MCP ServerSTDIOOfficialv3.9.2

Assay MCP Server

Enforce policies on MCP tool calls and capture portable evidence of execution. Built for developers who need audit trails, compliance checks, and reproducible records of model interactions.

io.github.Rul1an/assay-mcp-server

Hosted URL

Local install

Transport

STDIO

Auth

No auth required

What the Assay MCP server does

How models use it and what it is built for.

Enforce policies on MCP tool calls and capture portable evidence of execution. Built for developers who need audit trails, compliance checks, and reproducible records of model interactions.

Connect to Assay

Local install — runs as a subprocess.

https://github.com/Rul1an/assay/releases/download/v3.9.2/assay-mcp-server-v3.9.2-linux.mcpb

Resources

Where to find authoritative docs and source for Assay.

Example prompts for Assay

Paste any of these into Agent Studio after connecting Assay.

  • Show me the evidence output format for a tool call that was blocked by policy
  • How do I configure policy rules to restrict which tools an MCP client can invoke
  • What does the portable evidence include when a tool executes successfully
  • Explain how to set up policy enforcement between my LLM and downstream MCP servers

Assay MCP server — FAQ

Common questions about connecting and running Assay.

  • What is a policy-enforcing MCP proxy?

    It's a middleware layer that sits between an MCP client and servers, validating tool calls against configurable policies before they execute. It also generates portable evidence (audit logs) of what ran and why calls were allowed or blocked.

  • What does 'portable evidence output' mean?

    The server captures structured records of each tool invocation—including the call, the policy decision, and execution result—in a format you can export, audit, or replay independently of the original MCP session.

  • How do I install and run assay-mcp-server?

    Download the prebuilt binary from the GitHub releases page (v3.9.2 for Linux is available), then configure it as an MCP server in your client. It communicates via stdio transport.

  • Can I use this for compliance or audit requirements?

    Yes—the portable evidence output is designed for audit trails and compliance workflows. You can log and review all tool calls and policy decisions in a structured, reproducible format.

  • What policy rule formats does it support?

    The registry metadata does not specify the exact policy syntax. Refer to the GitHub repository documentation or source code for details on rule configuration and supported constraints.

Skip the local setup — run MCP in your browser

MCP Playground runs 10,000+ hosted MCP servers — GitHub, Linear, Notion, Stripe, Sentry and more — across Claude, GPT, Gemini, DeepSeek and 30+ AI models. Compare model answers side-by-side, save agent presets, share runs. Zero install.

Open Agent Studio

Related servers

More on MCP Playground