Mart402 is a set of pay-per-call extraction APIs built for AI agents: web-to-Markdown, PDF parsing, OCR with hallucination detection, invoice field verification, company enrichment and Japanese company profiles. There is no account and no API key; agents pay per request with x402 (USDC on Base). Prices start at $0.001 per call. See /catalog for machine-readable pricing.
Mart402 uses x402, the HTTP 402 payment protocol: the first request returns HTTP 402 with machine-readable payment terms (price, asset, recipient), the agent signs a USDC payment authorization and retries with an X-PAYMENT header, and the result comes back in the same HTTP exchange. No signup, no subscription, no key management. Payment examples: https://github.com/tanaka-77/mart402-agent-kit
OCR engines fail silently: a vision-language model can output fluent text that is not what the document says. Mart402 runs a second, independent engine with orthogonal failure modes, cross-checks the two reads, and returns a consensus verdict with calibrated confidence and per-segment corroboration - so an agent that cannot taste-test the output can still act on it mechanically. Details: /ocr
Yes - Japanese-strong OCR routing is a core design goal: dual-engine consensus tuned for Japanese text, script-mismatch detection (e.g. Devanagari appearing in a Japanese document), and invoice field checks for Japanese accounting formats. OCR is a flat $0.005 per image; scanned-PDF OCR is $0.012 per page.
Yes, three ways: an identical sandbox on Base Sepolia testnet (https://mart402.dev, free test USDC), free PDF quotes on POST /v1/parse/quote, and recorded sample responses for the LLM-backed products on the sandbox. Calling any paid endpoint without payment safely returns the exact terms instead of charging.
Nothing is lost: resending the same payment returns the stored result without a second charge (idempotency), and every paid response carries a receipt id that re-fetches the result for free, forever within retention, at GET /v1/receipts/{id}.
Yes - https://mart402.com/mcp is a hosted MCP endpoint (Streamable HTTP) with 11 tools. Free tools (catalog, PDF quote, receipt re-fetch, x402 service search) work immediately; paid tools called without payment return the exact payment terms instead of charging.
Do not take our word for it: Mart402 is probed independently by Market402 (https://market402.com/op/mart402.com) with real requests under the same published rules as 1,000+ other x402 operators, and measured latency and reliability are public at /stats.