diff --git a/wiki/Home.md b/wiki/Home.md
index b6e2cb3..0385142 100644
--- a/wiki/Home.md
+++ b/wiki/Home.md
@@ -1,260 +1,153 @@
# valveGroupControl
-> **Reflects code as of `ef34c82` · regenerated `2026-05-11` via `npm run wiki:all`**
-> If this banner is stale, the page may be out of date. Treat as informative, not authoritative.
+  
-## 1. What this node is
+A `valveGroupControl` (VGC) coordinates a group of `valve` children that share a common manifold — selector-valve banks, dosing-valve trains, mixing manifolds. It accepts a group-level total flow target, splits the flow proportional to each valve's Kv rating, runs a residual-reconciliation pass against what every valve actually accepted, and aggregates max delta-P across the group. It also reconciles upstream-source fluid-contract advertisements (`liquid` / `gas`) into one group-level service-type view that downstream consumers can read.
-**valveGroupControl** (VGC) is an S88 Unit coordinator for a group of `valve` children. It distributes a group-level flow target across registered valves proportional to their Kv rating, runs a residual-reconciliation pass to absorb per-valve acceptance limits, aggregates group max delta-P, and reconciles upstream fluid-contract advertisements into a single group-level service-type view.
+> [!NOTE]
+> Pending full node review (2026-05). Content reflects `CONTRACT.md` and current source only.
-## 2. Position in the platform
+---
+
+## At a glance
+
+| Thing | Value |
+|:---|:---|
+| What it represents | A parallel valve manifold — 2 + valves sharing a header, distributing one total flow target |
+| S88 level | Unit |
+| Use it when | You have 2 + parallel valves that should share an upstream flow target proportional to their Kv |
+| Don't use it for | A single valve (wire `valve` directly), series valves (the Kv-share solver assumes parallel branches), or a manifold whose upstream already publishes per-branch setpoints |
+| Children it accepts | `valve` (group members) + upstream sources (`machine` / `rotatingmachine` / `machinegroup` / `machinegroupcontrol` / `pumpingstation` / `valvegroupcontrol`) |
+| Parents it talks to | Any upstream node — typically `pumpingStation`, `reactor`, or another VGC; VGC registers via Port 2 |
+
+---
+
+## How it fits
```mermaid
flowchart LR
- src[machine / MGC / PS
upstream source]:::unit -.flow.predicted.-> vgc[valveGroupControl
Unit]:::unit
- vgc -->|updateFlow predicted| v1[valve A]:::equip
- vgc -->|updateFlow predicted| v2[valve B]:::equip
- v1 -->|positionChange| vgc
- v2 -->|positionChange| vgc
- v1 -->|deltaPChange| vgc
- v2 -->|deltaPChange| vgc
- vgc -->|child.register| parent[upstream parent]:::unit
+ src[machine / MGC /
pumpingStation
upstream source]:::unit -.flow.predicted.*.-> vgc[valveGroupControl
Unit]:::unit
+ vgc -->|updateFlow predicted
downstream| v1[valve A]:::equip
+ vgc -->|updateFlow predicted
downstream| v2[valve B]:::equip
+ v1 -->|positionChange
deltaPChange| vgc
+ v2 -->|positionChange
deltaPChange| vgc
+ vgc -->|child.register| parent[upstream parent]:::pc
+ classDef pc fill:#0c99d9,color:#fff
classDef unit fill:#50a8d9,color:#000
classDef equip fill:#86bbdd,color:#000
```
-S88 colours: Unit `#50a8d9`, Equipment `#86bbdd`. Source of truth: `.claude/rules/node-red-flow-layout.md`.
+S88 colours are anchored in `.claude/rules/node-red-flow-layout.md`.
-## 3. Capability matrix
+---
-| Capability | Status | Notes |
-|---|---|---|
-| Proportional flow distribution by Kv | ✅ | `groupOps/flowDistribution.js`. |
-| Two-pass residual reconciliation | ✅ | Default `maxPasses: 2`, `residualTolerance: 0.001`. |
-| Periodic tick re-balance | ✅ | `tick()` calls `calcValveFlows()`; `set.reconcileInterval` re-tunes interval. |
-| Group `maxDeltaP` aggregation | ✅ | Recomputed on any child `deltaPChange` event. |
-| Upstream fluid-contract aggregation | ✅ | `sources/fluidContract.js`; emits `fluidContractChange`. |
-| Group-wide sequence dispatch | ✅ | `cmd.execSequence` → `executeSequence` → per-state `transitionToState`. |
-| Emergency stop | ✅ | `cmd.emergencyStop` → `emergencystop` sequence on all valves. |
-| Per-valve positional override | ⚠️ | `set.position` is a debug-logged **no-op** pending Phase 7. See §14. |
-| Multi-source aggregation | ✅ | Multiple machines / MGCs / PSs may register as upstream sources. |
-| Cascaded VGC as upstream source | ⚠️ | Accepted by router but not exercised in production; test coverage absent. |
+## Try it — 3-minute demo
-## 4. Code map
+Import the basic example flow, deploy, and drive a 2-valve group with an injected total-flow setpoint.
-```mermaid
-flowchart TB
- subgraph nodeRED["nodeClass.js — adapter (BaseNodeAdapter)"]
- nc["buildDomainConfig()
static DomainClass, commands"]
- end
- subgraph domain["specificClass.js — orchestrator (BaseDomain)"]
- sc["ValveGroupControl.configure()
router.onRegister: valve + sources
tick() → calcValveFlows()"]
- end
- subgraph concerns["src/ concern modules"]
- gops["groupOps/
flowDistribution + calcMaxDeltaP"]
- srcs["sources/
fluidContract registration"]
- cmds["commands/
topic registry + handlers"]
- io["io/
getOutput + getStatusBadge"]
- end
- nc --> sc
- sc --> gops
- sc --> srcs
- sc --> io
- nc --> cmds
+```bash
+curl -X POST -H 'Content-Type: application/json' \
+ --data @nodes/valveGroupControl/examples/basic.flow.json \
+ http://localhost:1880/flow
```
-| Module | Owns | Read first if you're changing… |
-|---|---|---|
-| `groupOps/` | Kv-share solver, residual pass, max-deltaP aggregation | How the group divides flow between valves. |
-| `sources/` | Upstream-source registration, flow-event subscription, fluid-contract reconciliation | Service-type aggregation, source event wiring. |
-| `commands/` | Input-topic registry + per-topic handlers | New input topics or payload validation rules. |
-| `io/` | Port-0 output shape + status badge composition | What lands on the wire, badge text. |
+What to click after deploy (the inject buttons map to canonical topics in [Reference — Contracts](Reference-Contracts#topic-contract)):
-## 5. Topic contract
+1. `child.register` for each `valve` — or rely on Port-2 wiring to auto-register.
+2. `set.mode = auto` — lets the parent source drive the group.
+3. `data.totalFlow = 80` (with `unit: 'm3/h'`) — VGC splits 80 m³/h across the available valves by Kv share; runs up to `maxPasses: 2` residual passes; writes back `atEquipment_predicted_flow` = sum of accepted per-valve flows.
+4. `cmd.execSequence` with `{action: "startup"}` — runs the group-wide startup sequence through `executeSequence`, transitioning the group state machine through each step.
+5. `cmd.emergencyStop` — runs the `emergencystop` sequence on all valves (`[emergencystop, off]`).
+6. `set.reconcileInterval = 2` — re-tunes the periodic tick to 2 s (`reconcileIntervalChange` event triggers the adapter to restart its tick loop; minimum 100 ms).
-> **Auto-generated** from `src/commands/index.js`. Do NOT hand-edit between the markers. Re-run `npm run wiki:contract`.
+> [!IMPORTANT]
+> **GIF needed.** Demo recording of steps 1–6 with the live status panel. Save as `wiki/_partial-gifs/valveGroupControl/01-basic-demo.gif`, target ≤ 1 MB after `gifsicle -O3 --lossy=80`.
-The **Unit** column reflects the descriptor's `units: { measure, default }` declaration, rendered as ` (default )`. Topics without a `units` field show `—`. The **Effect** column is sourced from the descriptor's `description` field.
+---
-
+## The seven things you'll send
-| Canonical topic | Aliases | Payload | Unit | Effect |
-|---|---|---|---|---|
-| `set.mode` | `setMode` | `string` | — | Switch the valve group between auto / manual control modes. |
-| `set.position` | `setpoint` | `any` | — | Set the group-level valve position (currently a no-op pending Phase 7). |
-| `child.register` | `registerChild` | `string` | — | Register a child valve with this group. |
-| `cmd.execSequence` | `execSequence` | `object` | — | Run a group-wide sequence (startup / shutdown / emergencystop). |
-| `data.totalFlow` | `totalFlowChange` | `any` | — | Notify the group that the total flow setpoint has changed. |
-| `cmd.emergencyStop` | `emergencyStop`, `emergencystop` | `any` | — | Trigger an emergency stop across all valves in the group. |
-| `set.reconcileInterval` | `setReconcileInterval` | `any` | — | Update the reconciliation interval (seconds). |
+| Topic | Aliases | Payload | What it does |
+|:---|:---|:---|:---|
+| `set.mode` | `setMode` | `"auto"` \| `"virtualControl"` \| `"fysicalControl"` \| `"maintenance"` | Switch operational mode. Each mode has its own allow-list of sources (`mode.allowedSources`). |
+| `set.position` | `setpoint` | any | **No-op pending Phase 7.** Reserved for future per-valve positional override. Debug-logged only. |
+| `child.register` | `registerChild` | `string` (child node id) | Manually register a child via `RED.nodes.getNode`; Port 2 wiring does this automatically in most flows. |
+| `cmd.execSequence` | `execSequence` | `{ source, action, parameter }` | Forward to `source.handleInput(source, action, parameter)` — runs a group-wide sequence (`startup` / `shutdown` / `emergencystop` / `boot`). |
+| `data.totalFlow` | `totalFlowChange` | number, `{ value, position?, variant?, unit? }`, or `{ source, action, ... }` | Update the total measured/predicted flow at the configured position; triggers `calcValveFlows` to re-distribute across valves. |
+| `cmd.emergencyStop` | `emergencyStop`, `emergencystop` | optional `{ source }` | Run the `emergencystop` sequence on all valves. |
+| `set.reconcileInterval` | `setReconcileInterval` | number — seconds (> 0) | Re-tune the periodic flow-reconciliation interval. Min clamp 100 ms. |
-
+Aliases log a one-time deprecation warning the first time they fire.
-## 6. Child registration
+---
+
+## What you'll see come out
+
+Sample Port 0 message (delta-compressed, after a `data.totalFlow = 80` split across two valves):
+
+```json
+{
+ "topic": "valveGroupControl#VGC1",
+ "payload": {
+ "mode": "auto",
+ "maxDeltaP": 1450,
+ "atEquipment_measured_flow": 80,
+ "atEquipment_predicted_flow": 80,
+ "deltaMax_predicted_pressure": 1450
+ }
+}
+```
+
+Key shape: **`__`** — same as MGC's key shape (inverse of `rotatingMachine`'s per-measurement form). The output reflects the group aggregate, not per-valve snapshots; per-valve detail comes off each valve's own Port 0.
+
+| Field | Meaning |
+|:---|:---|
+| `mode` | Current operational mode (`auto` / `virtualControl` / `fysicalControl` / `maintenance`). |
+| `maxDeltaP` | Max delta-P across registered valves — refreshed whenever a child emits `deltaPChange`. Also surfaced as `deltaMax_predicted_pressure` via the measurement container. |
+| `atEquipment_measured_flow` | Total measured flow at the group inlet (from an upstream source's `flow.measured.*` event). |
+| `atEquipment_predicted_flow` | Sum of per-valve accepted flows after the Kv-share + residual pass. |
+| `deltaMax_predicted_pressure` | Max delta-P across the group, written via the measurement container at position `delta` / variant `predicted` / type `pressure`. |
+
+---
+
+## Flow-distribution loop — what one event does
+
+When a `data.totalFlow` arrives (or an upstream source publishes `flow.predicted.*` / `flow.measured.*`), VGC re-distributes by Kv share:
```mermaid
flowchart LR
- subgraph kids["accepted children (softwareType)"]
- v["valve"]:::equip
- src["machine / rotatingmachine /
machinegroup / pumpingstation /
valvegroupcontrol"]:::unit
- end
- v -->|positionChange| handler1[onPositionChange
→ calcValveFlows]
- v -->|deltaPChange| handler2[onDeltaPChange
→ calcMaxDeltaP]
- src -->|flow.predicted.*
flow.measured.*| handler3[updateFlow
atEquipment]
- src -->|fluidContractChange| handler4[sources.refresh
aggregate contract]
- classDef equip fill:#86bbdd,color:#000
- classDef unit fill:#50a8d9,color:#000
+ src[data.totalFlow /
upstream source event] --> upd[updateFlow
predicted/measured atEquipment]
+ upd --> avail[getAvailableValves
state ≠ off/maintenance, kv > 0]
+ avail --> solve[solveFlowDistribution
share by Kv / totalKv]
+ solve --> push[valve.updateFlow predicted
downstream]
+ push --> readback[read accepted from
flow.predicted.downstream]
+ readback --> residual[residual = target − sum(accepted)]
+ residual -->|residual > tol & passes < max| solve
+ residual --> writeback[write flow.predicted.atEquipment
= sum(accepted)]
+ writeback --> dp[calcMaxDeltaP]
+ dp --> emit[notifyOutputChanged]
```
-| softwareType | onRegister side-effect | Subscribed events |
-|---|---|---|
-| `valve` | Stored in `this.valves[id]`; binds `positionChange` (via `child.state.emitter`) + `deltaPChange` (via `child.emitter`); triggers `calcValveFlows` + `calcMaxDeltaP`. | `positionChange`, `deltaPChange`. |
-| `machine` / `rotatingmachine` | Stored as upstream source; reads `getFluidContract()` or infers `liquid` by default. | `flow.predicted.*`, `flow.measured.*`, `fluidContractChange`. |
-| `machinegroup` / `machinegroupcontrol` | Same as machine. | Same as machine. |
-| `pumpingstation` | Same as machine. | Same as machine. |
-| `valvegroupcontrol` | Cascaded VGC; accepted by router. Not exercised in production. | Same as machine. |
+Reconciliation defaults (`flowReconciliation`):
-## 7. Lifecycle — what one tick / event does
+| Field | Default | Notes |
+|:---|:---:|:---|
+| `maxPasses` | `2` | Max iterations of the residual-correction loop. |
+| `residualTolerance` | `0.001` | Stops the loop when `|residual| <` tolerance (canonical units — m³/s for flow). |
-```mermaid
-sequenceDiagram
- participant src as upstream source
- participant vgc as VGC
- participant v1 as valve A
- participant v2 as valve B
- participant out as Port-0
+A valve is **available** if: `state.getCurrentState() !== 'off'` and `!== 'maintenance'`, `currentMode !== 'maintenance'`, and `kv > 0`. Unavailable valves are skipped and receive `updateFlow('predicted', 0, 'downstream')`.
- src->>vgc: flow.predicted.downstream (m³/h)
- vgc->>vgc: updateFlow('predicted', value, 'atEquipment')
- vgc->>vgc: calcValveFlows()
- Note over vgc: solveFlowDistribution
by Kv share (≤ maxPasses)
- vgc->>v1: updateFlow('predicted', shareA, 'downstream')
- vgc->>v2: updateFlow('predicted', shareB, 'downstream')
- v1-->>vgc: positionChange / deltaPChange
- v2-->>vgc: positionChange / deltaPChange
- vgc->>vgc: calcMaxDeltaP
- vgc->>vgc: notifyOutputChanged()
- vgc->>out: msg{topic, payload (delta-compressed)}
-```
+VGC has **no FSM of its own** — state semantics belong to the child valves. `specificClass` instantiates a state object internally and stamps it `operational` at boot for sequence dispatch; the group's only coordination loop is the Kv-share solver above.
-## 8. Data model — `getOutput()`
+---
-What lands on Port 0. Composed in `io/output.getOutput()`, then delta-compressed by `outputUtils.formatMsg`.
+## Need more?
-
+| Page | What you'll find |
+|:---|:---|
+| [Reference — Contracts](Reference-Contracts) | Topic registry, config schema, child-registration filters |
+| [Reference — Architecture](Reference-Architecture) | Code map, flow-distribution loop, source aggregation, output ports |
+| [Reference — Examples](Reference-Examples) | Shipped flows, debug recipes |
+| [Reference — Limitations](Reference-Limitations) | When not to use, known issues, open questions |
-| Key | Type | Unit | Sample |
-|---|---|---|---|
-| `maxDeltaP` | number | — | `0` |
-| `mode` | string | — | `"auto"` |
-
-
-
-Measurement-derived keys follow the `__` shape and are emitted only when the container holds a finite value.
-
-| Example key | Unit | Description |
-|---|---|---|
-| `atEquipment_predicted_flow` | m³/h | Total group predicted flow (sum of per-valve assigned flows). |
-| `atEquipment_measured_flow` | m³/h | Total group measured flow (from upstream source). |
-| `deltaMax_predicted_pressure` | mbar | Max delta-P across registered valves. |
-
-> Delta compression: only changed fields are sent per tick. Consumers must cache and merge. See `outputUtils.formatMsg`.
-
-## 9. Configuration — editor form ↔ config keys
-
-```mermaid
-flowchart TB
- subgraph editor["Node-RED editor form (vgc.html)"]
- f1[Name]
- f2[Process output format]
- f3[Database output format]
- f4[Position vs parent]
- f5[Logger / log level]
- end
- subgraph config["Domain config (runtime / schema)"]
- c1[general.name]
- c2[output.process]
- c3[output.dbase]
- c4[functionality.positionVsParent]
- c5[logging.enableLog / logLevel]
- end
- f1 --> c1
- f2 --> c2
- f3 --> c3
- f4 --> c4
- f5 --> c5
-```
-
-| Form field | Config key | Default | Where used |
-|---|---|---|---|
-| Name | `general.name` | `""` | Node label, InfluxDB tag, status badge. |
-| Process output format | `output.process` | `"process"` | `outputUtils.formatMsg` Port-0 formatter. |
-| Database output format | `output.dbase` | `"influxdb"` | `outputUtils.formatMsg` Port-1 formatter. |
-| Position vs parent | `functionality.positionVsParent` | `""` | Child registration Port-2 message; read by upstream parent. |
-| Enable log / log level | `logging.enableLog`, `logging.logLevel` | `false` / `"error"` | Logger verbosity. Never ship `debug` in demos. |
-
-> Domain-level config (`mode.current`, `sequences`, `mode.allowedSources`, `flowReconciliation`) is loaded from the node's schema defaults and updated at runtime via `set.mode` / `set.reconcileInterval`. These fields are not exposed in the editor form.
-
-## 10. Flow-distribution loop (replaces state chart)
-
-VGC has no FSM of its own — state semantics belong to the child valves. The core coordination loop is the Kv-share solver described below.
-
-```mermaid
-sequenceDiagram
- participant tick as adapter tick / incoming event
- participant vgc as VGC
- participant solver as solveFlowDistribution
- participant valves as valve children
-
- tick->>vgc: calcValveFlows()
- vgc->>vgc: read flow.measured (or predicted) .atEquipment
- vgc->>solver: target=totalFlow, entries=availableValves
- loop ≤ maxPasses while |residual| > tolerance
- solver->>valves: updateFlow share by (Kv / totalKv)
- valves-->>solver: accepted flow (read back from child.measurements)
- solver->>solver: residual = target − sum(accepted)
- end
- solver-->>vgc: { flowsById, residual, passes }
- vgc->>vgc: write flow.predicted.atEquipment = assignedTotal
- vgc->>vgc: calcMaxDeltaP()
- vgc->>vgc: notifyOutputChanged()
-```
-
-A valve is **available** if: `state ≠ off|maintenance`, `mode ≠ maintenance`, and `kv > 0`. Unavailable valves receive `updateFlow('predicted', 0)` and are excluded from the solver.
-
-## 11. Examples
-
-| Tier | File | What it shows | Mandatory? |
-|---|---|---|---|
-| Basic | `examples/basic.flow.json` | Inject `data.totalFlow` + 2 valves (no parent) | ✅ |
-| Integration | `examples/integration.flow.json` | VGC + valves + upstream rotatingMachine | ✅ |
-| Edge | `examples/edge.flow.json` | Edge cases: no valves, residual non-convergence, cascaded VGC | ⭕ |
-
-Tier-1 / Tier-2 / Tier-3 naming scheme pending when existing flows are validated on live Node-RED. Screenshots under `wiki/_partial-screenshots/valveGroupControl/` when produced.
-
-## 12. Debug recipes
-
-| Symptom | First thing to check | Where to look |
-|---|---|---|
-| All valves receive `assigned flow = 0` | `getAvailableValves()` returns empty list; check Kv > 0 and child state ≠ `off` / `maintenance`. | `groupOps/flowDistribution.isValveAvailable` |
-| Residual never converges | `flowReconciliation.maxPasses` too low for valve curve shape; check `lastFlowSolve.residual`. | `groupOps/flowDistribution.js` |
-| Group `maxDeltaP` stale | Child `deltaPChange` not subscribed; valve emitter not exposed via `child.emitter`. | `specificClass._bindValveEvents` |
-| Service-type stays `unknown` | No upstream source registered, or all advertise unknown type. | `sources/fluidContract.refreshFluidContract` |
-| `data.totalFlow` silently ignored | Mode rejects the source id; check `mode.allowedSources` for the current mode. | `specificClass.isValidSourceForMode` |
-| `set.position` has no effect | Known limitation — handler is a no-op. See §14. | `commands/handlers.setPosition` |
-
-> Never ship `enableLog: 'debug'` in a demo — fills the container log within seconds and obscures real errors. Use only for live debugging.
-
-## 13. When you would NOT use this node
-
-- Use `valve` directly when you have a **single** valve under an upstream parent. VGC adds coordination overhead for no benefit with one child.
-- Do NOT use VGC to coordinate **series** valves — the Kv-share solver assumes parallel branches sharing a common header pressure.
-- Skip VGC when the upstream source already publishes **per-branch flow setpoints**; route those directly to each valve instead.
-
-## 14. Known limitations / current issues
-
-| # | Issue | Tracked in |
-|---|---|---|
-| 1 | `set.position` is a debug-logged **no-op** — per-valve positional override is reserved, pending Phase 7 topic standardisation of valve setpoint payloads. The handler in `commands/handlers.setPosition` intentionally does nothing. | `CONTRACT.md §Inputs`; `OPEN_QUESTIONS.md` Phase 7 |
-| 2 | Residual solver assumes Kv share is a valid first estimate. Pathological valve curves (e.g. very non-linear Kv vs position) may need more passes than the default `maxPasses: 2` to reach `residualTolerance`. | `groupOps/flowDistribution.js` |
-| 3 | Cascaded `valvegroupcontrol` registration (VGC as upstream source of another VGC) is accepted by the router but has no test coverage and is not exercised in production. | `CONTRACT.md §Children` |
+[EVOLV master wiki](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Home) · [Topology Patterns](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topology-Patterns) · [Topic Conventions](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topic-Conventions)
diff --git a/wiki/Reference-Architecture.md b/wiki/Reference-Architecture.md
new file mode 100644
index 0000000..ffeb0ce
--- /dev/null
+++ b/wiki/Reference-Architecture.md
@@ -0,0 +1,238 @@
+# Reference — Architecture
+
+
+
+> [!NOTE]
+> Pending full node review (2026-05). Content reflects `CONTRACT.md` and current source only.
+>
+> Code structure for `valveGroupControl`: the three-tier sandwich, the `src/` concern modules, the Kv-share flow-distribution loop, the source aggregation pipeline, the tick / event lifecycle, and the output-port shape. For an intuitive overview, return to [Home](Home).
+
+---
+
+## Three-tier code layout
+
+```
+nodes/valveGroupControl/
+|
++-- vgc.js entry: RED.nodes.registerType('valveGroupControl', NodeClass)
+| (LEGACY NAME — should be valveGroupControl.js; see Limitations)
++-- vgc.html editor HTML (LEGACY NAME — should be valveGroupControl.html)
+|
++-- src/
+| nodeClass.js extends BaseNodeAdapter (Node-RED bridge, tick loop)
+| specificClass.js extends BaseDomain (orchestration: valve + source routing)
+| |
+| +-- commands/
+| | index.js topic descriptors (canonical + aliases)
+| | handlers.js pure handler functions
+| |
+| +-- groupOps/
+| | flowDistribution.js Kv-share solver, residual pass, calcMaxDeltaP, isValveAvailable
+| |
+| +-- sources/
+| | fluidContract.js upstream-source registration, flow-event binding, fluid-contract reconciliation
+| |
+| +-- io/
+| output.js getOutput() + getStatusBadge()
+```
+
+### Tier responsibilities
+
+| Tier | File | What it owns | Touches `RED.*` |
+|:---|:---|:---|:---:|
+| entry | `vgc.js` (legacy filename) | Type registration | Yes |
+| nodeClass | `src/nodeClass.js` | Periodic tick (`tickInterval = 1000` ms), status badge (`statusInterval = 1000` ms), tick restart on `reconcileIntervalChange`. `buildDomainConfig()` returns `{}` (no domain overrides). | Yes |
+| specificClass | `src/specificClass.js` | Wire concern modules in `configure()`; router callbacks for `valve` + the 4 source softwareTypes; `_bindValveEvents` / `_unbindValveEvents`; mode/sequence dispatch via `handleInput`; expose `calcValveFlows`, `calcMaxDeltaP`, `getFluidContract`, `getOutput`, `getStatusBadge`. | No |
+
+`specificClass` is stitching. All real work lives in the concern modules: Kv-share + residual + max-deltaP in `groupOps/`; upstream-source registration + fluid-contract reconciliation in `sources/`; output shape in `io/`.
+
+---
+
+## What VGC does NOT have
+
+- **No FSM of its own.** `specificClass.configure()` instantiates `new state({}, this.logger)` and stamps `this.state.stateManager.currentState = 'operational'` immediately so `executeSequence` works for group-wide sequences. State semantics belong to the child valves.
+- **No predictors / curves.** Unlike `rotatingMachine`, VGC has no asset model, no characteristic curve, no prediction pipeline. The only "prediction" written is the per-valve assigned flow from the Kv-share solver.
+- **No drift assessment.** No EWMA, no NRMSE, no `predictionHealth`. The Port 0 emits only `mode`, `maxDeltaP`, and per-position flow / pressure keys.
+
+---
+
+## Flow-distribution loop
+
+The core coordination loop. VGC has no per-tick prediction recompute — the tick just re-runs `calcValveFlows()` to absorb any drift between event-driven recalcs.
+
+```mermaid
+sequenceDiagram
+ autonumber
+ participant src as upstream source / data.totalFlow
+ participant vgc as VGC
+ participant solver as solveFlowDistribution
+ participant valves as valve children
+ participant out as Port 0 / 1
+
+ src->>vgc: flow.predicted.downstream (m3/h) OR data.totalFlow
+ vgc->>vgc: updateFlow('predicted'|'measured', value, 'atEquipment')
+ vgc->>vgc: _write flow at position 'atEquipment'
+ vgc->>vgc: calcValveFlows()
+ vgc->>solver: target=totalFlow, entries=availableValves, recon
+ loop ≤ maxPasses while |residual| > tol
+ solver->>valves: updateFlow('predicted', share, 'downstream')
+ valves-->>solver: read accepted (flow.predicted.downstream)
+ solver->>solver: residual = target − sum(accepted)
+ end
+ solver-->>vgc: { flowsById, residual, passes }
+ vgc->>vgc: _write flow.predicted.atEquipment = sum(accepted)
+ vgc->>vgc: calcMaxDeltaP()
+ vgc->>out: notifyOutputChanged() → Port 0 / 1
+ valves-->>vgc: positionChange / deltaPChange (drives next calcValveFlows / calcMaxDeltaP)
+```
+
+### Availability filter
+
+A valve participates in the split if **all** are true (`groupOps/flowDistribution.isValveAvailable`):
+
+| Condition | Source |
+|:---|:---|
+| `valve.state.getCurrentState() !== 'off'` | child FSM |
+| `valve.state.getCurrentState() !== 'maintenance'` | child FSM |
+| `valve.currentMode !== 'maintenance'` | child mode |
+| `Number.isFinite(valve.kv) && valve.kv > 0` | child config |
+
+Unavailable valves still receive `updateFlow('predicted', 0, 'downstream', flowUnit)` so their state is consistent — they are simply excluded from the solver.
+
+### Residual reconciliation
+
+`flowReconciliation` defaults (`groupOps/flowDistribution.DEFAULT_RECONCILIATION`):
+
+| Field | Default | Effect |
+|:---|:---:|:---|
+| `maxPasses` | `2` | Bound on the correction loop. The first pass distributes by `share = (kv / totalKv) * residual`; subsequent passes correct for the residual between target and accepted total. |
+| `residualTolerance` | `0.001` | Loop exits when `|residual| < tolerance`. Units are canonical (m³/s for flow). |
+
+After the loop:
+
+- `lastFlowSolve = { passes, residual, targetTotal, assignedTotal }` is stamped on the domain for telemetry / debug.
+- `flow.predicted.atEquipment` is written equal to `assignedTotal` (sum of per-valve accepted).
+- `calcMaxDeltaP` re-reads every valve's `pressure.predicted.delta` and stores `vgc.maxDeltaP` plus `pressure.predicted.deltaMax` in the measurement container.
+
+### Pathological-curve case
+
+If `totalKv <= 0` or no valves are available, every valve is pushed `0`, `flow.predicted.atEquipment` is written `0`, and `lastFlowSolve` records `passes: 0, residual: target, assignedTotal: 0`. The status badge flips to `'No valves'` (red dot).
+
+---
+
+## Source aggregation
+
+Upstream nodes register as **sources** (not children that VGC controls). Source softwareTypes accepted by `_registerSource`:
+
+| Registered as (canonical) | Original softwareType examples |
+|:---|:---|
+| `machine` | `rotatingmachine` (canonicalised by `BaseDomain.router`) |
+| `machinegroup` | `machinegroupcontrol` (canonicalised) |
+| `pumpingstation` | `pumpingstation` |
+| `valvegroupcontrol` | `valvegroupcontrol` (cascaded VGC; see Limitations) |
+
+For each source `bindSource` attaches listeners to **six** flow event names on the source's `measurements.emitter`:
+
+```
+flow.predicted.downstream
+flow.predicted.atEquipment
+flow.predicted.atequipment
+flow.measured.downstream
+flow.measured.atEquipment
+flow.measured.atequipment
+```
+
+The handler routes any of these to `vgc.updateFlow(variant, value, 'atEquipment', unit)`. Position-label case variants are caught explicitly — the source may publish either `atEquipment` or `atequipment` and the router normalises both into the same internal write.
+
+### Fluid contract aggregation
+
+Each source contributes a fluid contract (`liquid` / `gas` / `conflict` / `unknown`). `extractFluidContract`:
+
+1. Calls `child.getFluidContract()` if present. A `conflict` status short-circuits to group conflict.
+2. Falls back to a normalised `serviceType` from the child / asset config.
+3. Falls back to a defaults table (`DEFAULT_SOURCE_SERVICE_TYPE` — everything maps to `liquid` except where overridden).
+
+`refreshFluidContract` aggregates across all registered sources:
+
+| Aggregate status | When |
+|:---|:---|
+| `conflict` | Any source's contract is `conflict`, OR more than one distinct `serviceType` is present. |
+| `resolved` | Exactly one distinct `serviceType` across all sources. |
+| `unknown` | No sources registered. |
+
+Changes emit `fluidContractChange` on `vgc.emitter` so downstream consumers (a valve checking compatibility, another VGC) can react.
+
+---
+
+## Lifecycle — tick + event sources
+
+| Source | Where it fires | What it triggers |
+|:---|:---|:---|
+| Periodic tick | `nodeClass` `setInterval(tickInterval = 1000 ms)` | `source.tick()` → `calcValveFlows()` → `notifyOutputChanged()`. |
+| Child `state.emitter` `'positionChange'` | per child valve | `onPositionChange` → `calcValveFlows()`. |
+| Child `emitter` `'deltaPChange'` | per child valve | `onDeltaPChange` → `calcMaxDeltaP()`. |
+| Source `measurements.emitter` flow events | per upstream source | `updateFlow(variant, value, 'atEquipment', unit)`. |
+| Source `emitter` `'fluidContractChange'` | per upstream source | Re-read source contract; `refreshFluidContract`. |
+| `source.emitter` `'reconcileIntervalChange'` | `setReconcileIntervalSeconds` | `nodeClass._restartTick(ms)` — clears + re-schedules tick. |
+| Inbound `msg.topic` | Node-RED input wire | `commandRegistry` dispatch (see [Contracts](Reference-Contracts#topic-contract)). |
+| `setInterval(statusInterval = 1000 ms)` | `BaseNodeAdapter` | Status badge re-render. |
+
+`tick()` itself is one line — `this.calcValveFlows()`. It exists so a child's accepted flow drift between event-driven recalcs gets re-absorbed.
+
+---
+
+## Output ports
+
+| Port | Carries | Sample shape |
+|:---|:---|:---|
+| 0 (process) | Delta-compressed snapshot — `mode`, `maxDeltaP`, per-position flow/pressure keys | `{topic, payload: {mode, maxDeltaP, atEquipment_predicted_flow, ...}}` |
+| 1 (telemetry) | InfluxDB line-protocol payload (same fields as Port 0) | `valveGroupControl,id=VGC1 mode="auto",maxDeltaP=1450,atEquipment_predicted_flow=80,...` |
+| 2 (register / control) | `child.register` upward at startup | `{topic: 'child.register', payload: , positionVsParent}` |
+
+Port-0 key shape is **`__`** (same as MGC) — written in `io/output.getOutput()` by walking `measurements.measurements` and emitting only keys whose `getCurrentValue()` is non-null. Plus the two scalar keys `mode` and `maxDeltaP`.
+
+> [!IMPORTANT]
+> See `.claude/rules/output-coverage.md` — every output should be enumerated in a `test/_output-manifest.md` and tested in both populated and degraded states. **Not yet produced** for VGC; tracked as backfill in `.agents/improvements/IMPROVEMENTS_BACKLOG.md` (TODO).
+
+---
+
+## Events emitted on `source.emitter` / `source.measurements.emitter`
+
+| Event | Emitter | Fires when |
+|:---|:---|:---|
+| `output-changed` | `source.emitter` | Public output state shifted; adapter listens and pushes Ports 0/1. |
+| `fluidContractChange` | `source.emitter` | Group-level fluid contract (status / serviceType / sourceCount) changed. |
+| `reconcileIntervalChange` | `source.emitter` | `setReconcileIntervalSeconds` was called; adapter restarts the tick loop. |
+| `flow.predicted.atequipment` | `source.measurements.emitter` | Group predicted flow changed (post-solve). |
+| `pressure.predicted.deltaMax` | `source.measurements.emitter` | Group max delta-P changed. |
+
+The exact emitter set is data-driven by what valves and sources publish.
+
+---
+
+## Where to start reading
+
+| If you're changing… | Read first |
+|:---|:---|
+| Kv-share solver, residual pass, availability filter | `src/groupOps/flowDistribution.js` |
+| `calcMaxDeltaP` aggregation | `src/groupOps/flowDistribution.js` `calcMaxDeltaP` |
+| Upstream-source registration, flow-event names, fluid contract | `src/sources/fluidContract.js` |
+| Valve event binding / unbinding | `src/specificClass.js` `_bindValveEvents` / `_unbindValveEvents` |
+| Mode validation, sequence dispatch | `src/specificClass.js` `setMode` / `executeSequence` / `handleInput` |
+| Reconcile-interval re-tuning | `src/specificClass.js` `setReconcileIntervalSeconds` + `src/nodeClass.js` `_restartTick` |
+| Topic registration, payload validation, alias deprecation | `src/commands/index.js` + `src/commands/handlers.js` |
+| Port-0 output keys, status badge | `src/io/output.js` |
+
+---
+
+## Related pages
+
+| Page | Why |
+|:---|:---|
+| [Home](Home) | Intuitive overview |
+| [Reference — Contracts](Reference-Contracts) | Topic + config + child filters |
+| [Reference — Examples](Reference-Examples) | Shipped flows + debug recipes |
+| [Reference — Limitations](Reference-Limitations) | Known issues and open questions |
+| [machineGroupControl wiki](https://gitea.wbd-rd.nl/RnD/machineGroupControl/wiki/Home) | The sibling Unit-level group controller for pumps |
+| [valve wiki](https://gitea.wbd-rd.nl/RnD/valve/wiki/Home) | The child node VGC coordinates |
+| [EVOLV — Architecture](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Architecture) | Platform-wide three-tier pattern |
diff --git a/wiki/Reference-Contracts.md b/wiki/Reference-Contracts.md
new file mode 100644
index 0000000..c7ec8c5
--- /dev/null
+++ b/wiki/Reference-Contracts.md
@@ -0,0 +1,257 @@
+# Reference — Contracts
+
+
+
+> [!NOTE]
+> Pending full node review (2026-05). Content reflects `CONTRACT.md` and current source only.
+>
+> Full topic contract, configuration schema, and child-registration filters for `valveGroupControl`. Source of truth: `src/commands/index.js`, `src/specificClass.js` `configure()`, and the schema at `generalFunctions/src/configs/valveGroupControl.json`.
+>
+> For an intuitive overview, return to the [Home](Home).
+
+---
+
+## Topic contract
+
+The registry lives in `src/commands/index.js`. Each descriptor maps a canonical `msg.topic` to its handler; aliases emit a one-time deprecation warning the first time they fire.
+
+
+
+| Canonical topic | Aliases | Payload | Unit | Effect |
+|:---|:---|:---|:---|:---|
+| `set.mode` | `setMode` | `string` (`auto` / `virtualControl` / `fysicalControl` / `maintenance`) | — | Switch operational mode via `source.setMode(payload)`. Each mode has its own allow-list of sources (`mode.allowedSources`). |
+| `set.position` | `setpoint` | any | — | **No-op pending Phase 7.** Reserved for future per-valve positional override; the handler is debug-logged only. |
+| `child.register` | `registerChild` | `string` (child node id) | — | Resolve via `RED.nodes.getNode`; if the child exposes `.source`, register through `childRegistrationUtils.registerChild(child.source, msg.positionVsParent)`. |
+| `cmd.execSequence` | `execSequence` | `{ source, action, parameter }` | — | Forward to `source.handleInput(source, action, parameter)`. The `action` typically names a sequence; the parameter typically names the state list. |
+| `data.totalFlow` | `totalFlowChange` | number, `{ value, position?, variant?, unit? }`, or `{ source, action, ... }` | `volumeFlowRate` (default `m3/h`) | Update total measured/predicted flow at the configured position; drives `calcValveFlows` to re-distribute. If `payload.source` is present, route via `handleInput(src, action, payload)`; otherwise treat as `parent`/`totalFlowChange`. |
+| `cmd.emergencyStop` | `emergencyStop`, `emergencystop` | optional `{ source }` | — | Run the `emergencystop` sequence via `handleInput(src, 'emergencystop')`. Default source is `parent`. |
+| `set.reconcileInterval` | `setReconcileInterval` | number — seconds (> 0) | seconds | Re-tune the periodic flow-reconciliation interval (`setReconcileIntervalSeconds`). Min clamp 100 ms. Non-finite or ≤ 0 logs a warn and is dropped. |
+
+
+
+### Mode / source allow-lists
+
+A topic that survives the registry still passes through `flowController` → `handleInput`, which enforces:
+
+```js
+if (!host.isValidSourceForMode(source, host.currentMode)) {
+ this.logger.warn(`Source '${source}' is not valid for mode '${this.currentMode}'.`);
+ return { status: false, feedback: ... };
+}
+```
+
+Defaults from the schema:
+
+| Mode | `allowedActions` | `allowedSources` |
+|:---|:---|:---|
+| `auto` | `statusCheck, execSequence, emergencyStop, valvePositionChange, totalFlowChange, valveDeltaPchange` | `parent, GUI, fysical` |
+| `virtualControl` | `statusCheck, execSequence, emergencyStop, valvePositionChange, totalFlowChange, valveDeltaPchange` | `GUI, fysical` |
+| `fysicalControl` | `statusCheck, emergencyStop` | `fysical` |
+| `maintenance` | `statusCheck` | (schema does NOT define `allowedSources.maintenance`; `isValidSourceForMode` returns `false` for every source — effectively monitoring-only) |
+
+> [!WARNING]
+> **Source contradiction:** `CONTRACT.md` describes `set.mode` as switching between "auto / manual control modes", but the schema defines four modes (`auto` / `virtualControl` / `fysicalControl` / `maintenance`) and `specificClass.setMode` validates against the schema's enum. The wider four-mode set is the implementation. TODO: tighten the prose in `CONTRACT.md` to enumerate the schema modes.
+
+> [!WARNING]
+> **Source contradiction:** the schema declares an `mode.allowedActions` table, but the running implementation only consults `isValidSourceForMode` — **`isValidActionForMode` is not implemented on VGC**. Action allow-lists are effectively dead config. TODO: either implement the action check (mirroring `rotatingMachine`'s pattern) or remove `allowedActions` from the schema.
+
+---
+
+## Data model — `getOutput()` shape
+
+Composed each tick by `src/io/output.getOutput()`. Delta-compressed: consumers see only keys whose `getCurrentValue()` is non-null.
+
+
+
+### Scalar keys
+
+| Key | Type | Source | Notes |
+|:---|:---|:---|:---|
+| `mode` | string | `vgc.currentMode` | `auto` / `virtualControl` / `fysicalControl` / `maintenance`. |
+| `maxDeltaP` | number | `vgc.maxDeltaP` | Cached max delta-P over registered valves (in output pressure unit, default `mbar`). Same data is also surfaced via the measurement-derived key `deltaMax_predicted_pressure`. |
+
+### Measurement-derived keys
+
+For every `(type, variant, position)` in MeasurementContainer with a finite value, the flattened output emits:
+
+```
+__
+```
+
+| Example key | Unit | Source | Notes |
+|:---|:---|:---|:---|
+| `atEquipment_measured_flow` | m³/h | upstream source `flow.measured.*` events; `data.totalFlow` with `variant=measured` | Total measured flow at the group inlet. |
+| `atEquipment_predicted_flow` | m³/h | written by `distributeFlow` as `sum(accepted)` | Sum of per-valve accepted flows after Kv-share + residual. |
+| `deltaMax_predicted_pressure` | mbar | written by `calcMaxDeltaP` | Max `pressure.predicted.delta` across registered valves. |
+
+> Delta compression: only changed fields are sent per tick. Consumers must cache and merge. See `outputUtils.formatMsg`.
+
+
+
+### Status badge
+
+`io/output.getStatusBadge`:
+
+```
+ | flow= | valve(s) connected | (or 'No valves')
+```
+
+| State | Fill |
+|:---|:---|
+| `getAvailableValves().length > 0` | green dot |
+| `getAvailableValves().length === 0` | red dot |
+
+`flow` is the rounded `flow.measured.atEquipment`, or `flow.predicted.atEquipment` if no measured value is available.
+
+---
+
+## Configuration schema — editor form to config keys
+
+Source of truth: `generalFunctions/src/configs/valveGroupControl.json` plus `nodeClass.buildDomainConfig` (which returns `{}` — no domain overrides).
+
+### General (`config.general`)
+
+| Form field | Config key | Default | Notes |
+|:---|:---|:---|:---|
+| Name | `general.name` | `"ValveGroupControl"` | Node label, status badge prefix (via `topic`). |
+| (auto-assigned) | `general.id` | `null` | Node-RED node id. |
+| Default unit | `general.unit` | `"unitless"` (schema) / `m3/h` (`configure()` overrides via `unitPolicy.output('flow')`) | Re-derived in `configure()`. |
+| Enable logging | `general.logging.enabled` | `true` | Master switch. |
+| Log level | `general.logging.logLevel` | `info` | `debug` / `info` / `warn` / `error`. |
+
+### Functionality (`config.functionality`)
+
+| Form field | Config key | Default | Notes |
+|:---|:---|:---|:---|
+| Position vs parent | `functionality.positionVsParent` | `""` (per `CONTRACT.md`) | Used in the Port-2 register payload sent to the upstream parent. (Not in the JSON schema; supplied at runtime from the editor.) |
+| (hidden) | `functionality.softwareType` | `"valvegroupcontrol"` | Constant. |
+| (hidden) | `functionality.role` | `"ValveGroupController"` | Constant. |
+
+### Asset (`config.asset`)
+
+VGC's asset block is informational — there is no curve to load, no model registry, no allowed-unit validation.
+
+| Form field | Config key | Default | Notes |
+|:---|:---|:---|:---|
+| Asset UUID | `asset.uuid` | `null` | Globally-unique identifier. |
+| Geolocation | `asset.geoLocation` | `{x:0, y:0, z:0}` | |
+| Supplier | `asset.supplier` | `"Unknown"` | Informational. |
+| Type | `asset.type` | `"valve"` | Classification only. |
+| Sub-type | `asset.subType` | `"Unknown"` | |
+| Model | `asset.model` | `"Unknown"` | Informational; no registry lookup. |
+| Accuracy | `asset.accuracy` | `null` | |
+
+### Mode (`config.mode`)
+
+| Form field | Config key | Default | Range | Notes |
+|:---|:---|:---|:---|:---|
+| Mode | `mode.current` | `auto` | `auto` / `virtualControl` / `fysicalControl` / `maintenance` | The active operational mode. |
+| (defaults) | `mode.allowedActions.` | see [Mode allow-lists](#mode--source-allow-lists) | enforced by `flowController` (NOT implemented — see warning above) |
+| (defaults) | `mode.allowedSources.` | see [Mode allow-lists](#mode--source-allow-lists) | enforced by `isValidSourceForMode` |
+
+### Sequences (`config.sequences`)
+
+Per-sequence state-transition lists. Defaults:
+
+| Sequence | States |
+|:---|:---|
+| `startup` | `[starting, warmingup, operational]` |
+| `shutdown` | `[stopping, coolingdown, idle]` |
+| `emergencystop` | `[emergencystop, off]` |
+| `boot` | `[idle, starting, warmingup, operational]` |
+
+`executeSequence(name)` iterates the list and awaits `state.transitionToState(stateName)` per step. The default state object is created at boot with `currentState = 'operational'` so `executeSequence` works without a pre-warmup phase. (See [Architecture — What VGC does NOT have](Reference-Architecture#what-vgc-does-not-have).)
+
+### Calculation mode (`config.calculationMode`)
+
+| Value | Description |
+|:---|:---|
+| `low` | Calculations run at fixed intervals (time-based). |
+| `medium` (default) | Calculations run when new setpoints arrive or measured changes occur (event-driven). |
+| `high` | Calculations run on all event-driven info, including every movement. |
+
+> [!WARNING]
+> `calculationMode` is in the schema but is not currently consulted by `specificClass` or `nodeClass`. The tick interval is fixed at `tickInterval = 1000 ms` and only retunable through `set.reconcileInterval`. TODO: wire `calculationMode` through or remove it.
+
+### Flow reconciliation (runtime only)
+
+`flowReconciliation` lives on the domain (not in the schema):
+
+| Field | Default | Notes |
+|:---|:---:|:---|
+| `maxPasses` | `2` | Max iterations of the Kv-share residual loop. |
+| `residualTolerance` | `0.001` | Stops loop when `|residual| < tolerance` (canonical units). |
+
+These are read by `solveFlowDistribution` each call; not currently exposed via a topic or editor field.
+
+### Unit policy
+
+Source: `src/specificClass.js`.
+
+| Quantity | Canonical (internal) | Output (rendered) | Required-unit |
+|:---|:---|:---|:---:|
+| Flow | `m3/s` | `m3/h` | ✓ |
+| Pressure | `Pa` | `mbar` | ✓ |
+
+`requireUnitForTypes: ['pressure', 'flow']` — MeasurementContainer rejects writes that omit `unit` for these types.
+
+---
+
+## Child registration
+
+Source: `src/specificClass.js` `_registerValve` / `_registerSource` and `src/sources/fluidContract.js`.
+
+| Software type | Filter | Wired to | Side-effect |
+|:---|:---|:---|:---|
+| `valve` | `child` exposes `updateFlow`, `state.getCurrentState`, `measurements` (`_isValveLike`) | Stored in `vgc.valves[id]`; events bound. | Subscribes to `state.emitter.positionChange` (→ `calcValveFlows`) and `emitter.deltaPChange` (→ `calcMaxDeltaP`). Triggers an initial `calcValveFlows` + `calcMaxDeltaP` + `refreshFluidContract`. |
+| `machine` (incl. canonicalised `rotatingmachine`) | router callback | `registerSource` (`sources/fluidContract`) | Subscribes to 6 flow event names on `child.measurements.emitter`; subscribes to `child.emitter.fluidContractChange`. |
+| `machinegroup` (incl. canonicalised `machinegroupcontrol`) | router callback | `registerSource` | Same as `machine`. |
+| `pumpingstation` | router callback | `registerSource` | Same as `machine`. |
+| `valvegroupcontrol` | router callback | `registerSource` | Cascaded VGC; accepted by router. Not exercised in production — see [Limitations](Reference-Limitations#cascaded-vgc-not-test-covered). |
+
+Position labels accepted from children are `upstream`, `downstream`, `atEquipment` (and case variants — normalised internally).
+
+### Source flow events
+
+`bindSource` attaches a listener for every event name in `SOURCE_FLOW_EVENTS`:
+
+```
+flow.predicted.downstream
+flow.predicted.atEquipment
+flow.predicted.atequipment
+flow.measured.downstream
+flow.measured.atEquipment
+flow.measured.atequipment
+```
+
+The handler reads `eventData.value` (number) and `eventData.unit` and writes `vgc.updateFlow(variant, value, 'atEquipment', unit)`. `variant` is derived from the event-name middle segment (`measured` vs `predicted`).
+
+### Fluid contract reconciliation
+
+See [Architecture — Source aggregation](Reference-Architecture#fluid-contract-aggregation) for the full reconciliation logic. The aggregated `fluidContract` is exposed via `vgc.getFluidContract()`:
+
+```json
+{
+ "status": "resolved" | "conflict" | "inferred" | "unknown",
+ "serviceType": "liquid" | "gas" | null,
+ "upstreamServiceTypes": ["liquid"],
+ "sourceCount": 2,
+ "message": "Upstream fluid resolved as liquid.",
+ "source": "valvegroupcontrol"
+}
+```
+
+Changes are broadcast via `source.emitter.emit('fluidContractChange', ...)`.
+
+---
+
+## Related pages
+
+| Page | Why |
+|:---|:---|
+| [Home](Home) | Intuitive overview |
+| [Reference — Architecture](Reference-Architecture) | Code map, flow-distribution loop, source aggregation |
+| [Reference — Examples](Reference-Examples) | Shipped flows + debug recipes |
+| [Reference — Limitations](Reference-Limitations) | Known issues and open questions |
+| [EVOLV — Topic Conventions](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topic-Conventions) | Platform-wide topic rules |
+| [EVOLV — Telemetry](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Telemetry) | Port 0 / 1 / 2 InfluxDB layout |
diff --git a/wiki/Reference-Examples.md b/wiki/Reference-Examples.md
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+++ b/wiki/Reference-Examples.md
@@ -0,0 +1,157 @@
+# Reference — Examples
+
+
+
+> [!NOTE]
+> Pending full node review (2026-05). Content reflects `CONTRACT.md` and current source only.
+>
+> Every example flow shipped under `nodes/valveGroupControl/examples/`, plus how to load them, what they show, and the debug recipes that go with them. Live source: `nodes/valveGroupControl/examples/`.
+
+---
+
+## Shipped examples
+
+| File | Tier | Dependencies | What it shows |
+|:---|:---:|:---|:---|
+| `basic.flow.json` | 1 | EVOLV only | Inject `data.totalFlow` + 2 `valve` children registered as the group. No parent. Verifies Kv-share split and residual reconciliation. |
+| `integration.flow.json` | 2 | EVOLV only | VGC + 2 valves + one upstream `rotatingMachine` source. Source's `flow.predicted.*` events drive the group; fluid-contract aggregation resolves to `liquid`. |
+| `edge.flow.json` | 3 | EVOLV only | Edge cases: no valves available, residual non-convergence, cascaded VGC as upstream source. Currently a structural placeholder — TODO consult `examples/edge.flow.json` for actual scenarios. |
+
+> [!IMPORTANT]
+> The Tier-1 / Tier-2 / Tier-3 naming convention (`01 - .json`) used by `rotatingMachine` has **not yet been applied** to VGC. Filenames are still the legacy `basic`/`integration`/`edge` triad. Migration tracked in `.agents/improvements/IMPROVEMENTS_BACKLOG.md`. When renaming, update `examples/README.md` in the same commit.
+
+---
+
+## Loading a flow
+
+### Via the editor
+
+1. Open the Node-RED editor at `http://localhost:1880`.
+2. Menu → Import → drag the JSON file.
+3. Click Deploy.
+
+### Via the Admin API
+
+```bash
+curl -X POST -H 'Content-Type: application/json' \
+ --data @"nodes/valveGroupControl/examples/basic.flow.json" \
+ http://localhost:1880/flows
+```
+
+---
+
+## Example: basic.flow.json
+
+> [!IMPORTANT]
+> **TODO: not yet validated against live Node-RED.** Steps below are inferred from `CONTRACT.md` + the topic registry. Consult `examples/basic.flow.json` directly for exact node ids and inject payloads. Screenshot needed once validated — save under `wiki/_partial-screenshots/valveGroupControl/01-basic-editor.png`.
+
+Single VGC with 2 `valve` children. Demonstrates:
+
+1. Wire each valve's Port 2 to VGC's input so `child.register` arrives automatically on deploy.
+2. Inject `data.totalFlow` with payload `{ value: 80, unit: "m3/h", position: "atEquipment", variant: "measured" }`. VGC runs `calcValveFlows`:
+ - Splits 80 m³/h by Kv share across the 2 valves.
+ - Each valve's `updateFlow('predicted', share, 'downstream')` push.
+ - Re-reads each valve's accepted `flow.predicted.downstream`.
+ - Residual loop runs up to `maxPasses: 2` until `|residual| < 0.001`.
+3. Watch Port 0 debug: `atEquipment_predicted_flow` settles at the assigned total; `deltaMax_predicted_pressure` updates as each valve emits `deltaPChange`.
+4. Toggle one valve to `off` — the next `data.totalFlow` (or tick) routes 100% to the remaining valve.
+5. Set the offlined valve back to operational — the next tick re-includes it in the split.
+
+### Try the residual pass
+
+After the group settles at `80 m³/h`:
+
+1. Inject `data.totalFlow = 200` (a value beyond aggregate Kv capacity). Watch `lastFlowSolve.residual` — it stays large because the valves cap at their accept limits. `flow.predicted.atEquipment` will read the sum of caps, not 200.
+2. Inject `data.totalFlow = 0`. Every valve receives `updateFlow('predicted', 0, 'downstream')`; `maxDeltaP` collapses to 0.
+
+---
+
+## Example: integration.flow.json
+
+> [!IMPORTANT]
+> **TODO: not yet validated.** Screenshot needed once validated — save under `wiki/_partial-screenshots/valveGroupControl/02-integration-editor.png`.
+
+VGC + 2 valves + 1 upstream `rotatingMachine`. Demonstrates:
+
+- Source registration: the rotatingMachine's `child.register` (softwareType `rotatingmachine` → canonical `machine`) lands on VGC; `_registerSource` subscribes to `flow.predicted.downstream`, `flow.measured.downstream`, etc.
+- Source-driven flow: a pump-state change emits `flow.predicted.downstream`; VGC's handler converts to `updateFlow('predicted', value, 'atEquipment', unit)` and re-runs `calcValveFlows`.
+- Fluid-contract resolution: the pump's `getFluidContract()` (or fallback `DEFAULT_SOURCE_SERVICE_TYPE.rotatingmachine = 'liquid'`) produces `serviceType: 'liquid'`; `fluidContract` resolves to `{status: 'resolved', serviceType: 'liquid'}`.
+
+---
+
+## Example: edge.flow.json
+
+> [!IMPORTANT]
+> **TODO: structural placeholder.** Consult the JSON directly for the scenarios it currently exercises. The edge scenarios this node ought to test (per `CONTRACT.md` + source review):
+>
+> - **No available valves** — all in `off` / `maintenance`. Expected: status badge `'No valves'` red, every valve pushed `0`, `lastFlowSolve.assignedTotal = 0`.
+> - **Residual non-convergence** — valve curve where Kv-share is a bad first estimate. Expected: loop exits after `maxPasses: 2` with non-zero residual; assignedTotal < target; behaviour graceful.
+> - **Cascaded VGC** — upstream source is another VGC. Expected: source registered, `flow.*` events bound, `getFluidContract()` propagated up. **Not exercised in production.**
+> - **Conflicting fluid contracts** — two sources advertise `liquid` vs `gas`. Expected: `fluidContract.status = 'conflict'`; `fluidContractChange` event emitted.
+
+---
+
+## Docker compose snippet
+
+To bring up Node-RED + InfluxDB with EVOLV nodes pre-loaded:
+
+```yaml
+# docker-compose.yml (extract)
+services:
+ nodered:
+ build: ./docker/nodered
+ ports: ['1880:1880']
+ volumes:
+ - ./docker/nodered/data:/data/evolv
+ influxdb:
+ image: influxdb:2.7
+ ports: ['8086:8086']
+```
+
+Full file: [EVOLV/docker-compose.yml](https://gitea.wbd-rd.nl/RnD/EVOLV/src/branch/development/docker-compose.yml).
+
+---
+
+## Debug recipes
+
+| Symptom | First thing to check | Where to look |
+|:---|:---|:---|
+| All valves receive `assigned flow = 0` | `getAvailableValves()` returns empty list: check every valve's state (`off` / `maintenance` excludes), `currentMode !== 'maintenance'`, and `kv > 0`. | `src/groupOps/flowDistribution.isValveAvailable` |
+| Residual never converges | Pathological valve curve: Kv-share is a bad first estimate. Check `vgc.lastFlowSolve.residual` and `.passes` — if `passes === maxPasses` and residual is large, the loop ran out. Raise `flowReconciliation.maxPasses` (no editor field yet — TODO Phase 7). | `src/groupOps/flowDistribution.solveFlowDistribution` |
+| Group `maxDeltaP` stale | Child `deltaPChange` not subscribed: valve emitter not exposed via `child.emitter`, or valve never registered. | `src/specificClass._bindValveEvents` |
+| Service-type stays `unknown` | No upstream source registered, or all advertise unknown type. Check `vgc.sources` — if empty, no Port-2 child.register reached VGC. | `src/sources/fluidContract.refreshFluidContract` |
+| `data.totalFlow` silently ignored | Mode rejects the source id: check `mode.allowedSources` for the current mode. `maintenance` rejects every source. Warn in log: `Source '' is not valid for mode ''.` | `src/specificClass.isValidSourceForMode` |
+| `set.position` has no effect | Known: handler is a debug-logged no-op pending Phase 7. See [Limitations](Reference-Limitations#set-position-is-a-no-op). | `src/commands/handlers.setPosition` |
+| `set.reconcileInterval = 0` (or negative) silently does nothing | The handler validates `Number.isFinite(nextSec) && nextSec > 0`. Otherwise warns and returns. | `src/commands/handlers.setReconcileInterval` |
+| Two emitters fight on the same flow channel (one source publishes `atEquipment`, another publishes `atequipment`) | Both event names are wired; the **last write wins** on each `updateFlow`. There is no source-priority logic. | `src/sources/fluidContract.SOURCE_FLOW_EVENTS` |
+| Cascaded VGC not propagating flow | Accepted by router, but no tests — treat as experimental. | `src/sources/fluidContract.SOURCE_SOFTWARE_TYPES` |
+| Output port-0 key shape differs from rotatingMachine's | VGC uses `__` (same as MGC) — the inverse of rotatingMachine's `...`. Don't mix. | `src/io/output.getOutput` |
+
+> Never ship `enableLog: 'debug'` in a demo — fills the container log within seconds and obscures real errors.
+
+---
+
+## Output coverage (TODO)
+
+> [!IMPORTANT]
+> Per `.claude/rules/output-coverage.md`: every output on every layer needs a manifest entry + populated + degraded test. **`test/_output-manifest.md` does not yet exist** for VGC. Backfill tracked in `.agents/improvements/IMPROVEMENTS_BACKLOG.md`.
+>
+> Minimum coverage to land before declaring trial-ready:
+>
+> - Port 0 / 1 keys: `mode`, `maxDeltaP`, `atEquipment_predicted_flow`, `atEquipment_measured_flow`, `deltaMax_predicted_pressure`. Each tested in populated AND degraded states.
+> - Port 2: `child.register` payload shape.
+> - Example flow function-node outputs: each `outputs > 1` fan-out enumerated; verify no `payload: null` literals (lint via `npm run lint:flow-outputs`).
+
+---
+
+## Related pages
+
+| Page | Why |
+|:---|:---|
+| [Home](Home) | Intuitive overview |
+| [Reference — Contracts](Reference-Contracts) | Topic + config + child filters |
+| [Reference — Architecture](Reference-Architecture) | Code map, flow-distribution loop, source aggregation |
+| [Reference — Limitations](Reference-Limitations) | Known issues and open questions |
+| [machineGroupControl — Examples](https://gitea.wbd-rd.nl/RnD/machineGroupControl/wiki/Reference-Examples) | Sibling group-control demo flows |
+| [valve wiki](https://gitea.wbd-rd.nl/RnD/valve/wiki/Home) | The child node VGC coordinates |
+| [EVOLV — Topology Patterns](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topology-Patterns) | Where valveGroupControl fits in a larger plant |
diff --git a/wiki/Reference-Limitations.md b/wiki/Reference-Limitations.md
new file mode 100644
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--- /dev/null
+++ b/wiki/Reference-Limitations.md
@@ -0,0 +1,150 @@
+# Reference — Limitations
+
+
+
+> [!NOTE]
+> Pending full node review (2026-05). Content reflects `CONTRACT.md` and current source only.
+>
+> What `valveGroupControl` does not do, current rough edges, and open questions. Open items live in `.agents/improvements/IMPROVEMENTS_BACKLOG.md` in the superproject.
+
+---
+
+## When you would not use this node
+
+| Scenario | Use instead |
+|:---|:---|
+| A single valve under one upstream parent | `valve` — VGC adds coordination overhead for no benefit with one child. |
+| Valves in **series** rather than parallel | The Kv-share solver assumes parallel branches sharing a common header pressure. Series valves need their own coordination model. |
+| Upstream already publishes per-branch flow setpoints | Route the per-branch setpoints directly to each `valve` — VGC's group-level redistribution would discard the upstream split. |
+| Curve-based pumps grouped on a manifold | `machineGroupControl` — that's the pump-side equivalent (BEP-aware optimizer + planner). VGC has no curves and no optimizer. |
+
+---
+
+## Legacy file-naming drift
+
+The entry file and editor HTML still use the abbreviated `vgc.{js,html}` filenames:
+
+| Path | Currently | Should be |
+|:---|:---|:---|
+| Entry file | `vgc.js` | `valveGroupControl.js` |
+| Editor HTML | `vgc.html` | `valveGroupControl.html` |
+
+Per the EVOLV folder-naming convention (`.claude/rules/node-architecture.md` and `CLAUDE.md`), every per-node file MUST match the folder name exactly — no abbreviations. The rename is queued for the next touch:
+
+```
+files to update in one commit:
+ - rename vgc.js → valveGroupControl.js
+ - rename vgc.html → valveGroupControl.html
+ - update package.json#node-red.nodes (currently maps "valveGroupControl": "vgc.js")
+ - update any require() / import paths
+ - update superproject submodule references
+```
+
+Sibling drift: `machineGroupControl/mgc.{js,html}` and `dashboardAPI/dashboardapi.{js,html}` are in the same state. See `.claude/refactor/MODULE_SPLIT.md`.
+
+---
+
+## Known limitations
+
+### `set.position` is a no-op
+
+`commands/handlers.setPosition` intentionally does nothing — the handler debug-logs the payload and returns. Per-valve positional override is reserved pending Phase 7 topic standardisation of valve setpoint payloads. The canonical topic and alias are reserved so callers can't squat them in the meantime.
+
+Workaround: route the position setpoint to the individual `valve` node directly.
+
+### `isValidActionForMode` is not implemented
+
+The schema declares `mode.allowedActions.` (`statusCheck` / `execSequence` / `emergencyStop` / `valvePositionChange` / `totalFlowChange` / `valveDeltaPchange`), but `specificClass.handleInput` only consults `isValidSourceForMode`. The action allow-list is effectively dead config. Source contradiction with `CONTRACT.md` which implies action gating is active.
+
+Workaround: rely on the source allow-list for now. TODO: implement the action check (mirror `rotatingMachine`'s pattern) OR strip `allowedActions` from the schema.
+
+### `calculationMode` is not consulted
+
+Schema field `calculationMode` (`low` / `medium` / `high`) is declared but ignored by both `specificClass` and `nodeClass`. The tick interval is fixed at `tickInterval = 1000 ms` and only re-tunable via `set.reconcileInterval`. TODO: wire it through or remove.
+
+### `mode.allowedSources.maintenance` is undefined
+
+The `maintenance` mode is enumerated in `mode.current` and `mode.allowedActions`, but `mode.allowedSources` only declares `auto` / `virtualControl` / `fysicalControl`. `isValidSourceForMode('any', 'maintenance')` returns `false` for every source — effectively monitoring-only. This may be intentional, but it's not stated explicitly in any contract.
+
+### Residual solver assumes Kv share is a valid first estimate
+
+Pathological valve curves (very non-linear Kv vs position) may need more passes than the default `maxPasses: 2` to reach `residualTolerance: 0.001`. The loop exits gracefully but `lastFlowSolve.residual` carries the gap; `flow.predicted.atEquipment` reads only the sum of what was accepted.
+
+There is no editor field for `flowReconciliation` — it's a runtime-only object. TODO: expose `maxPasses` / `residualTolerance` in the editor.
+
+### Cascaded VGC not test-covered
+
+`valvegroupcontrol` is in `SOURCE_SOFTWARE_TYPES` and `_registerSource` accepts it, so VGC-on-VGC cascades are wired by the router. But:
+
+- No integration tests cover the case.
+- No production deployments use it.
+- Fluid-contract propagation across two VGCs hasn't been validated.
+
+Treat as experimental. Open question whether to remove the entry or harden it.
+
+### Multi-source aggregation is "last write wins" on shared positions
+
+If two upstream sources both publish `flow.predicted.atEquipment` to the same VGC, the later write replaces the earlier one in the measurement container. There is no merge / max / priority logic. In practice this is fine when one VGC has one upstream source; with two upstream sources the behaviour is well-defined but may surprise.
+
+### Source flow events listen on both case variants
+
+`SOURCE_FLOW_EVENTS` includes both `flow.predicted.atEquipment` AND `flow.predicted.atequipment`. A source that emits the event twice (defensive code) will trigger `updateFlow` twice per change — harmless because the second call writes the same value, but it doubles the recompute. Open question whether to canonicalise the event name at the source.
+
+### No FSM — sequences depend on `state` being pre-stamped operational
+
+`specificClass.configure()` does `this.state.stateManager.currentState = 'operational'` immediately so `executeSequence('startup')` etc. can run. This is unusual — other nodes go through `boot` to reach `operational`. The shortcut is intentional (VGC doesn't model the group as a stateful machine; sequences are pass-through to valves) but it means `state.getCurrentState()` always reads `operational` regardless of what the valves are doing.
+
+### No `test/_output-manifest.md`
+
+Per `.claude/rules/output-coverage.md` every node should ship an output manifest with populated + degraded tests for each Port-0 / 1 / 2 key. **Not yet produced** for VGC. Backfill tracked in `.agents/improvements/IMPROVEMENTS_BACKLOG.md`.
+
+### Wiki source-of-truth contradictions found during this review
+
+| Source A | Source B | Issue | TODO |
+|:---|:---|:---|:---|
+| `CONTRACT.md` `set.mode` payload "`auto` / manual" | Schema enum `auto` / `virtualControl` / `fysicalControl` / `maintenance`; `setMode` validates against schema | `CONTRACT.md` prose understates mode count | Update `CONTRACT.md`. |
+| Schema `mode.allowedActions` | `specificClass` only consults `isValidSourceForMode` | Action allow-list dead config | Implement or remove (see above). |
+| Schema `calculationMode` | `specificClass` / `nodeClass` never read it | Dead config | Implement or remove. |
+| `CONTRACT.md` § Children: `valve`, `machine / rotatingmachine / machinegroup / machinegroupcontrol / pumpingstation / valvegroupcontrol` | `specificClass.SOURCE_SOFTWARE_TYPES` lists post-canonicalisation names only (`machine`, `machinegroup`, `pumpingstation`, `valvegroupcontrol`) | Pre-canonical aliases (`rotatingmachine`, `machinegroupcontrol`) are accepted by the router because BaseDomain normalises them — contract text remains correct in spirit | None — informational. |
+| `examples/README.md` lists 3 flows with stub descriptions | Actual flow content not validated against current source | Tier labelling missing; live-deploy validation outstanding | Backfill validation; rename to Tier-1/2/3 convention. |
+
+---
+
+## Open questions (tracked)
+
+| Question | Where it lives |
+|:---|:---|
+| Phase 7 standardisation of valve setpoint payloads (unblocks `set.position`) | `OPEN_QUESTIONS.md` Phase 7 |
+| Should `flowReconciliation.maxPasses` / `residualTolerance` be editor-configurable? | Internal — not yet ticketed |
+| Cascaded `valvegroupcontrol` as upstream source — harden or remove? | Internal |
+| Multi-source priority / merge strategy for shared positions | Internal |
+| Wire `calculationMode` through or strip from schema | Internal |
+| Implement `isValidActionForMode` or strip `allowedActions` from schema | Internal |
+| Output-coverage backfill (`test/_output-manifest.md` + populated/degraded tests) | `.agents/improvements/IMPROVEMENTS_BACKLOG.md` |
+| Rename `vgc.{js,html}` → `valveGroupControl.{js,html}` | `.claude/refactor/MODULE_SPLIT.md` |
+| Validate example flows against live Node-RED; rename to Tier-1/2/3 convention | Internal |
+
+---
+
+## Migration notes
+
+### From `setpoint` topic name (pre-canonical)
+
+The old `setpoint` alias for `set.position` still works but logs a one-time deprecation warning. Switch to `set.position` — though note the handler is currently a no-op (see above).
+
+### From `setMode` / `registerChild` / `execSequence` / `totalFlowChange` / `emergencyStop` / `emergencystop` / `setReconcileInterval` aliases
+
+Every legacy alias emits a one-time deprecation warning. Switch to the canonical topic names listed in [Contracts](Reference-Contracts#topic-contract).
+
+---
+
+## Related pages
+
+| Page | Why |
+|:---|:---|
+| [Home](Home) | Intuitive overview |
+| [Reference — Contracts](Reference-Contracts) | Topic + config + child filters (alias map) |
+| [Reference — Architecture](Reference-Architecture) | Code map, flow-distribution loop, source aggregation |
+| [Reference — Examples](Reference-Examples) | Shipped flows + debug recipes |
+| [machineGroupControl — Limitations](https://gitea.wbd-rd.nl/RnD/machineGroupControl/wiki/Reference-Limitations) | Sibling Unit-level controller's known limitations |
+| [valve wiki](https://gitea.wbd-rd.nl/RnD/valve/wiki/Home) | The child node VGC coordinates |
diff --git a/wiki/_Sidebar.md b/wiki/_Sidebar.md
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+++ b/wiki/_Sidebar.md
@@ -0,0 +1,20 @@
+### valveGroupControl
+
+- [Home](Home)
+
+**Reference**
+
+- [Contracts](Reference-Contracts)
+- [Architecture](Reference-Architecture)
+- [Examples](Reference-Examples)
+- [Limitations](Reference-Limitations)
+
+**Related**
+
+- [EVOLV master wiki](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Home)
+- [valve wiki](https://gitea.wbd-rd.nl/RnD/valve/wiki/Home)
+- [machineGroupControl wiki](https://gitea.wbd-rd.nl/RnD/machineGroupControl/wiki/Home)
+- [pumpingStation wiki](https://gitea.wbd-rd.nl/RnD/pumpingStation/wiki/Home)
+- [Topology Patterns](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topology-Patterns)
+- [Topic Conventions](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Topic-Conventions)
+- [Telemetry](https://gitea.wbd-rd.nl/RnD/EVOLV/wiki/Telemetry)