Connect your chargers with Django

How a roaming charge flows

Sajilo Charge driver       Sajilo Charge hub                 Your Django backend
      │ taps "Start" ────▶ POST /commands/START_SESSION ──▶ onStartSession(charge)
      │                                                      your CSMS starts the charger
      │   charging…   ◀── PUT  sessions push ◀───────────── setActive() / meter(kwh)
      │ taps "Stop"  ────▶ POST /commands/STOP_SESSION ───▶ onStopSession(charge)
      │ wallet debited ◀── POST cdrs ◀──────────────────────  complete(kwh, cost)
      │                    monthly netting ─────────────────▶ you get paid

1.Install the SDK

One download, one package-manager command.

curl -LO https://sajilocharge.com/static/downloads/sajilocharge-ocpi-django.zip
pip install ./sajilocharge-ocpi-django.zip

2.Configure and mount

Tell the SDK who you are and where your server is publicly reachable. This mounts the three /ocpi endpoints the hub calls on you — everything else is outbound from your side.

# settings.py
INSTALLED_APPS += ['sajilocharge_ocpi']

SAJILOCHARGE_OCPI = {
    'PARTY_ID': 'ABC',                       # your 3-char party id
    'COUNTRY_CODE': 'NP',
    'NAME': 'ABC Charging Pvt. Ltd.',
    'BASE_URL': 'https://csms.example.com',  # public URL of this app
    'HANDLERS': 'myapp.ocpi.Handlers',
}

# urls.py
urlpatterns += [path('ocpi/', include('sajilocharge_ocpi.urls'))]

# then:
#   python manage.py migrate

3.Wire your two charger callbacks

Every remote-start request becomes a RoamingCharge handed to your code. You implement exactly two methods; keep them fast and do the charger work asynchronously.

# myapp/ocpi.py — the only file you write
from sajilocharge_ocpi.handlers import BaseHandlers

class Handlers(BaseHandlers):
    def on_start_session(self, charge):
        # charge.location_id / charge.evse_uid say which charger
        my_csms.remote_start(charge.evse_uid, ref=str(charge.id))
        return True   # accepted; do the real work async

    def on_stop_session(self, charge):
        my_csms.remote_stop(ref=str(charge.id))
        return True

4.Drive the charge lifecycle

From your CSMS events, three calls push the matching OCPI Session objects — and the final CDR that bills the driver — to the hub. The CDR is idempotent: it goes out exactly once per charge.

from sajilocharge_ocpi.models import RoamingCharge

charge = RoamingCharge.objects.get(pk=ref)
charge.set_active()                          # energy started flowing
charge.meter(kwh=4.2)                        # periodic session kWh
charge.complete(kwh=18.5, total_cost=462.50) # NPR; issues the CDR

5.Join the network

Request a one-shot registration token from partners@sajilocharge.com. Deploy first — the hub calls your /ocpi endpoints back during the handshake — then run the join. Tokens rotate on every re-registration; the registration token dies on first use.

python manage.py sajilocharge_join --token <registration-token>
python manage.py sajilocharge_status        # → Status: ACTIVE

6.Publish your stations

Locations upsert by id — re-push whenever anything changes, keep live EVSE status fresh, and (optionally) verify drivers in real time for RFID or local starts.

from sajilocharge_ocpi.client import HubClient

HubClient().push_location({
    'id': 'LOC-KTM-01',
    'name': 'ABC Hub Thamel',
    'address': 'Thamel Marg 12',
    'city': 'Kathmandu',
    'coordinates': {'latitude': '27.7154', 'longitude': '85.3123'},
    'publish': True,
    'evses': [{'uid': 'EVSE-01', 'status': 'AVAILABLE',
               'connectors': [{'id': '1', 'standard': 'IEC_62196_T2',
                               'format': 'SOCKET', 'power_type': 'AC_3_PHASE'}]}],
})

# live availability + optional driver check
HubClient().update_evse('LOC-KTM-01', 'EVSE-01', {'status': 'CHARGING'})
HubClient().authorize(token_uid)   # ALLOWED | NO_CREDIT | BLOCKED

Money and settlement

• All amounts are NPR; costs are VAT-exclusive.
• Each CDR credits your inter-party ledger at the hub; settlement is monthly netting minus the hub clearing fee.
• Disputes: the hub's CDR dispute endpoint or partners@sajilocharge.com — open disputes pause netting for that CDR.

Troubleshooting

• Join fails with "could not fetch endpoints" — your base URL isn't publicly reachable, or the OCPI routes aren't mounted. The hub must be able to call you back during the handshake.
• 401 on hub calls — the connection was re-registered somewhere else; join again with a fresh registration token.
• Session push returns "No matching session" — push only charges the hub initiated, after START_SESSION was accepted.
• Rate limits — the hub throttles per-party (default 300 req/min); meter updates every 30–60 s are plenty.

Other stacks

Laravel (Laravel 10 / 11 / 12 · PHP ≥ 8.1) · Node.js (Node ≥ 18 · Express ≥ 4) · Spring Boot (Spring Boot 3.2+ · Java 17+)

Sajilo Charge Django SDK v0.1.0 · OCPI 2.2.1 · Questions: partners@sajilocharge.com