specmatic

specmatic is an MCP server for Claude Code, Codex, Cursor, Gemini CLI, OpenCode from jmanhype/speckit. Its token cost is not measured, scanned A, original, MIT.

An MCP server for Specmatic, a tool for checking software behavior against API contracts. An API contract describes the requests and responses that services agree to support.

In plain words
What is it for?
Use it when working with contract-based API validation and a Specmatic Central repository.
Why use it?
It can connect agent work to a shared contract repository, helping keep implementations aligned with agreed API behavior. The input does not specify the exact available commands.

MCP server for Claude CodeCodexCursorGemini CLIOpenCode

Written for no agent in particular: it speaks MCP, so any client can run it. Also seen: listed in a Claude config.

One of 3 entries in .mcp.json upstream. Installing this one merges just its entry into your config; the other 2 are separate, each on its own page.

Good fit Use it when working with contract-based API validation and a Specmatic Central repository.

Compare 6 mcp servers from other repositories ↓
Install with agentmods
npx agentmods add mcp/jmanhype/speckit/specmatic
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/jmanhype/speckit

Made for: Claude Code, Codex, Cursor, Gemini CLI, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for specmatic

README.md
[![agentmods](https://agentmods.dev/badge/mcp/jmanhype/speckit/specmatic/github.svg)](https://agentmods.dev/mcp/jmanhype/speckit/specmatic)
Your own site
<a href="https://agentmods.dev/mcp/jmanhype/speckit/specmatic"><img src="https://agentmods.dev/badge/mcp/jmanhype/speckit/specmatic/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for specmatic

Your own site · 80×15
<a href="https://agentmods.dev/mcp/jmanhype/speckit/specmatic"><img src="https://agentmods.dev/badge/mcp/jmanhype/speckit/specmatic.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

specmatic scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.mcp.json · 12 lines

What it actually says

{
  "specmatic": {
    "command": "npx",
    "args": [
      "-y",
      "@specmatic/mcp"
    ],
    "env": {
      "SPECMATIC_CENTRAL_REPO_URL": "${SPECMATIC_CENTRAL_REPO_URL}"
    }
  }
}
Same file

What else .mcp.json configures

This page is one entry in a file that holds 3. Installing the file brings all of them; each is measured and scanned on its own page.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 12 lines scan A d60c1234cf1e

Subscribe to this mod's changes

specmatic is an MCP server published in the GitHub repository jmanhype/speckit (26 stars, last pushed 6mo ago), licensed MIT. Its token cost is not measured: an MCP server costs its tool schemas, not its config file. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.