Carry each contribution, composed, and the consumer's address in its plan entry, and let a process read another module's state, so route-proxy serves routes from the seat's plans alone (issue 774, research 072 row 34)

go/catalogue/declaration.go

@@ -1076,6 +1076,11 @@ func (r Resolution) compose(with Rendering, owner map[string]string,
 					return nil, err
 				}
 				handed.name(m.Module, to, own)
+				given, err := r.givenOf(m, to, with.Settings[m.Module])
+				if err != nil {
+					return nil, err
+				}
+				handed.give(m.Module, to, r.At, given)
 			}
 		}
 		// A handed collector is filled from items alone: each old form its collections would have held is said
@@ -1823,6 +1828,32 @@ func (r Resolution) contributions(settings SettingsBy, grants []Grant,
 	return out, nil
 }
 
+// givenOf is each contribution m makes to one requirement, composed as its provider receives it in a received file
+// (contributions): the one of `contributes` with what the module shares of its bucket, then each of
+// `contributes-many` by local name. The plan carries them (PlanProvision.Given, issue 774), so the two forms cannot
+// say different things.
+func (r Resolution) givenOf(m Manifest, to string, layers []Layer) ([]PlanGiven, error) {
+	var out []PlanGiven
+	if raw, ok := m.Contributes[to]; ok {
+		values, err := r.composed(m, to, raw, layers, m.Module+" contributing to "+to)
+		if err != nil {
+			return nil, err
+		}
+		if values, err = withShares(m, to, values); err != nil {
+			return nil, err
+		}
+		out = append(out, PlanGiven{Values: values})
+	}
+	for _, local := range sortedKeys(m.ContributesMany[to]) {
+		values, err := r.composed(m, to, m.ContributesMany[to][local], layers, m.Module+" contributing "+local+" to "+to)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, PlanGiven{Local: local, Values: values})
+	}
+	return out, nil
+}
+
 // composed is one contribution as its provider receives it: settled with this node's settings, its
 // endpoint's port filled in, and its names composed from the label.
 //

go/catalogue/handed.go

@@ -134,6 +134,21 @@ type PlanProvision struct {
 	// alone knows the node's domains, and carried unchanged by the provider's helper into the consumer's entry. Nil
 	// where the consumer contributes nothing to the provision, and the entry is then as it was.
 	Names map[string]string `json:"names,omitempty"`
+	// Given is each contribution of the consumer to this provision as its provider receives it (issue 774, research
+	// 072 row 34: a route is a provision, served from the plans alone): settled with the node's settings, its
+	// endpoint's port filled in and its names composed, by the same composition a received file was written from.
+	// ConsumerAt is where the consumer's machine is on the private network, empty when it is not on one: a provider
+	// that reaches back to its consumer (a reverse proxy) is told it rather than deriving it from a node's name. Both
+	// are on the first entry of the provision alone, nil where the consumer contributes nothing to it.
+	Given      []PlanGiven `json:"given,omitempty"`
+	ConsumerAt string      `json:"consumer-at,omitempty"`
+}
+
+// PlanGiven is one contribution of a consumer to a provision, composed: Local is its local name among several
+// (`contributes-many`), empty for the one of `contributes`.
+type PlanGiven struct {
+	Local  string         `json:"local,omitempty"`
+	Values map[string]any `json:"values"`
 }
 
 // provisionsOf is, from a resolution's needs, each provision module requires and its provider, by provision then
@@ -603,6 +618,25 @@ type handedFiles struct {
 	// keyedOnly is each module with a plan only for what Keyed keys of a consumer not handed: a provision its
 	// provider's helper answers (issue 774), such as a route.
 	keyedOnly map[string]bool
+	// given is each handed module's contributions composed, by requirement, and at its machine's private name
+	// (PlanProvision.Given, issue 774).
+	given map[string]map[string][]PlanGiven
+	at    map[string]string
+}
+
+// give records a handed module's contributions to one requirement, composed, and where its machine is.
+func (h *handedFiles) give(module, provision, at string, given []PlanGiven) {
+	if len(given) == 0 {
+		return
+	}
+	if h.given == nil {
+		h.given, h.at = map[string]map[string][]PlanGiven{}, map[string]string{}
+	}
+	if h.given[module] == nil {
+		h.given[module] = map[string][]PlanGiven{}
+	}
+	h.given[module][provision] = given
+	h.at[module] = at
 }
 
 // keyed starts the plan of a module begin started none for, when the composition keys any of its needs as a consumer
@@ -830,6 +864,16 @@ func (h *handedFiles) finished(needs []Needed) map[string]Plan {
 			provisions[i].Names = maps.Clone(h.names[module][provisions[i].Provision])
 		}
 		sortProvisions(provisions)
+		// **What the consumer contributes, composed, on the provision's first entry** (issue 774): a provider serving
+		// from the plans alone reads each contribution once, however many local names the requirement has.
+		gave := map[string]bool{}
+		for i := range provisions {
+			if given := h.given[module][provisions[i].Provision]; len(given) > 0 && !gave[provisions[i].Provision] {
+				gave[provisions[i].Provision] = true
+				provisions[i].Given = slices.Clone(given)
+				provisions[i].ConsumerAt = h.at[module]
+			}
+		}
 		plan.Provisions = provisions
 		h.plans[module] = plan
 	}

go/catalogue/handed_providers_test.go

@@ -187,7 +187,9 @@ func TestAHandedModulesPlanEntryCarriesWhatItContributesToItsProvider(t *testing
 	want := []PlanProvision{{Provision: "postgres-database", Provider: "anchor", ProviderModule: "store",
 		CredentialForm: CredentialFormPair, Contributes: map[string]any{"name": "nextcloud"}, At: "anchor.internal", From: "anchor", As: ConsumerIdentity("workstation", "notify"),
 		// What the binding file says as `${bound:postgres-database:name}` (issue 792).
-		Names: map[string]string{"name": "nextcloud"}}}
+		Names: map[string]string{"name": "nextcloud"},
+		// And what a received file carried of it, composed, with where its machine is (issue 774).
+		Given: []PlanGiven{{Values: map[string]any{"name": "nextcloud"}}}, ConsumerAt: "workstation.internal"}}
 	if got := c.Plans["notify"].Provisions; !reflect.DeepEqual(got, want) {
 		t.Fatalf("the plan names %+v, want %+v", got, want)
 	}

go/catalogue/keyed_test.go

@@ -75,8 +75,9 @@ func TestAModuleNotHandedHasAPlanForWhatAHelperAnswers(t *testing.T) {
 	consumer := notifierConsumer(t, false, false)
 	consumer.Requires = append(consumer.Requires, "route")
 	consumer.Contributes = map[string]map[string]any{"route": {"host": "notify.example.org"}}
+	consumer.ContributesMany = map[string]map[string]map[string]any{"route": {"api": {"label": "notify-api", "port": 9000}}}
 	node := workstation()
-	node.At = "workstation.internal"
+	node.At, node.PublicDomain = "workstation.internal", "example.org"
 	proxy := Manifest{Module: "proxy", Version: "1", Provides: []Offer{{Name: "route", Scope: ScopeMesh, AnsweredBy: AnsweredByHelper}}}
 	store := Manifest{Module: "store", Version: "1", Provides: []Offer{{Name: "postgres-database", Scope: ScopeMesh,
 		Credential: &OfferCredential{Form: CredentialFormPair}}}, Serves: map[string]map[string]any{"postgres-database": {"port": 5432}}}
@@ -104,6 +105,13 @@ func TestAModuleNotHandedHasAPlanForWhatAHelperAnswers(t *testing.T) {
 		!strings.Contains(plan.Provisions[0].As, "notify") || plan.Provisions[0].Contributes["host"] != "notify.example.org" {
 		t.Fatalf("the plan names %+v", plan)
 	}
+	// What it contributes, composed as a received file carried it, and where its machine is (issue 774, research 072
+	// row 34): route-proxy serves the route from the plan alone.
+	if g := plan.Provisions[0].Given; len(g) != 2 || g[0].Local != "" || g[0].Values["host"] != "notify.example.org" ||
+		g[1].Local != "api" || g[1].Values["name"] != "notify-api.example.org" || g[1].Values["port"] != 9000 ||
+		plan.Provisions[0].ConsumerAt != "workstation.internal" {
+		t.Fatalf("the plan gives %+v at %q", g, plan.Provisions[0].ConsumerAt)
+	}
 	// And it hands nothing: Plan.Hands, the one rule every reader of a plan asks, by each part a plan can name.
 	if plan.Hands() {
 		t.Fatalf("a plan naming the route alone hands its module: %+v", plan)

go/process/state.go

@@ -43,9 +43,28 @@ func (s State) bucket() string { return s.Module + "_" + s.Name }
 // (js.KeyValue) is what asks $JS.API.STREAM.INFO.KV_<bucket>, so it is what withRefusal watches: a bucket
 // not granted is refused there, promptly, as nats.ErrPermissionViolation.
 func (c *Conn) State(name string) State {
-	bucket := c.account.Module + "_" + name
-	return State{Module: c.account.Module, Name: name, closed: func() bool { return c.nc.IsClosed() }, kv: func(ctx context.Context) (jetstream.KeyValue, error) {
-		if err := c.refusedUnannounced(name); err != nil {
+	return c.bound(c.account.Module, name, func() error { return c.refusedUnannounced(name) })
+}
+
+// Read is another module's state this connection's module reads, named as its manifest's `reads` names it
+// (`<module>.<state>`, novox/hq ADR 0495): bound like State to the bucket <module>_<state>, so Get, Keys and Watch
+// work as far as the account's read grant goes, and a write is refused by the bus (issue 774: route-proxy follows
+// the seat mesh-provisioner's plans). A name that is not `<module>.<state>` fails at the call that needed it.
+func (c *Conn) Read(read string) State {
+	module, name, ok := strings.Cut(read, ".")
+	return c.bound(module, name, func() error {
+		if !ok || module == "" || name == "" || strings.Contains(name, ".") {
+			return fmt.Errorf("%q is not a state another module keeps, <module>.<state>", read)
+		}
+		return nil
+	})
+}
+
+// bound is module's state name on this connection, checked by refused before every bind.
+func (c *Conn) bound(module, name string, refused func() error) State {
+	bucket := module + "_" + name
+	return State{Module: module, Name: name, closed: func() bool { return c.nc.IsClosed() }, kv: func(ctx context.Context) (jetstream.KeyValue, error) {
+		if err := refused(); err != nil {
 			return nil, err
 		}
 		js, err := jetstream.New(c.nc)

go/process/state_integration_test.go

@@ -353,6 +353,18 @@ func TestStateWatchRefusesAnUngrantedBucketNamingIt(t *testing.T) {
 	if err == nil || !errors.Is(err, nats.ErrPermissionViolation) || !strings.Contains(err.Error(), "mesh-mail_unrelated") {
 		t.Fatalf("Watch on an ungranted bucket: %v, want a refusal naming mesh-mail_unrelated", err)
 	}
+	// Another module's state, read as `reads` names it (issue 774): bound to its bucket, refused naming it when no read
+	// is granted; a name that is not <module>.<state> is refused before the bus is asked.
+	if _, err := adminJetStream.CreateKeyValue(ctxFor(t), jetstream.KeyValueConfig{Bucket: "mesh-provisioner_plans"}); err != nil {
+		t.Fatal(err)
+	}
+	err = conn.Read("mesh-provisioner.plans").Watch("", func(stdio.StateChange) error { return nil })
+	if err == nil || !errors.Is(err, nats.ErrPermissionViolation) || !strings.Contains(err.Error(), "mesh-provisioner_plans") {
+		t.Fatalf("Read of an ungranted state: %v, want a refusal naming mesh-provisioner_plans", err)
+	}
+	if _, err := conn.Read("plans").Get("x"); err == nil || !strings.Contains(err.Error(), "<module>.<state>") {
+		t.Fatalf("Read of a name that is no other module's state: %v", err)
+	}
 }
 
 // 1840/S1: given a process connection granted its bucket, when it deletes a key, then the key is gone and