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A pylon is the physical sign at a site that shows the current charging price and how many spots are free — familiar from fuel stations, and increasingly common at charging sites. By the end of this playbook you’ll be able to read both figures from the API and keep them current on the display.

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Before you start

You’ll need an API key, and the ID of the location the pylon serves. Both figures come from that location: its EVSEs carry their status, and their connectors carry the tariff that sets the price.

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Show the current price

1

Fetch the location and find its tariff

Fetch the site by ID. Each EVSE’s connectors carry tariffIds — the currently valid tariffs for that connector.
2

Fetch the tariff and read the price

Fetch the tariff by that ID:
The price per kWh is the price on the price component of type ENERGY; the currency sits on the tariff. The price is exclusive of VAT — apply the component’s vat if the pylon shows a consumer-facing, VAT-inclusive figure.
A tariff can hold more than one element, each with its own restrictions (time of day, day of week, date range). Elements are evaluated top to bottom, and the first whose restrictions match applies — so to show the current price, pick the first element whose restrictions are satisfied right now, then read its ENERGY component. A tariff with a single, unrestricted element has one price. The structure follows OCPI 2.1.1.

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Show charger availability

Fetch the same location and count the EVSEs whose status is AVAILABLE — that’s the number of free charging spots.
The status on each EVSE is an OCPI value — AVAILABLE, CHARGING, BLOCKED, OUTOFORDER, and so on — so a simple count of AVAILABLE EVSEs gives the free-spot figure for the display.

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Keep it current

A single location call returns both the EVSE statuses and the connector tariffIds, so one request per refresh covers availability. Tariffs change rarely — fetch each one once and cache it, refetching only when a connector’s tariffIds change.
  • Poll on a sensible interval and stay within the rate limit of 120 requests per minute — availability changes far faster than price, so you can refresh it more often.
  • Evaluate tariff restrictions in local time, so time-of-day pricing flips at the right moment on the display.
  • Fail gracefully. If a request errors, keep showing the last known values rather than blanking the pylon, and retry with backoff. See Errors.

Locations

The site, its EVSEs, and their connectors and status.

EVSEs

EVSE status values and what they mean.