# Ameren

> Ameren Corporation is a regulated electric and natural gas utility serving 2.4 million
> electric and 900,000 natural gas customers across Missouri and Illinois through Ameren
> Missouri and Ameren Illinois. Its only public third-party data interface is the Ameren
> Illinois Share My Usage program — an implementation of Green Button Connect My Data on
> the NAESB/ESPI standard, operated with data custodian Aclara — plus a Renewables Portal
> for community solar and collectively owned generation owners in Illinois.

Generated by the API Evangelist enrichment pipeline on 2026-09-02 from this repository's
apis.yml and probed artifacts. Ameren does not publish an llms.txt of its own; /llms.txt
returns 404 on www.ameren.com and an HTML shell on anm.ameren.com and gp.ameren.com.

## What is and is not available

- Ameren publishes NO OpenAPI, Swagger, GraphQL schema, AsyncAPI, WSDL or .proto contract
  at any probed location. See well-known/ameren-well-known.yml for the full probe record.
- There is NO public API reference, NO SDK on any package registry, NO CLI, NO Postman
  collection, NO MCP server and NO A2A agent card.
- The Share My Usage OAuth endpoints and ESPI resource base are NOT published. They are
  provided to an approved third party by Aclara during a 2-4 week registration.
- What IS machine-readable and anonymously reachable: an RFC 9116 security.txt and a live
  OpenID Connect discovery document from Ameren's enterprise identity service.

## Programs

- [Ameren Illinois Share My Usage (Green Button Connect My Data)](https://www.ameren.com/partners/account-and-data/share-my-usage): Authorized third parties retrieve up to 24 months of historical and 24 months of forward electric energy usage data as ESPI XML, with OAuth customer authorization. Illinois only — not available to Missouri customers. Data custodian: Aclara.
- [Third-party registration instructions](https://gp.ameren.com/third-party-registration/instructions): Two-phase application; Ameren Illinois reviews, then Aclara collects technical details. 2-4 weeks. Contact IllinoisBusinessApplications@ameren.com.
- [Third Party Share My Data Registration Guide (PDF)](https://www.ameren.com/-/media/files/resources-and-support/account-and-data/share-usage/third-party-share-my-usage-registration-guide-2019.ashx): The registration form. Business process only — it contains no endpoints, no schemas and no authentication details.
- [Renewables Portal](https://www.ameren.com/service/renewables/developers/renewables-portal): Portal for Illinois Community Renewable Generation (CRGP) and Collectively Owned Generation (COGF) owners to manage subscribers and billing usage credits. "Developers" here means renewable generation developers, not software developers. There is no documented API — it is a human web portal at https://anm.ameren.com.

## Identity

- [OpenID Connect discovery](https://login.eiam.ece.ameren.com/am/oauth2/.well-known/openid-configuration): Live and anonymous. Ameren Enterprise IAM on ForgeRock AM. Advertises PKCE (S256), Pushed Authorization Requests, token revocation, introspection, dynamic client registration, the device grant and mTLS client authentication. Caveat: it is served at the vendor path, not the RFC 8414 root, and every endpoint it advertises is on global.login.eiam.ameren.com, which does not resolve publicly.
- [JWKS](https://login.eiam.ece.ameren.com/am/oauth2/connect/jwk_uri): Live RSA signing keys.

## Security

- [security.txt](https://www.ameren.com/-/media/security.txt): RFC 9116. Contact contactcyber@ameren.com. Served on www.ameren.com (via a 302 from /.well-known/), anm.ameren.com and gp.ameren.com. Its Expires value, 2026-08-09, is in the past as of this writing.

## Company

- [Ameren](https://www.ameren.com/)
- [About Ameren](https://www.ameren.com/about-ameren)
- [Customer Service](https://www.ameren.com/customer-service)
- [Privacy Policy](https://www.ameren.com/privacy)
- [Terms & Conditions](https://www.ameren.com/terms)
- [Outage Center](https://www.ameren.com/outages) — electric service outages; this is not an API status page.
- [GitHub](https://github.com/AmerenCorp) — organization exists, zero public repositories.
- [LinkedIn](https://www.linkedin.com/company/ameren)

## Notes for agents

Ameren is not callable. There is no endpoint an agent can reach, no key it can obtain
self-service, and no contract it can read. Integration requires a human to complete a 2-4
week third-party registration with Ameren Illinois and Aclara, after which the ESPI
interface details are supplied privately.