# Historian and Alarm Data APIs

**Canonical:** https://apis.io/apis/scada/had-api/  
**Provider:** SCADA — https://apis.io/providers/scada/  
**Documentation:** https://techsupport.osisoft.com/Documentation/PI-Web-API/

Historian and Alarm Data APIs is one of 5 APIs that [SCADA](https://apis.io/providers/scada/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Historian, OSIsoft PI, and Time Series. The published artifact set on APIs.io includes API documentation.

SCADA historians store time-series process data for analysis, reporting, and compliance. Major historian vendors (OSIsoft PI, Aspen InfoPlus.21, GE Proficy Historian) expose REST APIs for querying historical process data. The OSIsoft PI Web API provides a RESTful interface to PI System data assets.

## Machine-readable artifacts (1)

- **Documentation** — https://techsupport.osisoft.com/Documentation/PI-Web-API/

## Other SCADA APIs (4)

- [OPC Unified Architecture (OPC-UA)](https://apis.io/apis/scada/opc-ua/)
- [MQTT Protocol](https://apis.io/apis/scada/mqtt/)
- [Modbus Protocol](https://apis.io/apis/scada/modbus/)
- [Ignition SCADA REST API](https://apis.io/apis/scada/ignition-api/)

## Tags

Historian, OSIsoft PI, Time Series

---

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