Onyx Platform vs Promptfoo MCP Proxy: Side-by-Side Comparison (2026)

Onyx Platform: AI control plane for enterprise AI agent security, governance, and observability. built by Onyx Security. Core capabilities include Real-time AI agent activity monitoring across LLMs and frameworks, Session replay and audit trail for compliance and forensics, Shadow AI and unapproved model deployment detection..

Promptfoo MCP Proxy: Proxy layer for controlling and monitoring MCP server access in AI apps. built by Promptfoo. Core capabilities include MCP server whitelisting to block unapproved servers, Granular access control per user and application, Real-time monitoring of MCP interactions..

Both serve the Agentic AI Security market but differ in approach, feature depth, and target audience.

Onyx Platform differentiates with Real-time AI agent activity monitoring across LLMs and frameworks, Session replay and audit trail for compliance and forensics, Shadow AI and unapproved model deployment detection. Promptfoo MCP Proxy differentiates with MCP server whitelisting to block unapproved servers, Granular access control per user and application, Real-time monitoring of MCP interactions.

Onyx Platform is developed by Onyx Security. Promptfoo MCP Proxy is developed by Promptfoo. Vendor maturity, funding stage, and team size can be important factors when evaluating long-term viability and support quality.

Onyx Platform and Promptfoo MCP Proxy serve similar Agentic AI Security use cases: both are Agentic AI Security tools, both cover MCP Security, Agentic AI Security, AI Observability. Review the feature comparison above to determine which fits your requirements.