# NYISO OASIS Postings

**Canonical:** https://apis.io/apis/nyiso/nyiso-oasis-postings/  
**Provider:** New York Independent System Operator (NYISO) — https://apis.io/providers/nyiso/  
**Base URL:** https://oasis-postings.nyiso.com  
**Documentation:** http://oasis.nyiso.com/

NYISO OASIS Postings is one of 6 APIs that [New York Independent System Operator (NYISO)](https://apis.io/providers/nyiso/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Open Data, Transmission, Grid, OASIS, and Electricity. The published artifact set on APIs.io includes API documentation.

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.

## Machine-readable artifacts (2)

- **Portal** — http://oasis.nyiso.com/
- **Documentation** — https://www.nyiso.com/energy-market-operational-data

## Other New York Independent System Operator (NYISO) APIs (5)

- [NYISO MIS Public Data Archive](https://apis.io/apis/nyiso/nyiso-mis-public-data/)
- [NYISO Finance Metering API](https://apis.io/apis/nyiso/nyiso-finance-metering-api/)
- [NYISO Finance Settlements API](https://apis.io/apis/nyiso/nyiso-finance-settlements-api/)
- [NYISO Finance Invoicing API](https://apis.io/apis/nyiso/nyiso-finance-invoicing-api/)
- [NYISO Metering API](https://apis.io/apis/nyiso/nyiso-metering-api/)

## Tags

Open Data, Transmission, Grid, OASIS, Electricity

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/nyiso/nyiso-oasis-postings/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/nyiso/.