Promptrejectormcp

A dual-layer security gateway for AI agents and applications. Prompt Rejector protects your AI-powered applications from prompt injection attacks, jailbreak attempts, and traditional web vulnerabilities (XSS, SQLi, Shell Injection) by screening untrusted input before it reaches your agent's control plane. It runs locally over stdio via the published package.

People connecting security tools to Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-05-18 · ★ 2 · #138 OF 182 MAINTAINED SECURITY · VERIFIED 2026-08-25

ISC · TypeScript servers · how we verify → /methodology

01 · Install Promptrejectormcp

before you install - you'll need

Set GEMINI_API_KEY, START_MODE, KEV_REFRESH_INTERVAL_HOURS, ATLAS_REFRESH_INTERVAL_HOURS, TASTE_TESTER_ENABLED, TASTE_TESTER_MODEL, TASTE_TESTER_MAX_TURNS, TASTE_TESTER_MAX_TOKENS, TASTE_TESTER_TIMEOUT_MS, CANARY_DEFAULT_TTL_SECONDS, GITHUB_TOKEN, NVD_API_KEY before connecting.

Claude Code

claude mcp add revsmoke-promptrejectormcp -- npx -y prompt-rejector

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "revsmoke-promptrejectormcp": {
      "command": "npx",
      "args": [
        "-y",
        "prompt-rejector"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license ISC - declared in the repository

npm package prompt-rejector - unscoped; check the name against the project README before installing

registry namespace io.github.revsmoke is GitHub-verified and matches the repo owner

03 · What Promptrejectormcp can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v1.0.2 · 2026-02-09

What's New · Added · Dynamic Pattern Library - File-based pattern CRUD via PatternService with patterns/ directory. Supports two detection modes: simple (any match) and threshold (count/length gating). · Vulnerability…

v1.0.1 · 2026-01-28

Highlights · Automated CI publish: GitHub Actions builds, validates server.json against MCP schema, publishes to npm, then publishes to the MCP Registry via OIDC. · Registry compliance: server.json description…

04 · Who maintains Promptrejectormcp

promptrejectormcp is maintained by revsmoke. It's the only MCP server we track from this author; the repo dates to Jan 2026.

05 · Facts

repository: github.com/revsmoke/promptrejectormcp
category: security - ranked #138 of 182 actively-maintained security servers as of 2026-08-25.
registry: io.github.revsmoke/promptrejectormcp (active, first published 2026-01-27 · 2 versions)
packages: npm:prompt-rejector

06 · Promptrejectormcp FAQ

What is Promptrejectormcp?

Is Promptrejectormcp still maintained?

Yes - as of 2026-08-25, its last commit was 2026-05-18. We re-verify nightly.

How do I install Promptrejectormcp?

Run `npx -y prompt-rejector`. The README documents 12 environment variables (GEMINI_API_KEY, START_MODE, KEV_REFRESH_INTERVAL_HOURS…) to set first. Set GEMINI_API_KEY, START_MODE, KEV_REFRESH_INTERVAL_HOURS, ATLAS_REFRESH_INTERVAL_HOURS, TASTE_TESTER_ENABLED, TASTE_TESTER_MODEL, TASTE_TESTER_MAX_TURNS, TASTE_TESTER_MAX_TOKENS, TASTE_TESTER_TIMEOUT_MS, CANARY_DEFAULT_TTL_SECONDS, GITHUB_TOKEN, NVD_API_KEY before connecting. You can also paste the ready-made client config above.

Does Promptrejectormcp run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Promptrejectormcp

Alternatives to Promptrejectormcp

Maintained security servers if Promptrejectormcp isn't the fit.

Pairs well with

Servers that cover what Promptrejectormcp doesn't - only shown when the pairing reason fits the companion.

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