Overview
In the rapidly evolving landscape of AI security, two distinct threats have emerged: unauthorized actions by AI agents and deepfake impersonation in video calls. Kastra addresses the former as a runtime authorization layer, while Halo tackles the latter with on-device deepfake detection. This comparison explores their features, pricing, and use cases to help you decide which is right for your organization.
Feature Comparison
| Feature | Kastra | Halo |
|---|---|---|
| Primary Focus | Runtime authorization for AI agents | Real-time deepfake detection for video calls |
| Deployment | Cloud, self-hosted, air-gap, local edge | On-device Windows app |
| Latency | Sub-millisecond (p99 0.8ms) | Real-time (~4 fps) |
| Integrations | Claude Code, Cursor, Codex, OpenClaw, SDKs | Zoom, Teams, Meet, WebEx, Slack |
| Security Mechanism | Policy enforcement (identity, scope, guardrails) | On-device face analysis for synthetic media |
| Audit & Compliance | Signed audit trail, SOC 2, ISO 27001, HIPAA, GDPR | On-device audit trail, privacy by design |
| Target User | Developers, platform teams | Finance, treasury, general business |
| Pricing | Free tier, paid plans (not detailed) | Not detailed |
Kastra: Runtime Authorization for AI Agents
Kastra sits in the path of every AI action—prompts, tool calls, shell commands, API requests—and decides allow or deny before execution. It supports multiple AI tools and SDKs, with a control plane for managing policies across the organization. Key features include:
- Sub-millisecond latency: p99 0.8ms decision time.
- Policy enforcement: Identity verification, scope evaluation, guardrails, and signed audit.
- Recon: Scans past agent actions to draft policies.
- Compliance: SOC 2, ISO 27001, HIPAA, GDPR, EU AI Act, FedRAMP.
- Deployment flexibility: Cloud, self-hosted, air-gap, and local edge.
Halo: On-Device Deepfake Detection
Halo is a Windows application that runs in the system tray, analyzing video frames from your conferencing app in real time. It flags synthetic faces and faceswaps, alerting you during the call. Key features include:
- On-device processing: No cloud upload, no network calls during detection.
- Real-time alerts: Detection at ~4 frames per second.
- Cross-platform support: Works with Zoom, Teams, Meet, WebEx, Slack.
- Privacy by design: Frames are analyzed in memory and discarded.
- Audit trail: On-device logs for fraud review.
Pricing
Kastra Pricing
Kastra offers a free tier for solo developers, with paid plans for teams and enterprises. Specific pricing is not listed, but it likely scales with usage (number of decisions, policies) and deployment model (cloud vs. self-hosted). The free tier includes a local edge agent and OpenAI-compatible proxy.
Halo Pricing
Halo's pricing is not explicitly stated on the website. It is available for download on Windows, suggesting a one-time purchase or subscription model. Given the target audience (finance, treasury), it may be priced per user or per organization.
Pros and Cons
Kastra Pros
- Sub-millisecond latency for real-time authorization.
- Comprehensive policy enforcement across multiple AI tools.
- Strong compliance certifications (SOC 2, ISO 27001, HIPAA, etc.).
- Flexible deployment options (cloud, self-hosted, air-gap).
- Recon feature for auditing past agent actions.
Kastra Cons
- Complex setup for non-technical users.
- Pricing not transparent for enterprise plans.
- Requires integration with existing AI infrastructure.
Halo Pros
- On-device processing ensures privacy and low latency.
- Easy to install and use for non-technical users.
- Real-time detection during live calls.
- Works across major video conferencing platforms.
- No cloud dependency, reducing attack surface.
Halo Cons
- Only available on Windows.
- Limited to video call deepfake detection, not broader AI security.
- Pricing not clearly communicated.
- May not detect all deepfake variations.
Verdict
Kastra is the go-to for organizations deploying AI agents that need granular, real-time authorization and compliance. Halo is essential for businesses concerned about deepfake video call fraud, offering a simple, private, on-device solution. Choose based on your primary threat model: AI agent misuse vs. synthetic media in communications.