Hydro One Green Button Connect My Data (CMD)
Hydro One's Green Button Connect My Data implementation, mandated by Ontario Regulation 633/21. A registered third-party vendor obtains an OAuth 2.0 authorization code after the customer authenticates with Hydro One and consents, then retrieves that customer's electricity usage and billing data as NAESB ESPI XML. The live authorization surface at https://www.hydroone.com/green-button-cmd-home was observed serving a real Green Button authorization request carrying ESPI function-block scope syntax (FB=1_3_4_5_13_15_16_31_37_39_51_53_54_55_56_57_58_59_60_64_65;historyLength=32148000) for a third-party redirect URI. Hydro One does not publish the CMD resource base URI, an OpenAPI definition, or any endpoint reference — Client ID, Client Secret, test accounts, and URI(s) are issued privately during vendor onboarding, followed by a 90-day connectivity test and an exchange of RSA 2048-bit certificates over TLS.