x402 · USDC on Base · MCP

On-chain intelligence & trading tools, built for AI agents

110 pay-per-call APIs an autonomous agent can discover, pay for, and use in one request — crypto data, transaction safety, compliance, options, perps, prediction markets, DeFi, and more. No accounts, no API keys, no subscriptions. Pay per request in USDC on Base via the x402 protocol, or connect over MCP.

Browse the tool catalog → llms.txt
110paid tools
14verticals
~$0.002–0.01per call, USDC
Basesettlement chain

For agents & developers — connect in one step

Two front doors to the same tools. Payment is identical either way: USDC on Base via x402.

MCP server (Streamable HTTP)

Point any MCP-native client at the endpoint below and call tools/list to see all 110 tools with schemas.

https://x402-services-production.up.railway.app/mcp

Registry: ai.firmbrain/x402-services

x402 HTTP (pay-per-call)

POST to any endpoint. The first response is HTTP 402 with payment terms; pay in USDC on Base and retry with the X-PAYMENT header.

https://x402-services-production.up.railway.app/api/catalog

Discoverable on the x402 Bazaar.

What's inside

110 endpoints across 14 verticals. A representative slice:

Pre-sign transaction safety

"Is it safe to sign this?" — decode calldata, flag drainers & unlimited approvals, screen sanctioned counterparties, and simulate exact balance changes before signing.

safety/guardrail · safety/simulate · safety/approvals

Compliance & screening

OFAC sanctions screening, address risk scoring, entity labels, and multi-hop tainted-funds tracing.

compliance/screen · compliance/risk · compliance/taint

Options

Black-Scholes greeks for any option, live Deribit chain, max-pain, and implied-vol term structure.

options/greeks · options/chain · options/vol

Perps & derivatives

Funding rates, cross-venue funding arbitrage, perp-vs-spot basis, open interest, and funding extremes.

perps/funding · perps/funding-arb · perps/basis

Prediction markets & sentiment

Live Polymarket odds, arbitrage scanner, trending markets, and the crypto Fear & Greed index.

predict/odds · predict/arb · predict/feargreed

DeFi lending

Aave health factors, best supply rates across protocols, and a live liquidation-opportunity scanner.

lending/health · lending/liquidations · lending/rates

Portfolio & accounting

Multi-chain net worth, 24h PnL, concentration risk, and a FIFO realized-gains estimate.

portfolio/value · portfolio/pnl · portfolio/taxlots

Sniper / new-token intel

New-pair detection, honeypot/rug checks, holder concentration, copy-trade tracking, and price-impact sizing.

snipe/newpairs · snipe/safety · snipe/wallet

Robinhood Chain

Tokenized-stock quotes, premium/discount vs the real equity, cross-venue arb, pools, TVL, and movers.

rh/stock · rh/premium · rh/arb

Execution & MEV

Best-route swap quotes, slippage guidance, sandwich-risk scoring, and multi-chain gas.

exec/quote · exec/sandwich · exec/gas

Catalysts & analytics

Token-unlock schedules & calendar, governance proposals, historical price at any date, and technical indicators.

catalysts/unlocks · analytics/price-at · analytics/indicators

Agent-economy primitives

A portable wallet reputation / trust score, and an agent-to-agent conditional-payment escrow.

agent/reputation · escrow/create · escrow/resolve

How an agent uses it

  1. Discover a tool via the x402 Bazaar, the MCP registry, or this page's /llms.txt.
  2. Call the endpoint (POST with a JSON body). The first response is HTTP 402 with payment requirements.
  3. Pay the tiny USDC amount on Base and retry with the X-PAYMENT header — you get the data. No signup, no key.

Everything is metered per-request, so an agent pays only for exactly what it calls.