generated: '2026-07-27'
method: searched
source: >-
  PJM Data Miner API Guide (v15, 02/10/2026) section V.C, plus HTTP statuses observed
  on anonymous probes of api.pjm.com, messages.pjm.com, services.pjm.com,
  pjmoasis.pjm.com and emergencyprocedures.pjm.com on 2026-07-27.
format: custom
rfc9457: false
note: >-
  PJM does not use RFC 9457 problem+json. Data Miner 2 returns a proprietary JSON
  envelope with an errors[] array; the eTools JAX-RS surfaces return a RESTEasy XML
  errorResponse document. No error code registry is published — the message strings
  below are quoted verbatim from PJM's own guide, and the status codes are the ones
  observed live.
envelopes:
- surface: PJM Data Miner 2 API
  media_type: application/json
  shape: '{"errors": [{"field": "<field>", "message": "<message>", "detail": ["<attribute>"]}]}'
  fields:
    field: The request component at fault (Filters, Order, Sort).
    message: Human-readable explanation.
    detail: Optional array naming the offending attribute(s).
- surface: PJM eTools JAX-RS (RESTEasy) browserless interfaces
  media_type: application/xml
  shape: '<errorResponse><errorType>...</errorType><message>...</message></errorResponse>'
  example_observed: >-
    HTTP 500 with errorType javax.ws.rs.NotFoundException and message
    "RESTEASY003210: Could not find resource for full path: ..." from GET
    https://emergencyprocedures.pjm.com/ep/rest/public/procedures on 2026-07-27.
statuses:
- status: 200
  meaning: Success.
  surfaces: [Data Miner 2, Messages public web service, OASIS public information page]
- status: 400
  meaning: >-
    Validation failure. Returned for the documented filter/sort/order errors below,
    and when download=true is used and the maximum row threshold is crossed.
  surface: Data Miner 2
- status: 401
  meaning: >-
    Missing or invalid Azure API Management subscription key. Every Data Miner feed
    answers 401 anonymously.
  surface: Data Miner 2
  verified:
  - 'GET https://api.pjm.com/api/v1/ -> 401'
  - 'GET https://api.pjm.com/api/v1/gen_by_fuel?rowCount=1 -> 401'
  - 'GET https://api.pjm.com/api/v1/gen_by_fuel/metadata -> 401'
  - 'GET https://api-train.pjm.com/api/v1/pnode -> 401'
  - 'GET https://services.pjm.com/PJMDataminerApi/api/Ancillary/GetDispatchReserves -> 401'
- status: 404
  meaning: >-
    Unknown feed short name. Distinguishes a non-existent route from a key-gated one —
    real feeds answer 401 anonymously, invented feed names answer 404.
  surface: Data Miner 2
  verified: 'GET https://api.pjm.com/api/v1/instantaneous-dispatch-rates -> 404'
- status: 405
  meaning: Method not allowed — the SSO authenticate endpoint is POST-only.
  surface: PJM single sign-on
  verified: 'GET https://sso.pjm.com/access/authenticate/ -> 405'
- status: 500
  meaning: >-
    Server error. Observed on the public Swashbuckle discovery path
    (https://services.pjm.com/PJMDataminerApi/swagger/docs/v1 returns
    {"message":"An error has occurred."}), and as the RESTEasy not-found envelope on
    the eTools JAX-RS surface.
  surfaces: [Data Miner 2 Swagger discovery, eTools JAX-RS]
problems:
- id: datetime-filter-missing
  status: 400
  field: Filters
  message: >-
    A datetime is missing. Please input values for datetime_beginning_ept or
    datetime_beginning_utc
  detail: [datetime_filter]
  cause: >-
    Both standard and historic queries against the archived feeds require a date
    parameter.
  remediation: Add datetime_beginning_ept or datetime_beginning_utc to the request.
  source: PJM Data Miner API Guide section V.C.i.i
- id: date-range-spans-archive-boundary
  status: 400
  field: Filters
  message: >-
    Date range in the API request spans over archived and standard data. Please
    update the request. Refer to API Guide for more information.
  cause: >-
    The requested window crosses the feed's archive cutoff (731 days for
    rt_hrl_lmps and da_hrl_lmps, 186 days for rt_fivemin_hrl_lmps).
  remediation: Split the request into one archived-side query and one standard-side query.
  source: PJM Data Miner API Guide section V.C.i.ii
- id: archived-range-outside-calendar-year
  status: 400
  field: Filters
  message: Archived data date range must be within same calendar year. Please enter valid dates
  cause: Historic (archived) queries must start and end within the same UTC calendar year.
  remediation: Break the query into one request per calendar year.
  source: PJM Data Miner API Guide section V.C.ii.v
- id: custom-order-not-available-on-archived-data
  status: 400
  field: Order
  message: Custom Order is not an available option on archived data. Please remove order from the request
  cause: Archived data is always returned sorted by datetime_beginning_utc ascending.
  remediation: Remove the order parameter from archived-data requests.
  source: PJM Data Miner API Guide section V.C.ii.vi
- id: custom-sort-not-available-on-archived-data
  status: 400
  field: Sort
  message: Custom Sort is not an available option on archived data. Please remove sort from the request
  detail: [datetime_beginning_utc]
  cause: Archived data has no sorting capability.
  remediation: Remove the sort parameter from archived-data requests.
  source: PJM Data Miner API Guide section V.C.ii.vi
- id: invalid-attribute-for-archived-data
  status: 400
  field: Filters
  message: >-
    The API request contains invalid attribute(s) for archived data - Pnode_Id.
    Please update the request and retry.
  detail: [pnode_id]
  cause: >-
    Archived data may only be filtered on dates, type, row_is_current and
    version_nbr. Note that type is not an allowed filter on Real-Time Five-Minute
    LMPs for either standard or archived data.
  remediation: Remove the unsupported filter, or query the standard (non-archived) window.
  source: PJM Data Miner API Guide section V.C.ii.vii
- id: date-range-exceeds-366-days
  status: 400
  field: Filters
  message: 'Error: Date range cannot exceed 366 days. Please ...'
  cause: The date-value range on a standard query must be less than 366 days.
  remediation: Split the request into windows shorter than 366 days.
  source: PJM Data Miner API Guide section III (date attribute descriptions)
  note: The guide truncates the remediation sentence in the rendered table; the leading text is quoted verbatim.