API and data

The data behind this site: a free JSON series for every chart, CSVs, paid x402 endpoints for bulk history and routing, and an MCP server.

x402 Clean Index API: free rate-limited chart series, paid bulk history, per-seller series and best-execution routing over x402, MCP server, CSVs.

Free: every chart series

One call per metric, no key, CORS open, cached for an hour, CC BY 4.0 (cite wknipe.com). Optional filters: &week=YYYY-MM-DD, &category=data. Rate limit: 60 calls a minute per client for the data routes. Past that, the same route answers HTTP 402 and serves the call for $0.001. The AI-policy check and the endpoint probe allow 30 a minute; they fetch other people's sites, so paying does not lift that limit.

curl -s "https://api.wknipe.com/v1/metrics"                       # list every metric
curl -s "https://api.wknipe.com/v1/series?metric=waterfall&week=2026-09-21"
curl -s "https://api.wknipe.com/v1/series?metric=concentration&category=data"
curl -s "https://api.wknipe.com/v1/latest"                        # headline numbers for the latest week
curl -s "https://api.wknipe.com/v1/method"                        # definitions and filters
curl -s "https://api.wknipe.com/v1/check?domain=theguardian.com"  # AI-policy check (cached 24 h)
curl -s "https://api.wknipe.com/v1/probe?url=https://api.wknipe.com/v1/sellers"  # unpaid x402 endpoint check (cached 10 min)
curl -s "https://api.wknipe.com/v1/badge/policy?domain=theguardian.com"          # AI-policy badge (SVG)
metric What it is Rows

These cost $0.001 per call in USDC on Base, paid with the x402 protocol (any x402 client or agent wallet). It seemed only fair to sell the data the way it measures. My own test payments are excluded from the index.

GET https://api.wknipe.com/v1/series?stage=clean&category=all   # stage x category weekly history + price index
GET https://api.wknipe.com/v1/sellers?category=data&n=50         # top demand-cleaned sellers, latest week
GET https://api.wknipe.com/v1/seller?address=0x…                  # one seller's full weekly series
# without payment each returns HTTP 402 with the payment requirements:
curl -si "https://api.wknipe.com/v1/sellers?n=5" | grep -i payment-required

Best execution for agents

GET https://api.wknipe.com/v1/route?need=web+search ranks the x402 endpoints for a task by relevance, my daily unpaid 402 check, whether the seller has 5+ genuine buyers, and price. It returns up to 40 results (&n=) and three picks (cheapest verified, best value, most used). Optional: &max_price=0.01, &verified=1. The free demo on Best execution shows the three picks only (/v1/route/demo, same rate limit).

MCP server

An MCP server exposes the index to AI assistants: latest numbers, series, sellers, method, and best_execution. That tool calls the paid route, so it needs a wallet (set X402_PAYER_PRIVATE_KEY to a Base wallet holding a little USDC). Without one, it returns the free three picks. Source and setup: apps/x402-index-mcp.

Bulk data

The CSVs behind the published index live in the public repo under data/ and update every Monday. Chart CSVs are also linked under each chart. Code MIT, data CC BY 4.0.