Kernel MCP

Connect your AI agent to Kernel, the verification layer for onchain software. Your agent can scan a GitHub repository or a Robinhood Chain contract before it ships, trades or integrates, and get back a score, a verdict and a step-by-step fix plan as JSON.

Paid tools are pay per call with x402, in USDG on Robinhood Chain. There is no account, API key or subscription, and a call that fails is never charged.

https://mcp.kernelcode.io/mcp

This repo has the config for popular MCP clients, a small TypeScript client that pays for you, and runnable examples. The Kernel service itself is closed source; the attestation contract is public.

Tools

Scans read code and bytecode only. They never execute it, and a clean scan is a scan, not a formal proof. For a proof, use prove_property: it runs on your own Aristotle API key (pass aristotle_api_key, or save it once in the Kernel app under API keys).

Related MCP server: gitlumen-mcp

Add it to your agent

Claude Code

claude mcp add --transport http kernel https://mcp.kernelcode.io/mcp

Cursor (.cursor/mcp.json)

{ "mcpServers": { "kernel": { "url": "https://mcp.kernelcode.io/mcp" } } }

VS Code, Claude Desktop, Windsurf, Codex and stdio-only clients are in clients/.

Any of these can use the free tools straight away. For the paid tools, the client has to answer the x402 payment request, which most editors don't do yet. The TypeScript client below does.

Paying with x402

1. Your agent calls a paid tool.

2. Kernel replies with a payment request: the amount in USDG, the recipient and the network.

3. The client signs a USDG transfer authorization (EIP-3009) from your wallet and calls again with it attached.

4. Kernel runs the tool. Only if it succeeds is the payment settled onchain, and the receipt comes back with the result.

Your wallet needs USDG on Robinhood Chain (chain 4663, token 0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168). It does not need ETH for these payments; the facilitator pays that gas. Only attest_verification asks your wallet to send a transaction itself.

USDG must be allowed explicitly

x402 clients only pay in a short list of default tokens, and USDG is not on it. Without an allowlist entry, every payment is refused on the client side before anything is signed. Add it with a cap:

import { createx402MCPClient } from '@x402/mcp';
import { ExactEvmScheme } from '@x402/evm/exact/client';
import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
import { privateKeyToAccount } from 'viem/accounts';

const wallet = privateKeyToAccount(process.env.KERNEL_PRIVATE_KEY as `0x${string}`);

const kernel = createx402MCPClient({
  name: 'my-agent', version: '1.0.0',
  schemes: [{ network: 'eip155:4663', client: new ExactEvmScheme(wallet) }],
  spendControls: {
    allowedAssets: [{
      network: 'eip155:4663',
      asset: '0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168', // USDG
      maxAmountPerPayment: '200000',                         // 0.20 USDG (6 decimals)
    }],
  },
  autoPayment: true,
});
await kernel.connect(new StreamableHTTPClientTransport(new URL('https://mcp.kernelcode.io/mcp')));

const result = await kernel.callTool('scan_contract', { address: '0x…' });
console.log(result.content[0]); // "0x…: 74/100 (grade C). …" followed by the JSON report

src/kernel.ts wraps this as connectPaid(), plus connectFree() and helpers to read results.

Examples

git clone https://github.com/kernelcode-labs/kernel-mcp && cd kernel-mcp
npm install
cp .env.example .env   # add KERNEL_PRIVATE_KEY for the paid examples

Use a dedicated wallet that holds only what you plan to spend. KERNEL_MAX_USD caps any single payment (default $0.20).

What comes back

Every scan tool returns the same shape as get_verification:

{
  "scan_id": "scan_…",
  "target": "owner/repo@<commit>",
  "score": 74,                 // 0-100, capped by the worst open severity
  "grade": "C",
  "verdict": "Not ready to ship: 1 high severity issue to fix first",
  "summary": "…what was checked, what wasn't",
  "severity_counts": { "critical": 0, "high": 1, "medium": 2, "low": 4, "info": 1 },
  "categories": [{ "area": "Dependencies", "status": "issues", "score": 60, "note": "…" }],
  "action_plan": [{ "step": 1, "priority": "now", "title": "…", "detail": "…", "items": ["pkg 1.2.3 → 1.2.9"] }],
  "top_findings": [{ "id": "dep-1", "severity": "high", "title": "…", "location": { "path": "package-lock.json" }, "recommendation": "…" }],
  "report_hash": "0x…",        // sha256 of the canonical report; what gets attested
  "public_url": null,          // set once the report is made public or attested
  "attestations": []
}

Pass detail: "full" to get_verification for the complete report with evidence.

REST

The paid tools are also plain HTTP endpoints that answer with 402 Payment Required. They accept GET with query parameters or POST with JSON:

Links

• Site: kernelcode.io · Tools and pricing: kernelcode.io/tools

• App: app.kernelcode.io

• Attestation contract: kernelcode-labs/KernelAttestations-contract

• X: @useKernelCode

License

MIT