare.Items) != 1 || len(bare.Degraded) != 0 {
+		t.Errorf("bare array decoded as %+v", bare)
+	}
+
+	var env praxisAttention
+	if err := json.Unmarshal([]byte(`{"items":[{"id":"item_2"}],"degraded":["src_a"]}`), &env); err != nil {
+		t.Fatalf("envelope: %v", err)
+	}
+	if len(env.Items) != 1 || len(env.Degraded) != 1 || env.Degraded[0] != "src_a" {
+		t.Errorf("envelope decoded as %+v", env)
+	}
+}
+
+// A source that reports no health at all counts as healthy. A Praxis that never
+// fills the field would otherwise make every quiet turn a hedge.
+func TestUnhealthySourcesTreatsAnAbsentHealthFieldAsHealthy(t *testing.T) {
+	praxis := newFakePraxisWithSources(t, `[]`, `[{"source_id":"src_a"},{"id":"src_b","health":"stale"}]`)
+	bad, total, err := newPraxisClient(praxis.URL).UnhealthySources(context.Background())
+	if err != nil {
+		t.Fatalf("UnhealthySources: %v", err)
+	}
+	if total != 2 {
+		t.Errorf("total = %d, want 2", total)
+	}
+	if len(bad) != 1 || bad[0] != "src_b" {
+		t.Errorf("bad = %v, want [src_b]", bad)
+	}
+}

cmd/mavend/ecosystem.go

@@ -263,18 +263,85 @@ func (c *praxisClient) getJSON(ctx context.Context, op, path string, out any) er
 	return nil
 }
 
-func (c *praxisClient) ListAttention(ctx context.Context, limit int) ([]map[string]any, error) {
+// praxisAttention — an attention response in either of the two shapes Praxis
-	var out []map[string]any
+// may send (Vikunja #540).
+//
+// ECOSYSTEM-SPEC §2.6 says the response carries `degraded: [source_ids]` when a
+// source is failed or stale, and that Maven is required to say so rather than
+// report all-clear. The deployed Praxis answers with a bare JSON array and no
+// envelope at all, so both are decoded here: an array is the items, an object is
+// the spec envelope. This lands the Maven half without waiting on the server,
+// and the sources read below is what makes the hedge work meanwhile.
+type praxisAttention struct {
+	Items    []map[string]any
+	Degraded []string
+}
+
+func (a *praxisAttention) UnmarshalJSON(data []byte) error {
+	trimmed := bytes.TrimSpace(data)
+	if len(trimmed) > 0 && trimmed[0] == '[' {
+		return json.Unmarshal(trimmed, &a.Items)
+	}
+	var env struct {
+		Items    []map[string]any `json:"items"`
+		Degraded []string         `json:"degraded"`
+	}
+	if err := json.Unmarshal(trimmed, &env); err != nil {
+		return err
+	}
+	a.Items, a.Degraded = env.Items, env.Degraded
+	return nil
+}
+
+func (c *praxisClient) ListAttention(ctx context.Context, limit int) (praxisAttention, error) {
+	var out praxisAttention
 	err := c.getJSON(ctx, "attention", fmt.Sprintf("/api/v1/tools/attention?limit=%d", limit), &out)
 	return out, err
 }
 
+// praxisSource — one polled source, as much of it as the hedge needs. The tools
+// API does not expose sources, so this decodes the plain `/api/v1/sources` rows.
+type praxisSource struct {
+	ID       string `json:"id"`
+	SourceID string `json:"source_id"`
+	Health   string `json:"health"`
+}
+
+func (s praxisSource) name() string {
+	if s.SourceID != "" {
+		return s.SourceID
+	}
+	return s.ID
+}
+
+// UnhealthySources reports which sources cannot be trusted to have reported,
+// and how many sources Praxis has at all (Vikunja #540).
+//
+// Only read when the attention list came back empty, which is the one turn where
+// an all-clear is at stake. A source whose health field is absent counts as
+// healthy: a Praxis that never reports health would otherwise make every quiet
+// turn a hedge, and an unreported field is not evidence of a fault. Everything it
+// does report other than "ok" — failed, stale, degraded, unknown — counts as
+// cannot-tell, because none of them mean the source has spoken.
+func (c *praxisClient) UnhealthySources(ctx context.Context) (bad []string, total int, err error) {
+	var out []praxisSource
+	if err := c.getJSON(ctx, "sources", "/api/v1/sources", &out); err != nil {
+		return nil, 0, err
+	}
+	for _, s := range out {
+		if s.Health != "" && s.Health != "ok" {
+			bad = append(bad, s.name())
+		}
+	}
+	return bad, len(out), nil
+}
+
 // ListAttentionForEntity is ListAttention scoped to a single canonical Nexus
 // entity, so callers already holding a resolved entity_id (e.g. after
 // resolveEntityReference) can ask "what needs attention for this entity"
 // instead of filtering the unscoped list client-side.
-func (c *praxisClient) ListAttentionForEntity(ctx context.Context, entityID string, limit int) ([]map[string]any, error) {
+func (c *praxisClient) ListAttentionForEntity(ctx context.Context, entityID string, limit int) (praxisAttention, error) {
-	var out []map[string]any
+	var out praxisAttention
 	err := c.getJSON(ctx, "attention_for_entity",
 		fmt.Sprintf("/api/v1/tools/attention?limit=%d&entity_id=%s", limit, url.QueryEscape(entityID)), &out)
 	return out, err

cmd/mavend/ecosystem_acts.go

@@ -154,14 +154,18 @@ func (listAttentionCapability) aliases() []string {
 
 func (listAttentionCapability) handle(ctx context.Context, h *reactiveHandler, px *praxisClient, _ router.Decision) string {
 	started := h.now()
-	items, err := px.ListAttention(ctx, 20)
+	att, err := px.ListAttention(ctx, 20)
 	if err != nil {
 		log.Printf("ecosystem: praxis attention: %v", err)
 		h.recordEcosystemTrace(ctx, "praxis", "list_attention", traceStatusForError(err),
 			started, traceErrorFields(err))
 		return phraser.A(phraser.AttentionFail, nil)
 	}
+	items := att.Items
 	if len(items) == 0 {
+		if hedge := h.attentionCannotTell(ctx, px, att.Degraded, started); hedge != "" {
+			return hedge
+		}
 		return phraser.A(phraser.AttentionNone, nil)
 	}
 	h.recordPraxisTrace(ctx, "list_attention", started, map[string]any{"count": len(items)})
@@ -299,14 +303,14 @@ func (entityAttentionCapability) handle(ctx context.Context, h *reactiveHandler,
 	}
 
 	queried := h.now()
-	items, err := px.ListAttentionForEntity(ctx, entityID, 20)
+	att, err := px.ListAttentionForEntity(ctx, entityID, 20)
 	if err != nil {
 		log.Printf("ecosystem: praxis attention for %s: %v", entityID, err)
 		h.recordEcosystemTrace(ctx, "praxis", "entity_attention", traceStatusForError(err),
 			queried, mergeFields(traceErrorFields(err), map[string]any{"entity_id": entityID}))
 		return phraser.A(phraser.AttentionFailEntity, map[string]string{"name": displayName})
 	}
-	items, scoped := scopedToEntity(items, entityID)
+	items, scoped := scopedToEntity(att.Items, entityID)
 	if !scoped {
 		// A Praxis old enough to ignore an unknown query parameter answers the
 		// scoped question with the unscoped list. Reading that back as "по
@@ -339,6 +343,11 @@ func (entityAttentionCapability) handle(ctx context.Context, h *reactiveHandler,
 		parts = append(parts, known)
 	}
 	if len(parts) == 0 {
+		// The scoped list is as exposed to a silent source as the unscoped one,
+		// and a per-entity all-clear is the more convincing of the two (#540).
+		if hedge := h.attentionCannotTell(ctx, px, att.Degraded, queried); hedge != "" {
+			return hedge
+		}
 		return phraser.A(phraser.AttentionNoneEntity, map[string]string{"name": displayName})
 	}
 	return phraser.A(phraser.AttentionListEntity, map[string]string{"name": displayName, "items": strings.Join(parts, "; ")})
@@ -783,3 +792,46 @@ func (h *reactiveHandler) hexisBeforeClarify(ctx context.Context, dec router.Dec
 	}
 	return h.handleHexisAct(ctx, dec)
 }
+
+// attentionCannotTell returns the hedge to say instead of an all-clear, or ""
+// when an empty attention list really does mean nothing needs looking at
+// (ECOSYSTEM-SPEC §2.6, Vikunja #540).
+//
+// "Nothing needs attention" and "I cannot currently tell" are different answers
+// and only one of them was ever said. The spec's mechanism is a `degraded` array
+// on the attention response, which the deployed Praxis does not send, so the
+// source health read is the half that works today. It costs one HTTP call and
+// only on the empty-list turn, which is the only turn where an all-clear is at
+// stake.
+//
+// A failed sources read is deliberately NOT a hedge. The attention call itself
+// succeeded, and not being able to ask about health is not evidence of a fault —
+// hedging on it would turn one flaky endpoint into a permanently uncertain
+// assistant.
+func (h *reactiveHandler) attentionCannotTell(ctx context.Context, px *praxisClient, degraded []string, started time.Time) string {
+	if len(degraded) > 0 {
+		h.recordPraxisTrace(ctx, "attention_degraded", started, map[string]any{
+			"degraded": strings.Join(degraded, ","), "source": "response",
+		})
+		return phraser.A(phraser.AttentionDegraded, map[string]string{"items": strings.Join(degraded, ", ")})
+	}
+	bad, total, err := px.UnhealthySources(ctx)
+	if err != nil {
+		log.Printf("ecosystem: praxis sources: %v", err)
+		return ""
+	}
+	if total == 0 {
+		// A Praxis that polls nothing knows nothing, so its silence is not an
+		// all-clear either. This is the state the box is in as of 2026-08-05:
+		// /api/v1/sources answers with an empty array.
+		h.recordPraxisTrace(ctx, "attention_no_sources", started, map[string]any{"sources": 0})
+		return phraser.A(phraser.AttentionNoSources, nil)
+	}
+	if len(bad) > 0 {
+		h.recordPraxisTrace(ctx, "attention_degraded", started, map[string]any{
+			"degraded": strings.Join(bad, ","), "sources": total, "source": "health",
+		})
+		return phraser.A(phraser.AttentionDegraded, map[string]string{"items": strings.Join(bad, ", ")})
+	}
+	return ""
+}

cmd/mavend/fakeecosystem_test.go

@@ -330,7 +330,17 @@ func newFakeNexus(t *testing.T, resolveBody string) *fakeServer {
 // Maven's praxisClient calls. Every route returns its fixed body until a
 // fault is injected via SetFault.
 func newFakePraxis(t *testing.T, attentionBody string) *fakeServer {
+	// One healthy source by default: an empty attention list only means
+	// all-clear when something is actually polling (Vikunja #540), and the
+	// other tests here are about attention rather than about source health.
+	return newFakePraxisWithSources(t, attentionBody, `[{"source_id":"src_ntfy","health":"ok"}]`)
+}
+
+// newFakePraxisWithSources is newFakePraxis with the /api/v1/sources body
+// under the test's control, for the degraded and no-sources hedges.
+func newFakePraxisWithSources(t *testing.T, attentionBody, sourcesBody string) *fakeServer {
 	return newFakeServer(t, map[string]http.HandlerFunc{
+		"GET /api/v1/sources":            jsonHandler(http.StatusOK, sourcesBody),
 		"GET /api/v1/tools/attention":    jsonHandler(http.StatusOK, attentionBody),
 		"GET /api/v1/tools/changes":      jsonHandler(http.StatusOK, `[]`),
 		"POST /api/v1/tools/surface":     jsonHandler(http.StatusOK, `{}`),

internal/phraser/acts.go

@@ -60,13 +60,17 @@ const (
 	AttentionNoneEntity = "attention_none_entity"
 	AttentionListEntity = "attention_list_entity"
 	AttentionFailEntity = "attention_fail_entity"
-	ChangesNone         = "changes_none"
+	// AttentionDegraded and AttentionNoSources — the two ways an empty
-	ChangesList         = "changes_list"
+	// attention list is not an all-clear (ECOSYSTEM-SPEC §2.6, Vikunja #540).
-	ChangesFail         = "changes_fail"
+	AttentionDegraded  = "attention_degraded"
-	HomeUnreachable     = "home_unreachable"
+	AttentionNoSources = "attention_no_sources"
-	HomeEmpty           = "home_empty"
+	ChangesNone        = "changes_none"
-	HomeOn              = "home_on"
+	ChangesList        = "changes_list"
-	HomeDark            = "home_dark"
+	ChangesFail        = "changes_fail"
+	HomeUnreachable    = "home_unreachable"
+	HomeEmpty          = "home_empty"
+	HomeOn             = "home_on"
+	HomeDark           = "home_dark"
 )
 
 var actKeys = []string{
@@ -76,6 +80,7 @@ var actKeys = []string{
 	EcoDenied, EcoDown, EcoAmbiguous, EcoUnknownEntity, EcoNoNexus, EcoAboutWhat, EcoRecall,
 	AttentionNone, AttentionList, AttentionFail,
 	AttentionNoneEntity, AttentionListEntity, AttentionFailEntity,
+	AttentionDegraded, AttentionNoSources,
 	ChangesNone, ChangesList, ChangesFail,
 	HomeUnreachable, HomeEmpty, HomeOn, HomeDark,
 }
@@ -113,6 +118,8 @@ var actFloor = map[string]string{
 	AttentionNoneEntity: "по «{name}» ничего нет.",
 	AttentionListEntity: "по «{name}»: {items}",
 	AttentionFailEntity: "не могу сейчас узнать, что требует внимания по «{name}».",
+	AttentionDegraded:   "за всё не отвечу — источники молчат: {items}.",
+	AttentionNoSources:  "мне пока нечего смотреть — у Praxis нет источников.",
 	ChangesNone:         "изменений нет.",
 	ChangesList:         "изменения: {items}",
 	ChangesFail:         "не могу сейчас узнать об изменениях.",

internal/phraser/acts_ru_v1.json

@@ -114,6 +114,14 @@
       "fixed": true,
       "variants": ["не могу сейчас узнать, что требует внимания по «{name}»."]
     },
+    "attention_degraded": {
+      "fixed": true,
+      "variants": ["за всё не отвечу — источники молчат: {items}."]
+    },
+    "attention_no_sources": {
+      "fixed": true,
+      "variants": ["мне пока нечего смотреть — у Praxis нет источников."]
+    },
     "changes_none": {
       "fixed": true,
       "variants": ["изменений нет."]