plan updated

setPath mutated nested sub-arrays in place; since graph-local slices (and
their nested sub-slices) may be read concurrently by other flow goroutines,
an action.array.set with a multi-level path raced readers of the same local.
The single-threaded TS source mutates in place safely, but the Go port runs
flows on concurrent goroutines, so setPath now copies on descent (every level
returns a freshly allocated slice). Adds a -race regression test that
concurrently drives nested set + inner-element reads, plus a nested-set
correctness test asserting the prior stored value is not mutated.

Found by whole-branch review (Opus); missed by the per-task reviews.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

TODO.md

@@ -94,14 +94,14 @@
   - [x] Live / debug mode in all three node editors — evaluate the graph online and badge each node's value at human speed (~0.5 s). Shared frontend `web/src/lib/flowDebug.ts` (badge/active classes, `useFlowDebug` poller) + CSS `.flow-node-active`/`.flow-node-badge`/`.flow-wire-active`; a green ◉ toggle in each `.flow-palette-toolbar`. Per-editor backends:
   - [ ] Syntetic signal editor:
     - [x] Implement live / debug mode where value are evaluated online and visualized at human speed (e.g. 0.5s) — server-side stateless single-shot trace: `POST /api/v1/synthetic/trace` snapshots live source signals (broker `ReadNow`) and runs `evalSampleTrace` with fresh state, returning every node's value; stateful ops (moving_average/rms/lowpass/derivative/integrate/lua) badged `~approx`
-  - [ ] Logic editor:
+  - [x] Logic editor:
     - [x] Implement live / debug mode where value are evaluated online and visualized at human speed (e.g. 0.5s) — editor spins up a second client-side `LogicEngine` in new `dryRun` mode (real writes/config/dialogs suppressed) loaded with the edited graph; per-node values polled into the shared badges; the view-mode singleton is untouched
-    - add full suppor to local array values: dynamic, dynamic but capped max, fixed size etc:
-      - array functions should work with new local array
-      - NOTE: **Phase 1 (panel logic, client-side TS) is DONE** — array statevars (dynamic/capped/fixed), value-polymorphic expression engine with indexing + array functions, `action.array.*` mutation nodes (legacy accumulate/export/clear unified + auto-migrated), panel-XML round-trip, editor declaration form, and widget array modes (plot/table/multi-LED). Box stays unchecked until **Phase 2** (server-side `internal/controllogic` Go port, see below) lands.
-  - [ ] Control loop:
+    - [x] add full suppor to local array values: dynamic, dynamic but capped max, fixed size etc:
+      - [x] array functions should work with new local array
+      - NOTE: **Phase 1 (panel logic, client-side TS) is DONE** — array statevars (dynamic/capped/fixed), value-polymorphic expression engine with indexing + array functions, `action.array.*` mutation nodes (legacy accumulate/export/clear unified + auto-migrated), panel-XML round-trip, editor declaration form, and widget array modes (plot/table/multi-LED). **Phase 2 (server-side `internal/controllogic` Go port, see below) has now landed**, so this feature is complete across both engines.
+  - [x] Control loop:
     - [x] Implement live / debug mode where value are evaluated online and visualized at human speed (e.g. 0.5s) — server pushes per-node events over the WS (`debugSubscribe`/`debugNode`) via a new `DebugObserver` on the engine (lock-free `atomic.Value`, gated by a per-graph watch set) + `internal/server/debughub.go` (drop-on-full fan-out). Two modes share one message shape: **Live** observes the running enabled graph; **Simulate** dry-runs the unsaved edits in a throwaway sandbox (`StartSimulate`, side effects suppressed). Live/Sim sub-toggle in the editor
-    - add full support to server side array values
+    - [x] add full support to server side array values — DONE (Phase 2): `Value = float64 | []Value` model (`internal/controllogic/value.go`), `Graph.StateVars` (number/bool/array with dynamic/capped/fixed sizing) persisted in store JSON, value-polymorphic `expr.go` (array literals, negative-wrap indexing, full array-function table), and `action.array.push|set|remove|pop|clear` nodes. Lua block stays scalar-only (array local → NaN); CSV export remains panel-logic-only
 - [x] Implement git style versioning for: synthetic variable, panels, control logic:
   - [x] possibility to fork any version
   - [x] click to view the version

docs/TECHNICAL_SPEC.md

@@ -376,9 +376,9 @@ now produces **index-aligned** CSV: each configured array becomes a column (cust
 labels supported), rows aligned by element index. Array statevars and all array nodes
 round-trip through the panel XML (`<statevar type="array" elem=… sizing=… capacity=…>`).
 
-> **Note:** This is Phase 1 (panel logic, client-side TypeScript). The equivalent array
-> support in the server-side control-logic engine (`internal/controllogic`) is a separate
-> Phase 2 effort and is not yet implemented.
+> **Note:** The above is Phase 1 (panel logic, client-side TypeScript). The equivalent array
+> support in the server-side control-logic engine (`internal/controllogic`) is Phase 2 and has
+> now landed — see the **Array-valued local variables** subsection of §3.9 below.
 
 ### 3.9 Control Logic Engine
 
@@ -389,6 +389,26 @@ and writes results back to signals. Graphs are persisted by a store and managed
 `/api/v1/controllogic`; each mutation calls `Engine.Reload()` to apply changes live. Graphs
 can be individually enabled/disabled.
 
+**Array-valued local variables (Phase 2).** Engine locals now carry a `Value` — the tagged
+union `Value = float64 | []Value` (`internal/controllogic/value.go`), the Go port of the
+panel-logic `ArrVal` model, with booleans represented as `1`/`0` at the leaves. A graph may
+declare `statevars`: each has a `Name`, a `Type` (`number` | `bool` | `array`), an `Initial`
+expression, and — for arrays — a `Sizing` policy and `Capacity`. The three sizing policies
+mirror the frontend: **dynamic** (unbounded up to `ARRAY_MAX = 1_000_000`, oldest dropped
+FIFO past the cap), **capped** (length kept ≤ `Capacity`, oldest dropped FIFO), and **fixed**
+(exactly `Capacity` elements — truncated or zero-padded). Sizing is enforced on write. State
+vars are persisted in the graph's store JSON and seeded into locals at compile time.
+
+The expression evaluator (`internal/controllogic/expr.go`) is value-polymorphic: it supports
+array literals `[a, b, c]`, indexing `arr[i]` (negative indices wrap from the end), and a
+table of array functions: `len`, `sum`, `mean`, `slice`, `concat`, `reverse`, `sort`, `scale`,
+`add`, `sub`, `push`, `set`, `insert`, `remove`, `pop`, `shift`, `indexOf`, `contains`, `fill`
+(plus `min`/`max`, which accept either scalars or an array). These are pure — they produce new
+values and never mutate a stored local. Five action nodes write back to a declared array
+statevar: `action.array.push`, `…set`, `…remove`, `…pop`, and `…clear`. The embedded Lua block
+remains **scalar-only**: reading an array local from Lua yields `NaN`. CSV export
+(`action.export`) is panel-logic-only and is **not** available in control logic.
+
 The engine also holds a `*confmgr.Store` (injected via `NewEngine`) for five config action
 nodes: `action.config.apply` resolves an instance + its set and runs `confmgr.Apply` with a
 broker-backed, audited write closure; `action.config.read` resolves a single parameter value

docs/superpowers/plans/2026-06-24-control-logic-arrays.md

@@ -224,13 +224,7 @@ func normalizeValue(v any) Value {
 			return 1.0
 		}
 		return 0.0
-	case []interface{}:
-		out := make([]Value, len(t))
-		for i, e := range t {
-			out[i] = normalizeValue(e)
-		}
-		return out
-	case []Value:
+	case []interface{}: // note: []Value == []interface{} since Value = any, so this covers both
 		out := make([]Value, len(t))
 		for i, e := range t {
 			out[i] = normalizeValue(e)

internal/controllogic/config_node_test.go

@@ -103,7 +103,7 @@ func setupConfigEngine(t *testing.T) (*Engine, *writableSource, string) {
 
 func TestApplyConfigWritesEveryParam(t *testing.T) {
 	e, src, instID := setupConfigEngine(t)
-	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]float64{}}
+	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]Value{}}
 
 	e.applyConfig(cg, instID)
 
@@ -117,7 +117,7 @@ func TestApplyConfigWritesEveryParam(t *testing.T) {
 
 func TestApplyConfigUnknownInstanceNoop(t *testing.T) {
 	e, src, _ := setupConfigEngine(t)
-	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]float64{}}
+	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]Value{}}
 
 	e.applyConfig(cg, "does-not-exist")
 
@@ -144,7 +144,7 @@ func TestReadConfigParam(t *testing.T) {
 
 func TestWriteConfigParam(t *testing.T) {
 	e, _, instID := setupConfigEngine(t)
-	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]float64{}}
+	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]Value{}}
 
 	e.writeConfigParam(cg, instID, "gain", 7.5)
 
@@ -163,7 +163,7 @@ func TestWriteConfigParam(t *testing.T) {
 
 func TestCreateConfigInstance(t *testing.T) {
 	e, _, srcID := setupConfigEngine(t)
-	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]float64{}}
+	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]Value{}}
 
 	src, err := e.cfg.GetInstance(srcID)
 	if err != nil {
@@ -197,7 +197,7 @@ func TestCreateConfigInstance(t *testing.T) {
 
 func TestSnapshotConfig(t *testing.T) {
 	e, src, instID := setupConfigEngine(t)
-	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]float64{}}
+	cg := &compiledGraph{name: "flow", engine: e, locals: map[string]Value{}}
 
 	// Seed current live values for the set's target signals.
 	_ = src.Write(context.Background(), "GAIN", 3.5)

internal/controllogic/debug.go

@@ -14,7 +14,7 @@ import (
 type DebugEvent struct {
 	GraphID  string `json:"graphId"`
 	NodeID   string `json:"nodeId"`
-	Value    float64 `json:"value"`
+	Value    any    `json:"value"`
 	HasValue bool   `json:"hasValue"`
 	TS       int64  `json:"ts"` // unix millis
 }
@@ -83,7 +83,7 @@ func (e *Engine) FireTrigger(graphID, triggerID string) bool {
 
 // emitDebug reports a node execution to the observer when the graph is watched
 // (or the graph is a simulate sandbox, which is always its own subscriber).
-func (cg *compiledGraph) emitDebug(nodeID string, value float64, hasValue bool) {
+func (cg *compiledGraph) emitDebug(nodeID string, value Value, hasValue bool) {
 	if !cg.alwaysDebug {
 		w, _ := cg.engine.debugWatch.Load().(map[string]bool)
 		if !w[cg.id] {

internal/controllogic/debug_test.go

@@ -79,7 +79,7 @@ func TestDebugObserverCapturesNodeValues(t *testing.T) {
 	if !ok {
 		t.Fatal("no event for write node 'w'")
 	}
-	if !wEv.HasValue || wEv.Value != 42 {
+	if !wEv.HasValue || wEv.Value != 42.0 {
 		t.Errorf("write node event = %+v, want value 42 hasValue true", wEv)
 	}
 	if wEv.GraphID != "g1" {
@@ -136,7 +136,7 @@ func TestFireTriggerForcesRun(t *testing.T) {
 		}
 		time.Sleep(10 * time.Millisecond)
 	}
-	if !wEv.HasValue || wEv.Value != 42 {
+	if !wEv.HasValue || wEv.Value != 42.0 {
 		t.Errorf("write node event = %+v, want value 42 hasValue true", wEv)
 	}
 
@@ -187,7 +187,7 @@ func TestSimulateSuppressesWrites(t *testing.T) {
 	if !ok {
 		t.Fatal("simulate produced no event for write node 'w'")
 	}
-	if !wEv.HasValue || wEv.Value != 42 {
+	if !wEv.HasValue || wEv.Value != 42.0 {
 		t.Errorf("simulate write event = %+v, want value 42 hasValue true", wEv)
 	}
 	if wEv.GraphID != "sim" {

internal/controllogic/engine.go

@@ -276,17 +276,51 @@ func (e *Engine) liveGet(ds, name string) float64 {
 	return v
 }
 
+// setPath assigns v at the nested index path within arr, growing (zero-filling)
+// as needed and resolving negative indices against length. Adapted from logic.ts;
+// unlike the single-threaded TS source it copies on descent rather than mutating in
+// place, because a graph-local slice (and its nested sub-slices) may be read
+// concurrently by other flow goroutines — in-place mutation of shared backing would
+// race. Every level returns a freshly allocated slice.
+func setPath(arr []Value, path []int, v Value) []Value {
+	if len(path) == 0 {
+		return arr
+	}
+	k := path[0]
+	if k < 0 {
+		k = len(arr) + k
+	}
+	if k < 0 {
+		return arr
+	}
+	out := append([]Value{}, arr...) // copy: backing may be shared with the live local
+	for len(out) <= k {
+		out = append(out, 0.0)
+	}
+	if len(path) == 1 {
+		out[k] = v
+		return out
+	}
+	sub, _ := out[k].([]Value)
+	out[k] = setPath(sub, path[1:], v)
+	return out
+}
+
 // write applies an action.write/lua-set to a target: a bare name updates a
 // graph-local var; a ds:name target writes to the data source.
-func (e *Engine) write(cg *compiledGraph, target string, val float64) {
+func (e *Engine) write(cg *compiledGraph, target string, val Value) {
 	ds, name, ok := parseRef(target)
-	if !ok || math.IsNaN(val) {
+	if !ok {
 		return
 	}
 	if ds == "local" {
 		cg.setLocal(name, val)
 		return
 	}
+	f, isNum := val.(float64)
+	if !isNum || math.IsNaN(f) {
+		return
+	}
 	if cg.dryRun {
 		return // simulate: no real data-source write
 	}
@@ -301,11 +335,11 @@ func (e *Engine) write(cg *compiledGraph, target string, val float64) {
 		Action:    "signal.write",
 		DS:        ds,
 		Signal:    name,
-		Value:     strconv.FormatFloat(val, 'g', -1, 64),
+		Value:     strconv.FormatFloat(f, 'g', -1, 64),
 		Detail:    "control logic: " + cg.name,
 		Outcome:   audit.OutcomeOK,
 	}
-	if err := src.Write(e.root, name, val); err != nil {
+	if err := src.Write(e.root, name, f); err != nil {
 		e.log.Warn("control logic: write failed", "ds", ds, "signal", name, "err", err)
 		ev.Outcome = audit.OutcomeError
 		ev.Error = err.Error()
@@ -608,7 +642,8 @@ type compiledGraph struct {
 	prevVal    map[string]float64 // last value for change triggers
 	hasVal     map[string]bool
 	lastFire   map[string]int64 // ns wall clock each trigger last fired
-	locals     map[string]float64
+	locals     map[string]Value
+	decls      map[string]StateVar
 }
 
 func compile(g Graph) *compiledGraph {
@@ -626,12 +661,21 @@ func compile(g Graph) *compiledGraph {
 		prevVal:    map[string]float64{},
 		hasVal:     map[string]bool{},
 		lastFire:   map[string]int64{},
-		locals:     map[string]float64{},
+		locals:     map[string]Value{},
+		decls:      map[string]StateVar{},
 		fireCh:     make(chan string, 16),
 	}
 	for _, n := range g.Nodes {
 		cg.byId[n.ID] = n
 	}
+	for _, sv := range g.StateVars {
+		cg.decls[sv.Name] = sv
+		if sv.Type == "array" {
+			cg.locals[sv.Name] = applySizing(parseInitialArray(sv), sv)
+		} else {
+			cg.locals[sv.Name] = parseScalarInitial(sv)
+		}
+	}
 	for _, w := range g.Wires {
 		port := w.FromPort
 		if port == "" {
@@ -672,6 +716,13 @@ func compile(g Graph) *compiledGraph {
 			}
 		case "action.write", "action.log":
 			wantExpr(n.param("expr"))
+		case "action.array.push":
+			wantExpr(n.param("expr"))
+		case "action.array.set":
+			wantExpr(n.param("expr"))
+			wantExpr(n.param("index"))
+		case "action.array.remove":
+			wantExpr(n.param("index"))
 		case "action.lua":
 			cg.luaNodes[n.ID] = newLuaRuntime(n.param("script"))
 			for _, r := range luaGetRefs(n.param("script")) {
@@ -682,18 +733,38 @@ func compile(g Graph) *compiledGraph {
 	return cg
 }
 
-func (cg *compiledGraph) setLocal(name string, v float64) {
+func parseScalarInitial(sv StateVar) float64 {
+	s := strings.TrimSpace(sv.Initial)
+	switch s {
+	case "true":
+		return 1
+	case "false":
+		return 0
+	}
+	f, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0
+	}
+	return f
+}
+
+func (cg *compiledGraph) setLocal(name string, v Value) {
 	cg.stateMu.Lock()
+	if sv, ok := cg.decls[name]; ok && sv.Type == "array" {
+		if arr, isArr := v.([]Value); isArr {
+			v = applySizing(arr, sv)
+		}
+	}
 	cg.locals[name] = v
 	cg.stateMu.Unlock()
 }
 
-func (cg *compiledGraph) getLocal(name string) float64 {
+func (cg *compiledGraph) getLocal(name string) Value {
 	cg.stateMu.Lock()
 	defer cg.stateMu.Unlock()
 	v, ok := cg.locals[name]
 	if !ok {
-		return 0
+		return 0.0
 	}
 	return v
 }
@@ -897,7 +968,7 @@ func (cg *compiledGraph) activate(triggerID string) {
 		dt = float64(now-last) / 1e9
 	}
 
-	resolve := func(ds, name string) Value { // shim: was float64 (Task 4 removes)
+	resolve := func(ds, name string) Value {
 		switch ds {
 		case "sys":
 			if name == "dt" {
@@ -986,7 +1057,7 @@ func (cg *compiledGraph) run(nodeID string, ctx *runCtx) {
 		cg.follow(node.ID, "done", ctx)
 
 	case "action.write":
-		val := EvalExpr(node.param("expr"), ctx.resolve)
+		val := EvalValue(node.param("expr"), ctx.resolve)
 		cg.emitDebug(node.ID, val, true)
 		cg.engine.write(cg, node.param("target"), val)
 		cg.follow(node.ID, "out", ctx)
@@ -1057,6 +1128,74 @@ func (cg *compiledGraph) run(nodeID string, ctx *runCtx) {
 		}
 		cg.follow(node.ID, "out", ctx)
 
+	case "action.array.push":
+		name := strings.TrimSpace(node.param("array"))
+		if name != "" {
+			val := EvalValue(node.param("expr"), ctx.resolve)
+			cur, _ := cg.getLocal(name).([]Value)
+			cg.setLocal(name, append(append([]Value{}, cur...), val))
+		}
+		cg.follow(node.ID, "out", ctx)
+
+	case "action.array.set":
+		name := strings.TrimSpace(node.param("array"))
+		if name != "" {
+			cur, _ := cg.getLocal(name).([]Value)
+			arr := append([]Value{}, cur...)
+			var path []int
+			ok := true
+			for _, s := range strings.Split(node.param("index"), ",") {
+				f := EvalExpr(strings.TrimSpace(s), ctx.resolve)
+				if math.IsNaN(f) {
+					ok = false
+					break
+				}
+				path = append(path, int(f))
+			}
+			val := EvalValue(node.param("expr"), ctx.resolve)
+			if ok && len(path) > 0 {
+				arr = setPath(arr, path, val)
+			}
+			cg.setLocal(name, arr)
+		}
+		cg.follow(node.ID, "out", ctx)
+
+	case "action.array.remove":
+		name := strings.TrimSpace(node.param("array"))
+		if name != "" {
+			cur, _ := cg.getLocal(name).([]Value)
+			arr := append([]Value{}, cur...)
+			i := int(EvalExpr(node.param("index"), ctx.resolve))
+			k := i
+			if k < 0 {
+				k = len(arr) + k
+			}
+			if k >= 0 && k < len(arr) {
+				arr = append(arr[:k], arr[k+1:]...)
+			}
+			cg.setLocal(name, arr)
+		}
+		cg.follow(node.ID, "out", ctx)
+
+	case "action.array.pop":
+		name := strings.TrimSpace(node.param("array"))
+		if name != "" {
+			cur, _ := cg.getLocal(name).([]Value)
+			arr := append([]Value{}, cur...)
+			if len(arr) > 0 {
+				arr = arr[:len(arr)-1]
+			}
+			cg.setLocal(name, arr)
+		}
+		cg.follow(node.ID, "out", ctx)
+
+	case "action.array.clear":
+		name := strings.TrimSpace(node.param("array"))
+		if name != "" {
+			cg.setLocal(name, []Value{}) // setLocal applies sizing (fixed → zero-pad)
+		}
+		cg.follow(node.ID, "out", ctx)
+
 	default:
 		cg.follow(node.ID, "out", ctx)
 	}

internal/controllogic/engine_helpers_test.go

@@ -87,7 +87,7 @@ func TestCoerceParamValue(t *testing.T) {
 }
 
 func TestSign(t *testing.T) {
-	if sign(5) != 1 || sign(-5) != -1 || sign(0) != 0 {
-		t.Errorf("sign mismatch: %d %d %d", sign(5), sign(-5), sign(0))
+	if signOf(5) != 1 || signOf(-5) != -1 || signOf(0) != 0 {
+		t.Errorf("sign mismatch: %d %d %d", signOf(5), signOf(-5), signOf(0))
 	}
 }

internal/controllogic/engine_test.go

@@ -0,0 +1,242 @@
+package controllogic
+
+import (
+	"context"
+	"reflect"
+	"sync"
+	"testing"
+)
+
+// runFlowOnce compiles g, wires a minimal engine/context onto the compiled graph
+// (enough for the run/follow path and the lock-free emitDebug guard), then drives
+// the flow from triggerID synchronously and returns the compiled graph so callers
+// can inspect locals.
+func runFlowOnce(t *testing.T, g Graph, triggerID string) *compiledGraph {
+	t.Helper()
+	cg := compile(g)
+	cg.engine = &Engine{}
+	cg.genCtx = context.Background()
+	R := func(ds, name string) Value {
+		switch ds {
+		case "local":
+			return cg.getLocal(name)
+		default:
+			return 0.0
+		}
+	}
+	ctx := &runCtx{fired: triggerID, resolve: R}
+	cg.follow(triggerID, "out", ctx)
+	return cg
+}
+
+func TestArrayPushNode(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "buf", Type: "array", Initial: "[1]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "p", Kind: "action.array.push", Params: map[string]string{"array": "buf", "expr": "5"}},
+		},
+		Wires: []Wire{{From: "t", To: "p"}},
+	}
+	cg := runFlowOnce(t, g, "t")
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{1.0, 5.0}) {
+		t.Fatalf("after push buf = %#v", got)
+	}
+}
+
+func TestArrayClearNode(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "buf", Type: "array", Initial: "[1,2,3]", Sizing: "fixed", Capacity: 3}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "c", Kind: "action.array.clear", Params: map[string]string{"array": "buf"}},
+		},
+		Wires: []Wire{{From: "t", To: "c"}},
+	}
+	cg := runFlowOnce(t, g, "t")
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{0.0, 0.0, 0.0}) {
+		t.Fatalf("after clear buf = %#v", got)
+	}
+}
+
+func TestArraySetNode(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "buf", Type: "array", Initial: "[0,0,0]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "s", Kind: "action.array.set", Params: map[string]string{"array": "buf", "index": "1", "expr": "9"}},
+		},
+		Wires: []Wire{{From: "t", To: "s"}},
+	}
+	cg := runFlowOnce(t, g, "t")
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{0.0, 9.0, 0.0}) {
+		t.Fatalf("after set buf = %#v", got)
+	}
+}
+
+func TestArrayRemoveNode(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "buf", Type: "array", Initial: "[10,20,30]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "r", Kind: "action.array.remove", Params: map[string]string{"array": "buf", "index": "-1"}},
+		},
+		Wires: []Wire{{From: "t", To: "r"}},
+	}
+	cg := runFlowOnce(t, g, "t")
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{10.0, 20.0}) {
+		t.Fatalf("after remove buf = %#v", got)
+	}
+}
+
+func TestArrayPopNode(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "buf", Type: "array", Initial: "[1,2,3]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "p", Kind: "action.array.pop", Params: map[string]string{"array": "buf"}},
+		},
+		Wires: []Wire{{From: "t", To: "p"}},
+	}
+	cg := runFlowOnce(t, g, "t")
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{1.0, 2.0}) {
+		t.Fatalf("after pop buf = %#v", got)
+	}
+}
+
+// TestArraySetNodeNested verifies set with a comma-separated path mutates a nested
+// sub-array, and (crucially) that setPath does not mutate the previously stored slice
+// in place — the stored value must be replaced by a fresh tree.
+func TestArraySetNodeNested(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "grid", Type: "array", Initial: "[[1,2],[3,4]]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "s", Kind: "action.array.set", Params: map[string]string{"array": "grid", "index": "0,1", "expr": "9"}},
+		},
+		Wires: []Wire{{From: "t", To: "s"}},
+	}
+	cg := compile(g)
+	before := cg.getLocal("grid")
+	cg.engine = &Engine{}
+	cg.genCtx = context.Background()
+	R := func(ds, name string) Value {
+		if ds == "local" {
+			return cg.getLocal(name)
+		}
+		return 0.0
+	}
+	cg.follow("t", "out", &runCtx{fired: "t", resolve: R})
+	want := []Value{[]Value{1.0, 9.0}, []Value{3.0, 4.0}}
+	if got := cg.getLocal("grid"); !reflect.DeepEqual(got, want) {
+		t.Fatalf("after nested set grid = %#v", got)
+	}
+	// The pre-mutation snapshot must be untouched (no shared-backing in-place write).
+	if !reflect.DeepEqual(before, []Value{[]Value{1.0, 2.0}, []Value{3.0, 4.0}}) {
+		t.Fatalf("setPath mutated the prior stored value in place: %#v", before)
+	}
+}
+
+// TestArraySetNodeConcurrentNoRace drives many concurrent set+read flows against the
+// same nested-array local; with -race it guards the setPath copy-on-descend fix.
+func TestArraySetNodeConcurrentNoRace(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{{Name: "grid", Type: "array", Initial: "[[0,0],[0,0]]", Sizing: "dynamic"}},
+		Nodes: []Node{
+			{ID: "t", Kind: "trigger.timer", Params: map[string]string{"interval": "1000"}},
+			{ID: "s", Kind: "action.array.set", Params: map[string]string{"array": "grid", "index": "0,0", "expr": "1"}},
+		},
+		Wires: []Wire{{From: "t", To: "s"}},
+	}
+	cg := compile(g)
+	cg.engine = &Engine{}
+	cg.genCtx = context.Background()
+	R := func(ds, name string) Value {
+		if ds == "local" {
+			return cg.getLocal(name)
+		}
+		return 0.0
+	}
+	var wg sync.WaitGroup
+	for i := 0; i < 32; i++ {
+		wg.Add(2)
+		go func() { defer wg.Done(); cg.follow("t", "out", &runCtx{fired: "t", resolve: R}) }()
+		go func() {
+			defer wg.Done()
+			// Read the inner element concurrently; with the in-place setPath bug the
+			// writer mutates this same sub-array backing, producing a data race.
+			if arr, ok := cg.getLocal("grid").([]Value); ok && len(arr) > 0 {
+				if sub, ok := arr[0].([]Value); ok && len(sub) > 0 {
+					_ = sub[0]
+				}
+			}
+		}()
+	}
+	wg.Wait()
+}
+
+func TestCompileInitsLocalsFromDecls(t *testing.T) {
+	g := Graph{
+		ID: "g", Name: "n",
+		StateVars: []StateVar{
+			{Name: "count", Type: "number", Initial: "7"},
+			{Name: "flag", Type: "bool", Initial: "true"},
+			{Name: "buf", Type: "array", Initial: "[1,2,3]", Sizing: "capped", Capacity: 4},
+		},
+	}
+	cg := compile(g)
+	if got := cg.getLocal("count"); got != Value(7.0) {
+		t.Fatalf("count = %#v", got)
+	}
+	if got := cg.getLocal("flag"); got != Value(1.0) {
+		t.Fatalf("flag = %#v", got)
+	}
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{1.0, 2.0, 3.0}) {
+		t.Fatalf("buf = %#v", got)
+	}
+}
+
+func TestSetLocalAppliesSizing(t *testing.T) {
+	g := Graph{ID: "g", Name: "n", StateVars: []StateVar{
+		{Name: "buf", Type: "array", Initial: "[]", Sizing: "capped", Capacity: 2},
+	}}
+	cg := compile(g)
+	cg.setLocal("buf", []Value{1.0, 2.0, 3.0, 4.0})
+	if got := cg.getLocal("buf"); !reflect.DeepEqual(got, []Value{3.0, 4.0}) {
+		t.Fatalf("sized buf = %#v", got)
+	}
+}
+
+func TestResolverReturnsLocalValue(t *testing.T) {
+	g := Graph{ID: "g", Name: "n", StateVars: []StateVar{
+		{Name: "buf", Type: "array", Initial: "[10,20]", Sizing: "dynamic"},
+	}}
+	cg := compile(g)
+	R := func(ds, name string) Value {
+		if ds == "local" {
+			return cg.getLocal(name)
+		}
+		return 0.0
+	}
+	if v := EvalExpr("buf[1]", R); v != 20 {
+		t.Fatalf("buf[1] = %v", v)
+	}
+	if v := EvalExpr("sum(buf)", R); v != 30 {
+		t.Fatalf("sum(buf) = %v", v)
+	}
+}
+
+func TestEmitDebugAcceptsArray(t *testing.T) {
+	g := Graph{ID: "g", Name: "n"}
+	cg := compile(g)
+	cg.engine = &Engine{} // no observer installed; emitDebug must not panic
+	cg.emitDebug("x", []Value{1.0, 2.0}, true)
+	cg.emitDebug("x", 3.0, true)
+}

internal/controllogic/expr.go

@@ -353,8 +353,6 @@ func signOf(x float64) int {
 	}
 }
 
-// sign is an alias for signOf, kept for backward compatibility with existing tests.
-func sign(x float64) int { return signOf(x) }
 func clampIdx(i, length int) int {
 	if i < 0 {
 		i = length + i

internal/controllogic/expr_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestEvalExpr(t *testing.T) {
-	resolve := func(ds, name string) Value { // shim: was float64 (Task 4 removes)
+	resolve := func(ds, name string) Value {
 		switch {
 		case ds == "stub" && name == "x":
 			return 10
@@ -46,7 +46,7 @@ func TestEvalExpr(t *testing.T) {
 }
 
 func TestEvalExprErrors(t *testing.T) {
-	r := func(ds, name string) Value { return 0 } // shim: was float64 (Task 4 removes)
+	r := func(ds, name string) Value { return 0 }
 	for _, bad := range []string{"1 +", "(1", "1 2", "{unterminated"} {
 		if v := EvalExpr(bad, r); !math.IsNaN(v) {
 			t.Errorf("EvalExpr(%q) = %v, want NaN", bad, v)

internal/controllogic/lua.go

@@ -1,6 +1,7 @@
 package controllogic
 
 import (
+	"math"
 	"sync"
 
 	lua "github.com/yuin/gopher-lua"
@@ -60,9 +61,9 @@ func (lr *luaRuntime) ensure() error {
 	L.SetGlobal("get", L.NewFunction(func(s *lua.LState) int {
 		target := s.CheckString(1)
 		ds, name, ok := parseRef(target)
-		var v float64
-		if ok && lr.curResolve != nil { // shim: Task 6 finalizes lua Value handling
-			if f, fok := lr.curResolve(ds, name).(float64); fok {
+		v := math.NaN()
+		if ok && lr.curResolve != nil {
+			if f, isNum := lr.curResolve(ds, name).(float64); isNum {
 				v = f
 			}
 		}

internal/server/debughub.go

@@ -58,7 +58,7 @@ type debugOut struct {
 	Type     string `json:"type"` // always "debugNode"
 	GraphID  string `json:"graphId"`
 	NodeID   string `json:"nodeId"`
-	Value    float64 `json:"value"`
+	Value    any    `json:"value"`
 	HasValue bool   `json:"hasValue"`
 	TS       int64  `json:"ts"`
 }

web/src/ControlLogicEditor.tsx

@@ -10,6 +10,8 @@ import { formatBadge, badgeTitle, nodeDebugClass, type DebugSnapshot } from './l
 import { wsClient } from './lib/ws';
 import { useAuth } from './lib/auth';
 import { ScopeFilter, ScopePicker, filterByScope, normalizeScope, type Bucket } from './lib/scope';
+import { LocalVars } from './LogicEditor';
+import type { StateVar } from './lib/types';
 
 // ── Types (mirror internal/controllogic/model.go) ────────────────────────────
 
@@ -27,6 +29,11 @@ type CLNodeKind =
   | 'action.log'
   | 'action.lua'
   | 'action.dialog'
+  | 'action.array.push'
+  | 'action.array.set'
+  | 'action.array.remove'
+  | 'action.array.pop'
+  | 'action.array.clear'
   | 'action.config.apply'
   | 'action.config.read'
   | 'action.config.write'
@@ -51,6 +58,7 @@ interface CLGraph {
   owner?: string;
   scope?: string;
   scopeGroups?: string[];
+  statevars?: StateVar[];
 }
 
 interface DataSource { name: string; }
@@ -101,6 +109,11 @@ const PALETTE: PaletteEntry[] = [
   { kind: 'action.log',        label: 'Log',       params: { expr: '', label: '' } },
   { kind: 'action.lua',        label: 'Lua script', params: { script: '-- get("ds:name") reads, set("ds:name", v) writes,\n-- log("msg") logs to the server.\n' } },
   { kind: 'action.dialog',     label: 'Dialog',    params: { kind: 'info', title: '', message: '', users: '', groups: '', target: '' } },
+  { kind: 'action.array.push',   label: 'Array push',   params: { array: '', expr: '' } },
+  { kind: 'action.array.set',    label: 'Array set',    params: { array: '', index: '0', expr: '' } },
+  { kind: 'action.array.remove', label: 'Array remove', params: { array: '', index: '0' } },
+  { kind: 'action.array.pop',    label: 'Array pop',    params: { array: '' } },
+  { kind: 'action.array.clear',  label: 'Array clear',  params: { array: '' } },
   { kind: 'action.config.apply', label: 'Apply config', params: { instance: '' } },
   { kind: 'action.config.read',  label: 'Read config',  params: { instance: '', key: '', target: '' } },
   { kind: 'action.config.write', label: 'Write config', params: { instance: '', key: '', expr: '' } },
@@ -122,6 +135,11 @@ const KIND_LABEL: Record<CLNodeKind, string> = {
   'action.log': 'Log',
   'action.lua': 'Lua script',
   'action.dialog': 'Dialog',
+  'action.array.push': 'Array push',
+  'action.array.set': 'Array set',
+  'action.array.remove': 'Array remove',
+  'action.array.pop': 'Array pop',
+  'action.array.clear': 'Array clear',
   'action.config.apply': 'Apply config',
   'action.config.read': 'Read config',
   'action.config.write': 'Write config',
@@ -377,6 +395,9 @@ export default function ControlLogicEditor({ onClose }: Props) {
                   <ScopePicker me={me} scope={normalizeScope(graph.scope)} groups={graph.scopeGroups ?? []}
                     onChange={(scope, scopeGroups) => patchGraph({ scope, scopeGroups })} />
                   <span class="hint">Saving a disabled graph stops it; enabling + saving starts it.</span>
+                  <LocalVars
+                    statevars={graph.statevars ?? []}
+                    onChange={(vars) => patchGraph({ statevars: vars })} />
                 </div>
                 <div class="cl-editor-main">
                   <FlowEditor graph={graph}
@@ -1158,6 +1179,51 @@ function FlowEditor({ graph, onChange }: {
               </Fragment>
             )}
 
+            {(selected.kind === 'action.array.push' || selected.kind === 'action.array.set' ||
+              selected.kind === 'action.array.remove' || selected.kind === 'action.array.pop' ||
+              selected.kind === 'action.array.clear') && (() => {
+              const arrayLocals = (graph.statevars ?? []).filter(v => v.type === 'array');
+              const cur = selected.params.array ?? '';
+              return (
+                <Fragment>
+                  <div class="wizard-field">
+                    <label>Array (local variable)</label>
+                    <select class="prop-select" value={cur}
+                      onChange={(e) => patchParams(selected.id, { array: (e.target as HTMLSelectElement).value })}>
+                      <option value="">— select array —</option>
+                      {arrayLocals.map(v => <option key={v.name} value={v.name}>{v.name}</option>)}
+                      {cur && !arrayLocals.some(v => v.name === cur) && <option value={cur}>{cur} (unknown)</option>}
+                    </select>
+                    {arrayLocals.length === 0 && (
+                      <p class="hint">No array locals declared yet — add one in the Local vars panel.</p>
+                    )}
+                  </div>
+                  {(selected.kind === 'action.array.set' || selected.kind === 'action.array.remove') && (
+                    <div class="wizard-field">
+                      <label>Index{selected.kind === 'action.array.set' ? ' (comma-separated for nested)' : ''}</label>
+                      <input class="prop-input" value={selected.params.index ?? ''}
+                        placeholder="e.g. 0  or  2,1"
+                        onInput={(e) => patchParams(selected.id, { index: (e.target as HTMLInputElement).value })} />
+                    </div>
+                  )}
+                  {(selected.kind === 'action.array.push' || selected.kind === 'action.array.set') && (
+                    <ExprField label="Value (expression)" value={selected.params.expr ?? ''}
+                      onChange={(v) => patchParams(selected.id, { expr: v })}
+                      onInsert={(ds2, sig) => insertRef(selected.id, 'expr', ds2, sig)}
+                      allSignals={allSignalOptions()} onOpenSignals={openAllSignals}
+                      hint={selected.kind === 'action.array.push'
+                        ? 'Value to append to the end of the array.'
+                        : 'Value to store at the given index / path.'} />
+                  )}
+                  {(selected.kind === 'action.array.pop' || selected.kind === 'action.array.clear') && (
+                    <p class="hint">{selected.kind === 'action.array.pop'
+                      ? 'Removes and returns the last element of the array.'
+                      : 'Removes all elements from the array.'}</p>
+                  )}
+                </Fragment>
+              );
+            })()}
+
             {selected.kind === 'action.delay' && (
               <div class="wizard-field">
                 <label>Delay (ms)</label>
@@ -1426,6 +1492,11 @@ function nodeSummary(n: CLNode): string {
     case 'action.log':        return `log ${n.params.label ? n.params.label + ': ' : ''}${n.params.expr || ''}`;
     case 'action.lua':        return 'Lua script';
     case 'action.dialog':     return `${n.params.kind || 'info'} dialog${n.params.title ? ': ' + n.params.title : ''}`;
+    case 'action.array.push':   return `push ${n.params.expr || ''} → ${n.params.array || '?'}`;
+    case 'action.array.set':    return `${n.params.array || '?'}[${n.params.index || '?'}] = ${n.params.expr || ''}`;
+    case 'action.array.remove': return `remove ${n.params.array || '?'}[${n.params.index || '?'}]`;
+    case 'action.array.pop':    return `pop ${n.params.array || '?'}`;
+    case 'action.array.clear':  return `clear ${n.params.array || '?'}`;
     default:                  return '';
   }
 }

web/src/LogicEditor.tsx

@@ -1448,7 +1448,7 @@ function nodeSummary(n: LogicNode): string {
 
 // Inline editor for the panel's local state variables, shown in the logic
 // palette so they can be created without leaving the (full-width) logic tab.
-function LocalVars({ statevars, onChange }: {
+export function LocalVars({ statevars, onChange }: {
   statevars: StateVar[];
   onChange: (vars: StateVar[]) => void;
 }) {