Rey — Virtual OCPP Charge Point Simulator

Rey is a browser-based virtual charge point — an OCPP charge-point simulator you drive in a browser. Point it at a real CSMS to test your backend with no hardware, or explore a full OCPP session against a built-in demo CSMS with zero setup. Every OCPP-J frame is shown live.

Speaks OCPP 1.6, 2.0.1 and 2.1 — pick the version in the UI before you connect. Rey is the one charger across versions, so each speaks its own real message set (StartTransaction / MeterValues / StopTransaction in 1.6, the TransactionEvent lifecycle in 2.0.1 / 2.1).

[ browser UI ] ── ws ──▶ [ Rey relay ] ── wss/ws (ocpp1.6 / 2.0.1 / 2.1) ──▶ [ CSMS ]

The relay exists because a browser WebSocket can't set the Authorization header (OCPP Basic auth) or present a client certificate (mTLS) — the relay holds the real OCPP socket and does that. Each browser session gets its own isolated charger, so many people can use it at once (the CSMS just sees N distinct stations).

Rey does not require you to build a CSMS. It's the OCPP client; it connects to a CSMS that already exists — your own, or an open-source one like CitrineOS (OCPP 2.0.1) or SteVe (OCPP 1.6).

Run it locally

npm install
npm start             # relay + UI on http://localhost:8080 (a demo CSMS runs in-process)

Open http://localhost:8080. Pick an OCPP version (1.6 / 2.0.1 / 2.1), then choose a mode:

• 🎬 Explore — demo CSMS (default): a built-in CSMS runs inside the server and answers whichever version you picked, so you just click Connect and drive the station — no backend of your own needed. Boot → Plug in → Tap RFID → Start → Stop → Unplug, and watch every frame in the live log.
• 🔌 Connect my CSMS: enter your CSMS's wss:// URL (+ station id / Basic-auth password) and Rey connects to it — the relay presents the auth your browser can't.

npm run smoke         # headless end-to-end check across 1.6 / 2.0.1 / 2.1
npm run mock-csms     # (optional) run the mock CSMS standalone on ws://localhost:9000

What works today

• Real OCPP-J WebSocket to a CSMS on all three versions (subprotocols ocpp1.6, ocpp2.0.1, ocpp2.1), Basic-auth ready.
• Built-in demo CSMS (in-process, loopback-only) that speaks all three, so anyone can try it with no setup.
• OCPP 1.6: Boot + heartbeat, StatusNotification, Authorize (idTag), the StartTransaction → MeterValues → StopTransaction session (CSMS-assigned transactionId), flat GetConfiguration / ChangeConfiguration. Responds to RemoteStartTransaction, RemoteStopTransaction, Reset, ChangeAvailability, TriggerMessage, UnlockConnector, DataTransfer.
• OCPP 2.0.1 / 2.1: Boot + heartbeat, connector status, Authorize (idToken), the full TransactionEvent lifecycle (Started / Updated / Ended) with meter values. Responds to RequestStartTransaction, RequestStopTransaction, Reset, TriggerMessage, ChangeAvailability, GetVariables, SetVariables, GetBaseReport → NotifyReport.
• Authentication modes — pick RFID, App (CSMS-driven remote start), or Plug & Charge. PnC (OCPP 2.0.1/2.1): the SECC presents its EVSEID at SessionSetup, then authorises by eMAID and sends Get15118EVCertificate + Authorize — the OCPP-visible half of PnC is real; the ISO 15118 EV↔charger leg itself is represented, not wire-accurate (a browser can't do it).
• Local Authorization List — whitelist an RFID/eMAID on the station and it authorises locally (no Authorize sent to the backend — how a station stays usable offline); unknown tokens still go to the CSMS. Also handles SendLocalList.
• Station nameplate & identity — every session shows the charge point's full identity: CBID (charge point id), OCPP version, vendor / model, serial and firmware (now sent in BootNotification), connector type + count, rated power / voltage / current, plus the ISO 15118 EVSE ID in eMI3 form <Country>*<Operator>*<EVSE id> (e.g. DE*REY*E000001), Charging Station ID and tariff.
• Editable "Station profile" (commissioning) — set any of those before you connect and Rey reports them to the backend: serial / firmware in BootNotification, NumberOfConnectors, rated power driving the meter simulation, and the EVSE ID the SECC presents at Plug & Charge SessionSetup. Inputs are sanitised / clamped server-side.
• Configuration panel with two-way sync — the whole nameplate is mirrored into the device model (2.0.1 / 2.1) / configuration keys (1.6), the same field set across all three versions. Edit a value there — or have the CSMS SetVariables / ChangeConfiguration it — and the nameplate updates live (the EVSE ID recomposes). The panel is labelled "Device model" on 2.0.1 / 2.1 and "Configuration keys" on 1.6.
• Certificate management (all three versions) — click Request a certificate and the charge point generates a real RSA key pair + PKCS#10 CSR (openssl-verifiable) and sends SignCertificate; the demo CSMS drives the full sequence — installs the root trust anchor (InstallCertificate), then returns the signed leaf chain (CertificateSigned: leaf → Sub-CA 2 → Sub-CA 1 from a real 3-tier PKI). Rey shows every cert on the station by tier (subject, issuer, serial, validity, SHA-256 fingerprint). Also handles GetInstalledCertificateIds and DeleteCertificate. On OCPP 1.6 this rides the Security Whitepaper extension (ExtendedTriggerMessage, SignChargePointCertificate). This is the OCPP cert lifecycle (security profiles 2/3, and the rails PnC certs ride on) — not the ISO 15118 EV-side handshake.
• A live frame log with direction, CALL/CALLRESULT/CALLERROR badges, correlated message ids, and expandable JSON.
• Relay guardrails: wss:// (any) or ws://localhost only.
• Charge-point-id clash handling — a CSMS accepts one live connection per id, so if a Connect my CSMS attempt fails, Rey explains the likely cause and offers a one-click "use a unique Station ID & retry".

Roadmap

• Smart charging — SetChargingProfile with a power-limit chart.
• mTLS transport — present a client cert on the OCPP socket (security profile 3), building on the certificate store already here.
• OCPP 2.1 extras — bidirectional / V2X, DER control, battery swap.
• Faults, multi-EVSE, reservations, scenario replay.
• A headless npm package to wire Rey into CSMS CI suites.

Layout

server.js               relay: serves the UI + bridges browser ⇄ CSMS + built-in demo CSMS
src/charger-factory.js  createCharger(version, opts) — picks the right station
src/charger.js          the virtual charge point state machine (OCPP 2.0.1)
src/charger-16.js       the OCPP 1.6 station (StartTransaction / MeterValues / StopTransaction)
src/charger-21.js       the OCPP 2.1 station (2.0.1 messages over the ocpp2.1 subprotocol)
src/certs.js            real X.509 crypto (key/CSR/CA-sign/parse) via node-forge
mock-csms/              a minimal multi-version CSMS + mini-CA (the built-in demo backend)
public/                 the browser UI (station console + live log)
test/smoke.js           end-to-end check across all three versions

A free teaching + testing tool from Learn EV Charging. Not a product — a tool. Contributions welcome via pull request.