Virtual

An in-memory connector with no hardware behind it. A Virtual connector holds values, computed properties and methods that dashboards and scripts read and write exactly like a device — but nothing is connected. Use it as a shared scratchpad: setpoints a dashboard slider adjusts and a script reads, status text a script writes and a dashboard shows, counters, flags, derived values.

The driver itself declares no properties and no actions. Everything the connector exposes comes from the connector file's own properties: and methods: blocks. State lives in the file's module-scope variables.

Safety gate

This driver ships with requiresSafetyGates: false — there is no hardware to protect, so writes and calls bypass the safety gate entirely and no audit rows are written. See Per-driver opt-out.

Declaring one

The driver: keyword is optional. A connector file with no driver: / protocol: / engine: key resolves to Virtual automatically, as long as every top-level key is a standard connector key:

config, properties, methods, poll, ai, hide, expose, safety, allowedConnectors, allowedHosts

// workspace/connectors/store.js
let setpoint = 20;
let running = false;
let status = "Idle";

export default {
  ai: { instructions: "In-memory store with no hardware attached. Safe to read and write freely." },

  properties: {
    setpoint: { get: () => setpoint, set: (v) => { setpoint = Number(v); },  description: "Target setpoint", poll: true },
    running:  { get: () => running,  set: (v) => { running = Boolean(v); },  description: "Run flag",        poll: true },
    status:   { get: () => status,   set: (v) => { status = String(v); },    description: "Status line",     poll: true },
    summary:  { get: () => `${status} — setpoint ${setpoint}${running ? " (running)" : ""}`, poll: true },
  },

  methods: {
    reset: [() => { setpoint = 20; running = false; status = "Idle"; }, "Restore defaults"],
  },
};

driver: "Virtual" (or engine: "Virtual") is accepted too if you prefer the keyword spelled out — that's what the Add Connector template uses.

Unknown keys still fail

Only files whose top-level keys are all standard resolve to Virtual. A misspelt keyword is an unknown key, so it keeps the usual load error and the connector shows as disabled in the Hardware panel with the offending key named:

Connector config missing 'driver' / 'protocol' / 'engine': …/psu.js (unrecognised top-level key: drivr)

This is deliberate: drivr: "Webcam" must not quietly turn into an empty store.

.json connector files are unaffected — they still require an explicit "driver" field.

Properties

None from the driver. A property with a set is writable (R/W); one with only a get is read-only (R). The type shown in the Hardware panel is inferred from the last value read.

Actions

None from the driver. Declare them under methods: in any of the three usual forms (bare function, [fn, "description"], { fn, description }).

Config Options

None. A config: block is allowed but ignored by the driver — use it for your own constants if you like.

Using it

From a script:

const s = connector("store");
s.setpoint = 42;          // write — dashboards update immediately
if (s.running) { … }      // read
s.reset();                // method

From a dashboard: bind any widget to store.setpoint, store.running, store.status, … A slider bound to store.setpoint writes it; a gauge bound to the same property follows.

From another connector: list it in that connector's allowedConnectors and call connector("store") from its methods.

Polling and updates

• A direct property write (script, dashboard, AI) updates the value and broadcasts a state: event immediately. No polling is involved.
• A value changed inside a method (reset() above) is only noticed by the poller, so mark such properties poll: true (or list them in a top-level poll: [...] array) to keep dashboards in sync.
• Computed read-only properties (summary) are re-read on each poll, so they follow the values they derive from.

Persistence

In memory only. Values reset to the file's initial let values whenever the server restarts or the connector reloads. If a value must survive, write it out with FileAccess and read it back in a getter or a startup script.

Limits

Virtual connectors count against your tier's connector limit like any other connector.