An agent that can spend needs a limit it cannot reason around and a way to know what a plan costs before it starts. estimate_plan runs free, needs no wallet, and returns a per-step price plus a cheaper alternative — which is the call that makes handing over a wallet key defensible at all.
A budget and metering layer for agents that pay per call, plus a set of crypto and web tools to spend it on. A session opens with a cap enforced at the payment layer, a plan can be priced before anything is spent, and every call lands in a receipt.
- Budget control — session_create opens a budget-capped session; estimate_plan prices a multi-tool plan before spending, per step and in total, with a fits-budget verdict and a cheaper alternative per paid step
- Market data — token_price, token_market_data, gas_tracker, fear_greed_index, defi_tvl, yield_scanner, funding_rates, open_interest, orderbook_depth with slippage at $10k, $50k and $250k, and market_snapshot for macro and crypto together
- Risk — token_security scans a contract for honeypot, tax, mint and blacklist risk; pre_trade_check combines slippage at your size, funding carry, open-interest crowding and contract security into one ok, caution or avoid verdict
- Wallets and chains — wallet_balance across Ethereum and Stellar, whale_activity for large transfers, dune_query for onchain analytics
- Web — url_reader returns a page as clean markdown, web_search returns results with their page content, crypto_news pulls headlines with sentiment
- Marketplace — verified_route vets the x402 marketplace, drops stubs and factory clones, ranks by real usage and returns one recommendation; route is its legacy alias
The npm package @romudille/agentpay-mcp over stdio; the Python side is agentpay-x402 on PyPI, with a [base] extra for the tools that settle on Base. The free tools need no wallet, no USDC and no key. AGENTPAY_BASE_KEY is an optional EVM private key that settles paid tools in place — use a dedicated low-balance wallet — and AGENTPAY_MAX_SPEND caps per-session spending, defaulting to 0.10. The live gateway is https://agentpay.tools.
One command — npx -y @romudille/agentpay-mcp