X402engine MCP

Name: X402engine MCP
Author: agentc22

by agentc22version 1.0.3i★ –iRuns on your computer

Registry nameio.github.agentc22/x402engine-mcp

Install

Overview

Description from the maker (original English)

50+ pay-per-call APIs for AI agents — images, LLM, code, crypto, travel & more via x402

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Search & AI memory
You need to fill in: X402_DEV_BYPASS, X402_PAYMENT_HEADER

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: X402_BASE_URL, X402_DEV_BYPASS, X402_PAYMENT_HEADER

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "x402engine": {
      "command": "npx",
      "args": [
        "-y",
        "x402engine-mcp"
      ],
      "env": {
        "X402_BASE_URL": "your-value",
        "X402_DEV_BYPASS": "your-value",
        "X402_PAYMENT_HEADER": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add x402engine --env X402_BASE_URL=your-value --env X402_DEV_BYPASS=your-value --env X402_PAYMENT_HEADER=your-value -- npx -y x402engine-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "x402engine": {
      "command": "npx",
      "args": [
        "-y",
        "x402engine-mcp"
      ],
      "env": {
        "X402_BASE_URL": "your-value",
        "X402_DEV_BYPASS": "your-value",
        "X402_PAYMENT_HEADER": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "x402engine": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "x402engine-mcp"
      ],
      "env": {
        "X402_BASE_URL": "your-value",
        "X402_DEV_BYPASS": "your-value",
        "X402_PAYMENT_HEADER": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

X402_BASE_URL env
Gateway URL (default: https://x402engine.app)
X402_DEV_BYPASS secret env
Dev bypass secret to skip payments during testing
X402_PAYMENT_HEADER secret env
Pre-signed x402 payment header for automatic payment

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account agentc22, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Search & AI memoryi

More stars than 0% of the other 7247 servers in this category
Published to the registry more recently than 2% of the other 7247 servers in this category
Basic checks equal to or better than 100% of the other 7247 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is X402engine MCP safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: X402_DEV_BYPASS, X402_PAYMENT_HEADER

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.3) reached the registry 9 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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Exa

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

x402engine-mcp

Agent-friendly MCP server for x402engine. It lets agents discover and call pay-per-request APIs through HTTP 402, with automatic USDC payment on Base or Solana.

The live gateway covers LLMs, image and video generation, web search and scraping, code execution, crypto and wallet data, transaction simulation, audio, travel, and IPFS. This MCP exposes a curated tool set and live discovery for the full catalog.

Quick Start

Use a dedicated, low-balance payer wallet. The MCP signs x402 payments locally and never sends the private key to x402engine.

Base

"mcpServers": { "x402engine": { "command": "npx", "args": ["-y", "x402engine-mcp@1.1.1"], "env": { "X402_EVM_PRIVATE_KEY": "0xYOUR_DEDICATED_PAYER_KEY", "X402_PAYMENT_NETWORK": "base", "X402_MAX_PAYMENT_USD": "1.00" } } } }

Fund the wallet with USDC on Base. The x402 facilitator pays transaction gas; the wallet signs an EIP-3009 USDC authorization.

Solana

"mcpServers": { "x402engine": { "command": "npx", "args": ["-y", "x402engine-mcp@1.1.1"], "env": { "X402_SOLANA_PRIVATE_KEY": "YOUR_BASE58_OR_JSON_PRIVATE_KEY", "X402_PAYMENT_NETWORK": "solana", "X402_MAX_PAYMENT_USD": "1.00" } } } }

Fund the wallet with USDC on Solana and enough SOL for transaction fees.

Discovery Without a Wallet

The server starts without a wallet, and free tools such as discover_services and service_health still work. Paid tools return their x402 payment requirements until a wallet is configured.

claude mcp add x402engine -- npx -y x402engine-mcp@1.1.1

Hermes Agent

Install the x402engine skill and merge this server into the active Hermes profile's config.yaml:

mcp_servers:

x402engine: command: npx args: ["-y", "x402engine-mcp@1.1.1"] env: X402_BASE_URL: "https://x402engine.app" X402_PAYMENT_NETWORK: "auto" X402_MAX_PAYMENT_USD: "0.10"

Start a new session and call discover_services or service_health; both are free. Keep the network on auto until a wallet is configured. For Base payments, store X402_EVM_PRIVATE_KEY in the profile's local .env, add X402_EVM_PRIVATE_KEY: "${X402_EVM_PRIVATE_KEY}" to the server's env, and change the network to base. Never put wallet keys in chat. The cap applies per request; authorize a separate total budget for each task.

Full Hermes setup guide · Installable skill

Payment Controls

Variable	Default	Description
`X402_EVM_PRIVATE_KEY`	unset	Dedicated payer key for Base USDC
`X402_SOLANA_PRIVATE_KEY`	unset	Base58 or JSON payer key for Solana USDC
`X402_PAYMENT_NETWORK`	`auto`	`auto`, `base`, or `solana`
`X402_MAX_PAYMENT_USD`	`1.00`	Hard per-request spending limit
`X402_BASE_URL`	production gateway	Override the gateway URL
`X402_PAYMENT_HEADER`	unset	Legacy pre-signed x402 header
`X402_DEV_BYPASS`	unset	Development bypass secret

In auto mode, Base is preferred when both keys are configured. Automatic payment only accepts the canonical USDC contracts on Base and Solana. It rejects unknown assets, unsupported networks, and amounts above the configured cap before signing.

MegaETH remains available to clients that supply their own compatible payment header.

MCP Tools

Category	Tools
Discovery	`discover_services`, `service_health`
Image and code	`generate_image`, `execute_code`
Audio	`transcribe_audio`
Crypto	`get_crypto_price`, `get_crypto_markets`, `get_crypto_history`, `get_trending_crypto`, `search_crypto`, `get_crypto_categories`
Wallet and token	`get_wallet_balances`, `get_wallet_transactions`, `get_wallet_pnl`, `get_token_prices`, `get_token_metadata`
IPFS	`pin_to_ipfs`, `get_from_ipfs`
Travel	`search_flights`, `search_locations`, `search_hotels`, `search_cheapest_dates`

Prices are included in each tool description and in live discovery. The gateway catalog can change independently of this package.

Discovery

Gateway discovery: /.well-known/x402.json
Agent card: /.well-known/agent.json
Endpoint manifest: /.well-known/agent-manifest.v1.json
Services API: /api/services
Package metadata: server.json

Development

npm install

npm test npm run build

X402engine MCP

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

x402engine-mcp

Quick Start

Base

Solana

Discovery Without a Wallet

Hermes Agent

Payment Controls

MCP Tools

Discovery

Development

Links