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Prose, not a list: a bare bibliography belongs to /bulk.","outputModes":["application/json"]},{"id":"watch_add","url":"https://agents.factstamp.dev/watch","name":"watch_add","method":"POST","payment":"x402","price_usd":0.5,"inputModes":["application/json"],"description":"Buy a standing re-check of ONE citation or package version, when an answer must stay true for a month rather than once: daily re-checks for 30 days. US$0.50 the month — 1.7 cents a check, under a 2-cent lookup. The first check is answered and signed on purchase, and each real change (a retraction, a new advisory, a yanked version) gets its own signed receipt. One subject only: for a list use /watch/portfolio. Pay per call here, or redeem a pack code (10 credits).","outputModes":["application/json"]},{"id":"watch_portfolio","url":"https://agents.factstamp.dev/watch/portfolio","name":"watch_portfolio","method":"POST","payment":"x402","price_usd":5,"inputModes":["application/json"],"description":"Watch a whole list at once, when a bibliography or a dependency manifest has to stay true: up to 25 citations or package versions re-checked every day for 30 days under one token. US$5 a portfolio — 20 cents a reference, under a cent a check. Every reference is answered and signed on purchase, and each real change gets its own signed receipt. Nothing is sent when nothing changed. A single subject on its own is /watch. 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Pay per call here, or redeem a prepaid pack code (one answer-pack credit per three items, up to 25 items on that rail).","outputModes":["application/json"]}],"version":"0.1.3","provider":{"url":"https://agents.factstamp.dev","organization":"Alpine AI"},"receipts":{"alg":"Ed25519","key_set":true,"verify_offline":true,"issuer_document":"https://agents.factstamp.dev/.well-known/factstamp-issuer.json"},"transports":{"a2a":null,"mcp":{"url":"https://agents.factstamp.dev/mcp","type":"streamable-http"}},"description":"Paid verification for agents: cited, dated answers about a company, a figure or a citation, each with an Ed25519 receipt that verifies offline.","a2a_endpoint":null,"capabilities":{"streaming":false,"pushNotifications":false},"protocolVersion":"0.3.0","securitySchemes":{"x402":{"type":"http","scheme":"x402","description":"Pay per call in USDC on Base (eip155:8453). 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