@keyhalve/verify-mcp

Verify KeyHalve-sealed documents from any MCP client. This package is a thin stdio bridge to the free, public, no-account KeyHalve verification server — if your client supports remote MCP servers, you don't need it: just add https://mcp.keyhalve.com/mcp directly.

• Read-only. Three tools (keyhalve_verify, keyhalve_status, keyhalve_explain), all annotated readOnlyHint: true. Verification is free and requires no account.
• Never sees your document. The server checks seals and live status; it never receives decryption keys (#key= URL fragments are discarded unread) and cannot read sealed contents — no single party can unseal a document alone. Sealed contents decrypt only in the document holder's browser.
• Zero dependencies. Node ≥ 18.

Quick start

npx @keyhalve/verify-mcp

Embed in your own MCP server

Building an MCP server of your own? Mount the KeyHalve verify toolset with one dependency and one line — your users get document verification without leaving your connector:

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { mountKeyhalveVerify } from "@keyhalve/verify-mcp";

const server = new McpServer({ name: "my-platform", version: "1.0.0" });
mountKeyhalveVerify(server);
// … register your own tools, connect your transport as usual.

The mounted handlers proxy to the hosted KeyHalve verifier (https://mcp.keyhalve.com/mcp) — no verdict logic runs in your process, so you always get current verdict behavior without upgrading. Options are deliberately minimal: { baseUrl } (point at a staging worker) and { toolPrefix } (renames the tools if your server has a name collision — descriptions and the credit line are library-fixed and not overridable).

One-way rule: this export is verify-only, forever. Sealing never ships here — verification is the free, neutral, embeddable surface; sealing belongs to the platforms.

Remote endpoint (preferred where supported)

{ "mcpServers": { "keyhalve": { "url": "https://mcp.keyhalve.com/mcp" } } }

This canonical JSON works verbatim in Cursor (~/.cursor/mcp.json), LM Studio (~/.lmstudio/mcp.json), JetBrains AI Assistant, LibreChat, and Claude-family clients.

Per-client setup

Claude (claude.ai — all plans, including Free)

Settings → Connectors → Add custom connector → URL https://mcp.keyhalve.com/mcp (no authentication).

Claude Code

claude mcp add --transport http keyhalve https://mcp.keyhalve.com/mcp

ChatGPT (Developer mode — Plus/Pro/Business/Enterprise/Edu)

Settings → Connectors → Advanced → Developer mode → Add server → https://mcp.keyhalve.com/mcp, No authentication.

Cursor (~/.cursor/mcp.json)

{ "mcpServers": { "keyhalve": { "url": "https://mcp.keyhalve.com/mcp" } } }

VS Code (.vscode/mcp.json)

{ "servers": { "keyhalve": { "type": "http", "url": "https://mcp.keyhalve.com/mcp" } } }

Local-only clients (this package, stdio)

{
  "mcpServers": {
    "keyhalve": {
      "command": "npx",
      "args": ["-y", "@keyhalve/verify-mcp"]
    }
  }
}

Codex CLI (~/.codex/config.toml)

[mcp_servers.keyhalve]
command = "npx"
args = ["-y", "@keyhalve/verify-mcp"]

Gemini CLI

gemini mcp add --transport http keyhalve https://mcp.keyhalve.com/mcp

(In settings.json use the httpUrl key — plain url means SSE.)

Open WebUI

Settings → External Tools → add https://mcp.keyhalve.com/mcp (Streamable HTTP, authentication: none).

Perplexity (Pro/Max/Enterprise)

Settings → Connectors → Add connector → remote MCP URL https://mcp.keyhalve.com/mcp, open (no) authentication.

Microsoft Copilot Studio

Tools → Add a tool → New tool → Model Context Protocol → https://mcp.keyhalve.com/mcp, authentication: None.

Zed (settings.json)

{ "context_servers": { "keyhalve": { "url": "https://mcp.keyhalve.com/mcp" } } }

Windsurf (~/.codeium/windsurf/mcp_config.json)

{ "mcpServers": { "keyhalve": { "serverUrl": "https://mcp.keyhalve.com/mcp" } } }

What the tools return

keyhalve_verify takes a verify URL, KeyHalve QR text, or document id (vp_…, kh_…, cb_…) and returns the cryptographic verdict: seal existence, live status (active/revoked/expired), ciphertext integrity against the issuance commitment, the KeyHalve rail's independent attestation, the validity window, and issuer trust context. Seals are tamper-evident — a modified document fails integrity. The tool never decrypts contents.

More: https://keyhalve.com/mcp · Privacy: https://keyhalve.com/privacy