aid: trolie name: TROLIE description: TROLIE (Transmission Ratings and Operating Limits Information Exchange) is an open-source LF Energy project, hosted under LF Projects, that defines an OpenAPI-based REST specification for exchanging transmission facility ratings and operating limits. It responds to FERC Order 881, which requires North American Transmission Owners, Transmission Operators, Transmission Providers and Reliability Coordinators to exchange ambient-adjusted and forecasted ratings. The project publishes the 1.0 specification, usage examples for forecast, real-time, seasonal and temporary ratings, decision records, a conformance suite and a Java client SDK on GitHub. url: https://raw.githubusercontent.com/api-evangelist/trolie/refs/heads/main/apis.yml x-type: company x-source: harvest:spectral-ruleset-github x-tier: profiled x-tier-reason: enrichment pass 2026-10-09 (modular-v1; was harvest) specificationVersion: '0.20' created: '2026-10-09' modified: '2026-10-09' tags: - Company - Energy - Electric Grid - Transmission - Open Standards - OpenAPI - LF Energy - Open Source maintainers: - FN: Kin Lane email: kin@apievangelist.com - FN: APIs.json email: info@apis.io image: https://trolie.energy/images/TROLIE-icon-white.svg common: - type: AgenticAccess url: agentic-access/trolie-agentic-access.yml - type: Spectral url: rules/trolie-spec-spectral-rules.yml - type: Spectral url: rules/trolie-rules.yml - type: JSONLD url: json-ld/trolie-context.jsonld - type: Vocabulary url: vocabulary/trolie-vocabulary.yml - type: AgentSkill url: skills/_index.yml - type: DataModel url: data-model/trolie-data-model.yml - type: ChangeLog url: changelog/trolie-changelog.yml - type: Conventions url: conventions/trolie-conventions.yml - type: Deprecation url: lifecycle/trolie-lifecycle.yml - type: Lifecycle url: lifecycle/trolie-lifecycle.yml - type: ErrorCatalog url: errors/trolie-problem-types.yml - type: Conformance url: conformance/trolie-conformance.yml - type: Overlay url: overlays/trolie-openapi-overlay.yaml - type: WellKnown url: well-known/trolie-well-known.yml - type: Hosts url: hosts/trolie-hosts.yml - type: Vendors url: vendors/trolie-vendors.yml - type: SDKs url: packages/trolie-packages.yml - type: Packages url: packages/trolie-packages.yml - type: Authentication url: authentication/trolie-authentication.yml - type: OAuthScopes url: scopes/trolie-scopes.yml - type: DomainSecurity url: security/trolie-domain-security.yml - type: Website url: https://trolie.energy/ - type: SpectralRules url: https://github.com/trolie/spec/blob/39741d03365cb430ab5d7e677312759a7f4a6d14/.spectral.yaml - type: APIReference url: https://trolie.energy/spec-1.0 - type: GettingStarted url: https://trolie.energy/concepts.html - type: UsageExamples url: https://trolie.energy/usage-examples.html - type: FAQ url: https://trolie.energy/faq.html - type: Blog url: https://trolie.energy/community_events.html - type: GitHubOrganization url: https://github.com/trolie - type: GitHubRepository url: https://github.com/TROLIE/spec - type: ChangeLog url: https://github.com/trolie/spec/releases - type: Issues url: https://github.com/trolie/spec/issues - type: Support url: https://lists.lfenergy.org/g/trolie-general - type: Foundation url: https://lfenergy.org/projects/trolie/ apis: - aid: trolie:trolie-forecasting-api name: TROLIE Forecasting API description: >- The Forecasting API operations define the exchange of forecasted ratings, including the 240-hour-ahead forecasted AAR data exchange required by FERC Order 881. The operations support submitting rating proposals, querying in-use limits, and monitoring the health and validity of submissions against the Rating Provider's obligations. humanURL: https://trolie.energy/spec-1.0 tags: - Forecasting properties: - type: OpenAPI url: openapi/trolie-forecasting-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json - aid: trolie:trolie-monitoring-sets-api name: TROLIE Monitoring Sets API description: >- [Monitoring Sets](https://trolie.energy/concepts#monitoring-sets) are named sets of power system resources that may be used to filter ratings and limits returned by queries against these APIs. How Monitoring Sets are defined is beyond the scope of the TROLIE specification, and it is assumed that the sender and receiver have predefined the appropriate Monitoring Sets. humanURL: https://trolie.energy/spec-1.0 tags: - Monitoring Sets properties: - type: OpenAPI url: openapi/trolie-monitoring-sets-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json - aid: trolie:trolie-seasonal-api name: TROLIE Seasonal API description: >- Seasonal ratings are static ratings associated with extended durations, typically months. These are typically used in both planning and operations. Power system resources that are exempt from providing AARs generally operate at a seasonal rating. Even for resources using dynamic ratings, a seasonal rating is still necessary. This acts as a recourse when a dynamic rating is unavailable. For example, a dynamic rating might be unavailable during communication outages or for forecasts beyond the ten-day period required by FERC Order 881. humanURL: https://trolie.energy/spec-1.0 tags: - Seasonal properties: - type: OpenAPI url: openapi/trolie-seasonal-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json - aid: trolie:trolie-seasonal-overrides-api name: TROLIE Seasonal Overrides API description: >- A Seasonal Override instructs the system to use a temporary static rating instead of any concurrent Seasonal Rating for a resource. A typical use case is a so-called 'de-rate' due to a temporary clearance issue for a transmission facility that is exempt from providing AARs. Exempt facilities typically operate at a seasonal rating. However, instead of updating the seasonal rating schedule, a Ratings Provider can send a Seasonal Override. During the override period, the Clearinghouse uses the Seasonal Override rating instead of any scheduled seasonal ratings. For resources required to provide AARs, a Ratings Provider would issue a Temporary AAR Exception to address temporary conditions requiring a static rating. humanURL: https://trolie.energy/spec-1.0 tags: - Seasonal Overrides properties: - type: OpenAPI url: openapi/trolie-seasonal-overrides-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json - aid: trolie:trolie-temporary-aar-exceptions-api name: TROLIE Temporary AAR Exceptions API description: "A [Temporary AAR Exception](https://trolie.energy/concepts#temporary-aar-exception) is\n\ provided by the Ratings Provider when a Ratings Obligation cannot be\nfulfilled, due to some temporary\ \ operating condition impacting the related\npower system resource. This could occur in various scenarios:\n\ \n * An equipment failure.\n * An unforeseen condition on a related part of the power grid.\n *\ \ Some ambient condition that is not part of the model is heating the\n line, like a wildfire.\n\ \ * Something in the surrounding environment is affecting the amount that a\n line is allowed\ \ to sag. For example, this may occur for lines over\n rivers when very large ships pass under\ \ them\n\nA Temporary AAR Exception serves two main purposes: documenting the reason\nfor the exception\ \ and providing a temporary rating value set. It is employed\nin three distinct circumstances:\n\n\ 1. Firstly, Order 881 mandates documentation and archival of all use of\n alternate ratings in lieu\ \ of AARs. Ratings Providers should continue to\n provide real-time and forecast ratings for the affected\ \ resource, but\n these should match the rating provided with the Temporary AAR Exception\n while\ \ the latter is in effect. This temporary rating, and the reason that\n it occurred, must be captured\ \ in history regardless of the provided\n ratings. The reason and the end date of the effective window\ \ may be\n updated after the object has been created, up to a configurable threshold.\n\n If the\ \ Ratings Providers provides ratings that deviate from the static\n Temporary AAR Exception rating,\ \ the Clearinghouse Provider must decide\n whether to use those or the static rating. The Clearinghouse\ \ Provider\n advise its Ratings Providers on how it will choose ahead of time. This\n specification\ \ recommends using the dynamic rating provided, but it does\n not mandate it.\n\n2. Secondly, Temporary\ \ AAR Exceptions apply when the Clearinghouse\n Provider is generating forecast rating proposals\ \ on behalf of the Ratings Provider, e.g., when lookup tables are provided ahead of time by the Ratings\ \ Provider.\n Since there is no external ratings, the Clearinghouse Provider\n wouldn't otherwise\ \ know that a temporary static rating is needed. \n\n3. Finally, for facilities where dynamic ratings\ \ are provided, it is\n possible that a communications outage or other issue could prevent the\n\ \ Clearinghouse Provider from receiving the dynamic ratings. In this case,\n the Clearinghouse Provider\ \ would use a Temporary AAR Exception rating." humanURL: https://trolie.energy/spec-1.0 tags: - Temporary AAR Exceptions properties: - type: OpenAPI url: openapi/trolie-temporary-aar-exceptions-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json - aid: trolie:trolie-realtime-api name: TROLIE Realtime API description: >- If permitted by the Clearinghouse Provider, its Ratings Providers can use these functions to exchange real-time ratings, supplementing or replacing traditional telemetry protocols like ICCP. humanURL: https://trolie.energy/spec-1.0 tags: - Realtime properties: - type: OpenAPI url: openapi/trolie-realtime-api-openapi.yml - type: Documentation url: https://trolie.energy/spec-1.0 - type: JSONSchema url: json-schema/trolie-forecast-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-real-time-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-seasonal-ratings-proposal-status-schema.json - type: JSONSchema url: json-schema/trolie-realtime-proposal-schema.json - type: JSONSchema url: json-schema/trolie-forecast-limits-snapshot-slim-inputs-used-schema.json - type: JSONSchema url: json-schema/trolie-realtime-limits-snapshot-slim-inputs-used-schema.json x-enrichment: date: '2026-10-09' status: enriched artifacts_added: 43 pass: modular-v1 engine: identity=anthropic,contract=anthropic,surfaces=anthropic,docs=anthropic,regulatory=anthropic