generated: '2026-07-27'
method: searched
source: >-
  CAISO API Terms of Use (https://www.caiso.com/privacy-terms-of-use#api-terms-of-use),
  Interface Specification for OASIS v3.04, OASIS FAQ, CAISO release planning page, and
  live probes on 2026-07-27
description: >-
  CAISO runs the OASIS interface as regulated market infrastructure rather than as a
  developer product, and its lifecycle communication reflects that. There is no versioned
  API path, no published deprecation policy, no Sunset or Deprecation header support, and
  no SLA or status page for the API. Change is announced through the market-participant
  channels — market notices, the release planning process, and the access-gated developer
  site — and the API Terms of Use explicitly warn that backwards-incompatible changes can
  land without notice. The one durable version signal a caller controls is the per-report
  `version` query parameter.
versioning:
  scheme: per-report query parameter
  path_versioning: false
  current: 'varies by report: version=1, version=2 and version=12 all appear in CAISO''s own current FAQ examples'
  docs: https://www.caiso.com/documents/oasis-frequently-asked-questions.pdf
  note: >-
    The context path itself moved from /mrtu-oasis (as published in the v3.04 interface
    specification) to /oasisapi, which is what CAISO's current FAQ examples use and what
    responds today.
deprecation:
  policy_url: null
  policy_published: false
  sunset_header: false
  deprecation_header: false
  statement: >-
    "CAISO will occasionally make changes to its API, including backwards incompatible
    changes. Accordingly, you should consider registering at developer.caiso.com to access
    API specifications and scheduled modifications. Also, parts of the CAISO API are
    undocumented, including certain methods, events, and properties." — CAISO API Terms of
    Use, last updated 2019-08-22.
  observed_retirements:
  - what: oasissta.caiso.com (staging alias)
    evidence: >-
      The v3.04 specification notes "the 'oasissta' version will be retired at some point
      in the future"; the host does not resolve as of 2026-07-27.
  - what: oasismktsim.caiso.com (market simulation environment)
    evidence: >-
      Documented in the specification as the simulation host; does not resolve publicly as
      of 2026-07-27, so there is no publicly reachable OASIS sandbox.
  - what: /mrtu-oasis context path
    evidence: >-
      Superseded by /oasisapi in CAISO's current published examples.
sla:
  url: null
  uptime_target: null
  note: >-
    No service-level commitment is published for the API. The API Terms of Use disclaim all
    warranties, provide the API "as is", and prohibit using the API to monitor CAISO system
    availability or performance.
status_page: null
status_note: >-
  CAISO publishes grid and market condition surfaces (Today's Outlook, ISO Today, the
  Daily Briefing, market notices) but no availability status page for the OASIS API or the
  Today's Outlook feeds.
data_retention:
  window: 39 months
  source: OASIS FAQ Question Two
  note: >-
    Applies to the majority of OASIS reports. Requests whose start date falls outside the
    retained window return error 1014.
change_communication:
- channel: Release planning
  url: https://www.caiso.com/systems-applications/release-planning
  note: >-
    Dated implementation milestones, business requirements specifications and market
    simulation materials for each release.
- channel: Notices
  url: https://www.caiso.com/notices
- channel: Daily Briefing
  url: https://www.caiso.com/daily-briefing
- channel: Developer site (access-gated)
  url: https://developer.caiso.com/
  note: Holds the interface specification, API URL example documents and scheduled modifications.
deprecated_operations: []