# x402 Supply MCP tools for AI agents. Paid calls use x402 (USDC on Base) with no accounts or API keys. Endpoint Diligence's compare_price and reseller_check previews are free (30 calls per IP per UTC day each); full check_endpoint reports remain $0.02/call. Payment flow: call the endpoint -> HTTP 402 with a signed payment challenge -> pay in USDC on Base -> retry with an X-PAYMENT header -> result. Protocol: https://www.x402.org/ Trust leaderboard (free): - https://x402supply.com/trust — human-readable leaderboard and evidence pages - https://x402supply.com/trust.json — machine-readable leaderboard - https://x402supply.com/badge/.svg — embeddable score badge Weekly market report (free): - https://x402supply.com/reports — latest weekly x402 market report - https://x402supply.com/reports/ — a specific week's report ## Entity Resolve endpoint: https://entity-resolve.x402supply.com/mcp price: $0.02/call openapi: https://entity-resolve.x402supply.com/openapi.json description: Blocks by normalized token prefix, scores with Jaro-Winkler + token-set matching (exact on email/phone), unions matches above threshold, and returns a merged canonical record per cluster with a confidence score. Deterministic, no LLM calls. Up to 10,000 records per call. ## HTS Classify endpoint: https://hts-classify.x402supply.com/mcp price: $0.10/call openapi: https://hts-classify.x402supply.com/openapi.json description: Deterministic BM25 retrieval over the full USITC HTS schedule with heading-agreement boosting, returning the full parent-chain description, general duty rate, and a score-gap confidence per candidate. disclaimer: Informational classification aid — not a customs ruling. Verify with a licensed customs broker for binding classification. ## Chess Eval endpoint: https://chess-eval.x402supply.com/mcp price: $0.005/call openapi: https://chess-eval.x402supply.com/openapi.json description: Real Stockfish 10 (single-threaded asm.js, no SharedArrayBuffer/Worker requirement) runs in-isolate per call. `evaluate_position` returns best move, centipawn/mate score, principal variation, and up to 5 distinct multipv lines; `best_line` plays out the predicted line as SAN moves with a per-ply eval. FEN is validated strictly (piece placement, castling rights, en-passant, side-to-move-in-check) before the engine runs. Depth capped at 18 with a ~9.5s wall-clock budget per call — a deep request may return early with `depthReached` below the requested depth and `timedOut: true` rather than being killed mid-flight. ## PII Redact endpoint: https://pii-redact.x402supply.com/mcp price: $0.02/call openapi: https://pii-redact.x402supply.com/openapi.json description: Recognizers are pure pattern/checksum matching (regex + Luhn/mod-97/SSN-area validation) — no LLM calls, no external services. Person names and dates of birth are matched only via nearby context (e.g. 'Mr. Smith', 'DOB: ...'), not general NER, to keep false positives low. ## Endpoint Diligence endpoint: https://diligence.x402supply.com/mcp price: compare_price + reseller_check free (30/IP/day each); check_endpoint $0.02/call openapi: https://diligence.x402supply.com/openapi.json description: Free compare_price calls expose category market percentiles; free reseller_check calls compare a live 402 challenge or supplied description against a dated upstream API catalog and report possible resemblance plus markup math without asserting resale as fact. Paid check_endpoint live-probes the endpoint's 402 challenge for x402 spec compliance (v2/v1-legacy detection, scheme/network/asset/amount/payTo validation), checks its price against market percentiles from our daily x402 doodlebug snapshot, inspects the payTo address on Base (contract/EOA, USDC balance, recent transfer activity via public RPC), checks third-party directory presence (x402scan + our own market baseline), and checks infra hygiene (HTTPS, free-host domains, domain age via RDAP), and includes the full reseller/markup evidence. Returns a 0-100 score, pass/caution/fail verdict, and per-check evidence — never a fabricated claim, unreachable sub-checks report 'unknown' rather than being scored against the endpoint. ## Page Extract endpoint: https://page-extract.x402supply.com/mcp price: $0.001/call openapi: https://page-extract.x402supply.com/openapi.json description: Fetches a URL and runs deterministic, pure-JS extraction (Readability-based article parsing with a hand-rolled boilerplate-stripper fallback for thin/non-article pages) to return markdown and/or plain text, title, byline, language, an excerpt, word count, OpenGraph/canonical meta, and a link census (internal/external counts, up to 10 absolute top links). Static HTML only, no JS rendering. An SSRF guard blocks private/reserved network targets — including decimal/octal/hex-encoded raw-IP forms — re-checked on every redirect hop; non-HTML responses, responses over 2MB, and fetch failures/timeouts return a structured error instead of partial data. Discovery (free, no payment required): - POST {jsonrpc: "2.0", id: 1, method: "tools/list", params: {}} to any endpoint above for its full input schema. - GET /openapi.json for an OpenAPI 3.1 document with pricing, schema, and agent-facing usage guidance.