diff --git a/cmd/mesh-controller/modules.go b/cmd/mesh-controller/modules.go
index 66804655..aeac0218 100644
--- a/cmd/mesh-controller/modules.go
+++ b/cmd/mesh-controller/modules.go
@@ -571,18 +571,14 @@ func settingsCommand(ctx context.Context, args []string) error {
 			return err
 		}
 		m, ok := known[positionals[0]]
-		if !ok || len(m.Settings) == 0 {
+		if !ok || len(catalogue.PreferencesOf(m)) == 0 {
 			return nil
 		}
 		var layers []catalogue.Layer
 		if *node != "" {
-			if mesh, has, err := inv.Layer(ctx, "", positionals[0]); err != nil {
+			// Every source on the node: mesh config, node config, then the module's own (novox/hq issue 630).
+			if layers, err = inv.SettingsFor(ctx, *node, positionals[0]); err != nil {
 				return err
-			} else if has {
-				layers = append(layers, catalogue.Layer{From: catalogue.MeshWideLayer, Values: mesh})
-			}
-			if has {
-				layers = append(layers, catalogue.Layer{From: *node, Values: values})
 			}
 		} else if has {
 			layers = append(layers, catalogue.Layer{From: catalogue.MeshWideLayer, Values: values})
@@ -612,7 +608,7 @@ func settingsCommand(ctx context.Context, args []string) error {
 		var listed []preferencesOf
 		for _, e := range entries {
 			m := e.Manifest
-			if len(m.Settings) == 0 || (only != "" && m.Module != only) {
+			if len(catalogue.PreferencesOf(m)) == 0 || (only != "" && m.Module != only) {
 				continue
 			}
 			if *node != "" && !containsString(e.On, *node) {
@@ -682,7 +678,11 @@ func describeEffective(module, where string, values []catalogue.SettingSource) s
 	fmt.Fprintf(&b, "%s on %s, every value and where it comes from:\n", module, where)
 	for _, v := range values {
 		value, _ := json.Marshal(v.Value)
-		fmt.Fprintf(&b, "  %s = %s  (%s", v.Key, value, v.From)
+		from := v.From
+		if v.From == where && where != "the whole mesh" {
+			from = valueSource(module, where, v)
+		}
+		fmt.Fprintf(&b, "  %s = %s  (%s", v.Key, value, from)
 		if v.HasDefault && !v.FromDefault {
 			d, _ := json.Marshal(v.Default)
 			fmt.Fprintf(&b, "; the default is %s", d)
@@ -723,28 +723,27 @@ func describePreferences(modules []preferencesOf) string {
 			on = "on " + strings.Join(p.Nodes, ", ")
 		}
 		fmt.Fprintf(&b, "%s (%s)\n", p.Manifest.Module, on)
-		keys := make([]string, 0, len(p.Manifest.Settings))
-		for k := range p.Manifest.Settings {
+		declared := catalogue.PreferencesOf(p.Manifest)
+		keys := make([]string, 0, len(declared))
+		for k := range declared {
 			keys = append(keys, k)
 		}
 		sort.Strings(keys)
 		for _, k := range keys {
-			d := p.Manifest.Settings[k]
+			d := declared[k]
 			def, _ := json.Marshal(d.Default)
-			fmt.Fprintf(&b, "  %s, default %s: %s\n", k, def, d.Why)
+			falls := ""
+			if d.Predefined != "" {
+				falls = ", falls back to the predefined key " + d.Predefined
+			}
+			fmt.Fprintf(&b, "  %s, default %s%s: %s\n", k, def, falls, d.Why)
 			for _, n := range p.Nodes {
 				for _, s := range p.On[n] {
 					if s.Key != k {
 						continue
 					}
 					v, _ := json.Marshal(s.Value)
-					from := s.From
-					if s.FromDefault {
-						from = catalogue.DefaultLayer
-					} else if s.From != catalogue.MeshWideLayer {
-						from = "the node"
-					}
-					fmt.Fprintf(&b, "    %s: %s (%s)\n", n, v, from)
+					fmt.Fprintf(&b, "    %s: %s (%s)\n", n, v, valueSource(p.Manifest.Module, n, s))
 				}
 			}
 		}
@@ -752,6 +751,18 @@ func describePreferences(modules []preferencesOf) string {
 	return b.String()
 }
 
+// valueSource is where a value on a node comes from, as the four sources are said (novox/hq issue 630):
+// "default", "mesh config", "node config (<node>)", or "<module> on <node>" for the module's own value.
+func valueSource(module, node string, s catalogue.SettingSource) string {
+	switch {
+	case s.FromDefault:
+		return catalogue.DefaultLayer
+	case s.From == catalogue.MeshConfigLayer, s.From == catalogue.NodeConfigLayer(node), s.From == catalogue.MeshWideLayer:
+		return s.From
+	}
+	return module + " on " + node
+}
+
 // nodeFlag is ` --node <node>` for a machine's layer, nothing for the whole mesh's.
 func nodeFlag(node string) string {
 	if node == "" {
diff --git a/cmd/mesh-controller/operator_wait.go b/cmd/mesh-controller/operator_wait.go
index 48e8bae4..d006e501 100644
--- a/cmd/mesh-controller/operator_wait.go
+++ b/cmd/mesh-controller/operator_wait.go
@@ -88,7 +88,7 @@ func checkWait(module, machine string, w inventory.Wait, f operatorWaitFacts) er
 	case w.Provision != "":
 		return checkProvisionWait(module, machine, w, m, f)
 	case w.Setting != "":
-		if _, declared := m.Settings[w.Setting]; !declared {
+		if !catalogue.DeclaresPreference(m, w.Setting) {
 			return fmt.Errorf("says it waits for the setting %s, which %s does not declare", w.Setting, module)
 		}
 		return nil
diff --git a/cmd/mesh-controller/probe_agent_root.go b/cmd/mesh-controller/probe_agent_root.go
index 95111959..d9b0245b 100644
--- a/cmd/mesh-controller/probe_agent_root.go
+++ b/cmd/mesh-controller/probe_agent_root.go
@@ -211,7 +211,7 @@ func (r *rootReader) executeServed(ctx context.Context, machine string) (bool, s
 		}
 		holders++
 		var setting *any
-		if _, declared := e.Manifest.Settings[loginShellVerb]; declared {
+		if catalogue.DeclaresPreference(e.Manifest, loginShellVerb) {
 			layers, err := r.settings(ctx, machine, e.Manifest.Module)
 			if err != nil {
 				served = true
diff --git a/cmd/mesh-controller/proposals.go b/cmd/mesh-controller/proposals.go
index 6dd4d000..5a5a1416 100644
--- a/cmd/mesh-controller/proposals.go
+++ b/cmd/mesh-controller/proposals.go
@@ -542,6 +542,11 @@ const (
 
 // proposeCommand is `settings propose`, on this controller's stores and bus.
 func proposeCommand(ctx context.Context, module, node, valuesArg string, clear, replace bool) error {
+	if node == "" && !clear {
+		// There is no module layer for the whole mesh (novox/hq issue 630); clearing one left over still works.
+		return fmt.Errorf("%s: there is no module layer for the whole mesh — an assignment is one module on one "+
+			"node (novox/hq issue 630). Propose it for one node with --node. Nothing was proposed", module)
+	}
 	var values map[string]any
 	if !clear {
 		if valuesArg == "" {
diff --git a/cmd/mesh-controller/seatverbs.go b/cmd/mesh-controller/seatverbs.go
index ff43179d..3660438d 100644
--- a/cmd/mesh-controller/seatverbs.go
+++ b/cmd/mesh-controller/seatverbs.go
@@ -881,6 +881,48 @@ func (a *verbArguments) commandLine() ([]string, error) {
 			argv = append(argv, "--adopted")
 		}
 		return argv, nil
+	case "config":
+		// Config values from four sources (novox/hq issue 630): mesh config and node config for a predefined
+		// key, and a module's own value on one node. A listing without key; a set or clear says why.
+		key := str("key")
+		if str("module") != "" && str("node") == "" && (key != "" || on("clear")) {
+			return nil, errors.New("config: there is no module layer for the whole mesh — an assignment is one module " +
+				"on one node (novox/hq issue 630); give node, or leave module out to set mesh config for a predefined key")
+		}
+		place := func(argv []string) []string {
+			if n := str("node"); n != "" {
+				argv = append(argv, "--node", n)
+			}
+			if m := str("module"); m != "" {
+				argv = append(argv, "--module", m)
+			}
+			return argv
+		}
+		switch {
+		case key == "":
+			if str("value") != "" || on("clear") || on("history") || str("why") != "" {
+				return nil, errors.New("config: a set, a clear or a history names its key")
+			}
+			return place([]string{"config", "list"}), nil
+		case on("history"):
+			if str("value") != "" || on("clear") || str("module") != "" || str("why") != "" {
+				return nil, errors.New("config: history reads a key's mesh or node config, and takes only node")
+			}
+			return place([]string{"config", "history", key}), nil
+		case on("clear") && str("value") != "":
+			return nil, errors.New("config: a value or clear, not both")
+		case on("clear"):
+			if err := need("why"); err != nil {
+				return nil, err
+			}
+			return append(place([]string{"config", "clear", key}), "--why", str("why")), nil
+		case str("value") != "":
+			if err := need("why"); err != nil {
+				return nil, err
+			}
+			return append(place([]string{"config", "set", key, str("value")}), "--why", str("why")), nil
+		}
+		return nil, errors.New("config: with key, give value, clear or history")
 	case "settings":
 		// Every module's preferences, their defaults and each machine's value (novox/hq ADR 0262):
 		// the one interface for them, so no module builds a settings tool of its own. Asked for by
@@ -1614,6 +1656,7 @@ var commandReadForms = map[string]func(rest []string) bool{
 	"node":       func(r []string) bool { return subIn(r, "list", "show") },
 	"module":     func(r []string) bool { return subIn(r, "list") },
 	"settings":   func(r []string) bool { return subIn(r, "show", "preferences", "proposals") },
+	"config":     func(r []string) bool { return flagsOnly(r) || subIn(r, "list", "history") },
 	"retire":     func(r []string) bool { return subIn(r, "list") },
 	"cleanup":    func(r []string) bool { return subIn(r, "list") },
 	"delivery":   func(r []string) bool { return subIn(r, "plan", "walks") },