# OTRF/OSSEM

Open Source Security Events Metadata (OSSEM)

Repository: https://github.com/OTRF/OSSEM
Canonical: https://ross.abutalabs.com/products/ossem
Language: Python
License: MIT
License Family: permissive
Last push: 2023-02-27T02:58:11+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3110, "days_push": 1283, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1300, forks 209 (observed 2026-08-28T04:04:17.556339+00:00)

## What it is
OSSEM is a community-led project that documents, standardizes, and models security event logs through data dictionaries, a common data model, and a detection model. It provides structured metadata about security event logs from Windows, Linux, macOS, Azure, AWS, and other sources to support log parsing and detection engineering.

## Use cases
- standardize security event log field names across data sources
- normalize security logs into a common data model for SIEM pipelines
- look up field definitions for Windows, Linux, macOS, Azure, or AWS event logs
- map relationships among security events to build threat detection analytics
- validate detection coverage of adversary techniques against event data
- build a data wiki documenting security event logs in an organization

## When to choose
- you are a detection engineer or threat hunter needing standardized log schemas
- you want to normalize heterogeneous security event logs into a common schema
- you need reference documentation for security event log fields and providers
- you are developing analytics and want event relationship models to guide detections

## When to avoid
- you need a tool that actively parses or ingests logs rather than schema documentation
- you require a maintained product with frequent releases (latest release was early 2023)
- you need vendor-specific log formats not covered by the community dictionaries

## Facets
- artifact type: dataset
- maturity: maintenance
- function: documentation, security, parser, data-science
- domain: security, documentation, developer-tools
- platform: cross-platform, python
- tags: security-event-logs, data-dictionaries, common-data-model, detection-model, siem, threat-detection, log-normalization, metadata

## Member repositories
- OTRF/OSSEM (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:17.556339+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:52:17.245152+00:00, confidence not recorded.
  - readme: https://github.com/OTRF/OSSEM (fetched 2026-08-28T04:04:17.556339+00:00, sha 37124466752e)
- Data as of 2026-08-30T08:39:29.467469+00:00.