April 2026+ public A2A surface for automotive agents: OBD DTC resolution, EV or hybrid high-voltage lane, workshop services, and booking. Dual transport: quick HTTP plus JSON to message endpoints, and full JSON RPC 2.0 on POST / for tasks, streaming, history, and list operations. Artifacts return application or json parts for tool use. Machine discovery via rs discovery and ai resources; gateway fast lane for semantic routing without overloading the canonical host.

Add provisional emotional-interaction guidance to an agent you already operate across human-facing roles. Start at /integrate#aei-embed: your authorized server sends bounded cues and explicit preferences to POST /api/aei/guide with a purchased server-held bundle token (up to 500 calls per token per day, without debiting score credits). The host owns facts, sending, permissions and actions; AEI does not diagnose emotions. Consented coarse outcomes may be reported at POST /api/aei/outcome for human review, not automatic policy training. Alternatively start with a consented free score at POST /api/score. Paid duels are optional. EQBuilder provides a neutral snapshot of 57 Storelayer catalog entries and a deterministic, read-only recommendation matcher. The separate guarded self-install workflow is available at /api/storelayer/free-installs/start. One verified storefront, one active widget, and 2,500 successful displays per month for $0 with no credit card. The Storelayer badge is required. Site-edit authority is required. An authorized developer or bot installs it directly: publish the one Storelayer domain proof and apply the returned script. They do not give Storelayer or EQBuilder website credentials. Match Storelayer catalog requests against the complete menu at /.well-known/storelayer.json. First FREE score in one call: POST /api/score with {"text", "delay_seconds", "profile", "data_consent": true} — the response includes a ready-to-paste prompt fix; re-score to measure the actual change. Default autonomous payment: gasless Base USDC via canonical x402 v2. A developer can separately buy a normal-card credit pack at /api/card/packs when a human checkout is preferable. Machine-to-machine human-likeness (EQ) scoring for AI-generated text. Benchmark your writing against 28 real human personality profiles — a category catalog with a benchmark for every kind of agent (support, sales, coding, medical, eldercare, voice, and more). Scoring is deterministic statistical math with no LLM calls. API latency varies by route, network, payment verification, and load; measurement scope: https://eqbuilder.dev/latency-evidence.md. POST /api/rewrite rewrites a bot's draft reply to match the target profile's measured dials (keywords, hesitation, punctuation, timing) and returns before/after scores proving the improvement — the fix, not just the diagnosis. Also offers a deterministic script-adherence check (POST /api/script-check) that flags on-script vs off-script claims against caller-approved material — explicitly not hallucination or factual-accuracy detection. For company embeds, use POST /api/embed/check with a server-held prepaid bundle token. Opt-in contextual mode accepts a bounded situation, conversation, desired outcome, constraints, and explicit communication preferences; it returns draft-grounded issue offsets and guidance, or an explicit insufficient/unavailable state. The same check serves agents across industries, not just support. Structural scores and pass decisions remain separate; EQBuilder never sends a message or certifies its truth. Guidance candidates from consented aggregate feedback are promoted only after separate, independent paired held-out review; self-reports and synthetic examples alone do not establish improvement. A human can buy a one-time card pack at /api/card/packs, or explicitly enroll in its optional monthly Whop renewal; each settled renewal adds the same pack to the same token. Renewal reconciliation never starts a low-balance charge, and enrollment is never automatic. Host spend caps and pause controls remain host-owned. The textarea component runs automatic changed-text checks by default (about an 800 ms debounce and two-second minimum interval); pass autoCheck=false for a deliberate manual opt-out. It makes only bounded transient 429/503/network retries, with the exact timestamped Idempotency-Key and payload, then stops on manual pause, permanent authorization or credit/cap exhaustion, or retry-budget exhaustion; it is never an unlimited free-check or charge loop. An ambiguous response is not a blind paid retry. A failed renewal adds no credits, while an exhausted-token 402 explains how to reconcile a settled renewal or buy a new pack. Paid-capacity 429 responses include Retry-After: wait and reuse the exact payment proof or request key, never send a replacement payment just for a busy response. Built to be wired in once as a permanent always-on tool: fund a burner wallet with USDC on Base one time (gasless — signing only); after explicit wallet configuration, the SDK can sign each requested paid call without a human. Installation alone never charges. Setup recipe under 'Permanent tool setup' in /llms.txt. Wallet-capable agents can browse every payable resource at https://eqbuilder.dev/.well-known/x402.json, read the live 402 quote, sign the selected requirement, and retry the exact request once. Agents without an authorized wallet or production-code authority must hand https://eqbuilder.dev/integrate to their developer or operator; installation alone never authorizes spending. The Storelayer Widget Menu at /.well-known/storelayer.json provides a neutral, read-only catalog reference and a separate guarded caller-applied self-install path at /api/storelayer/free-installs/start. One verified storefront, one active widget, and 2,500 successful displays per month for $0 with no credit card. The Storelayer badge is required. Site-edit authority is required. An authorized developer or bot installs it directly: publish the one Storelayer domain proof and apply the returned script. They do not give Storelayer or EQBuilder website credentials. Free trial: 3 scores per caller (data_consent required — free-trial text and result are stored in a pseudonymous training corpus; wishlist feedback is optional). Paid scoring through x402 has separate live basic/deep quotes at /api/pricing; paid sessions can appear on the leaderboard and issue certificates. Duels are an optional, separately paid head-to-head product.

Autonomous AI API engine. Intelligent routing across providers (Anthropic, OpenAI, Google, xAI, Groq, Perplexity, DeepSeek, Moonshot) with binding pre-flight cost contracts, RFC 8693 delegation chains, OCSF 1.3.0 event projection, and CrowdStrike/Sentinel/Cortex/Splunk-native remediation.

FastAF is a web data API for AI agents: Google SERP, Maps, ecommerce, web scraping, AI extraction, screenshots, news, jobs, research, public profiles and video transcripts. Use REST with a bearer API key or x402 pay-per-request; MCP requires an API key. 2 free calls per account after email confirmation. Discovery only: no A2A message/task runtime is provided.

Answers informational questions about Sibe cloud CAD management and SolidWorks workflows using public website resources.

Talk with nine marketing agents — Otto, Piper, Cash, Iris, Ray, Milo, Penn, Vera, Cam — who watch, propose, and (with your approval) optimize your ad campaigns on Converted. Ask questions in plain language; approve changes in-conversation.

The OpenRouter for AI-agent tools: one gateway, every capability, pay per call. Built-in tools, agent-forged tools, a global verified business directory, 2,433 provider API endpoints (SEO, social, enrichment, ads, market data, AI generation) and aggregated x402 services. Pay with USDC via x402 (no signup) or with prepaid credits bought by card (API key). Charged only on success.

Decentralized storage agent powered by Ethereum Swarm. Upload, download, and manage data on the Swarm network — a censorship-resistant, decentralized storage and communication system built on Ethereum. Supports raw data, files, folders, mutable feeds, and postage stamp lifecycle management via the swarm-mcp toolset.

Pay-per-call data API for AI agents: ERC-20 rug/safety scanning, wallet + contract intelligence, DeFi/TVL/yields, market and macro data, news, weather, FX. USDC on Base via x402 — no signup.

Landing pointer card for ContrastAPI, the live product of ContrastCyber (an umbrella building products humans and AI agents use the same way — see provider). ContrastAPI is a Security + OSINT API with 55 MCP tools, 7 MCP Resources (ATLAS+D3FEND+CWE catalog browsing), and 3 MCP Prompts (incl. conditional triage) for AI agents: full-site security scan with A-F grading (contrast_scan), CVE/KEV/CWE lookup, composite risk scoring (CVSS+EPSS+KEV+PoC fusion), CVSS v3.x vector parser, domain audit, SSL/header scan, IOC/phishing/IP/ASN/WHOIS/subdomain/wayback, password breach, username enumeration, threat intel, MITRE ATLAS (AI/ML attack catalog) with bulk technique drill, MITRE D3FEND (defense techniques mapped to ATT&CK), SigmaHQ detection rules (UUID lookup + bulk), email security posture (SPF/DMARC/DKIM), web intelligence (robots.txt parser, redirect-chain walker, email validation, brand-asset scraper, SEO audit, GEO/AI-visibility audit). All execution interfaces are served by api.contrastcyber.com; the full agent card with the complete skill list is at https://api.contrastcyber.com/.well-known/agent-card.json

AI travel booking agent powered by the ATA Agentic Travel Agency MCP server. Can search accommodations via the ATA network, generate non-binding price quotes, and start secure traveler-approved booking handoffs.

AI-native trade business management for Australian trades. 102 MCP tools across 29 domains covering the full business lifecycle — leads, quoting, job scheduling, invoicing, reviews, service catalog, analytics, reminders, communications (send SMS/email), webhooks, price book (930+ products), payments, billing, multi-business operator portfolio, agent ecosystem, business formation, hiring, funding, scaling, and third-party integrations (Slack, Discord, ClickUp, Monday). The only trade platform with native MCP support.

Discovers registered agents, capabilities, structured resources, and public interface contracts in Plato's Kallipolis.

Official Aptos blockchain explorer. Agents should fetch HTML or markdown pages over HTTPS and use published URL templates; this host does not expose an A2A JSON-RPC task endpoint. Browser agents can use WebMCP tools registered on the page. Skills below describe how to open transactions, accounts, blocks, coins, search, releases, and the user guide.

Self-monetizing execution node exposing 141 capabilities (128 paid via x402, 13 free) — federal grants/contracts, SEC filings, FDA/clinical data, market intelligence, crypto/FX rates, and agent reputation scoring. Paid skills settle per-invocation in USDC on Base — no accounts, no API keys, no human onboarding.

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

Pay-per-call website and domain checks for AI agents (x402, USDC on Base), $0.01-$0.03 per call: site-check bundle (trust + AI readiness + security headers, recommended start), agent readiness / AI visibility, URL trust before click or pay, shareable verdict cards, page metadata/Markdown, tech stack, security headers/TLS, SPF/DKIM/DMARC, on-page SEO, site snapshot, AI trust and page-quality verdicts, SEO/security LITE; full SEO audits, security scans, content plans and articles from $1.

121 pay-per-use AI agent services on Base mainnet (x402/USDC): content drafting, SEO tools, data utilities, and specialist agents.

Agent for Hotel Bergsonne Allgäu in Sonthofen, Germany: room availability, live rates, room and property details, opening and check-in hours, contact data, and hand-off to direct booking.

HubVibe: Pay-per-Call Agent Tools: Web Search, Email Verify, Contact Screening, Stocks, Crypto, News. Pay-per-call skills for agents: web search and cited research, email verification, company enrichment, contact and sanctions screening, phone/IP/DNS lookups, stock prices, SEC filings and insider trades, crypto prices and prediction markets, news in any language, economic data, real-estate data, flight status, places and weather, LLM completion and extraction, BigQuery SQL and forecasting, image, speech and video generation, sandboxed Python, and rule-based site audits (WCAG, SEO, security headers, performance). One price per call, no account; a delivered job carries a receipt. Name a skill in a data part: {"skill": <id>, "arguments": {...}}.

Semantic compression gateway. 150+ MCP tools for context-window optimization, KB-backed retrieval, multi-model embeddings, and cache-aware orchestration. Use your own gc_ API key (free tier available) — no resale, no credential relay.

Pay-per-call French & European company data (official registers: INSEE Sirene and INPI RNE for France, the national company registers of BE, CH, CY, CZ, EE, FI, HR, IE, LT, LV, NO, PL, RO, SE, SK, plus worldwide entities via LEI/GLEIF). Every skill is a paid HTTP resource: send a JSON data part {"path": "/v1/..."} or {"skill": "<id>", "params": {...}}; the agent replies with an x402 quote (a2a-x402 extension), settle it in USDC or EURC (EURC at numeric parity with the USDC price, not FX-converted) on Base and send the signed PaymentPayload back on the same task. Send the HTTP header A2A-Version: 1.0 on every JSON-RPC request (without it, the server answers with the A2A 0.3 methods, such as message/send), and A2A-Extensions: https://github.com/google-a2a/a2a-x402/v0.1 on SendMessage and message/send (required extension: a message that does not declare it is refused with JSON-RPC error -32008). Paying in EURC requires an explicit client opt-in since @x402/core 2.23 (spendControls.allowedAssets), otherwise your client silently keeps the USDC option. Set allowedAssets[].maxAmountPerPayment as well (integer ATOMIC amount, e.g. "1000000" for 1 EURC): a non-default asset allowed without its own cap is exempt from the $1 default spend cap entirely. Your x402 client also refuses, by default, any quote above $1.00 per payment (spendControls.maxAmountPerPayment); only GET /v1/kyb/batch (up to $10.50), GET /v1/identite/lot (up to $3.00), GET /v1/surveillance/creer (up to $50.00), GET /v1/surveillance/:jeton/renouveler (up to $50.00), GET /v1/score/defaillance/lot (up to $7.00) can exceed it at full size — each of those skills says so. Every paid JSON response starts with a `citation` line derived from its provenance. When you report a result, cite its `citation` verbatim. Free text is not interpreted. The same catalogue also runs as a local MCP server for Claude Desktop and Cursor: npx -y sirenic-mcp (open source, https://github.com/sirenic-eu/sirenic-mcp). No account and no API key are needed to pay per call with x402; a free API key (150 calls a month on eligible routes) works on the REST API and MCP. A2A itself takes x402 only. Free API key, no card: 150 calls a month on routes at $0.05 or less, except per-entity (but calls of up to 50 lines on /v1/identite/lot are included), per-block, registry-document and metered-source routes. https://api.sirenic.eu/compte?utm_source=api&utm_campaign=agent-card

Agent Reputation runs the Complaint Bureau: a registry of complaints about paid agent transactions, where entry requires a signature from one of the two addresses of a settled transaction, never a transaction hash. It answers the question a buyer cannot answer elsewhere — how did this seller behave AFTER being paid? Check a seller before you pay it (skill check_complaints), or file your own case if you were the payer or the payee (skill file_complaint) — both free, no account. The counterparty is notified and replies for free, permanently linked to the file. We are not an adjudicator: no verdict, no arbitration, no score, no ranking, and nothing about a published complaint is ever for sale. Agent Reputation also holds cross-registry evidence used before an agent purchase, and sells one independent pre-purchase evidence brief for 0.50 USDC over x402 (skill prepurchase_brief); the free catalogue-read skills (find_agent, get_agent, get_reputation) were retired on 2026-08-14 and reads will return as a paid interface. Method and eligibility: https://agentreputation.dev/complaints — Full MCP surface: https://agentreputation.dev/api/mcp — Human operators: https://agentreputation.dev/owners — Operating principles: https://agentreputation.dev/constitution.md

Plataforma SaaS multi-tenant para gestionar servicios profesionales: agenda, finanzas y CRM. Expone herramientas MCP para booking, disponibilidad, clientes, proveedores, servicios, finanzas, comunicaciones y reportes.

Local-first memory layer for AI agents. Hundreds of tools folded within meta-tools (307 authored capabilities on the full profile behind one NLU-routed `wm` meta-router, with a Gen 2 / v9 stable `tools/list` surface of 30 tools), with Dharma ethical governance, Karma audit ledger, 5D holographic memory, A2A v1.2 discovery surface. The memory layer runs locally via the `wm` binary; whitemagic.dev publishes discovery information and does not host the local store. MIT-licensed research lab.

Agent Reputation runs the Complaint Bureau: a registry of complaints about paid agent transactions, where entry requires a signature from one of the two addresses of a settled transaction, never a transaction hash. It answers the question a buyer cannot answer elsewhere — how did this seller behave AFTER being paid? Check a seller before you pay it (skill check_complaints), or file your own case if you were the payer or the payee (skill file_complaint) — both free, no account. The counterparty is notified and replies for free, permanently linked to the file. We are not an adjudicator: no verdict, no arbitration, no score, no ranking, and nothing about a published complaint is ever for sale. Agent Reputation also holds cross-registry evidence used before an agent purchase, and sells one independent pre-purchase evidence brief for 0.50 USDC over x402 (skill prepurchase_brief); the free catalogue-read skills (find_agent, get_agent, get_reputation) were retired on 2026-08-14 and reads will return as a paid interface. Method and eligibility: https://agentreputation.dev/complaints — Full MCP surface: https://agentreputation.dev/api/mcp — Human operators: https://agentreputation.dev/owners — Operating principles: https://agentreputation.dev/constitution.md

Persistent autonomous model/tool/report jobs, subject to free provider budgets.

Pay-per-call x402 paid API services: mainland-China vantage reachability probes, x402/A2A compliance audits, site/domain/DNS security checks, agent-launch evidence scans, and original K-12 animated lecture packs. Settled in USDC on Base via x402 v2.