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X402 Tools MCP Server

Developer ToolsLow Risk10.0MCP RegistryLocal
Free

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melis x402 Tools — 22 pay-per-call APIs for AI agents. No accounts, no API keys. USDC on Base.

About

melis x402 Tools — 22 pay-per-call APIs for AI agents. No accounts, no API keys. USDC on Base.

Security Report

10.0
Low Risk10.0Low Risk

Valid MCP server (2 strong, 4 medium validity signals). No known CVEs in dependencies. Package registry verified. Imported from the Official MCP Registry. Trust signals: trusted author (4/4 approved).

3 files analyzed · 1 issue found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Required

This plugin requests these system permissions. Most are normal for its category.

HTTP Network Access

Connects to external APIs or services over the internet.

env_vars

Check that this permission is expected for this type of plugin.

What You'll Need

Set these up before or after installing:

Signed x402 payment token from your wallet client. Set if handling payments manually.Required

Environment variable: X402_PAYMENT_HEADER

Bypass key for trusted internal callers — skips x402 payment flow entirely.Required

Environment variable: X402_INTERNAL_KEY

How to Install

Add this to your MCP configuration file:

{
  "mcpServers": {
    "io-github-mizukaizen-x402-tools-mcp": {
      "env": {
        "X402_INTERNAL_KEY": "your-x402-internal-key-here",
        "X402_PAYMENT_HEADER": "your-x402-payment-header-here"
      },
      "args": [
        "-y",
        "@melis-ai/x402-tools-mcp"
      ],
      "command": "npx"
    }
  }
}

Documentation

View on GitHub

From the project's GitHub README.

@melis-ai/x402-tools-mcp

npm version License: MIT MCP compatible x402 Catalogue

Boring infrastructure for agent builders. 22 pay-per-call utility tools served as an MCP server — scrape, validate, embed, store, moderate, notify, convert, prevent loops. No accounts, no API keys, no subscriptions. Pay with USDC on Base via the x402 protocol.

npx @melis-ai/x402-tools-mcp

→ Full catalogue with prices and live examples: agents.melis.ai → Canonical 5-step RAG pipeline: agents.melis.ai/pipelines/rag → 5-minute getting started: agents.melis.ai/docs/getting-started


Tool catalogue (22)

ToolPrice (USDC)Description
list_servicesfreeReturns the full catalogue with prices and endpoint URLs
cacheserve$0.001Fetch a URL with server-side caching — avoids redundant origin hits
docconvert_text$0.001Format conversion: md↔html, json↔csv, html→txt, etc.
intentflow$0.001Context handoff relay for multi-agent delegation (async, returns retrieve_url)
memoryserve_write$0.001Store text + embedding in Qdrant + SQLite, namespaced per agent_id
memoryserve_query$0.001Recall most-similar memories by semantic query
memscrub$0.001Scan retrieved RAG content for indirect prompt injection (10 patterns)
notifyrelay_webhook$0.001POST a JSON payload to a URL with optional HMAC-SHA256 signing
schemagate$0.001Validate a JSON response against a JSON Schema, return a hint on failure
loopwall_hop$0.0005Validate one hop of a signed multi-agent chain (loop / budget enforcement)
loopwall_issue$0.001Issue a signed Job Envelope at chain start with budget + hop cap
imageguard$0.002NSFW image classification (multi-class moderation on roadmap)
notifyrelay_telegram$0.002Send a Telegram message to a known chat ID
promptguard$0.002Score untrusted input for prompt injection risk (0–100)
structextract$0.002Extract structured JSON from HTML — tables, links, emails, phones
xaudit$0.002Validate API response content with a cryptographically signed certificate
docconvert_pdf$0.005Convert HTML or markdown to PDF (base64 output)
kyaoracle$0.005On-chain trust score (0–100) for an Ethereum/Base wallet address
linkrisk$0.005URL risk profile — heuristic phishing signals, redirect tracing
markdownopt$0.005Convert URL or HTML to clean LLM-ready markdown (~70% token reduction)
notifyrelay_email$0.005Send a transactional email via Resend (allowlisted, rate-limited)
embedpay$0.00005 / 1k tokensOpenAI text-embedding-3-small wrapper, batch tier available
linksafe$0.01Definitive URL safety check via Playwright sandbox + VirusTotal
scrapepay$0.01Web extraction via Playwright (robots.txt enforced, SSRF-safe)
pdf_render$0.49High-fidelity URL or HTML → PDF via Playwright

22 services. Live prices and live wallet on Basescan.


Why x402, why pay-per-call

  • No signup tax. Every tool here works the moment your wallet has USDC. No accounts to provision, no API keys to rotate, no subscription tiers to forecast.
  • Charge-on-success-only. Every service settles payment only on HTTP 2xx with non-empty content. Failed calls cost nothing — your retry budget is preserved.
  • Composes naturally. ScrapePay → MarkdownOpt → EmbedPay → MemoryServe → MEMSCRUB is the canonical RAG pipeline. Each step's payment is independent and verifiable on-chain.
  • MCP-native. One install, all 22 tools appear in Claude Desktop, Cursor, Cline, Continue, Claude Code, or any MCP-aware agent runtime.
  • No vendor lock-in. x402 is a Linux Foundation protocol (April 2026) co-signed by Google, AWS, Stripe, Visa, Mastercard. Other providers will offer x402 services; your wallet client works with all of them.

Installation — Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "x402-tools": {
      "command": "npx",
      "args": ["@melis-ai/x402-tools-mcp"]
    }
  }
}

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

Restart Claude Desktop. All 22 tools appear in the tool picker.

Installation — Cursor, Cline, Continue, Claude Code

See agents.melis.ai/docs/install-mcp for per-client setup.


Example: canonical RAG pipeline

// All 22 tools registered as MCP tools — your agent calls them like any function
const page    = await callTool('scrapepay',   { url: 'https://example.com/article' });
const md      = await callTool('markdownopt', { html: page.content });
const vec     = await callTool('embedpay',    { input: md.markdown });
const stored  = await callTool('memoryserve_write', {
  agent_id: 'agent-1', content: md.markdown, vector: vec.embedding,
});

// Later — recall and guard against indirect injection
const hits    = await callTool('memoryserve_query', {
  agent_id: 'agent-1', query: 'what did we learn about X?',
});
for (const chunk of hits.matches) {
  const scrub = await callTool('memscrub', { content: chunk.content });
  if (scrub.risk_level === 'safe') useChunk(chunk);
}

Total cost per 5k-token page: ~$0.017 USDC. Detailed walkthrough: agents.melis.ai/pipelines/rag.


Funding the wallet

x402 settles in USDC on Base (Coinbase L2). Two paths:

  • Coinbase Wallet — buy USDC, switch to Base network, send to your agent's wallet.
  • Bridge from Ethereum mainnetbridge.base.org.

$1.00 of USDC covers 100 ScrapePay calls, 200 PromptGuard calls, or one full RAG-pipeline ingestion run.


Discovery surfaces (for agent builders + AI consumers)

URLPurpose
agents.melis.ai/llms.txtConcise LLM-readable catalogue
agents.melis.ai/llms-full.txtFull schemas + composition recipes
agents.melis.ai/openapi.jsonOpenAPI 3.1 spec for all 22 endpoints
agents.melis.ai/ai-plugin.jsonChatGPT-plugin manifest
https://<service>.melis.ai/.well-known/mcp.jsonPer-service MCP discovery
agents.melis.ai/agents-faqAgent-builder FAQ (distinct from human FAQ)

Comparisons


Source & licensing

  • MCP wrapper source (this repo): MIT licensed.
  • Service code (the 22 services themselves): closed source for security.
  • Site content (agents.melis.ai docs): CC-BY-4.0 — attribute "melis x402 Tools" with a link to agents.melis.ai.

Security

Found a vulnerability? See SECURITY.md. Email mizukaizen@proton.me. Critical issues acknowledged within 24 hours.


Citing this work

If you use melis x402 Tools in research or downstream products, see CITATION.cff for the canonical citation.


Author

mizukaizen — agent operator and builder. Catalogue: agents.melis.ai · Email: mizukaizen@proton.me

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