diff --git a/.gitignore b/.gitignore
index 332399c..ef6e397 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,14 @@
+# Repo dev artifacts. Mirrors the deny list in .npmignore so the two stay
+# in sync — anything that shouldn't be committed AND shouldn't ship in the
+# npm tarball goes in both files.
+node_modules/
+package-lock.json
+*.tgz
+.env
+.env.*
+.DS_Store
+npm-debug.log*
+
 # Large local artifacts that don't belong in Git.
 # wiki/test.gif: screen recordings of the dashboard are kept locally for
 # reference but exceed 100 MB — use Git LFS or external storage if they
diff --git a/.npmignore b/.npmignore
new file mode 100644
index 0000000..cd49559
--- /dev/null
+++ b/.npmignore
@@ -0,0 +1,28 @@
+# === Mirrors .gitignore — items below this block are also excluded from
+#     the npm tarball. Kept here verbatim so npm pack doesn't fall back to
+#     the .gitignore inheritance (silent + surprising). ===
+node_modules/
+package-lock.json
+*.tgz
+.env
+.env.*
+.DS_Store
+npm-debug.log*
+
+# Large local screen recording (>100 MB) — kept out of both repo and pack.
+wiki/test.gif
+
+# === Dev-only content the npm tarball doesn't need ===
+# Tests + their harness — Node-RED loads the entry .js, not the test tree.
+test/
+*.test.js
+
+# Wiki / docs — useful in the repo, big in the pack.
+wiki/
+
+# Project memory + IDE configs.
+.claude/
+.codex/
+.repo-mem/
+CLAUDE.md
+CLAUDE.local.md
diff --git a/src/commands/handlers.js b/src/commands/handlers.js
index c88b65f..46d1797 100644
--- a/src/commands/handlers.js
+++ b/src/commands/handlers.js
@@ -10,8 +10,6 @@
 // Pure functions: no module-level state. The registry already enforces the
 // typeof-check ladder; per-topic semantic validation lives here.
 
-const { convert } = require('generalFunctions');
-
 function _logger(source, ctx) {
   return ctx?.logger || source?.logger || null;
 }
@@ -61,8 +59,8 @@ exports.setDemand = async (source, msg, ctx) => {
   //   payload = { value, unit:'m3/h' | 'l/s' | 'm3/s' | ... } → absolute flow
   //   payload < 0 (any unit)       → operator stop-all signal
   //
-  // The handler is the only place that resolves units. _runDispatch sees a
-  // single canonical m³/s number and never branches on scaling.
+  // Unit resolution + canonical dispatch lives in source.setDemand. The
+  // handler's job is payload parsing, mode gating, and the "done" reply.
   const p = msg?.payload;
   let rawValue;
   let unit;
@@ -88,33 +86,8 @@ exports.setDemand = async (source, msg, ctx) => {
   else if (source?.mode === 'priorityControl') action = 'execSequentialControl';
   else action = 'execOptimalCombination';
   if (!_gate(source, action, msg)) return;
-  // Negative is the operator's "stop all" signal regardless of unit.
-  if (value < 0) {
-    try {
-      await source.turnOffAllMachines();
-    } catch (err) {
-      log?.error?.(`set.demand: turnOffAllMachines failed: ${err && err.message}`);
-    }
-    return;
-  }
-  // Resolve to canonical m³/s.
-  let canonicalDemand;
-  if (unit === '%') {
-    const dt = source.calcDynamicTotals();
-    // Linear interpolation: 0 % → dt.flow.min, 100 % → dt.flow.max. The
-    // interpolation helper also clamps so 110 % can't run pumps past max.
-    canonicalDemand = source.interpolation.interpolate_lin_single_point(
-      value, 0, 100, dt.flow.min, dt.flow.max);
-  } else {
-    try {
-      canonicalDemand = convert(value).from(unit).to('m3/s');
-    } catch (err) {
-      log?.error?.(`set.demand: cannot convert ${value} ${unit} → m3/s: ${err && err.message}`);
-      return;
-    }
-  }
   try {
-    await source.handleInput('parent', canonicalDemand);
+    await source.setDemand(value, unit);
   } catch (err) {
     log?.error?.(`set.demand: failed to process Qd: ${err && err.message}`);
     return;
diff --git a/src/specificClass.js b/src/specificClass.js
index 59805e1..dd826b4 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -359,6 +359,39 @@ class MachineGroup extends BaseDomain {
         return this._demandDispatcher.fireAndWait({ source, demand, powerCap, priorityList });
     }
 
+    // Operator-style entry point: accepts a (value, unit) pair and resolves
+    // to canonical m³/s before delegating to handleInput. Single source of
+    // truth for the unit math shared by the set.demand command handler and
+    // by parent nodes (e.g. pumpingStation level-based control) that hold a
+    // direct reference to this specificClass and need to push a % demand
+    // without re-implementing the interpolation. Negative value is the
+    // stop-all signal regardless of unit.
+    async setDemand(value, unit = '%') {
+        const v = Number(value);
+        if (!Number.isFinite(v)) {
+            this.logger?.error?.(`setDemand: invalid value '${value}'`);
+            return undefined;
+        }
+        if (v < 0) {
+            await this.turnOffAllMachines();
+            return undefined;
+        }
+        let canonical;
+        if (unit === '%') {
+            const dt = this.calcDynamicTotals();
+            canonical = this.interpolation.interpolate_lin_single_point(
+                v, 0, 100, dt.flow.min, dt.flow.max);
+        } else {
+            try {
+                canonical = convert(v).from(unit).to('m3/s');
+            } catch (err) {
+                this.logger?.error?.(`setDemand: cannot convert ${v} ${unit} -> m3/s: ${err?.message || err}`);
+                return undefined;
+            }
+        }
+        return this.handleInput('parent', canonical);
+    }
+
     async _runDispatch(source, demand, powerCap, priorityList) {
         const demandQ = parseFloat(demand);
         if (!Number.isFinite(demandQ)) {
diff --git a/test/basic/commands.basic.test.js b/test/basic/commands.basic.test.js
index 96ea339..a814409 100644
--- a/test/basic/commands.basic.test.js
+++ b/test/basic/commands.basic.test.js
@@ -65,9 +65,25 @@ function makeSource({
       if (handleInputResult instanceof Error) throw handleInputResult;
       return handleInputResult;
     },
-    // Used by set.demand handler when unit is %: needs dt.flow + interpolation.
-    // With min=0, max=100, the linear interpolation is identity so a bare
-    // numeric demand round-trips through handleInput unchanged.
+    // Mirror of the real specificClass.setDemand: resolves unit -> canonical
+    // m³/s and forwards to handleInput. With dt.flow {min:0,max:100} the %
+    // interpolation is identity, so a bare numeric demand round-trips through
+    // handleInput unchanged — keeping the existing assertions stable.
+    setDemand: async (value, unit = '%') => {
+      const v = Number(value);
+      if (!Number.isFinite(v)) return undefined;
+      if (v < 0) { await source.turnOffAllMachines(); return undefined; }
+      let canonical;
+      if (unit === '%') {
+        canonical = source.interpolation.interpolate_lin_single_point(
+          v, 0, 100, dt.flow.min, dt.flow.max);
+      } else {
+        const { convert } = require('generalFunctions');
+        canonical = convert(v).from(unit).to('m3/s');
+      }
+      return source.handleInput('parent', canonical);
+    },
+    // Retained for completeness — the mock setDemand uses these internally.
     calcDynamicTotals: () => dt,
     interpolation: {
       interpolate_lin_single_point: (x, ix, iy, ox, oy) => {