Official multi-language client library, Model Context Protocol (MCP) server, and Coinbase AgentKit ActionProvider for M2M Sentinel — deterministic EVM bytecode capability observations and common-proxy resolution for autonomous applications operating on Base. Callers own transaction policy.

⚡ 1. Model Context Protocol (MCP) Server

Connect M2M Sentinel directly to Claude Desktop, Cursor, Windsurf, or any MCP-compliant LLM agent.

Option A: 1-Click via Smithery

npx -y @smithery/cli mcp add M2M-Sentinel/m2m-sentinel-sdk --client claude

Option B: Local Stdio (`claude_desktop_config.json`)

{
  "mcpServers": {
    "m2m-sentinel": {
      "command": "npx",
      "args": ["-y", "m2m-sentinel-sdk"],
      "env": {
        "M2M_SENTINEL_API_KEY": ""
      }
    }
  }
}

Option C: Remote Streamable HTTP

Current MCP endpoint: https://api.m2msentinel.com/mcp
Legacy HTTP+SSE compatibility: https://api.m2msentinel.com/sse with messages at https://api.m2msentinel.com/messages

🤖 2. Coinbase AgentKit Integration

import { AgentKit } from "@coinbase/agentkit";
import { m2mSentinelActionProvider } from "m2m-sentinel-sdk";

const agentKit = await AgentKit.from({
  walletProvider,
  actionProviders: [
    m2mSentinelActionProvider({
      apiKey: process.env.M2M_SENTINEL_API_KEY
    })
  ]
});

📦 3. JavaScript / TypeScript Client

npm install m2m-sentinel-sdk

const { M2MSentinelClient } = require('m2m-sentinel-sdk');

const client = new M2MSentinelClient();

async function main() {
  const audit = await client.auditContract('0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913');
  console.log('Proxy Detected:', audit.audit.proxyResolution.isProxy);
  console.log('Proxy Target:', audit.audit.proxyResolution.targetAddress);
  console.log('Capabilities:', audit.audit.verdict.executableCapabilities);
  console.log('Evidence:', audit.audit.dissection.capabilities);
}

main().catch(console.error);

🛡️ Base Account `wallet_sendCalls` Guard

The public SDK includes guardWalletSendCalls, a customer-side execution-identity boundary for Base Account / EIP-5792 batches. It preflights the anchor call and evaluates its caller policy before scheduling any remaining call, then pins remaining calls to the first trusted block identity in waves of at most four. Each settled wave is validated and policy-checked in ascending request-index order before a later wave starts; a failure or rejection stops later scheduling. The original detached request is forwarded only after all checks pass. It does not sign, broadcast, custody funds, infer inner UserOperation semantics, or make a safety claim. See examples/base_account_paymaster_guard.js for a no-network fixture.

🐍 4. Python Client

pip install m2m-sentinel

from m2m_sentinel import M2MSentinelClient

client = M2MSentinelClient()
audit = client.audit_contract("0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913")
print("Proxy detected:", audit["audit"]["proxyResolution"]["isProxy"])
print("Proxy target:", audit["audit"]["proxyResolution"].get("targetAddress"))
print("Capabilities:", audit["audit"]["verdict"]["executableCapabilities"])
print("Evidence:", audit["audit"]["dissection"]["capabilities"])

Transaction-specific preflight example

The public repository includes a standalone, mock-only transaction boundary example at examples/transaction_preflight.js. From this repository root, run:

node examples/transaction_preflight.js

It observes one caller-supplied Base transaction, passes the observation to a caller-owned policy, and reaches only a mock signing/send callback. It refuses to continue on unverified evidence, unresolved execution, an observation mismatch, or a missing Diamond selector mapping. It never signs or sends a transaction; optional live mode uses only a caller-supplied API-key header and remains the caller's responsibility.

💳 5. Autonomous x402 Micropayments (Headless M2M)

import { x402SignerClient } from "m2m-sentinel-sdk";

const client = new x402SignerClient({
  walletSigner: myAgentWallet,
  baseUrl: "https://api.m2msentinel.com"
});

const result = await client.request("/v1/audit/0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913");