openapi: 3.0.3 info: title: Xcel Energy Green Button Connect My Data ApplicationInformation Time API summary: OAuth 2.0 authorized customer energy usage data based on the NAESB ESPI standard. description: 'Xcel Energy Green Button Connect My Data API based on the ESPI (Energy Services Provider Interface) standard developed by NAESB. Enables authorized third-party applications to access customer electricity and natural gas usage data captured by Xcel Energy smart meters. Resources are exposed as Atom feeds and entries containing UsagePoint, MeterReading, IntervalBlock, ReadingType, ElectricPowerUsageSummary, ElectricPowerQualitySummary, LocalTimeParameters, and customer information. Customer authorization is granted via OAuth 2.0 and follows the Green Button Connect specification used by utilities across North America. ' version: 1.1.0 contact: name: Xcel Energy Developer Portal url: https://developer-apim.aws.xcelenergy.com/ license: name: Proprietary url: https://www.xcelenergy.com/privacy_policy x-generated-from: documentation x-last-validated: '2026-05-03' x-standards: - NAESB ESPI 1.1 - Green Button Connect My Data servers: - url: https://api.xcelenergy.com/DataCustodian/espi/1_1/resource description: Xcel Energy Data Custodian (Production) - url: https://developer-apim.aws.xcelenergy.com/DataCustodian/espi/1_1/resource description: Xcel Energy Developer Sandbox tags: - name: Time description: Current device time and time-zone configuration. paths: /tm: get: operationId: getTime summary: Get device time and time-zone parameters description: Returns the Time resource describing the current UTC time and the device time zone. tags: - Time security: - mtls: [] responses: '200': description: Time resource. content: application/sep+xml: schema: $ref: '#/components/schemas/Time' '401': $ref: '#/components/responses/Unauthorized' x-microcks-operation: delay: 0 dispatcher: FALLBACK components: schemas: Time: allOf: - $ref: '#/components/schemas/Resource' - type: object properties: currentTime: type: integer description: Current time as epoch seconds. tzOffset: type: integer description: Offset of local time from UTC in seconds. dstOffset: type: integer description: DST offset from local standard time in seconds. dstStartTime: type: integer dstEndTime: type: integer quality: type: integer description: Time-source quality enumerated value. localTime: type: integer Resource: type: object description: Base IEEE 2030.5 Resource type that all resources inherit from. properties: href: type: string description: Stable URI of the resource. responses: Unauthorized: description: TLS authentication failed or the client certificate is not authorized. securitySchemes: accessToken: type: oauth2 description: Customer-scoped access token issued via the OAuth 2.0 authorization-code grant. flows: authorizationCode: authorizationUrl: https://api.xcelenergy.com/DataCustodian/oauth/authorize tokenUrl: https://api.xcelenergy.com/DataCustodian/oauth/token refreshUrl: https://api.xcelenergy.com/DataCustodian/oauth/token scopes: FB=4_5_15;IntervalDuration=900;BlockDuration=monthly;HistoryLength=34128000: Standard ESPI scope string for 15-minute electric usage data with 13 months of history. clientAccessToken: type: oauth2 description: Application-scoped client access token used for management endpoints (Authorization list, Bulk, ServiceStatus). flows: clientCredentials: tokenUrl: https://api.xcelenergy.com/DataCustodian/oauth/token scopes: DataCustodian_Admin_Access: Administrative scope used for application-level operations. registrationAccessToken: type: http scheme: bearer bearerFormat: Registration Access Token description: Token issued at application registration; used to read or update ApplicationInformation.