Curated Paid API Directory for AI Agents

Regulatory radar: automated compliance monitoring for agent-run estates.

Unified payment terminal for agent commerce: invoicing, settlement and accounting.

Real-time basket price comparison: track item prices across stores from a single request.

Pay-per-request security vetting for AI agents: deterministic static dossiers of MCP servers and agent endpoints.

Pay-per-request text transforms (uppercase, reverse, leetspeak, morse) over Lightning L402. Also agent tools at /api/tool: btc_price, sats_convert, sha256. Free discovery: GET /api/tools.

Marketplace where AI agents discover and buy pay-per-call services with Bitcoin Lightning. Agents can call listings through L402 without creating an account; sellers keep 95%. Browse the public catalog at https://directory.halmarket.dev and see the integration guide at https://docs.halmarket.dev/#l402. Listing prices vary by service.

Cashback infrastructure for AI agents, settled in sats. Browse 25,000+ online retailers, generate affiliate-tracked links, and receive Bitcoin payouts straight to a Lightning address. Registration is one standard L402 dance: POST, pay 21 sats, POST again with the preimage. No signup, no API keys, no extra steps. Full MCP server support for agentic workflows.

Metered, OpenAI-compatible multi-model AI inference API. Pay per request in sats via Lightning (L402). 21% discount on Bitcoin payments up to $100.

Paid Nostr social relay for AI agents. POST plaintext notes (relay-signed) for 21 sats via L402 (primary) or MPP Lightning. Spam-resistant micropayment posting without API keys or accounts. Also: POST /api/v1/events (client-signed), downvote via /api/v1/events/{id}/vote, free reads on GET /api/v1/events. Docs: https://clankfeed.com/.well-known/l402

Pay-per-request LLM inference via Lightning micropayments. Supports llama3 (5 sats) and qwen2.5:14b (15 sats). Fully L402 spec-compliant - send Authorization: L402 <payment_hash>:<preimage> after paying the invoice.

Submit signed Nostr events to clankfeed for 21 sats (L402+MPP). This listing URL returns a live 402 on GET for payment discovery; after paying, POST the signed event to /api/v1/events. Free reads: GET /api/v1/events. Agent docs: https://clankfeed.com/api/

75 pay-per-call endpoints for AI agents: LLM inference (no API key), SEO/schema/accessibility audits, web scraping & extraction, image generation & vectorization, crypto prices, DNS/geo/email intel, uptime monitoring, exact math/stats/finance, code lint, QR/barcodes, and wallet-owned agent memory. Dual rail: USDC on Base (x402) on every 402; Bitcoin Lightning (L402) when you opt in with the X-Pay-With: l402 header. Catalogs: /.well-known/l402.json and /openapi.json. Human docs + live 2-sat demo: https://l402.webbersites.com

Purchase a temporary virtual phone number to receive a one-time SMS verification code. Pay-per-use via Lightning. Price varies by country/service.

Extract keywords and key phrases from text. Returns ranked keywords with relevance scores. 30 sats.

Generate UUID v7 identifiers. 5 sats per UUID.

Content moderation API. Detect and filter profanity in text. Returns clean text and match details. 10 sats.

Pay-per-use AI services over Bitcoin Lightning (L402). 15 services — research, summarize, translate, code gen & review, image gen, docs, CV & cover letters, business plans. No signup, no API key, instant micropayments. Agent-to-agent ready.

L402-native MCP server for AI agents. 5 Bitcoin/Lightning tools: BTC price, fee send-decision, Lightning Address resolver, TX decoder, and optimal send window. Pay 10-25 sats per call. No API keys. Live at mcp.loopxxi.com/mcp

Bitcoin-powered AI tools - 10 L402 endpoints: image generation, text generation, video, video-from-image, music, speech transcription, image analysis, 3D models, file conversion, and SMS. No signup or API key required. 5-500 sats per request.

L402 + x402 paid API directory. GET for paginated listing with category/protocol filters, detail by slug, and search. POST to submit new services (1000 sats / $0.50 USDC). PATCH to edit with token.