What Skarn is

The facts

A consolidated, verifiable summary of what Skarn does.

Category

AI coding session security scanner, and shadow-AI data-loss detection for engineering teams. It scans the on-disk session transcripts of AI coding assistants - a surface git secret scanners do not look at.

Assistants covered

Claude Code, Gemini CLI, Codex CLI, Cursor, GitHub Copilot, Kimi Code CLI, Grok Build, Grok Bot, Antigravity, from a single binary, including the SQLite state databases Cursor and Copilot use.

What it detects

Leaked credentials across 200+ types using 248 built-in rules (93 AI-specific plus 155 community), and multi-stage attack chains - prompt injection to secret read to exfiltration - correlated across MITRE ATLAS tactic-aligned stages. Each session and team gets a 0-100 risk score.

Standards mapping

Every finding is crosswalked against MITRE ATLAS, the OWASP Top 10 for LLM Applications 2025, and CWE, emitted as SARIF 2.1.0 taxonomies and mirrored to result tags for GitHub code scanning. Run skarn taxonomies to see the pinned frameworks, or read the full standards crosswalk.

How it handles data

No upload, no telemetry, and zero network calls by default. Secrets are redacted by an enforced gate, so no raw credential appears in any output. Optional online checks are opt-in, and an offline flag hard-disables them.

Outputs and integration

Human-readable, JSON, and SARIF 2.1.0 output; CI gating by severity or risk score; a baseline for diffing; and a real-time pre-execution guard hook for Claude Code, Cursor, Codex CLI, GitHub Copilot, Gemini CLI, Grok Build, Antigravity that refuses a malicious tool call before it runs.

Platforms and licensing

A single static binary on macOS, Windows, and Linux, on both Intel and ARM. Skarn is a closed-source commercial product with a free tier that includes the full local scanner under a license anyone can register for, an individual or an organization alike; the org capabilities are licensed per developer for security and engineering teams.

Who is behind it

Skarn is founded and developed by Srđan Marković and made by Skarn Software OÜ, Tallinn, Estonia (registry code 17585335) - the licensor of the Software and the data controller for the registration and purchase data described in the privacy policy. Skarn Software OÜ took over the Skarn business from Red Black Tree d.o.o., Cacak, Republic of Serbia, on 2026-08-27, by the assignment notice published at getskarn.com/terms/. The publisher page lists every official distribution channel and publisher account.

How it is different from git secret scanners

Traditional secret scanners scan your git repositories; Skarn scans the AI session logs those scanners never look at. The key an engineer pasted into a chat and never committed is invisible to them and obvious to Skarn. See the tools comparison.