@usekova/mcp

Model Context Protocol (MCP) integration -- wraps any MCP server with Stele covenant enforcement, audit logging, and compliance proofs.

Installation

npm install @usekova/mcp

Key APIs

• SteleGuard.wrap(server, options): Wrap an MCP server with constraint enforcement using CCL text or a preset name. Returns a WrappedMCPServer.
• SteleGuard.fromCovenant(server, covenant, keyPair): Wrap an MCP server using a pre-built CovenantDocument (for externally managed covenants).
• PRESETS: Built-in CCL constraint presets (standard:data-isolation, standard:read-write, standard:network, standard:minimal).
• WrappedMCPServer: Extended server with getMonitor(), getAuditLog(), generateProof(), getReceipt(), and getCovenant() accessors.

Usage

import { SteleGuard } from '@usekova/mcp';

// Your existing MCP server
const mcpServer = {
  tools: [{ name: 'readFile' }, { name: 'writeFile' }],
  handleToolCall: async (name: string, args: Record<string, unknown>) => {
    // ... tool implementation
  },
};

// Wrap with a built-in preset (2 lines)
const guarded = await SteleGuard.wrap(mcpServer, {
  constraints: 'standard:data-isolation',
  mode: 'enforce', // or 'log_only'
  onViolation: (v) => console.warn(`Blocked: ${v.toolName} - ${v.constraint}`),
});

// Tool calls are now intercepted and enforced
await guarded.handleToolCall!('readFile', { path: '/data/report.csv' });

// Retrieve audit trail and compliance proof
const auditLog = guarded.getAuditLog();
const proof = await guarded.generateProof();
const receipt = guarded.getReceipt();

Using a pre-built covenant

import { SteleGuard } from '@usekova/mcp';
import { buildCovenant } from '@usekova/core';
import { generateKeyPair } from '@usekova/crypto';

const keyPair = await generateKeyPair();
const covenant = await buildCovenant({ /* ... */ });

const guarded = await SteleGuard.fromCovenant(mcpServer, covenant, keyPair);

Presets

| Preset | Description | |---|---| | standard:data-isolation | Read-only data access, no writes or network | | standard:read-write | Read + scoped writes, no network | | standard:network | Full I/O with PII guards and rate limits | | standard:minimal | Deny everything, audit only |

Docs

See the Stele SDK root documentation for the full API reference.