# PJM Messages Public Web Service

**Canonical:** https://apis.io/apis/pjm/pjm-messages-public-api/  
**Provider:** PJM Interconnection — https://apis.io/providers/pjm/  
**Base URL:** https://messages.pjm.com/messages/rest/public  
**Documentation:** https://www.pjm.com/markets-and-operations/etools/upcoming-changes

PJM Messages Public Web Service is one of 6 APIs that [PJM Interconnection](https://apis.io/providers/pjm/) publishes on the [APIs.io](https://apis.io/) network. This API exposes 1 JSON Schema definition. Tagged areas include Status, Notification, Planned Outages, Grid Operations, and Open Access. The published artifact set on APIs.io includes API documentation and 1 JSON Schema.

The only fully anonymous PJM REST API found on the public surface. It backs the PJM Upcoming Changes page and returns the current planned-outage, delayed-data and impact notices for the whole PJM eTools estate — affected applications by name and numeric id, the change window as epoch milliseconds, required actions, and an access-blocking flag. GET https://messages.pjm.com/messages/rest/public/messages returned HTTP 200 with no credential on 2026-07-27, serving application/xml;charset=UTF-8 by default and JSON under Accept: application/json. There are no documented query parameters, no paging and no filtering — it returns the current notice set as one small document. It is poll-only; PJM registers no webhooks, and the alternative subscription channel is email.

## Machine-readable artifacts (6)

- **Documentation** — https://www.pjm.com/markets-and-operations/etools/upcoming-changes
- **Guide** — https://www.pjm.com/-/media/etools/upcoming-changes-how-to-guide.pdf
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/pjm/refs/heads/main/json-schema/pjm-message.json
- **Examples** — https://raw.githubusercontent.com/api-evangelist/pjm/refs/heads/main/examples/_index.yml
- **AgentSkill** — https://raw.githubusercontent.com/api-evangelist/pjm/refs/heads/main/skills/pjm-watch-tool-change-notices.md
- **StatusPage** — https://www.pjm.com/markets-and-operations/etools/upcoming-changes

## Other PJM Interconnection APIs (5)

- [PJM Data Miner 2 API](https://apis.io/apis/pjm/pjm-data-miner-2-api/)
- [PJM OASIS Template API](https://apis.io/apis/pjm/pjm-oasis-template-api/)
- [PJM Browserless Authentication API](https://apis.io/apis/pjm/pjm-browserless-authentication-api/)
- [PJM InSchedule Browserless API](https://apis.io/apis/pjm/pjm-inschedule-api/)
- [PJM eDART Browserless API](https://apis.io/apis/pjm/pjm-edart-api/)

## Tags

Status, Notification, Planned Outages, Grid Operations, Open Access

---

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