Duckdns

Duckdns is an x402-native service at https://concordancehq.duckdns.org, indexed from the x402 Bazaar (Coinbase's public discovery directory). It charges callers itself in USDC on Base and is paid directly at its own wallet; Monex Protocol passes your request and payment headers through untouched. 2 endpoints listed.

Base

Offers

Offer	Endpoint	Price
Tools Search Full-text search across every aggregated data source in one call: news, SEC filings, court opinions, academic papers, government records, and developer discussions. One query surfaces everything concordant across independently-sourced, citable results -- not a single-source wrapper. Optional source/category/since filters.	`/m/bz-concordancehq-duckdns-org/tools/search`	0.01 USDC
Tools Series Tabular time-series lookup across economic indicators (FRED, World Bank, UN Comtrade), crypto TVL, weather, and stock quotes -- by source + series_id, with an optional date range.	`/m/bz-concordancehq-duckdns-org/tools/series`	0.01 USDC

Machine-readable: openapi.json with x-payment-info offers.

Try it live

Run the full MPP flow from your browser: catch the 402, sign the payment with your wallet, and watch it settle on-chain.

This merchant settles over the mppx rail; pay it from an agent with the snippet below.

Pay with an agent

Any MPP or x402-compatible client works. With mppx, payment is automatic:

import { Mppx, evm } from 'mppx/client'
import { privateKeyToAccount } from 'viem/accounts'

const mppx = Mppx.create({
  methods: [evm({
    account: privateKeyToAccount(process.env.KEY),
    currencies: [evm.assets.base.USDC],
  })],
})

const res = await mppx.fetch('https://api.meshgateway.co/m/bz-concordancehq-duckdns-org/tools/search')
// 402 challenge signed and settled automatically; response includes Payment-Receipt

Or inspect the challenge yourself:

curl -i https://api.meshgateway.co/m/bz-concordancehq-duckdns-org/tools/search
# HTTP/1.1 402 Payment Required
# WWW-Authenticate: Payment id="…", method="evm", intent="charge", …