Zaptec
How Joulo connects a Zaptec charger: Cloud API, OAuth, sync cadence and the OCPP alternative.
Zaptec chargers connect through the Zaptec Cloud API. You sign in with your Zaptec account once. The Go, Go 2 and Pro also speak OCPP 1.6J, so you can choose the direct route instead.
At a glance
| Property | Value |
|---|---|
| Route | Cloud API, or OCPP 1.6J |
| API | Zaptec Cloud API |
| Authentication | OAuth 2.0 |
| Sync | Every 5 minutes |
| MID detection | Zaptec cloud signal, then the Joulo charger catalog |
| Backfill | Automatic, to 1 January 2026 |
How the connection works
Joulo authenticates against the Zaptec Cloud API and lists the chargers on your account. Older integration rows stored a serial number where the API expects a UUID. Joulo resolves the UUID once and writes it back, so the lookup happens only on the first run after an upgrade.
Accounts created before Zaptec offered refresh tokens fall back to credentials held in Supabase Vault.
The OCPP alternative
The Zaptec Go, Go 2 and Pro can connect straight to wss://ocpp.joulo.nl instead of through the Zaptec cloud. You pick the route in the connect wizard. OCPP gives live meter values during a session and removes the dependency on a third-party cloud.
Pointing a charger at Joulo over OCPP disconnects it from any backoffice it currently uses. Check that nobody else operates the charger before you switch.
What Joulo reads
Joulo reads the charge history per charger. Each entry becomes one session with a start time, an end time and the metered energy in kWh.
MID certification
Zaptec reports metering capability per charger, and Joulo checks the model against its hardware catalog as well. The Go 2 and the Pro carry a MID meter. The original Go does not.
Limitations
- Sessions appear once Zaptec closes them in its cloud, so a running session shows partial energy.
- A charger moved between Zaptec installations keeps its UUID. Its history follows the charger, not the site.