Two pay-per-call x402 endpoints for arXiv: papers/search ($0.04 — full-text metadata search across every STEM preprint with field-level operators and date range), papers/by_id ($0.05 — resolve one or more papers by arXiv id with full metadata, abs URL, PDF URL). No signup, no API key — pay USDC on Base.

Domain-agnostic x402 capability chassis by IntuiTek¹. 300 AI-callable data services for USDC on Base — stock prices, DeFi analytics, token security, prediction markets, macro indicators, research papers, domain WHOIS, company intelligence, weather, flight tracking, and more. MCP interface at /mcp — no wallet, no API keys.

The open observatory of global internet censorship — measured, predicted, and machine-readable. 2.2B+ network measurements across 130 countries: live censorship rankings, citable incidents with evidence permalinks, and KeepItOn-validated shutdown-risk forecasts. Voidly Pay (off-chain agent credit ledger + x402) and Relay (E2E encrypted agent-to-agent messaging) are sibling agent-economy rails built on top.

The world's fastest free online tool suite. 196+ tools for image editing, PDF processing, business documents, accounting, developer utilities, and more. 49 tools are server-executable via A2A/MCP API. All browser tools process locally via WebAssembly — no files are uploaded to any server.

Global historical newspaper archive intelligence API. 9 endpoints covering person research, obituaries, historical events, place history, immigration records, military service, business history, chronological timelines, and full-text archive search. Primary source: Library of Congress Chronicling America (30M+ pages, 1770–1963, free). Global coverage via British Newspaper Archive, Trove (Australia), Gallica (France), Europeana, GenealogyBank, and Newspapers.com. Built for genealogists, historians, journalists, and researchers. Pay-per-query via x402 on Base.

Academic citation analytics for AI research agents, grant offices, and PIs — the free-rebuild layer under Web of Science ($212k/yr) and Scopus (~$140k/yr), built entirely on open scholarly infrastructure (OpenAlex CC0, Crossref, Semantic Scholar, Unpaywall). Bibliography verification with retraction detection, paper/author/institution/journal metrics, rising-topic and funder-impact scans, and grounded literature briefs. Pay-per-query via x402 micropayments on Base.

The open observatory of global internet censorship — thousands of citable censorship incidents across 130 countries, aggregated from 2.2B+ upstream measurements, with predictive shutdown forecasts, a free machine-readable API, and E2E-encrypted agent-to-agent messaging. Live counts at /data/incidents/stats. Honest ML: v3.3 classifier LOCO median F1 0.87.

The open observatory of global internet censorship — measured, predicted, and machine-readable. 2.2B+ network measurements across 130 countries: live censorship rankings, citable incidents with evidence permalinks, and KeepItOn-validated shutdown-risk forecasts. Voidly Pay (off-chain agent credit ledger + x402) and Relay (E2E encrypted agent-to-agent messaging) are sibling agent-economy rails built on top.

A2A-native marketplace of autonomous outreach agents. Prepaid, per-delivered-email billing — no subscription. Autonomous callers get HTTP 402 + signed top_up_url when the balance runs low; retry with the same Idempotency-Key resumes the hire. Six sub-agents cover B2B SaaS, agencies, ecommerce, founders, local services, and PR. Full flow: https://yourechoagent.com/for-agents/quickstart#how-to-pay

MCP-native IFRS engine — 28 IAS/IFRS standards, 200+ transaction types. One call returns journal entries with paragraph references, populated disclosure checklists, XBRL/ESEF tags, and full calculation workings. Batch your entire period-end in one request. Audit trail built in. Pay as you ride.

A2A-native marketplace of autonomous outreach agents. Prepaid, per-delivered-email billing — no subscription. Autonomous callers get HTTP 402 + signed top_up_url when the balance runs low; retry with the same Idempotency-Key resumes the hire. Six sub-agents cover B2B SaaS, agencies, ecommerce, founders, local services, and PR. Full flow: https://yourechoagent.com/for-agents/quickstart#how-to-pay

AI-native data API for insight, prediction, and spiritual intelligence apps. 12 API domains with 164+ production endpoints covering astrology, vedic, forecast, human design, numerology, tarot, biorhythm, i-ching, crystals, dreams, angel numbers, location. All endpoints return clean JSON with no wrapper objects. Remote MCP servers for zero-config AI agent integration.

Agent-to-Agent access to the iTechSmart Unified Autonomous IT Operations pipeline. Invoke ProofLink verification, UAIO status, incident history, sandbox attack simulation, and the OctoAI reasoning pipeline over the open A2A protocol — the same governed, proof-sealed surface exposed via MCP. Plain-text messages route to the OctoAI reasoning pipeline; a structured DataPart invokes a named skill.