x402engine

50+ pay-per-call APIs for AI agents via HTTP 402 crypto micropayments. $0.001–$0.12 per call with USDC and USDm.

x402engine-mcp

MCP server for x402 Engine — giving AI agents access to 16 pay-per-call APIs via HTTP 402 micropayments.

Payments are made with USDC on Base, USDC on Solana, or USDm on MegaETH. Prices range from $0.001 to $0.12 per call.

Quick Start

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "x402engine": {
      "command": "npx",
      "args": ["-y", "x402engine-mcp"],
      "env": {
        "X402_DEV_BYPASS": "your-dev-bypass-secret"
      }
    }
  }
}

Claude Code

claude mcp add x402engine -- npx -y x402engine-mcp

Available Tools

Image Generation

Tool	Price	Description
`generate_image`	$0.015-$0.12	AI image generation (fast/quality/text tiers)

Code Execution

Tool	Price	Description
`execute_code`	$0.005	Sandboxed code execution (Python, JS, Bash, R)

Audio

Tool	Price	Description
`transcribe_audio`	$0.10	Audio-to-text transcription (Deepgram Nova-3)

Crypto & Market Data

Tool	Price	Description
`get_crypto_price`	$0.001	Current crypto prices
`get_crypto_markets`	$0.002	Top coins by market cap
`get_crypto_history`	$0.003	Historical price charts
`get_trending_crypto`	$0.001	Trending coins
`search_crypto`	$0.001	Search for coins

Blockchain & Wallet

Tool	Price	Description
`get_wallet_balances`	$0.005	Token balances for any wallet
`get_wallet_transactions`	$0.005	Transaction history
`get_wallet_pnl`	$0.01	Profit & loss analysis
`get_token_prices`	$0.005	DEX-derived token prices
`get_token_metadata`	$0.002	Token metadata

IPFS Storage

Tool	Price	Description
`pin_to_ipfs`	$0.01	Pin JSON to IPFS
`get_from_ipfs`	$0.001	Retrieve content from IPFS

Discovery

Tool	Price	Description
`discover_services`	Free	List all services and pricing

Environment Variables

Variable	Required	Description
`X402_BASE_URL`	No	Gateway URL (default: `https://x402-gateway-production.up.railway.app`)
`X402_DEV_BYPASS`	No	Dev bypass secret to skip payments
`X402_PAYMENT_HEADER`	No	Pre-signed payment header

Payment Networks

Base (EVM) — USDC, 6 decimals, ~2s confirmation
Solana — USDC, 6 decimals, ~400ms confirmation
MegaETH (EVM) — USDm, 18 decimals, ~10ms confirmation

How It Works

Agent calls an MCP tool (e.g., get_crypto_price)
MCP server makes HTTP request to x402engine.app
Gateway returns 402 Payment Required with pricing
Agent pays with crypto via the x402 protocol
Gateway verifies payment on-chain and returns data

For automatic payment handling, use @x402/fetch in your agent code.

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