x402engine-mcp

MCP server for x402 Engine — giving AI agents access to 38 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

LLM Inference

Tool	Price	Description
llm_chat	$0.002-$0.09	Chat completion with any supported model

Supported models: GPT-4o ($0.04), GPT-4o Mini ($0.003), OpenAI o1 ($0.03), Claude Opus 4.6 ($0.09), Claude Sonnet 4.5 ($0.06), Claude Haiku 4.5 ($0.02), Gemini 2.5 Pro ($0.035), Gemini 2.5 Flash ($0.009), Grok 4 ($0.06), DeepSeek V3 ($0.005), DeepSeek R1 ($0.01), Llama 3.3 70B ($0.002), Mistral Large 3 ($0.006), Qwen3 235B ($0.004), Perplexity Sonar Pro ($0.06).

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)
tts_openai	$0.01	Text-to-speech (OpenAI)
tts_elevenlabs	$0.02	Text-to-speech (ElevenLabs)

Text Embeddings

Tool	Price	Description
create_embeddings	$0.001	Text embeddings (OpenAI text-embedding-3-small)

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
simulate_transaction	$0.01	Transaction simulation (Tenderly)

Web

Tool	Price	Description
web_scrape	$0.005	Scrape and extract web page content
web_screenshot	$0.01	Capture web page screenshot

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

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

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

Links

• Gateway: x402engine.app
• Discovery: x402engine.app/.well-known/x402.json
• GitHub: github.com/agentc22/x402engine-mcp
• Protocol: x402.org