OECS — Open EV Charger Specification

A vendor-neutral JSON Schema for describing the functional and technical specification of an EV charger: hardware ( electrical, mechanical, connectors), software (communication protocols, configuration, smart-charging capability), payment (accepted methods, terminal), and the compliance metadata (datasheets, certificates) behind that data.

One OECS document describes one charger model - a machine-readable counterpart to a manufacturer's datasheet.

Repository layout

schema/1.0.0/           JSON Schema (draft 2020-12), split into modules
  charger.schema.json      root document schema — start here
  hardware.schema.json     housing, electrical I/O, protection, UI, connectivity, safety
  connector.schema.json    per-connector (plug) definition
  software.schema.json     firmware, protocols/profiles, smart charging, configuration
  payment.schema.json      accepted payment methods, ad-hoc payment, terminal hardware
  metadata.schema.json     sources, certificates, document bookkeeping
  common.schema.json       shared primitives (quantities, ranges, ratings, dates)

examples/                Example documents validated against the schema
  minimal.json              smallest valid document
  ac-wallbox-full.json      AC Level 2 wallbox, most fields populated
  dc-fast-charger-full.json DC fast charger with two connectors (CCS2 + CHAdeMO)

docs/GUIDELINE.md        Narrative guide: how to fill out a spec, field-by-field

scripts/bundle.go        Generates dist/<version>/oecs.<version>.schema.json (see Bundled distribution below)
Makefile                 `make bundle` / `make clean`

Bundled distribution

schema/1.0.0/*.schema.json is the maintained source, split into modules for reuse and easier review (see docs/GUIDELINE.md's note on why). For consumers who want one self-contained file with no cross-file $refs, run:

make bundle

This regenerates dist/1.0.0/oecs.1.0.0.schema.json — a single-file, fully self-contained equivalent of schema/1.0.0/charger.schema.json, at a path derived from the schema's own declared version. It's generated output, not hand-edited; re-run make bundle after any change under schema/1.0.0/. make clean removes dist/.

Versioning

Schema modules live under a version directory (schema/1.0.0/). Breaking changes to the schema get a new version directory (e.g. schema/2.0.0/) rather than mutating an existing one in place, so documents can declare version and keep validating against the schema version they were written for.

Contributing

Extend enums and add optional fields freely — the schema favors additive, non-breaking changes. Where a field's value comes from an external, evolving standard (protocol names, connector types), prefer an enum with an other/ otherName escape hatch over an exhaustive closed list. See docs/GUIDELINE.md for the conventions used throughout ( units, ranges, extensibility).