Overview
Joulo REST API reference • base URL, authentication, rate limits, and response format
The Joulo API gives you programmatic access to your EV charger data, charging sessions, and energy statistics. All API access is over HTTPS and returns JSON.
Base URL
https://api.joulo.nl/functions/v1/apiThe sandbox runs the same code on test data at https://api-staging.joulo.nl/functions/v1/api.
Four parts, one base URL
| Part | Token | Reference |
|---|---|---|
| Personal API | An API token from your dashboard, or an OAuth2 token | The endpoints below |
| Partner API | A partner API key: jpk_live_ on production, jpk_test_ on the sandbox | Partner API in the menu |
| CPO API | A client credentials token from /functions/v1/oauth-token | CPO API in the menu |
| Sandbox helpers | Your sandbox partner key or CPO client, on the sandbox only | Sandbox in the menu |
Every part is described in one OpenAPI document. We announce breaking changes in the API changelog before they take effect.
Authentication
All requests must include a valid token in the Authorization header:
Authorization: Bearer YOUR_API_TOKENGenerate your API token from the Joulo dashboard under Developer → API. See Authentication for full details, including OAuth2 support.
Personal API endpoints
| Method | Path | Description |
|---|---|---|
GET | /chargers | List all chargers with status and active session info |
POST | /chargers | Register a new charger (OCPP) |
GET | /sessions | List charging sessions with filtering and pagination |
GET | /energy | Get monthly energy aggregates and lifetime totals |
GET | /ere-position | Get your ERE reserve/sell/forecast position with per-quarter sales |
Response format
All responses are JSON with Content-Type: application/json. Timestamps are in ISO 8601 format (YYYY-MM-DDTHH:mm:ssZ). Numeric values (kWh, credits) are rounded to two decimal places.
Pagination
The GET /sessions endpoint supports pagination with limit and offset query parameters.
| Parameter | Type | Default | Max | Description |
|---|---|---|---|---|
limit | integer | 20 | 100 | Number of records to return |
offset | integer | 0 | • | Number of records to skip |
Rate limits
Requests are rate-limited per token. If you exceed the limit, the API returns 429 Too Many Requests.
The GET /energy endpoint is ideal for infrequent polling (e.g. once per hour) since it returns aggregated data. Reserve GET /chargers for more frequent checks when you need real-time status.