# ENMAX

> ENMAX Corporation is the Calgary-based energy company owned outright by The City of Calgary — a regulated wires company (ENMAX Power), a competitive generator and retailer (ENMAX Energy, Easymax brand), and, through Versant Power, the transmission and distribution utility for northern and eastern Maine. ENMAX publishes **no developer portal, no API documentation and no machine-readable API contract**. It does publish real, anonymously queryable grid data as ArcGIS REST feature services. Customer energy usage data is completely closed — ENMAX's own support page states it "is view-only within your online account and can't be exported at this time," so there is no API, no CSV, no XML and no Green Button.

This file was generated by API Evangelist from verified probes of ENMAX's public surfaces on 2026-07-27. https://www.enmax.com/llms.txt returns HTTP 404 — ENMAX publishes no llms.txt of its own.

## What actually exists

- [ENMAX Power System Capacity ArcGIS Feature Services](https://services1.arcgis.com/NKgP4VcXUzEyOnmg/arcgis/rest/services?f=json): The service directory for ENMAX Power's public grid data. Anonymous, no key, no signup, no terms. Nine FeatureServers, three of which carry the published maps.
- [Hosting capacity](https://services1.arcgis.com/NKgP4VcXUzEyOnmg/arcgis/rest/services/Generation_Capacity_Layers_20250219_PUBLIC/FeatureServer): Estimated remaining DER interconnection headroom by three-phase feeder segment, vintage February 2025, 2,852 features.
- [Load capacity](https://services1.arcgis.com/NKgP4VcXUzEyOnmg/arcgis/rest/services/Feeder_Load_Capacity_Rev9_20251211/FeatureServer): Estimated remaining load capacity by two- and three-phase feeder segment, vintage December 2025, 30,057 features.
- [Service area](https://services1.arcgis.com/NKgP4VcXUzEyOnmg/arcgis/rest/services/ENMAX_Service_Area_for_LAF_Verification/FeatureServer): The ENMAX Power distribution boundary as three polygons, each carrying the connection-enquiry URL for that zone.

## How to call it

Issue an anonymous HTTPS GET. No credential of any kind is required.

    GET https://services1.arcgis.com/NKgP4VcXUzEyOnmg/arcgis/rest/services/Feeder_Load_Capacity_Rev9_20251211/FeatureServer/0/query?where=1%3D1&outFields=*&returnGeometry=false&resultRecordCount=10&f=json

Four things an agent must know before doing so:

1. **Errors come back as HTTP 200.** An invalid field, a missing layer and a missing service all return status 200 with `{"error":{"code":400,...}}` in the body. Branch on the body, never on the status line.
2. **Results are truncated silently at 1,000 rows.** Watch `exceededTransferLimit` and page with `resultOffset` / `resultRecordCount`. `returnCountOnly=true` gives the total.
3. **The URL is the version.** Service names are date-stamped (`Rev9_20251211`) and roll over with no deprecation notice. Re-read the service directory on every run rather than pinning a path. The superseded `Feeder_Load_Capacity_Rev8_20240731` is still live and still answering with year-old figures.
4. **Rate limits are real but shared.** Every response carries `x-esri-org-request-units-per-min: usage=N;max=6000`, metered across the whole hosting tenant. Cache — the data changes a few times a year.

## What does not exist

- No developer portal. `developer.enmax.com`, `developers.enmax.com`, `api.enmax.com`, `docs.enmax.com` and `data.enmax.com` are wildcard DNS with no origin behind them (HTTP 525). `/developers`, `/developer`, `/api`, `/data`, `/open-data` on www.enmax.com all 404.
- No OpenAPI, Swagger, AsyncAPI, GraphQL, MCP server, SDK, CLI, Postman collection or sandbox.
- No OAuth 2.0, no OpenID Connect, no API keys, no scopes, no third-party registration.
- No Green Button (DMD or CMD), no NAESB ESPI, no IEEE 2030.5, no OpenADR, no IEC CIM. ENMAX is under no mandate to provide any of them — Alberta has no equivalent of Ontario's O. Reg. 633/21, Canada has no federal energy data right, and Maine imposes none on Versant Power.
- No changelog, no SLA, no API status page, no deprecation policy, no data licence, no rate-limit documentation and no API support contact.
- No consumer energy data path at all. The customer cannot export their own usage, so no third party can be delegated it.

Note: the word "developer" across enmax.com refers to LAND and PROPERTY developers building subdivisions that need electrical service. It is never a software developer. Anything keyed on the word alone will misclassify this provider.

## API Evangelist artifacts for ENMAX

Repo: https://github.com/api-evangelist/enmax

- [apis.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/apis.yml): APIs.json index for the provider.
- [review.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/review.yml): The full mandate/no-mandate review, jurisdiction by jurisdiction, with every probe and status code.
- [conventions/enmax-conventions.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/conventions/enmax-conventions.yml): Observed request/response semantics — format negotiation, filtering, pagination, caching, CORS, tracing.
- [errors/enmax-problem-types.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/errors/enmax-problem-types.yml): The error envelope and every failure mode reproduced anonymously.
- [rate-limits/enmax-rate-limits.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/rate-limits/enmax-rate-limits.yml): The Esri request-unit quota signalled on every response.
- [authentication/enmax-authentication.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/authentication/enmax-authentication.yml): The auth posture — none on the published surface, session-only for customers.
- [data-model/enmax-data-model.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/data-model/enmax-data-model.yml): Entities, fields, the FEEDERID join and the Calgary 3TM spatial reference.
- [lifecycle/enmax-lifecycle.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/lifecycle/enmax-lifecycle.yml): Versioning by service name, and what happens when a revision rolls.
- [conformance/enmax-conformance.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/conformance/enmax-conformance.yml): Standard-by-standard conformance, including every energy-sector standard checked and ruled out.
- [security/enmax-domain-security.yml](https://raw.githubusercontent.com/api-evangelist/enmax/refs/heads/main/security/enmax-domain-security.yml): TLS, HSTS, DNSSEC, CAA, SPF and DMARC posture.
- [examples/](https://github.com/api-evangelist/enmax/tree/main/examples): Verbatim live responses — Esri JSON, GeoJSON, and the error body.

## Human pages

- [ENMAX](https://www.enmax.com/)
- [System resources — where the three maps are linked](https://www.enmax.com/system-resources)
- [Hosting capacity map](https://www.enmax.com/system-resources/hosting-capacity-map)
- [Load capacity map](https://www.enmax.com/system-resources/load-capacity-map)
- [Service area map](https://www.enmax.com/system-resources/service-area-map)
- [About ENMAX](https://www.enmax.com/about-us)
- [News](https://www.enmax.com/news)
- [Customer support](https://www.enmax.com/customer-support)
- [Contact us](https://www.enmax.com/contact-us)
- [Terms of use](https://www.enmax.com/terms-of-use)
- [Privacy](https://www.enmax.com/privacy)
- [Outage portal (electricity outages, not API status)](https://outages.enmax.com/)
- [MyAccount sign in](https://myaccount.enmax.com/)

## Elsewhere

Alberta wholesale market and transmission data is not ENMAX's to publish — it belongs to the Alberta Electric System Operator. ENMAX's own system-resources page defers to [AESO's transmission capability map](https://www.aeso.ca/grid/connecting-to-the-grid/transmission-capability-map/) and to the [City of Calgary development map](https://developmentmap.calgary.ca/).