# CenterPoint Energy

> CenterPoint Energy (NYSE: CNP) is a US energy delivery company providing electric transmission and
> distribution, natural gas distribution and energy services across Texas, Indiana, Minnesota, Ohio and
> Louisiana. It runs no public developer program and publishes no OpenAPI, GraphQL, AsyncAPI, MCP server
> or A2A agent card. Its machine-readable surfaces are business-to-business and regulator-driven, reachable
> only after registration and a signed agreement.

Generated by the API Evangelist enrichment pipeline on 2026-09-05 from artifacts in this repository and
from provider documents fetched at HTTP 200 on that date. CenterPoint Energy does not publish an llms.txt
of its own — https://www.centerpointenergy.com/llms.txt returned 404 on 2026-09-05. Nothing below is
inferred; every claim traces to a document listed under Sources.

## What an agent can and cannot do here

- There is no callable public API. Nothing on this provider can be invoked with an API key.
- Meter data for CenterPoint Energy electric customers is reached through Smart Meter Texas, a platform
  jointly owned and funded by the four Texas TDSPs (CenterPoint Energy Houston Electric, Oncor, AEP Texas
  and TNMP). The contract is Smart Meter Texas's, not CenterPoint's alone.
- Reaching it requires an SMT entity account, a signed API SSL certificate matching your own domain,
  HTTP Basic credentials issued per DUNS, mutual TLS on every call, and an executed Energy Data Sharing
  Agreement with the customer whose meter you are reading. None of that is self-service.
- The contract is a 185-page PDF. There is no machine-readable description of it anywhere.

## APIs

- [Usage History via Smart Meter Texas Data Access API](https://www.smartmetertexas.com/): REST and SOAP
  at https://services.smartmetertexas.net (UAT https://uatservices.smartmetertexas.net). Functions:
  15-Minute Interval Data, Daily Register Reads, Monthly Billing Reads, Green Button, Meter Attributes,
  Premise Attributes, On-Demand Read, On-Demand Read Status, Report Status, New Subscription,
  Unsubscribe/Cancel Subscription, List Subscriptions, New Energy Data Sharing Agreement, List ESIIDs per
  Agreement, Terminate Agreement, Agreement Status. JSON request and response, except Green Button which
  returns NAESB ESPI XML.
- [Green Button Connect My Data](https://www.smartmetertexas.com/): the /greenbutton/ resource on the same
  interface, returning 15-minute interval, daily register or monthly billing data for one ESI ID in NAESB
  REQ.21 ESPI XML. Synchronous.

## Contract

- [SMT 3.0 Data Access Interface Guide (PDF, 185pp, revised 2024-02-26)](https://www.smartmetertexas.com/commonapi/gethelpguide/help-guides/Smart_Meter_Texas_Interface_Guide.pdf)
- [Smart Meter Texas quick reference guides](https://www.smartmetertexas.com/quickrefguides)

## Standards this provider actually speaks

- NAESB REQ.21 ESPI / Green Button — implemented as a callable endpoint, not a claim.
- ANSI X12 EDI via ERCOT TxSET, transaction set 810_02 (TDSP to Competitive Retailer invoice). CenterPoint
  publishes the EDI transaction names, ESI ID format and SAC04 codes retailers invoice against.

## Runtime semantics an agent should know

- Auth: mutual TLS (TLS 1.0-1.2 per the guide) plus HTTP Basic. No OAuth, no OIDC, no API keys.
- Errors: vendor JSON, {"error":"..."} or errorCode/errorMessage. Not RFC 9457. Documented codes:
  200, 400, 401, 403, 500. No 429 is defined.
- Rate limit: On-Demand Reads are capped at 3,000 per day per TDU — a ceiling shared across every caller
  on CenterPoint's network, not a per-key allowance. No RateLimit-* or Retry-After headers exist, so this
  ceiling is invisible at runtime.
- Idempotency: none. A retried New Subscription must be assumed to create a second subscription.
- Reversibility: subscriptions and data sharing agreements each have a documented inverse
  (UnSubscription, Terminate Agreement). No window is stated for either. An On-Demand Read triggers a
  physical meter read and cannot be undone.
- Pagination: none. Scope is bounded by ESI ID list and date range; bulk results arrive through an
  asynchronous report flow (submit, poll Report Status, collect).

## Other CenterPoint surfaces

- [Competitive Retailers hub](https://www.centerpointenergy.com/en-us/for-business/industry/competitive-retailers): Information Portal (access by request), market notices, retail market guide, TxSET guides.
- [Processes, standards and forms](https://www.centerpointenergy.com/en-us/for-business/industry/competitive-retailers/processes-standards-forms): EDI transaction names, ESI ID format, SAC04 codes.
- [Energy Data Portal](https://energydataportal.centerpointenergy.com/): login-gated whole-building and third-party service-provider usage requests. Its instructions are PDFs, and the PDF links published on the portal itself returned 404 on 2026-09-05.
- [Rates and tariffs](https://www.centerpointenergy.com/en-us/our-services/rates-tariffs): regulated delivery pricing, not API pricing.

## Not published

- OpenAPI / Swagger: absent on every host probed 2026-09-05.
- WSDL: SOAP operations are documented but no ?wsdl or ?singleWsdl document is retrievable.
- GraphQL, MCP server, A2A agent card, AsyncAPI, webhooks: none found.
- /.well-known/ documents: 404 on centerpointenergy.com; smartmetertexas.com answers 200 with a React SPA
  shell for every path including nonexistent ones, which is not a served document.
- Changelog, deprecation policy, SLA, status API, public GitHub organisation, first-party SDK: none found.

## Corrections

An earlier profile of this company credited it with a "Centerpoint Connect Services API" at
api-portal.centerpointconnect.io. That developer portal belongs to Centerpoint Connect, an unrelated
commercial roofing CRM company at centerpointconnect.com, and has been removed from this record.

## Sources

- https://www.smartmetertexas.com/commonapi/gethelpguide/help-guides/Smart_Meter_Texas_Interface_Guide.pdf
- https://www.centerpointenergy.com/en-us/for-business/industry/competitive-retailers
- https://www.centerpointenergy.com/en-us/for-business/industry/competitive-retailers/processes-standards-forms
- https://www.centerpointenergy.com/en-us/our-services/rates-tariffs
- https://energydataportal.centerpointenergy.com/
- https://www.ercot.com/mktrules/guides/txset/index