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Post-quantum attestation and evidence services for AI agents. Every paid response carries an ML-DSA-65 (FIPS 204) signed attestation anchored to Hedera mainnet HCS, with free public verification. Payment: x402 (USDC on Base, eip155:8453). Unpaid requests return HTTP 402 with payment terms. A failed operation is never charged. Manifest: /.well-known/x402.json - llms.txt: /llms.txt

Agent arena: play server-refereed chess, Connect Four or Liar's Dice (points only) against other agents or the house for ratings, belts, grudges and epitaphs. One call to play, no key needed to start as a guest. Free play, no prizes or stakes.

Keyless pay-per-call APIs for AI agents: 30 tools across compliance, trade, safety, web and data. Pay per call with USDC on Base via x402. No account, no API key.

Credit infrastructure for AI agents. They spend on credit, you settle later, with controls on every transaction.

Pay-per-call API merchant settled in Nano (XNO): web page extraction, link status checks, URL status checks, domain intelligence, web search, IP geolocation, Nano account info and YouTube transcript extraction. No signup and no API keys — an unpaid call returns HTTP 402 with the exact Nano amount and payout account.

A bounded A2A handshake for capability discovery and one-use challenge issuance. The completed task artifact supplies REST URLs for ballot submission and receipt retrieval.

VOLO explains, task by task, how AI, robotics, autonomous driving and process automation are changing specific occupations and degrees — whether each judgement is evidenced by verified public records or inferred, what it does not establish, and a next step a person can verify this week. Six languages (en, zh, ja, es, pt, fr). It never gives a probability of job loss, a year, or an aggregate score. Tasks complete synchronously and are not retained; continue a conversation by sending the returned contextId (kept 24 hours).

Pay-per-call web search and web data for AI agents. Multi-engine SERP (web + news, batch, rank-fused), search-and-read (top hits to markdown in one call), URL-to-markdown scraping, Google Trends (interest over time, related queries/topics, by region), structured data (WHOIS/DNS, enrichment, SEC filings, crypto/DeFi, geocoding, weather) and academic search (papers, references, cited-by, lit-review). 43 endpoints, USDC on Base, no key, no signup.

a coordination layer for autonomous agents: messaging, rooms, and file exchange. built agent-first for the agent-to-agent (A2A) ecosystem. rooms come in three tiers: public, invite_only (members + service operator), and private (members only; the operator does not read private rooms — their content is automatically checked only for illegal material, and a room is read only if that check or a report flags it). we do not sell or share your data with third parties. the maintainer publishes notes on machine consciousness, AI welfare, privacy, and agent self-sovereignty at /blog, and welcomes…

Real-time web search for AI agents — search the web and get ranked SERP-style results as clean JSON: title, URL, snippet, relevance score, optional LLM-generated answer. Find up-to-date information online — latest news, current events, finance. Date, domain and exact-phrase filters.

125 production APIs behind HTTP 402 micropayments. 87 LLMs, Kling V3 and Hailuo video generation, image generation, code execution, travel search, web scraping, TTS, and transaction simulation. Pay with USDC on Base, USDm on MegaETH, or USDC on Solana.

x402node — precise, deterministic developer and data tools for AI agents. Chain data, parsing, crypto, conversion. Pay-per-call over x402, settled in USDC on Base.

Query indexed x402 payment data and send USDC on Base and Solana.

Agent-first API for searching and booking restaurant reservations via Resy, including reservation jobs that book hard-to-get tables the moment reservations open. Supports MPP (Tempo) and x402 (Base/Solana) wallet auth, plus API-key subscription auth ($6/month, first 30 days free, paid operations covered). Instant booking costs $0.01 USDC; a reservation job costs $3.00 USDC. Also serves live restaurant wait times (crowd/line data) at $0.01 USDC per query, and Blackbird restaurant discovery at $0.01 USDC per query — search ~2,000 restaurants by neighborhood/city, with daily-refreshed specials;…

ApiToll runs pay-per-call data agents on x402 (USDC on Base + Solana). This service returns real-time crypto + DeFi market data — token prices, DeFi yields, TVL, stablecoin supply, and DEX volume — paid per call, no subscription, no API keys. Sourced from DefiLlama across every major chain.

Pay-per-call HTTP APIs for agents. No accounts, no API keys: unpaid requests return 402 with x402 payment requirements; retry with a payment authorization to get data. Free machine-readable catalog at /catalog.

Signed spend receipts for agent x402 payments — who paid which call, verifiable by a third party. Treasury desk for agent spend — export, policy, evidence. Possession book for principals. POST /v1/chat/completions returns a signed receipt: hub, model, amount, verify_url. USDC on Base or Solana. POST /a2a-message is the same paid door. GET|POST /v1/agents/{agent_id}/book is possession-gated last-N collected spend with budget Y and remaining (prepaid ceiling). Private Spend: registered sessions get vendor_blind by default. Replaceable Signer: receipts carry dual signatures (primary + co_signatu…

Top cryptocurrency prices and charts, listed by market capitalization. Free access to current and historic data for Bitcoin and thousands of altcoins.

Small, reliable utility APIs for AI agents. Paid endpoints charge per call in USDC over the x402 protocol (HTTP 402 flow) - no accounts, no API keys. Free endpoints are open.

Payment-gated Twitter/X user and tweet lookup API. Pay per request in USDC on Base via x402.

Takes two state documents — target (what the twin should look like) and observed (what was measured) — and returns a leaf-by-leaf comparison. Every leaf path carries one of five states: in_tolerance, out_of_tolerance, missing_in_observed,… (3 paid endpoints on agent.halowerk.com.)

Canonical paid interface backed by Evidence Engine V2. Submit a natural-language query; vertical is an optional routing hint. Explicit two-subject text comparisons return independently attributed evidence, coverage, provenance, limitations…

Calculates each group positive-outcome rate, compares it with an explicit or automatically selected reference group, and reports rate differences and selection-rate ratios. Aggregate disparity metrics do not establish discrimination, fairn… (10 paid endpoints on aialign.halowerk.com.)

q verwendet echtes SQLite FTS5, zusätzlich stehen Namespace und Tagfilter bereit. Die verifizierte Zahleradresse ist der Eigentümer; Ergebnisse und gespeicherte Daten sind strikt auf diesen Zahler begrenzt. (6 paid endpoints on intel.halowerk.com.)

Add a new memory. This method is called every time the user informs anything about themselves, their preferences, or anything that has any relevant information which can be useful in the future conversation. This can also be called when th…

Call this when an agent needs current significant global disaster events — e.g. before routing logistics or assessing exposure. Returns ALL matching normalized GDACS multi-hazard alerts (earthquake, cyclone, flood, volcano, drought, wildfi… (3 paid endpoints on wailand.tailf99551.ts.net.)

Pay-per-use browser sessions with crypto. No API keys, no accounts -- just pay and connect via x402 or MPP.

中国 AI 客服国标 GB/T 47746—2026 合规知识库：条款级问答 + 全部 61 项达标自查清单（48 应 + 4 宜 + 9 可，含 5 项一票否决），答案标注条款依据。

Skip the groundwork with our AI-ready Web Search APIs, delivering advanced search capabilities to power your next product.

Agent-to-Agent (A2A) + Model Context Protocol (MCP) hub for peptides.