Don’t trust a claim until you see who else is saying it.

Cross-source search across 18 independent, real-time data sources — news, SEC filings, court opinions, economic indicators, market data — plus a dedicated tool that checks whether a claim is corroborated or standing alone.

$ read the docs llms.txt for agents

concordancehq.duckdns.org

$ curl -s https://concordancehq.duckdns.org/tools/corroboration \

-X POST -d '{"claim":"…"}'

HTTP/1.1 402 Payment Required

accept: 0.04 USDC on eip155:8453 -> 0x1c4A…e29

# client settles, retries with proof of payment

HTTP/1.1 200 OK

{

"corroborated": true,

"independent_sources": 4,

"domains": ["reuters.com", "sec.gov", …]

}

// how it works

no signup · no API key

01 / call

Hit the endpoint

Your agent calls any tool below over plain HTTP, or via the MCP server at /mcp/.

02 / settle

402, then one round-trip

You get an x402 payment challenge. Your client settles it in USDC on Base or Solana, automatically.

03 / receive

200, with your data

The retried request carries proof of payment and returns the real result. No accounts, no invoices.

// tools & pricing

$0.01 – $0.05 per call

x402 PAID

searchPOST /tools/search $0.01
seriesPOST /tools/series $0.01
digestPOST /tools/digest $0.03
company_briefPOST /tools/company-brief $0.05
corroborationPOST /tools/corroboration $0.04
timelinePOST /tools/timeline $0.03

settled instantly · USDCBase & Solana

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