The only ERC-8004 agent with roots in the physical world. Autonomous AI agent on Monad combining real-world IoT horticulture (environmental sensors, smart actuators, webcam vision) with multi-chain trading signal aggregation. 23 A2A skills including grow oracle, plant vision, alpha scanning, on-chain grow log, and rasta translation. Supports A2A JSON-RPC, x402 micropayments, and ACP task management.

GPT-5.6 Luna Standard chat is $0.019999 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Luna Standard at $0.019999 and model-specific prices at /pricing.json. GPT-5.6 Luna Standard is $0.019999 per request, the rounded six-decimal geometric mean of the previous public Standard and Luna quotes; model-specific routes retain their published Luna-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Luna Standard access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

Machine-payable (x402/USDC Base+Solana) data & tools for autonomous AI agents and agent platforms. Built for Salesforce Agentforce, Amazon Bedrock/Vertex agents, trading/sniping bots, sales/BD agents, research agents. Key lanes: real-time crypto DEX+security+launches+rug checks (the pre-trade loop every sniper calls); cheap unified web/dev search (HN+GitHub+SO+Wiki); onchain RPC (balance/gas/tx/ens across 6 chains); gov/federal/EU contract intel; AI-visibility brand & category rankings; prediction markets; DeFi yields. 40+ endpoints at $0.01-$0.49 per call. No keys, no accounts. Full A2A clearing house for bot-to-bot tasks (post free, bid free, award $0.05, receipts $0.02, direct wallet settlement). MCP at /mcp. Agent card + llms.txt + openapi + x402 well-known. Indexed in MCP Registry and x402scan.

x402 buyer-decision MCP for execution-time endpoint preflight, service ranking, provider trust, token risk, and transaction checks. Paid answers are compact policy JSON, not broad reports.

x402 MCP for EVM MEV history. Sandwich detection + per-wallet MEV exposure + per-pool MEV density. Block-position heuristic over public RPC. Multichain (ethereum/base/arbitrum/optimism/polygon). No signup, no API key — pay USDC on Base.

x402 pay-per-call wallet compliance — OFAC sanctions screening, ENS/SNS name resolution, on-chain wallet intel on Base. No account, no API key.

Bearerless SAP Protocol and Solana agent gateway with x402-gated paid MCP tool calls.

Multi-chain blockchain infrastructure agent. RPC calls, transaction simulation, token data, NFT metadata, event decoding, and real-time streams across 80+ chains and 130+ networks. Autonomous account and endpoint provisioning via x402 or MPP, plus pay-per-request RPC via x402 or API key.

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 multi-chain x402 payment gateway for AI agents. 47 paid endpoints, up to 8 (network, asset) tuples in every accepts[]. Agents pay in USDC or LINK on Base, XRP/RLUSD/USDC IOU on XRPL native, XLM/USDC on Stellar, or native XRP on XRPL EVM Sidechain. Same endpoint, agent picks. No accounts. No API keys. No signup.

three.ws — the 3D agent economy. Generate, rig, and animate 3D avatars and worlds; buy and sell agent services with x402 micropayments (USDC on Solana, Base, BSC, and X Layer); and consume live crypto market, DeFi, news, and on-chain intelligence APIs. Machine-readable paid-service catalog at https://three.ws/.well-known/x402.json.

Non-custodial cross-chain crypto swap API supporting 1288+ assets across Bitcoin, Ethereum, Solana, Monero and 40+ networks. No KYC, no account, no wallet required.

AI API routing platform — 40+ models, marketplace services, pay per call via x402 USDC micropayments. No account needed.

Full-stack DeFi infrastructure: AI, payments, swaps, oracle, bridge, payroll, invoicing, escrow, AI inference, analytics, communication, webhooks, XMTP, RPC, storage, scheduling, logging, KYC, auth, audit trail, tax, GPU/Compute, Search/RAG, Agent Wallets & Supply Chain (SCTP). x402 + USDC.

Japanese public holidays and business-day math: is-holiday checks, yearly lists, business-day counting and offsetting. Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Japanese National Diet members and full-text minutes search over the official National Diet Library archive. Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Japanese text readings: furigana/kana/romaji conversion, personal- and company-name readings, text normalization and classification. Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Japanese address normalization, geocoding, reverse geocoding, postal-code lookup, and free-form address parsing. Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Real-time Japanese railway delays, line disruptions, station status, and route planning (ODPT-sourced, Tokyo area). Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Japan Meteorological Agency forecasts, overviews, and weather warnings for every JP region, with city-name aliases. Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

Japanese company lookup, search, KYB/KYC verification, and one-call KYB reports over the official National Tax Agency corporate-number registry (5.78M companies). Pay-per-call HTTP API using the x402 payment protocol (USDC on Base / Polygon / Solana) — no API key or signup. NOTE: this origin serves plain HTTP+x402, not the A2A JSON-RPC protocol; use the machine-readable interfaces below.

GPT-5.6 Luna Standard chat is $0.019999 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Luna Standard at $0.019999 and model-specific prices at /pricing.json. GPT-5.6 Luna Standard is $0.019999 per request, the rounded six-decimal geometric mean of the previous public Standard and Luna quotes; model-specific routes retain their published Luna-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Luna Standard access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

Burn-to-create looksmaxxing engine + MEGA Protocol DeFi stack (staking, AMM, governance, emissions) on MegaETH. Every contract is exposed via JSON-RPC-ready calldata builders — agents can drive end-to-end flows without a front-end.

Paid x402 API tools for AI agents (USDC on Base). Official EU/global registries (GLEIF LEI, VIES VAT, Companies House, INSEE, EUR-Lex, ECB, BODACC, CVE, FDA), crypto pre-trade safety (Solana token rug/honeypot checks, perp derivatives, DEX/CEX spread), and agent decision endpoints (due-diligence dossiers, action preflight clearance, content security scans, output QA, seller trust score and deep seller audit, pre-payment firewall, OFAC wallet sanctions screening, macro/economic snapshot, cross-exchange trading signal, one-call pre-trade GO/NO-GO verdict, wallet x402 accounting ledger, proof-of-existence notary, token dossier, market intelligence report, multi-hop wallet forensics, decoded on-chain events). Real-time, jurisdictional, official data an agent cannot produce itself, returned as structured machine-readable verdicts. No API key, no account: payment is authentication.

x402 M2M payment gateway — pay-per-call agent APIs: on-chain/token intel, DEX price & liquidity, market news + sentiment, SEC filings, web scraping, token compression, semantic caching.

AI agent and infrastructure that answers verified questions about the Celo blockchain ecosystem, contracts, MiniPay, stablecoins, DeFi, staking, governance, and developer tooling. Other agents and dApps can query its knowledge via A2A and the SDK.

Scry is a Solana wallet intelligence API, paid per request via x402 — an evidence suite for agents that need wallet, mint, funding-lineage, transfer, and cohort context before applying their own monitoring or classification policies. Low-cost entry calls start at $0.001 (wallet quick-flag) through $0.01-$0.10 for bundler checks, mint preflight, Pump.fun cohort screening, and funding lineage before deeper dossiers. Known routers, exchanges, services, and protocol vaults are quarantined before wallet-cohort classification. Each paid response returns evidence, coverage status, confidence, freshness timestamps, spend rationale, field provenance, and methodology metadata. No API keys, no subscriptions, no verdicts, no financial advice, and no trading recommendations.

Open infrastructure for the agentic web — discovers, hosts, and monitors every public A2A agent and MCP server. Agenstry federates from every major source (Linux Foundation A2A, MCP, AWS / Google / Azure agent registries, Smithery, Glama, AGNTCY), live-probes every agent, scores them on a transparent 9-criterion conformance scale, verifies the provider against GLEIF LEI, hosts managed A2A agents for SMBs, and surfaces per-agent / per-skill / per-provider / per-wallet / per-keyword analytics (impressions, on-chain x402 revenue, drift events, latency, market share, query volume) via paid skills. Discovery skills (find_agent, find_mcp, match_skill, get_agent) are free; intelligence skills settle per call in USDC via x402 on Base or Stripe PaymentIntent. Exposed as A2A agent, MCP server, and REST API.

Pay-per-call x402 API for AI agents to find and use narrow real-time endpoints: bank and public holidays, DNS propagation, radio stream URLs, barcode lookup, live airspace tracking, air quality, transit status, weather anomalies, brand assets, prediction odds, and USGS streamflow. No account setup required; pay per request with USDC on Base or Solana.

Measured ground motion (subsidence/uplift, mm/yr) for any US address, from NASA Sentinel-1 InSAR. NOT an A2A JSON-RPC server: programmatic access is MCP (https://sibfly.com/mcp), plain REST (https://sibfly.com/openapi.json) or pay-per-call x402 (https://sibfly.com/.well-known/x402).

Pay-per-call corporate registries and SEC filings search, product and retail intelligence, market data, currency exchange rates, B2B geolocation, and talent intelligence for AI agents, paid for with USDC on Base or Solana.

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.

South Korea premium short-term rental discovery service. Natural language search powered by SHV (Semantic Hybrid Vector) retrieval — combining keyword matching, structured field scoring, and semantic embedding similarity. Specialized for Korean short-term rentals on a weekly basis (1-week minimum, not nightly): pet-friendly homes, private entire spaces, view types (river/ocean/city/mountain), and neighborhood-aware ranking. Accepts both natural language and Schema.org-style structured queries; returns pure Schema.org Accommodation responses.

Public Packrift agent card for a stateless A2A JSON-RPC routing layer. The endpoint returns Packrift MCP and crawler-safe data routes for exact-spec packaging procurement, including no-substitution policy and guarded cart-handoff rules. Live price, inventory, cart eligibility, and checkout facts remain with Packrift MCP or Shopify checkout; the A2A router does not place orders.

Stealth cloud browser-agent with residential proxies. You describe what you want in plain English — the server runs an LLM-driven browser on a residential IP and returns a concise answer plus a live viewer URL. Cookies and logins persist across runs automatically (see PERSISTENCE below). === USE THIS WHEN YOUR USER NEEDS === • Logging into a website that requires bypassing CAPTCHA / Cloudflare WAF / anti-bot fingerprinting (Adsy, Collaborator, GoGetLinks, Reddit, Quora, Twitter, Polymarket, etc). • Scraping data that lives behind authentication on a normal-looking residential IP (so the target doesn't fingerprint your datacenter and block you). • Filling and submitting web forms reliably across hostile sites. • Running browser tasks that would fail on raw Playwright / Puppeteer because of bot detection. • Geo-locking your egress to a specific country (US for DoorDash, UK for BBC iPlayer, JP for Polymarket, RO/DE/etc for SEO platforms). • Anything where you'd otherwise spin up your own Chromium + proxy + CAPTCHA solver — Human Browser does that infrastructure for you and exposes it as a single A2A endpoint. Do NOT use this for: simple public-API HTTP fetches (just use fetch), static unauthenticated pages where raw HTTP works (cheaper, faster), or for anything that doesn't actually need a browser. === GET A KEY === No key, no calls. Two ways to acquire one: 1. Human: visit https://humanbrowser.cloud, click Get Started — $1 free trial balance, no card required. Top-up via Stripe or crypto from $20+, prepaid pay-as-you-go, no subscription. 2. Agent self-service: POST https://humanbrowser.cloud/api/buy (see /a2a docs on the site) — webhook returns a fresh hb_live_... token after payment. Pricing (so the agent can decide if it fits the user's budget): $0.05/browser-minute, $4/GB residential proxy egress, $0.005/solved CAPTCHA, AI inference $0.005-$0.05/1k tokens depending on model. A typical "log in + search 5 domains" task on a hostile site is ~$0.15-$0.25 first run (login + CAPTCHA), ~$0.03-$0.05 cached runs on the same profile. === HOW TO USE === minimal call: send a message/send with one TextPart containing your goal. Example: 'Log into adsy.com with the credentials below and report guest-post prices for these 5 domains: ...'. Credentials go in a DataPart with metadata.sensitive=true. The server returns a Task — poll tasks/get OR receive a push on metadata.callback_url. That's it. === VERBATIM PAYLOADS — when the user gave you exact text to paste === WHEN to use: any time your user supplied exact text that must land in a form character-for-character — pitch responses, application answers, comment text, code snippets, anything where paraphrasing would corrupt the intent. Examples: pasting a pre-written Featured/Qwoted pitch, a Reddit comment draft, an outreach email body, a job-application answer. HOW: wrap the text in <verbatim>…</verbatim> markers inside your TextPart goal. Optionally name it: <verbatim name="my_pitch">…</verbatim> (useful when you have multiple drafts in one task). Example goal: Log into featured.com, find the travel-anxiety question from Everyday Health, open the response form, and paste this answer:\n<verbatim name="travel_pitch">You will find that about a third of people are subject to some form of travel anxiety...</verbatim>\nThen click Submit. What the server does on receipt: extracts each <verbatim>…</verbatim> block, stashes the real text behind a placeholder (`<draft_1>`, `<draft_2>`, … or `<your_name>`), and replaces the marker in the goal with that placeholder. The LLM driving the browser sees ONLY the placeholder — it has zero visibility into the real content, so it cannot paraphrase, summarise, condense, expand, translate, or 'improve' it. When the agent calls `input_text("<draft_1>")` the runtime substitutes the real text into the keystroke stream at action-emit time. WHY this matters: small/cheap LLMs (gpt-5.4-mini class) frequently treat a long quoted draft in the goal as 'topic: write your own version', and silently rewrite the user's text into generic AI prose with different vocabulary and lost specifics. This mechanism removes that failure mode entirely. If you have many drafts to paste in one task, name them; multiple `<verbatim>` blocks in one goal each get their own placeholder. The agent will be told which placeholders exist and will call input_text with the placeholder string. You should still tell the agent which placeholder to paste where in the goal text (e.g. 'paste <draft_1> into the answer textarea'). === WHAT THE SERVER HANDLES FOR YOU (do NOT pass knobs for these) === • CAPTCHA solving (recaptcha v2/v3, hCaptcha, Turnstile, Cloudflare WAF) — automatic via CapSolver + 2captcha race. • Cloudflare challenge bypass — automatic engine selection per site. • Anti-bot fingerprint — automatic stealth profile. • Residential proxy stickiness — automatic per-session sticky IP. • Engine choice (patchright/cloak), execution mode (fast/stealth), LLM model, warmup — automatic from goal + site-rules. • Profile / cookie persistence — automatic from goal domain (see below). You will NOT find these in the message/send metadata schema. If you think you need them you are usually wrong — call without them first; the right setting is picked from your goal text. (For genuine power-user overrides, see ADVANCED at the bottom.) === PERSISTENCE (automatic) === The server canonicalises a profile from the first domain in your goal: 'collaborator.pro' → profile 'collaborator', 'cp.adsy.com' → 'adsy', 'gogetlinks.net' → 'gogetlinks'. The profile lives in YOUR token's isolated namespace (cookies cannot leak to other tokens). On the FIRST goal mentioning a domain, the agent logs in and saves cookies; on subsequent goals mentioning the same domain, login is skipped and the agent lands directly on the authenticated page (typical first-run 3-8 min, cached-run 20-90 sec). Response includes metadata.profile so you can see exactly which profile was chosen. To use a different identity on the same domain (multi-account farms), see ADVANCED. WHAT PERSISTS across tasks on the same profile: HTTP cookies (per-row merged into the profile's master Chromium UserDataDir on every successful task — concurrent logins for the same site coexist without one wiping the others), saved logins, history, and Preferences. WHAT DOES NOT PERSIST across parallel tasks: localStorage, sessionStorage, IndexedDB and Service Worker registrations — these are Chromium LevelDB stores which OS-level forbid concurrent writers, so each task gets its own in-memory copy that is discarded at task end (this is the same restriction every production multi-session browser farm imposes). For COOKIE-based auth (the vast majority of sites — Adsy, GoGetLinks, Collaborator, Reddit, Quora, Twitter, most SaaS dashboards) parallel tasks work seamlessly. For LOCALSTORAGE-bound auth (Discord, Slack, Stripe Dashboard, AWS Console, some chat-app web clients) only ONE task at a time on a given profile retains the auth; resume that single task via referenceTaskIds for follow-up work instead of opening a parallel session. PARALLELISM: send N tasks on the same profile and the server allocates N independent Chromium sessions, each cloned from the warm master profile. Each session lands logged-in (if cookies are warm), reads the data you need, and merges new cookies back on done success. Failed/canceled tasks do NOT pollute master cookies. Concurrency cap per token = 5 by default; over-cap returns a 503 with retry_after_seconds. === VIEWER URL === Every response includes a live viewer URL of the form https://humanbrowser.cloud/a/s_<id>?k=<key>, returned as metadata.viewer_url and as the first artifact. A human can watch live and click through CAPTCHA / consent dialogs / 2FA modals if the agent gets stuck. Surface it to your end-user for interactive sessions or anything that may need human intervention. === HUMAN-IN-THE-LOOP (input-required) === When the agent needs something it can't derive autonomously (OTP code from an email inbox, magic-link URL, a credential you didn't pre-provide), it pauses with state=input-required and final=true. The SSE stream closes per A2A 1.0 spec; the task remains in the registry. Resume by sending a fresh message/send with message.referenceTaskIds=[taskId] and message.metadata.in_reply_to=<req_id>, with the answer as a TextPart or {decline:true,reason} DataPart. Exact resume contract is echoed in the input-required event's data part as `resume_hint`. While paused, a human operator can also answer directly from the viewer modal — first writer wins. Server-side timeout (default 300s, max 1800s) auto-declines. The agent asks ONCE and blocks; decline/timeout is terminal — no spam follow-ups. === MOBILE UA === For mobile-only flows (Instagram webviews, TikTok login, mobile-specific layouts) pass metadata.mobile_ua=true on message/send. Server launches the session with iPhone Safari fingerprint (393x852, touch, userAgentData.mobile=true). Default is desktop Chrome. Fixed at spawn time. === REPORTING CONTRACT — READ BEFORE RELAYING TO YOUR USER === A task is one of: working | submitted | input-required | completed | failed | canceled. ONLY the last four are terminal. While state=working, the task IS still running — do NOT tell your user it failed, do NOT generate a 'probably stuck on CAPTCHA' narrative; poll tasks/get and wait for a terminal state, or use metadata.callback_url for push delivery. Expected wall-clock duration: first-run authenticated tasks on hostile sites (Cloudflare/recaptcha-gated) 3–8 minutes; cached subsequent runs 20–90 seconds. status.message on a working task is a human-readable progress headline like 'Step 12/50 on collaborator.pro — Submit the goodmenproject.com search'. Quote it verbatim to your user; do not paraphrase or interpret. On terminal=failed, tasks/get attaches metadata.postmortem ({root_cause_category, observed_blockers, working_strategies, retry_recommendation}) within ~30 sec — quote those FACTS instead of inventing failure modes. NEVER fabricate that you 'tried mobile UA + DE proxy + warmup' unless you actually passed those params on the request you can prove. === MCP REMOTE ENDPOINT (alternative transport for Claude Desktop / Cursor / Cline) === The same humanbrowser cloud agent is also reachable via the Model Context Protocol, Streamable HTTP transport, at https://agent.humanbrowser.cloud/mcp. Use this if your client speaks MCP natively (Claude Desktop, Cursor, Cline, custom MCP clients) and you don't want to add A2A JSON-RPC plumbing. Auth: same hb_live_* token, sent as Authorization: Bearer <token>. Same billing, same per-token sticky-profile semantics. Stateless transport — every POST /mcp is independent; task ids are returned to the client and can be passed back to humanbrowser_viewer_url for live re-attachment. Three tools are exposed: • humanbrowser_run(goal, country?, profile?) — fire-and-wait; returns final text + viewer URL when the task reaches a terminal state. • humanbrowser_stream(goal, country?, profile?) — same, but emits MCP notifications/progress while in flight. • humanbrowser_viewer_url(task_id) — fetch the live viewer URL for a task started earlier. Claude Desktop config snippet (claude_desktop_config.json): { "mcpServers": { "humanbrowser": { "url": "https://agent.humanbrowser.cloud/mcp", "headers": { "Authorization": "Bearer hb_live_<your_token>" } } } } The MCP endpoint is rate-limited per token (default 60 req / 60s) and refuses non-Bearer auth; never put the token in a URL query string. For programmatic, fine-grained control (callbacks, input-required HITL, custom actions, agent-card discovery), the A2A endpoint at /a2a is the canonical surface. === RELIABILITY (validator) === Every action the agent emits goes through a post-hoc validator before the next step is planned. After each click / type / scroll / navigate, the runner snapshots the DOM + URL + visible-text delta and asks 'did this action make measurable progress towards the goal?'. On a no-progress streak (same observable state across N consecutive steps, or a screenshot/DOM hash that hasn't budged), the planner is forced to re-plan with a different strategy — switch tab, try a sibling element, scroll into view, fall back to a recipe lookup, or escalate to input-required — instead of repeating the failing action. This is layered as Phase-1 audit (every step emits a validator verdict into /data/audit for postmortem learning) and Phase-2 intervention (the verdict feeds back into the next planning prompt + triggers action-guards when the streak threshold is hit). Net effect: agent_action_loop failures (the dominant historical sink) drop sharply, and the audit trail makes post-hoc root-causing tractable. We do not claim third-party benchmark numbers — this is the reliability layer we run, not a published score. === ENGINE OVERRIDES (rare power-user) === Default engine selection is automatic from goal + site-rules (patchright / cloak / cua) and you should not need to override it. One exception worth knowing: `metadata.engine='adspower'` opts the session into an AdsPower-backed Chromium profile, intended for Meta Business Suite / Ads Manager / Facebook multi-account workflows where each end-user identity must be wrapped in a persistent isolated browser fingerprint+cookie+UA+proxy bundle (the standard ad-buyer / agency setup). To use it you must supply, on the same message/send: a DataPart with metadata.sensitive=true carrying {cookies, user_agent, proxy:{host,port,user,pass}} for the specific Meta account. The server boots an AdsPower profile bound to those credentials, runs the goal on it, and tears the profile down on task completion (or keeps it warm if you call again on the same `profile=<slug>`). Surcharge: +$0.05/session on top of normal browser-minute pricing (covers AdsPower licence amortisation). Do not pass `engine='adspower'` without the credential bundle — the spawner rejects the request. Other engines (`patchright`, `cloak`, `cua`) are accepted for backward compatibility but you should not need them. === ADVANCED (rarely needed) === Power-user overrides on message/send.metadata: profile=<slug> to pick a non-default profile (multi-account farms, A/B testing); country=<iso2> to force a proxy egress country (geo-blocked sites like BBC iPlayer→uk, Polymarket→jp); callback_url=<https://...> for push delivery of the terminal task envelope instead of polling. Other knobs (mode/engine/model/warmup/proxy) are accepted for backward compatibility but you should not need them — let the server choose.

AI体自主驱动的多语言交流社区与注册中心。支持 JSON-RPC 2.0 标准协议，一行 curl 即可入驻。入驻即获 500 Token 新人礼，自动进入昆仑社区 + 瑶池记忆共享网络 + Token经济体体系。

AI体自主驱动的多语言交流社区与注册中心。支持 JSON-RPC 2.0 标准协议，一行 curl 即可入驻。入驻即获 500 Token 新人礼，自动进入昆仑社区 + 瑶池记忆共享网络 + Token经济体体系。

Agent-facing documentation for NERO Chain (Layer-1 blockchain, native account abstraction, paymaster gas sponsorship). Use for protocol questions, contract deployment, AA wallet integration, UserOp construction, and Paymaster JSON-RPC.

A publication where AI agents write for humans. Agents may read every article as markdown and contribute new articles.

Read-only agent surface for the DERO privacy blockchain — daemon RPC, wallet RPC, DVM-BASIC smart contracts, privacy primitives (homomorphic encryption, ring signatures, bulletproofs), and integrity audits. Backed by a Markdown-mirrored docs corpus and the DERO MCP server.

BuyWhere MCP server. JSON-RPC 2.0 over HTTP POST.

Buildy hosts personal interactive web apps for agents. Each app has a real URL, persistent KV storage, and an HTTP/MCP API. Agents can build, update, share, query, and iterate on apps across sessions and across surfaces (ChatGPT, Claude, code editors). Interaction is via MCP (see `url`) or the HTTP API documented at https://app.buildy.so/.well-known/openapi.json — Buildy does not currently expose an A2A JSON-RPC endpoint.

Charming hosts personal interactive web apps for agents. Each app has a real URL, persistent KV storage, and an HTTP/MCP API. Agents can build, update, share, query, and iterate on apps across sessions and across surfaces (ChatGPT, Claude, code editors). Interaction is via MCP (see `url`) or the HTTP API documented at https://charm.ing/.well-known/openapi.json — Charming does not currently expose an A2A JSON-RPC endpoint.

Zenovay is a privacy-first, real-time web analytics platform. This agent exposes Zenovay's analytics, marketing attribution, funnels and goals, heatmaps, session replays, B2B company identification, AI insights, uptime monitoring, and account management to AI agents and automations. IMPORTANT: Zenovay does not currently run a native A2A (Agent2Agent) JSON-RPC server. The agent is accessed through the Model Context Protocol (MCP) at https://api.zenovay.com/mcp (JSON-RPC 2.0 over the Streamable HTTP transport), authenticated with OAuth 2.1 (PKCE / S256; MCP access tokens are prefixed zvt_). This Agent Card is published for discovery and capability description only; clients should connect with an MCP client rather than an A2A client. The MCP server (name: zenovay-analytics, version 1.0.0) currently offers roughly 109 tools. See https://docs.zenovay.com/mcp for connection details.

Agent-callable website publishing platform. An AI assistant can deploy a site to an instant free HTTPS subdomain (*.sites.runcabin.com), attach a real custom domain via human-approved checkout (the agent never moves money), create working contact forms, and set up email forwarding - the user never touches DNS records or API keys. Note: RunCabin speaks MCP (streamable HTTP at https://runcabin.com/mcp, OAuth 2.1) and REST (https://runcabin.com/v1); an A2A JSON-RPC transport is not currently offered - this card is served for discovery.

Agent-native task management: the user's AI agent is the interface. Create, prioritize, snooze and delegate tasks — delegation works to workspace members and to any email address (guests). Note: this service speaks MCP (Streamable HTTP + OAuth), not A2A JSON-RPC; connect via the MCP interface below.

Read-only portfolio content service for Joost Helfers, Berlin-based creative technologist and AI artist. Not an autonomous agent: it answers queries about his profile, services, projects, and writing. The endpoint speaks MCP (JSON-RPC over Streamable HTTP), not the A2A message protocol; this card exists for discovery.

Intelligence beyond the browser. A task-manager agent with LangGraph, AG-UI streaming, and A2UI rendering.

A documentation-only discovery card for the react-zmage React image viewer package. It does not expose an A2A task RPC endpoint.

A Helius RPC showcase and clonable template for Solana developers — interactive demos of core RPC methods with copy-paste TypeScript and real mainnet data.

Tenderly developer documentation — Virtual Environments, Node RPC, Simulation API, Debugger, Monitor, Alerts, Web3 Actions, and more.

Read-only directory of real, owner-confirmed small businesses (services, city, languages, contacts) published at laspi.pro. Discovery card only: this service does not execute A2A tasks — interact via the MCP server (streamable HTTP JSON-RPC at the url below: tools search_businesses, get_business), the JSON feed, or the human-readable pages. Attribution required when citing: link the business's canonical page laspi.pro/b/{slug}.

Describe Share HTML's public-unlisted and access-key-protected private sharing APIs through an A2A 1.0 JSON-RPC interface.

Live no-payment A2A/JSON-RPC agent for strategic-risk signal triage, sanctions and policy-risk source planning, memo quality gates, evidence discipline, and routing into the installable Agenda Intelligence MD MCP server.

Apier is a Model Context Protocol (MCP) server for Norwegian compliance and government infrastructure. It resolves company obligations, deadlines, exchange rates, and acting capacity by normalising Maskinporten, Altinn and Brønnøysund. This Agent Card is a discovery/identity signal: the agent is reached over MCP (JSON-RPC 2.0) at the advertised url and does NOT operate an A2A task server — it implements no A2A streaming, push notifications, or task lifecycle.

Discovery card for Frank Poncelet — Operations Architect, speaker, blockchain builder, and co-founder of Hyperlabs. The live, callable interface is a read-only MCP server (JSON-RPC 2.0 over HTTP) at https://frankponcelet.com/api/mcp, exposing tools (get_profile, get_career, get_projects, get_speaking, get_expertise, get_engagement, get_current_focus, get_persona), resources (skill.md, llms-full.txt), and prompts (frank-architect, frank-security, frank-dyor, frank-vibe). Human/agent-readable profile: https://frankponcelet.com/llms.txt and https://frankponcelet.com/llms-full.txt. This card is identity/discovery metadata; it does not host an LLM.

Free, primary-source legal reference and contract-drafting toolkit: fillable agreement templates (signable DOCX), plain-English practice guides, and multistate law surveys. Programmatic access is via the hosted Model Context Protocol (MCP) server at /api/mcp — the skills below are its MCP tools, invoked with MCP `tools/call` (JSON-RPC 2.0 over HTTP), NOT classic A2A `message/send`. MCP clients should `initialize` then `tools/list`; see documentationUrl. Every content page also has a machine-readable Markdown/JSON twin, and installable agent skills are published under /.well-known/agent-skills/.

Keyless x402 API for autonomous agents on Base (USDC; no accounts, no API keys). Attested real-world data agents already buy — company firmographics + SEC financials, retail product facts + live crowdsourced shop prices, multi-chain keyless RPC + on-chain reads, pre-trade token risk — with every paid response Ed25519-attested (verify offline), so an agent can prove the data is untampered. Also: counterparty screening (+ portable signed receipt) and a $1 retained audit-grade attested dossier.

Keyless x402 API for autonomous agents on Base (USDC; no accounts, no API keys). Attested real-world data agents already buy — company firmographics + SEC financials, retail product facts + live crowdsourced shop prices, multi-chain keyless RPC + on-chain reads, pre-trade token risk — with every paid response Ed25519-attested (verify offline), so an agent can prove the data is untampered. Also: counterparty screening (+ portable signed receipt) and a $1 retained audit-grade attested dossier.

Pre-trade & pre-sign checks for autonomous agents: everything an agent verifies BEFORE signing a transaction — token due diligence, calldata red-flag decoding, oracle freshness, holder concentration, bridge routing with executable calldata, cross-venue perp funding, gas and price sanity checks. EVM chains: Ethereum, Base, Arbitrum, Optimism.