openapi: 3.2.0 info: title: SCVD General Store Ask API version: 0.3.0 description: 'scvd.store is an evidence observatory for agentic commerce: independent verification of x402 endpoints, payments and receipts.' contact: url: https://scvd.store email: sean@recordcreativeco.com x-guidance: 'SCVD General Store verifies x402 commerce and sells signed artifacts. Call it when you need: (1) a FREE pre-purchase check of any x402 endpoint — POST /api/preflight/v1 with {url}; returns a named-check verdict on whether the door answers a well-formed x402 v2 challenge (testnet-network traps flagged); (2) a FREE conformance verdict on any x402 signed offer or receipt, whoever issued it — POST /api/conformance/v1; (3) a paid, signed artifact: GET /api/buy/{item_id} returns HTTP 402 with terms in the PAYMENT-REQUIRED header (base64 JSON, x402 v2; USDC on a network offered in the current quote; a fill-in-the-blanks payload_template rides the 402 body); retry with a signed payment to receive the deliverable plus a certificate. Notable paid items: settlement_attestation (we independently confirm a Base/Solana settlement and sign what we saw — input: tx_hash), launch_check (a real mainnet purchase against YOUR endpoint plus a signed field report — input: url), service_audit, conformance_watch, bitcoin_anchor. Inputs are query parameters, declared per item in /menu.json; outputs are JSON with a certificate id. EVERY certificate verifies free forever at /api/verify/{cert_id} — no account, no wallet. Starting prices run $0.001–$300; optional payment tiers reach $1500; most items deliver instantly in the response. Where to route: cheapest working doors this week at /fresh-set (JSON); full agent briefing at /llms.txt. Before you start: free instruments need only plain HTTPS (no account, key or SDK); a purchase needs an x402 v2 client and a wallet holding USDC on Base (eip155:8453), Polygon (eip155:137), Arbitrum (eip155:42161), World (eip155:480), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), paid only on a network the 402 offers; the stock client refuses payments above $1 by default and 14 of 35 priced doors sit above it; optional tooling (scvd-tab, the MCP stdio bridge, the scvd CLI) is listed at https://scvd.store/agents.md and none of it is required.' servers: - url: https://scvd.store tags: - name: Ask paths: /ask: get: summary: Ask this store a question about itself description: 'NLWeb. Ranks what this store publishes — the rooms, the shelf, the defect vocabulary, the free instruments — against your words and returns schema.org objects with recomputable scores. An INDEX, not a model: nothing is generated, and mode=summarize / mode=generate return 501 rather than a paraphrase. Send streaming=true for text/event-stream. No query at all answers 400 with a worked example. Free, no account.' security: [] responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/AskAnswer' '304': $ref: '#/components/responses/NotModified' '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/ServerError' parameters: - name: query in: query required: true schema: type: string example: how do I pay description: Your question, in words. `q` is accepted as an alias. - name: mode in: query required: false schema: type: string enum: - list - summarize - generate default: list description: NLWeb mode. Only `list` answers; the generative modes return 501 on purpose. - name: limit in: query required: false schema: type: integer minimum: 1 description: How many ranked entries to return. `num_results` is accepted as an alias. - name: streaming in: query required: false schema: type: boolean default: false description: true for text/event-stream, one entry per event. - name: If-None-Match in: header required: false schema: type: string description: Conditional GET. Send the ETag a previous answer carried (a SHA-256 of the exact bytes served, not a version somebody maintains) and an unchanged document answers 304 with no body. Send it on a schedule instead of re-downloading what you already hold. operationId: get_ask tags: - Ask post: summary: Ask this store a question about itself (POST) description: 'The same door as GET /ask, taking the query as a JSON body for callers that would rather not build a query string. Cross-origin browser callers are served: the preflight is answered and the allowance covers the event-stream too. No Idempotency-Key: this is a READ expressed as a POST — it writes nothing and stores nothing about the asker, so it is safe to retry by construction.' security: [] responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/AskAnswer' '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/ServerError' requestBody: required: true description: The question, and how you want it answered. content: application/json: schema: type: object required: - query additionalProperties: false properties: query: type: string minLength: 1 description: The natural-language question, about this store and what it publishes. mode: type: string enum: - list - summarize - generate default: list description: Only `list` is implemented. The other two are real NLWeb modes this store has not built, and asking for one returns 501 naming what to send instead — never a paraphrase assembled from keyword matches. limit: type: integer minimum: 1 maximum: 50 default: 10 description: Maximum results to return. streaming: type: boolean default: false description: True for a text/event-stream response instead of JSON. prefer: type: object additionalProperties: false description: NLWeb's nested spelling of the same preference. Honoured identically to `streaming` above. properties: streaming: type: boolean query_id: type: string description: 'Optional. Echoed back so you can pair a response with its question in a log. Never stored: nothing about a query is kept, here or anywhere.' operationId: post_ask tags: - Ask /ask/feed.json: get: summary: The askable index, as a schema.org DataFeed description: Every entry /ask can return, in the same order it ranks them — for a reader that would rather hold the index than interrogate it, and for anyone checking that /ask draws on a published list rather than inventing per request. Free. security: [] responses: '200': description: OK content: application/json: schema: type: object required: - '@context' - '@type' - name - url - dataFeedElement properties: '@context': type: string '@type': type: string enum: - DataFeed name: type: string description: type: string url: type: string format: uri isAccessibleForFree: type: boolean license: type: string format: uri publisher: type: object properties: '@type': type: string name: type: string url: type: string dataFeedElement: type: array description: Every entry /ask can return, in the order it ranks them. items: type: object properties: '@type': type: string enum: - DataFeedItem item: type: object '304': $ref: '#/components/responses/NotModified' '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/ServerError' operationId: get_ask_feed_json parameters: - name: If-None-Match in: header required: false schema: type: string description: Conditional GET. Send the ETag a previous answer carried (a SHA-256 of the exact bytes served, not a version somebody maintains) and an unchanged document answers 304 with no body. Send it on a schedule instead of re-downloading what you already hold. tags: - Ask components: schemas: AskAnswer: type: object required: - _meta - query_id - query - site - mode - count - results properties: _meta: type: object required: - response_type - version description: 'NLWeb''s envelope: which shape this response is and which revision of the protocol produced it.' properties: response_type: type: string enum: - list version: type: string protocol: type: string site: type: string query_id: type: string description: Yours if you sent one, ours if not. Echoed so you can pair a response with its question; never stored. query: type: string site: type: string mode: type: string enum: - list count: type: integer results: type: array items: type: object required: - url - name - site - score - description - schema_object properties: url: type: string format: uri name: type: string site: type: string score: type: number description: Recomputable from scoring_rule and the entry returned. Not a rating of anything. description: type: string schema_object: type: object description: The entry as a schema.org object. properties: '@context': type: string '@type': type: string name: type: string description: type: string url: type: string format: uri this_is_an_index_not_a_model: type: string scoring_rule: type: string description: The rule itself rather than a link to it, so any score above can be recomputed by the reader holding it. the_whole_index: type: string format: uri every_result_is_a_live_url: type: boolean nothing_matched: type: string description: Present only when the index matched nothing. Problem: type: object description: An RFC 9457 problem object. `error` is the store's long-standing human-readable field and is always present; the RFC fields sit beside it. properties: type: type: string format: uri description: A URI identifying the problem class. Dereferenceable at this origin where one exists. title: type: string description: A short, stable summary of the problem class. status: type: integer description: The HTTP status code, repeated in the body. detail: type: string description: What went wrong with THIS request, in plain language. instance: type: string format: uri description: The request path. error: type: string description: The store's human-readable message. Always present, including on responses that predate the typed model. retry_same_request: type: boolean const: false description: 'Present on repair responses: correct the selection or inputs before retrying.' next_step: type: object description: Optional free read after a refusal. Catalog and input repairs also include an equivalent MCP read. No payment or buyer arguments are forwarded. required: - method - url - payment_required properties: method: type: string const: GET url: type: string format: uri payment_required: type: boolean const: false mcp: type: object required: - url - tool - arguments properties: url: type: string format: uri tool: type: string const: find_in_catalog arguments: type: object properties: item_id: type: string additionalProperties: false required: - error responses: NotFound: description: No such resource. The body names where to look instead. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' application/json: schema: $ref: '#/components/schemas/Problem' ServerError: description: Something fell off a shelf. Nothing was charged. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' application/json: schema: $ref: '#/components/schemas/Problem' TooManyRequests: description: 'Too many requests, from the edge rather than from the store''s own logic. Retry after the interval named in Retry-After; the store does not charge for a refusal. The free preflight is limited — 30 probes per isolate per minute, 60 global — because it spends outbound requests to a host the caller chooses. Every answer the limiter METERED carries the IETF RateLimit fields — the 200 and the 429 — so you can pace against the live number instead of discovering the ceiling by being refused: RateLimit-Limit / -Remaining / -Reset report whichever of the two buckets is closer to binding, and RateLimit / RateLimit-Policy name both. Past either ceiling it returns 429 with Retry-After. A validation refusal (400, e.g. a missing or unprobeable URL) returns BEFORE either bucket is touched and carries no RateLimit fields, because a malformed request never spent a probe; this contract used to declare them on those responses too, which described a header that had never been sent. No other operation enforces an application-level ceiling, and so returns no RateLimit headers: declaring a ceiling nothing enforces would be worse than declaring none. A 429 can also arrive from the edge under abuse conditions. A refused request is never charged for. The two figures above are read from the limiter''s own constants, not restated here — this string asserted that NO limit existed for a day after one shipped.' content: application/problem+json: schema: $ref: '#/components/schemas/Problem' application/json: schema: $ref: '#/components/schemas/Problem' headers: Retry-After: schema: type: integer description: Seconds to wait before retrying. NotModified: description: 'Not Modified: the ETag you sent still names these exact bytes. No body; every other header is as the 200 would carry it.' BadRequest: description: The request was malformed or a required parameter was missing. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' application/json: schema: $ref: '#/components/schemas/Problem' securitySchemes: purchaseStatusToken: type: http scheme: bearer description: Private recovery.status_token returned by a catalogue purchase. This capability reads only its original purchase status. externalDocs: url: https://scvd.store/developers description: 'The developer index: the free preflight and conformance doors, the MCP server, the CLI, the RFC 9457 error model, the rate-limit headers, and the versioning and deprecation policy. The full agent briefing is at /llms.txt.' x-agentcash-provenance: ownershipProofs: - '0xd0716b334368fed445d000f12c7e586a6c86e13bd543333bab6c04695df236320c5dbfa4f0beb6807cc486c0ed4fd5a38892a8148d5aa80377db9f35ed4c4b151c' - 4HduymBCHhwyLgtMyXRpDX3JHQR3oyqTSytsXqCamzCc4ed9fJeBSpDUDSLwfZ59mZaw9ggdMNURPNBi4P6BRU47 x-scvd-ucp: profile: https://scvd.store/.well-known/ucp checkout: advertised x-scvd-native-checkout: mcp: protocol: mpp payment_method: evm intent: charge transport: mcp method: tools/call path: /mcp challenge_key: org.paymentauth/payment-required challenge_location: error.data, or result._meta with ?payment=tool-result credential_meta_key: org.paymentauth/credential receipt_meta_key: org.paymentauth/receipt idempotency_meta_key: x402/idempotency-key terms: 'each item''s payment_capabilities row with transport http: same network, asset and amount_atomic' webmcp: protocol: mpp payment_method: evm intent: charge transport: webmcp script: /webmcp.js quote_tool: quote_store_purchase challenge_field: payment_challenge complete_tool: complete_store_purchase credential_argument: signed_credential receipt_field: payment_receipt terms: 'each item''s payment_capabilities row with transport http: same network, asset and amount_atomic' x-rate-limiting: application_level_limit: true limited_paths: - /api/preflight/v1 - /api/preflight/v2 - /api/before-you-pay/v1 - /api/look/v1 - /api/preflight/batch headers_returned: - RateLimit-Limit - RateLimit-Remaining - RateLimit-Reset - RateLimit-Policy - RateLimit note: 'The free preflight is limited — 30 probes per isolate per minute, 60 global — because it spends outbound requests to a host the caller chooses. Every answer the limiter METERED carries the IETF RateLimit fields — the 200 and the 429 — so you can pace against the live number instead of discovering the ceiling by being refused: RateLimit-Limit / -Remaining / -Reset report whichever of the two buckets is closer to binding, and RateLimit / RateLimit-Policy name both. Past either ceiling it returns 429 with Retry-After. A validation refusal (400, e.g. a missing or unprobeable URL) returns BEFORE either bucket is touched and carries no RateLimit fields, because a malformed request never spent a probe; this contract used to declare them on those responses too, which described a header that had never been sent. No other operation enforces an application-level ceiling, and so returns no RateLimit headers: declaring a ceiling nothing enforces would be worse than declaring none. A 429 can also arrive from the edge under abuse conditions. A refused request is never charged for. The two figures above are read from the limiter''s own constants, not restated here — this string asserted that NO limit existed for a day after one shipped.' policy_url: https://scvd.store/developers x-versioning: scheme: url-path note: 'Breaking changes arrive as a new version in the path (/api/preflight/v1 → /v2). A published version''s SHAPE never changes under a client: fields are added, never removed or retyped.' deprecation: A version being retired serves the RFC 8594 Deprecation and Sunset headers on every response for at least 90 days before it stops answering, and the date is published at /developers before the headers appear. sunset_headers: - Deprecation - Sunset - Link; rel="successor-version" policy_url: https://scvd.store/deprecation currently_deprecated: [] versions: - path: /api/preflight/v1 status: supported since: '2026-08-03' sunset: null successor: /api/preflight/v2 - path: /api/preflight/v2 status: current since: '2026-08-23' sunset: null successor: null - path: /api/look/v1 status: current since: '2026-09-02' sunset: null successor: null - path: /api/conformance/v1 status: current since: '2026-08-03' sunset: null successor: null