SimIt simulates entire charging networks — virtual charging stations, EVSEs, and electric vehicles — so CSMS vendors can test every edge case before going live.
From a single connector to hundreds of concurrent stations — SimIt covers every scenario your CSMS needs to handle.
Simulate multiple EVSEs and virtual chargepoints per station. Configure any topology your CSMS expects, from single-port units to large multi-port sites.
Virtual EVs with live battery tracking. Watch the charge level rise as your CSMS manages the session — just like a real vehicle plugged in.
Meter readings flow to your CSMS on schedule, indistinguishable from physical hardware. Your billing and reporting features get real data to work with.
Supports both AC (up to 11 kW) and DC fast-charging (up to 90 kW) modes with dynamic power distribution and charging profile management.
Full programmatic control over every simulator lifecycle. Integrate directly with your test harness, CI pipeline, or load-testing scripts.
Simulate disconnects, reconnects, and error states on demand. Verify your CSMS handles degraded conditions safely and recovers correctly.
Run time-dependent scenarios — session timeouts, reservation expiry, scheduled charging — instantly, without waiting for real time to pass.
Spin up hundreds of concurrent charging stations and EVs simultaneously. SimIt's cloud infrastructure handles the scale — no setup, no provisioning required on your end.
Each station reconnects automatically with random jitter on connection loss, mirroring real-world charger behaviour your CSMS must handle.
Sign up for free and get your API key instantly — no installation, no setup, no waiting.
POST to the API with your CSMS WebSocket URL. SimIt connects immediately and begins the OCPP handshake.
Create a virtual EV, connect it to a connector, and configure battery capacity and initial SOC.
Start transactions, inject faults, disconnect the network — then verify your CSMS responds correctly.
All operations are available as REST endpoints secured with an API key header (SIMIT-API-KEY).
Create a free account at simit.ddosoft.com and get your API key instantly — no credit card needed.
POST to /cs/create/{id} with your CSMS WebSocket URL. SimIt connects immediately over OCPP.
Create an EV and connect it to a connector. Configure battery capacity and initial SOC as needed.
Trigger a charge session and watch MeterValues flow to your CSMS in real time.
Everything you need to know about OCPP, EV charging simulation, and SimIt.
Understanding OCPP
OCPP (Open Charge Point Protocol) is the open communication standard between EV charging stations and a back-end management platform (CSMS). It defines how a charger authenticates drivers, starts and stops sessions, reports energy, and receives remote commands. OCPP 1.6 over JSON/WebSocket is the most widely deployed version today.
A CSMS (Charge Station Management System) is the server-side software that manages a network of EV chargers — handling driver auth, billing, remote control, energy reporting, firmware updates, and smart charging. SimIt lets CSMS vendors test all of this without physical hardware.
EVSE (Electric Vehicle Supply Equipment) is the logical or physical unit that supplies power to an EV — what most people call a charging point or connector outlet. One station can contain multiple EVSEs, each with one or more connectors. SimIt simulates this full hierarchy.
OCPP 1.6 uses a flat message model over a single WebSocket per station. OCPP 2.0.1 introduces a structured device model, native multi-EVSE support, enhanced security (TLS, certificates), improved smart charging, and display message support. SimIt fully supports OCPP 1.6; 2.0.1 is in active development.
SimIt fully implements OCPP 1.6 — including BootNotification, Heartbeat, Authorize, StartTransaction, StopTransaction, MeterValues, StatusNotification, RemoteStart/Stop, Reset, GetConfiguration, ChangeConfiguration, and more. OCPP 2.0.1 and 2.1 are on the roadmap.
Getting Started
Yes. Sign up and receive your API key instantly — no credit card, no trial period, no waiting. Each key has a CS limit (concurrent stations) and EV limit (concurrent virtual vehicles). Contact us for higher limits needed for large-scale load testing.
No. SimIt is a cloud service at simit.ddosoft.com. Sign up, get your API key, and start making REST API calls immediately — no Docker, no server to manage. It works from any environment: dev machine, CI pipeline, or load-testing script.
Pass your CSMS WebSocket URL when creating a station. SimIt opens the connection immediately, sends BootNotification, and begins periodic Heartbeats at the interval your CSMS specifies. Both unauthenticated and Basic-auth endpoints are supported, as well as WSS.
SimIt connects out to your CSMS URL, so it must be publicly reachable. For local dev: ngrok (ngrok http 9000, free tier, random subdomain) or Cloudflare Tunnel (cloudflared tunnel --url http://localhost:9000, free, persistent subdomain, no rate limits).
Simulating Charging Sessions
Create a station, connect it to your CSMS, create a virtual EV, and plug it into a connector. Your CSMS sends RemoteStartTransaction — SimIt responds Accepted, opens the transaction, and begins sending periodic MeterValues. The EV's SOC rises realistically throughout the session.
Use the error endpoints to set any OCPP 1.6 error code on a connector: Faulted, GroundFailure, HighTemperature, InternalError, OverCurrentFailure, PowerMeterFailure, OtherError. SimIt sends a StatusNotification immediately. Use the reset endpoint to clear it.
Call network/disconnect to drop the WebSocket instantly — as if the charger lost internet. SimIt then reconnects automatically with exponential backoff and random jitter, exercising your CSMS reconnect logic and session recovery. Call network/connect to reconnect on demand.
Scale & Performance
Yes. Each station runs as an independent asyncio task with its own WebSocket connection. Create, update, and delete hundreds simultaneously via the REST API. SimIt's cloud infrastructure handles the concurrency — no configuration needed on your side.
Yes, this is a primary use case. Script the REST API to spin up hundreds of stations and EVs, start transactions across all of them, and observe how your CSMS handles concurrent BootNotifications, Heartbeats, MeterValues, and transaction messages — all sending realistic OCPP 1.6 traffic, not synthetic pings.
Integration & Security
No. SimIt simulates charging stations, EVSEs, connectors, and electric vehicles entirely in software. From your CSMS's perspective it is indistinguishable from real hardware. Ideal for teams building a CSMS before chargers are available, or for automated regression testing after every code change.
SimIt REST API calls require the SIMIT-API-KEY header. For outbound CSMS connections, SimIt supports unauthenticated WebSocket URLs, Basic-auth credentials embedded in the URL (ws://user:pass@csms.example.com/...), and TLS/WSS connections.