authprobe, from Authprobe, is a command-line diagnostic tool that analyzes Model Context Protocol OAuth authentication flows. It scans MCP endpoints to detect authentication failures and malformed metadata, producing actionable diagnostics and evidence for debugging. The tool pairs raw traces with optional LLM-generated explanations and a funnel view of the handshake, aimed at MCP server authors, client implementers, and security teams who need focused, reproducible audit artifacts.

What tasks can you actually use it for?

authprobe focuses on targeted OAuth diagnostics for MCP endpoints. The CLI scans authentication handshakes to identify missing headers, incorrect content types, and malformed metadata that break integrations. Outputs include a funnel-style visualization of where a handshake fails, verbose trace logs, and an evidence bundle that collects logs and request/response data for reproducing issues during debugging or audit workflows. The tool supports custom headers for testing nonstandard flows.

How reliable are the diagnostics and generated explanations?

Diagnostics produce reproducible artifacts while explanatory text is optional and model-driven. Core scanning features operate without an LLM, producing trace output and evidence bundles suitable for developer inspection. An integrated LLM can translate RFC compliance gaps into human-readable explanations, but those explanations are auxiliary; teams should treat them as interpretive aids and verify conclusions against the RFC and raw traces when accuracy matters.

Does it require technical setup and where does it fit in a workflow?

The tool is a cross-platform CLI installed via Go or run in Docker, so it fits into developer and CI toolchains. Installation choices let implementers run it locally or inside containers for automated checks. Verbose tracing and custom-header options support deep inspection during development and security reviews. Authprobe is designed for technical users who can read HTTP traces and integrate evidence bundles into bug reports or audit records.

Authprobe is a practical diagnostic choice for technical MCP implementers

Authprobe suits server authors and security teams that need task-focused, evidence-grade debugging of MCP OAuth handshakes. Its output-oriented design helps reduce investigation time by collecting reproducible traces and highlighting protocol failures. Treat any LLM-produced explanations as interpretive assistance and confirm important compliance decisions against the raw traces and relevant RFC language.