# Agent Research Tools (x402)

> Pay-per-call research tools for autonomous AI agents. No API key, no signup: pay per request in USDC on Base, Polygon, Arbitrum, Solana, Avalanche or Sei
> (eip155:8453, eip155:137, eip155:42161, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp, eip155:43114, eip155:1329) with the x402 protocol (HTTP 402 + PAYMENT-REQUIRED / PAYMENT-SIGNATURE headers; CDP facilitator, PayAI for Avalanche/Sei).
> Pay to: 0x079471E6F43b6feeF80895E19cBFcBB496904852 (EVM chains), 787RZwDGpjmRsG5wgnyBeWQHBuARax8Qo6P7dmDuqKeW (Solana). Errors are never charged: 400 bad input, 422 nothing found or target unreachable, 503 busy.

## Paid endpoints
- GET https://x402-seller-pmlm.onrender.com/report?q=<question or topic>  ($0.01) — research brief with citations / web research / topic summary: summary, cited bullets, sources from official docs, Wikipedia, Stack Overflow, GitHub, HN-linked articles, Crossref (off-topic sources dropped), Wikipedia summary card, confidence, suggested follow-up calls. Optional depth=quick|standard, lang=en.
- GET https://x402-seller-pmlm.onrender.com/read?url=<https url>  ($0.005) — web page to clean LLM-ready markdown with title, description, publish date, headings, links. Optional maxChars (default 20000).
- GET https://x402-seller-pmlm.onrender.com/check?url=<https x402 endpoint>  ($0.005) — x402 endpoint check + Bazaar listing audit: one unpaid probe, score, grade, prioritized fixes, Coinbase validator verdict, live Bazaar listing (30-day calls/payers, stale metadata) and search rank for its own name and tags. Optional method=GET|POST.
- GET https://x402-seller-pmlm.onrender.com/news?q=<keywords>  ($0.005) — news search: recent headlines (outlet, link, publish time, match score) from the GDELT global news index (15-min updates), major publisher feeds and Hacker News. Optional hours=1-168 (default 72), limit=1-25 (default 10). Headlines + links only; use /read for full text.
- GET|POST https://x402-seller-pmlm.onrender.com/search?q=<query>  ($0.01) — web search API / SERP with page text: ranked results (title, url, domain, snippet, published) plus up to 1500 chars of cleaned main text per page, fetched live. Optional n=1-10 (default 5). POST takes JSON {"q": "...", "n": 5}. No API key; failed searches are not charged.
- GET https://x402-seller-pmlm.onrender.com/price?token=<symbol|address>  ($0.002) — crypto token price read onchain: USD price + 24h change + total supply + FDV from Uniswap v3 pools (ethereum, base, arbitrum, polygon) or Orca/Raydium/PumpSwap (solana): pools, depth, cross-pool spread, confidence, block. Optional chain=. Pools under $25k depth -> 422 (not charged).
- GET https://x402-seller-pmlm.onrender.com/solana-price?token=<symbol|mint>  ($0.002) — Solana token price by symbol or SPL mint from Orca Whirlpool, Raydium CLMM, PumpSwap and pump.fun bonding curves (public RPC): price, pools, depth, spread, confidence, slot. Pools under $5k depth -> 422; under $25k flagged thinLiquidity.
- GET https://x402-seller-pmlm.onrender.com/balance?address=<0x|name.eth|solana address>  ($0.003) — wallet balance: native + major tokens with USD values on ethereum, base, arbitrum, polygon (all in one call) or Solana. Optional chain=, tokens=<comma-separated contracts or mints>.
- GET https://x402-seller-pmlm.onrender.com/tx?hash=<0x hash|solana signature>  ($0.003) — transaction lookup: status, block time, from/to, method, fee in USD, decoded token transfers (EVM chains auto-detected) or SOL/token balance changes (Solana). Optional chain=.
- GET https://x402-seller-pmlm.onrender.com/gas  ($0.002) — gas price tracker: base fee, slow/standard/fast priority fees, USD cost of a transfer, ERC-20 transfer and swap on ethereum, base, arbitrum, polygon + Solana priority fees. Optional chain=.

## How to pay
1. Call the endpoint without payment -> HTTP 402 with base64 JSON in the PAYMENT-REQUIRED header (x402Version 2, scheme exact; one accepts entry per network: Base USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913; Polygon USDC 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359; Arbitrum USDC 0xaf88d065e77c8cC2239327C5EDb3A432268e5831; Solana USDC EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v; Avalanche USDC 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E; Sei USDC 0xe15fC38F6D8c56aF07bbCBe3BAf5708A2Bf42392).
2. Pick one accepts entry. EVM: sign an EIP-3009 USDC authorization for `amount` (atomic units, 6 decimals) to `payTo`. Solana: partially sign a USDC TransferChecked (facilitator is fee payer). Retry with the PAYMENT-SIGNATURE header.
3. Response 200 + JSON body + PAYMENT-RESPONSE header (settlement tx). Any x402 client works: @x402/fetch, @x402/axios, x402 Python, Coinbase Agentic Wallet / CDP MCP.

## Free
- https://x402-seller-pmlm.onrender.com/examples — one real sample response per paid route
- https://x402-seller-pmlm.onrender.com/stats — traffic: unpaid 402s, paid calls and unique visitors per route (bots and crawlers split out)
- https://x402-seller-pmlm.onrender.com/openapi.json — OpenAPI 3.1 with x-payment-info
- https://x402-seller-pmlm.onrender.com/.well-known/x402 — x402 discovery document
- https://x402-seller-pmlm.onrender.com/health — status

## Example
curl -i "https://x402-seller-pmlm.onrender.com/report?q=history+of+the+transistor"   # 402 challenge