Authprobe is a specialized MCP server tool developed by Authprobe, designed to identify and diagnose OAuth failures within Model Context Protocol OAuth discovery flows. Built with Go, it offers a single binary, zero config distribution, making it straightforward to deploy. This free tool focuses on OAuth 2.1 authentication flow analysis for MCP servers, providing critical diagnostic capabilities for developers, CI/CD pipeline operators, and security reviewers. Its primary function is to ensure OAuth compliance and pinpoint issues efficiently.

What does Authprobe connect to?

Authprobe connects directly to Model Context Protocol (MCP) endpoints. Its core function is to probe and diagnose OAuth 2.1 authentication flows on MCP servers. The tool specifically targets the MCP OAuth discovery flow to pinpoint and identify OAuth failures. It acts as an OAuth compliance and diagnostic utility, ensuring that MCP servers adhere to OAuth 2.1 standards. This direct interaction with MCP endpoints allows for precise failure detection and analysis.

Core features and tools

Authprobe exposes its primary capabilities through a command-line interface. Key commands include authprobe scan <MCP_ENDPOINT> for basic scanning, authprobe scan --explain for detailed insights, and authprobe scan --trace-failure to follow issue paths. For strict compliance, authprobe scan --rfc strict --mcp strict is available. Output options range from streaming JSON to standard output using authprobe scan --json - to file-based reports in Markdown, JSON, or ZIP formats with authprobe scan --md report.md --json report.json --bundle evidence.zip. It also lists internal capabilities via authprobe scan --tool-list and details specific tools with authprobe scan --tool-detail "my_tool_name".

Who is it for?

Authprobe is designed for developers who need to diagnose OAuth issues in MCP environments. CI/CD pipeline operators can use it to gate deployments based on OAuth compliance. Security reviewers will find it useful for auditing OAuth 2.1 authentication flows on MCP servers. The tool helps identify failures and map findings to RFCs for deterministic diagnosis. Skip this if you are not working with Model Context Protocol servers or OAuth 2.1 authentication flows.

How to get started

No credentials are required for basic scanning functions. When performing AI-driven root cause analysis, the server authenticates using an API key passed as an environment variable. For example, an OpenAI API key can be provided via the OPENAI_API_KEY environment variable.

Use cases

• Pinpointing MCP OAuth failures and mapping findings to RFCs for deterministic diagnosis.
• Integrating into CI/CD pipelines as a GitHub Action to gate deployments on OAuth compliance.
• Performing AI-driven root cause analysis of identified failures by using OpenAI or Anthropic LLMs.
• Generating detailed reports in Markdown, JSON, or ZIP formats for sharing and attaching to GitHub issues.

Authprobe is a specialized diagnostic tool for MCP server OAuth 2.1 compliance, offering both direct scanning and AI-assisted root cause analysis. Its single binary, zero config distribution simplifies deployment for developers, CI/CD operators, and security reviewers. The tool provides clear output options for reporting and evidence collection.