Releases: markndg/varden
Release list
v0.2.1 — Rules pack Import & save status fix
Fix
- Rules workspace: after Import & save, pack cards now update immediately (green edge,
N/N present, Fully added) without clicking the rule-count chip.
Note
Patch over 0.2.0. Upgrade with pip install -U varden.
Varden v0.2.0 — Browser AI Runtime Security
This release introduces Web Shield, extending Varden's runtime governance to browser-based WebMCP tool surfaces.
As AI models begin discovering and interacting with tools exposed directly by websites, Web Shield enables those tools to be inspected, governed and audited before they are trusted. It applies the same deterministic policy engine that Varden already uses for MCP, HTTP, subprocesses and other runtime operations.
🚀 Highlights
🛡️ Web Shield
Web Shield provides runtime governance for browser-exposed AI tools.
Features include:
- Prompt injection detection in tool metadata
- Hidden instruction and Unicode obfuscation detection
- Capability and schema mismatch detection
- Tool lifecycle monitoring and metadata drift detection
- Explainable deterministic risk scoring
- Policy-based allow, warn, sanitise, approval and block decisions
🌐 Browser Extension
A Chromium extension observes WebMCP tool registrations and forwards them to Varden for inspection and policy evaluation.
The extension provides visibility into browser AI tool surfaces while integrating seamlessly with the existing Varden runtime.
📦 JavaScript SDK
A first-party JavaScript SDK allows applications to integrate directly with Varden.
Unlike browser observation alone, SDK integration enables applications to withhold registration or execution until policy evaluation has completed.
📋 Tool Inventory & Provenance
Web Shield maintains a complete inventory of observed tools, including:
- Tool registrations
- Registration instances
- Metadata history
- Provenance
- Lifecycle events
- Policy decisions
This provides a full audit trail showing how a browser AI tool has changed over time and why Varden reached a particular decision.
🔒 Security Hardening
Before release, Web Shield underwent a dedicated security hardening pass.
Key improvements include:
- Scoped browser message protocol
- Fail-closed metadata sanitisation
- Provenance-aware trust model
- Registration-instance tracking
- Recursive metadata canonicalisation
- Scoped idempotency handling
- Pre-parse request size limits
- Expanded adversarial test coverage
- Clear documentation of browser extension security boundaries
📊 Evaluation
The bundled evaluation corpus achieved:
| Metric | Result |
|---|---|
| Precision | 0.944 |
| Recall | 1.000 |
| F1 Score | 0.971 |
📦 Installation
pip install varden📁 Release Assets
This release includes:
- Python wheel
- Source distribution
- Chromium Web Shield extension
⚠️ Current Limitations
Web Shield is designed to provide deterministic governance over browser AI tool surfaces while remaining transparent about current platform limitations.
The browser extension operates in an untrusted webpage environment and is therefore primarily an observation and governance layer. Strong enforcement is available through the first-party JavaScript SDK, allowing applications to defer registration or execution until policy evaluation has completed.
I appreciate anyone providing feedback.
Apache-2.0 release
v0.1.2
Licensing
- Relicensed Varden under Apache-2.0.
- Removed AGPL references.
- Removed commercial licensing requirements.
No functional changes.
Initial release
docs: document varden-mcp in root README - Mention varden_mcp and [mcp] extra in install blurb - Add developer adoption bullet with link to varden_mcp/README.md - Add varden-mcp section after varden session (install, scope, env vars) Co-authored-by: Cursor <cursoragent@cursor.com>