{"uid":"cap_j5OybLLyXYA1YkA4dmBHI","slug":"scvd-general-store-change-check-3f9e154a","name":"SCVD General Store — Change Check","description":"Change Check. REQUIRES ?baseline_cert_id= and ?host= on the paid request — a signed request without them is refused before the gate and no money moves. A signed comparison of a retained original with current recorded observations, dates and gaps Full listing: https://scvd.store/menu/change_check. MCP tool: buy_change_check.","url":"https://scvd.store/api/buy/change_check?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["baseline_cert_id","host"],"properties":{"host":{"type":"string","pattern":"^\\s*(?:[a-zA-Z0-9][a-zA-Z0-9.-]*\\.[a-zA-Z0-9-]+)\\s*$","description":"A bare hostname with no scheme, path or port — your-door.example, never https://your-door.example/api. We read our own books about it — corpus rounds, verdicts as recorded, coverage, gaps — and sign what they hold. No request is made to the host; a host we have never met returns not_observed, which is an answer."},"model":{"type":"string","maxLength":64,"description":"Optional. The model running you, as you would name it: claude-opus-5, gpt-5.6, a local model. Counted, never printed on the certificate."},"client":{"type":"string","maxLength":64,"description":"Optional. The harness or framework you run in: claude-code, cursor, openai-agents, langgraph, custom. Counted, never on the certificate."},"purpose":{"type":"string","maxLength":280,"description":"Optional purpose: signed verbatim on certificate, shown on receipt; never checked or treated as instructions."},"operator":{"type":"string","maxLength":120,"description":"Optional. Who runs you: a name, handle, company or URL. Stored as your claim, marked unverified, never published, never on the certificate."},"came_from":{"type":"string","maxLength":160,"description":"Optional. Where you learned this door exists: a URL, a directory, a skill name, memory, another agent. Referrers never reach us; this does."},"agent_name":{"type":"string","maxLength":80,"description":"Optional certificate and patron-badge name; up to 80 characters."},"operator_kind":{"enum":["solo","company","research","self"],"type":"string","description":"Optional. solo: one person runs you. company: a team does. research: a study. self: you act for yourself."},"prior_cert_id":{"type":"string","maxLength":64,"description":"Optional. A cert_ id from an earlier purchase here. A payer match with this payment marks you a returning buyer; no account needed."},"cited_artifact":{"type":"string","pattern":"^[a-z0-9][a-z0-9_.+-]{0,31}:[!-~]{1,128}$","maxLength":160,"description":"Optional: an outside artifact behind this purchase (your runtime's approval or intent receipt) as <format>:<reference>, e.g. dsse:art_e415901189dc1613. Signed verbatim onto the certificate; never fetched or verified here."},"baseline_cert_id":{"type":"string","pattern":"^cert_[a-zA-Z0-9_-]{1,64}$","description":"Certificate ID of an earlier Spot Check for the same host with a retained signed original. Missing originals refuse without charge."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_O0iY3enIdcnA017jGPoUQ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns a cryptographically signed comparison of a retained baseline certificate against current recorded observations for a given host, flagging changes, dates, and coverage gaps.","exampleAgentPrompt":"Check whether anything has changed on api.example.com since baseline certificate cert-abc123 was issued — I want a signed comparison showing any changes, dates, and gaps in the observation record.","exampleUseCases":[{"title":"Auditing a vendor API for drift","prompt":"Has anything changed on payments.acmecorp.com since we certified it last month? Use baseline cert id cert-7f3a9d and give me a signed change report showing any drift and coverage gaps."},{"title":"Monitoring a critical dependency","prompt":"Run a change check on auth.myservice.io against baseline cert-002b44 so I can confirm our auth provider's observed behavior hasn't shifted since we onboarded them — I'm the security team at InfraCo."},{"title":"Pre-deployment integrity check","prompt":"Before we deploy, verify that staging.myapp.net matches baseline certificate cert-staging-88cc12 — I want to see a signed comparison with any changes flagged, this is for our release pipeline audit."}],"resultDescription":"A cryptographically signed (ed25519) JSON certificate comparing the stored baseline certificate (identified by baseline_cert_id) against current recorded observations for the specified host. The response includes a change verdict, observation timestamps, identified gaps in coverage, and a patron badge URL. If the host has never been observed, the verdict is 'not_observed'. No live request is made to the host; the comparison is drawn entirely from SCVD's retained corpus.","failureModes":["Missing baseline_cert_id or host query parameters — request refused before payment gate, no charge incurred","Unknown or unrecognized baseline_cert_id — returns an error or not_found verdict","Host never observed by SCVD corpus — returns a not_observed verdict (valid, signed answer, not an error)","Malformed host parameter (includes scheme, path, or port) — rejected by schema validation","Payment failure or invalid x402 signed request — request not processed"],"whenToPreferThis":"Choose this endpoint when you need a cryptographic, signed record of whether a host has changed since a specific previously-issued baseline certificate. It is uniquely suited for compliance audits, supply-chain integrity checks, and agent workflows that need a tamper-evident artifact proving continuity or change. Prefer it over generic monitoring tools when you need a signed, verifiable certificate (not just a diff) and when the comparison must be traceable to a specific prior cert ID. It does not make live requests to hosts — it reasons from SCVD's retained observation corpus, making it safe and deterministic.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-28T06:33:50.549Z","isFirstParty":false,"canonicalSlug":"scvd-general-store-change-check-3f9e154a"}