Pay-per-call web services for AI agents (127 tools: web scraping and crawling to Markdown, AI summaries, data extraction and cited answers, checks before installing a package or citing a source, screenshots and PDF, PDF, OCR and document conversion, news, paper and developer search, memory, messaging and service discovery for agents, discussions and trends, company checks (KYB, LEI, VAT, IBAN, sanctions), EU website compliance (GDPR, imprint, accessibility), Bitcoin data and OpenTimestamps proofs, Tron USDT and Sui wallet data, IOTA notarization and ledger data, change monitoring with webhooks, crypto prices, token risk and DeFi data, exchange rates and macro data, weather, geocoding, holidays and satellite images, email, phone, DNS, SSL and domain checks, VIN and barcode lookups, translation, embeddings, speech to text and text to speech, charts, diagrams, QR codes and image resizing). Paid per request with USDC on Base, Solana, Polygon or Arbitrum via x402. No account or API key.

Pay-per-use text micro-services (summarize, FR<->EN translate, JSON extract) for developers and AI agents. Paid per call in USDC on Base via x402.

HALOWERK buerowerk. Bezahlung über x402 in USDC auf Base Mainnet.

Voidly provides hosted agent tools, a Base mainnet x402 service marketplace, agent identity and messaging, and Atlas research. Recommended hosted MCP: https://api.voidly.ai/mcp. Public discovery is keyless; private reads and writes retain their own authorization requirements. Hosted tools do not hold wallet keys, sign payments, or pay. Product-specific endpoints and optional local packages remain separate integrations. This card is descriptive discovery only; it advertises no supportedInterfaces or A2A transport endpoint.

One MCP endpoint with 41 tools for autonomous agents to turn live compliance, blockchain, market and public-web data into bounded decisions with source evidence, freshness and signed receipts where applicable. Includes a professional 1 USDC EU counterparty dossier, a free deterministic tool router, an offline x402 Purchase Guard, 28-chain read-only RPC, wallet and contract evidence, market-positioning decisions, EU payment and invoice guards, official company-register access including France, US import readiness and three fixed-price AgentLLM tiers. Pay per successful call in USDC through x402 without an account, API key or subscription; 10 preparation, routing and verification tools are free.

Real-time cryptocurrency intelligence API. Synthesizes live data from DeFiLlama, CoinGecko, and Tavily into structured, actionable intelligence. 11 endpoints covering DeFi yield, personalized strategy, security frameworks, threat intelligence, exchange comparison, tax guidance, first-time buyer onboarding, crypto spending, banking, merchant payments, and institutional-grade research briefs. Pay-per-query via x402 micropayments on Base.

Verifiable trust infrastructure for AI agents. Third-party security audits (MASSAT, covering all 10 OWASP Agentic Security categories ASI01-ASI10), ERC-8004 on-chain agent identity, and cryptographic proof records for every transaction. Agents hire verified services via MCP and REST, paid with x402 USDC micropayments on Base -- every call marketplace-mediated (request, bid, accept, complete, signed proof) so buyers get an auditable receipt, not a promise.

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

Read-only agent surface for $BOBAI, plus Brain Plaza — a census of every ERC-8004 agent on BNB Chain, which of them actually answer, and what they expose. The tools here are free, no key, open to any agent; what this operator sells is named below and lives on agent.brainonbnb.com.

One MCP endpoint with 41 tools for autonomous agents to turn live compliance, blockchain, market and public-web data into bounded decisions with source evidence, freshness and signed receipts where applicable. Includes a professional 1 USDC EU counterparty dossier, a free deterministic tool router, an offline x402 Purchase Guard, 28-chain read-only RPC, wallet and contract evidence, market-positioning decisions, EU payment and invoice guards, official company-register access including France, US import readiness and three fixed-price AgentLLM tiers. Pay per successful call in USDC through x402 without an account, API key or subscription; 10 preparation, routing and verification tools are free.

Investment-migration intelligence from Mirabello Consultancy: citizenship- and residency-by-investment programmes, costs, eligibility, mobility, tax and origin-aware path planning. Exposed as an MCP server (streamable HTTP) with a read-only REST mirror.

Verifiable business authorization infrastructure for AI agents and enterprise systems.