New York Independent System Operator (NYISO)

NYISO OASIS Postings

NYISO's Open Access Same-Time Information System (OASIS) node, the FERC Order 889/890 transmission-service transparency surface. The operator front-end at oasis.nyiso.com is a single-page application backed by a publicly readable object store at oasis-postings.nyiso.com, which answers an anonymous S3 ListBucket request with 200 application/xml and serves each posting in parallel CSV, HTML and PDF renderings under keys such as ACTIVE_TRANSMISSION_NODE/CSV/activetransmissionnodes.csv and ATC_TTC/CSV/YYYY/MM/DD/atc_ttc-YYYYMMDD.csv with history reaching back to 1999. No credentials of any kind are required. Verified by probe on 2026-07-27. Conformance to the NAESB WEQ-001 OASIS template interface was NOT verified - template-style paths under oasis.nyiso.com returned the SPA's HTML shell rather than a template response - so this is recorded as an open postings surface, not as a confirmed WEQ-001 implementation.

Documentation GitHub

Documentation

📖

Documentation

https://www.nyiso.com/energy-market-operational-data

Other Resources

🔗

Portal

http://oasis.nyiso.com/

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API entry from apis.yml

aid: nyiso:nyiso-oasis-postings
name: NYISO OASIS Postings
description: NYISO's Open Access Same-Time Information System (OASIS) node, the FERC Order 889/890 transmission-service
  transparency surface. The operator front-end at oasis.nyiso.com is a single-page application backed
  by a publicly readable object store at oasis-postings.nyiso.com, which answers an anonymous S3 ListBucket
  request with 200 application/xml and serves each posting in parallel CSV, HTML and PDF renderings under
  keys such as ACTIVE_TRANSMISSION_NODE/CSV/activetransmissionnodes.csv and ATC_TTC/CSV/YYYY/MM/DD/atc_ttc-YYYYMMDD.csv
  with history reaching back to 1999. No credentials of any kind are required. Verified by probe on 2026-07-27.
  Conformance to the NAESB WEQ-001 OASIS template interface was NOT verified - template-style paths under
  oasis.nyiso.com returned the SPA's HTML shell rather than a template response - so this is recorded
  as an open postings surface, not as a confirmed WEQ-001 implementation.
humanURL: http://oasis.nyiso.com/
baseURL: https://oasis-postings.nyiso.com
tags:
- Open Data
- Transmission
- Grid
- OASIS
- Electricity
properties:
- type: Portal
  url: http://oasis.nyiso.com/
- type: Documentation
  url: https://www.nyiso.com/energy-market-operational-data