{"openapi":"3.1.0","info":{"title":"2s — the (most) everything API","version":"1","summary":"The (most) everything API.","description":"The (most) everything API for AI agents: 575+ pay-per-call endpoints on one origin. More live, ground-truth data than any other x402 service — public records, finance & SEC filings, crypto & web3, security & CVEs, legal, medical, weather, geocoding, and B2B/EDI. A full AI gateway: chat, image, and multi-model consensus across every major model, priced per request in the 402 before you pay. And agent infrastructure with no account: wallet-scoped storage (kv/docs/vectors/files), locks, queues, scheduled callbacks, pub/sub, and watchers that push signed webhooks when the world changes. Pay per call in USDC on Base or Solana via x402 — no API keys, no signup, no subscription. The first x402 API with upto billing: on AI endpoints, authorize the quoted max and settle only your actual usage. Try before you buy: add ?trial=1 (or header X-2s-Trial: 1) to any endpoint for one free real call per endpoint per hour — no wallet needed. New endpoints land constantly.","contact":{"name":"2s","url":"https://2s.io","email":"alley@2s.io"},"x-logo":{"url":"https://2s.io/icon-512.png","altText":"2s"},"x-guidance":"Pay-per-call REST API for AI agents — hundreds of endpoints returning ground-truth data (US public records, company & legal identifiers, finance/SEC, crypto/web3, security & CVEs, medical codes, weather & geocoding, agriculture, energy, maritime, music, and more). Every endpoint is paid per call in USDC via x402 (Base or Solana) — no API key, no signup. Call any endpoint with no auth to get a 402 PaymentRequirements envelope, sign it (EIP-3009 on Base, partial SPL transfer on Solana), and retry with the PAYMENT-SIGNATURE header. Add ?trial=1 for one free real call per endpoint per hour to test before paying. To discover the right endpoint: GET https://2s.io/api/directory for the full catalog, or GET https://2s.io/api/search/endpoints?q=<natural-language task> for a ranked match. Per-call price is on each operation as x-payment-info (from $0.001). Batch up to 50 calls behind one payment via POST https://2s.io/api/batch/run."},"servers":[{"url":"https://2s.io"}],"components":{"responses":{"BadRequest":{"description":"Bad request — invalid parameters."},"PaymentRequired":{"description":"Payment required. Body contains the x402 PaymentRequirements envelope with a multi-network accepts array; the per-call price is in accepts[].amount (and on the operation as x-2s-price). Sign for whichever rail you hold USDC on (EIP-3009 for Base, partial SPL transfer for Solana) and retry with the PAYMENT-SIGNATURE header (X-PAYMENT also accepted for v1 clients).","content":{"application/json":{"schema":{"$ref":"#/components/schemas/X402PaymentRequiredV2"}}}},"MethodNotAllowed":{"description":"Method not allowed — see `Allow` header for the supported method."},"ServerError":{"description":"Internal server error."},"UpstreamError":{"description":"Upstream provider error."}},"parameters":{"TrialMode":{"name":"trial","in":"query","required":false,"description":"Try before you buy. Set to 1 for one free real call per endpoint per hour — no wallet or payment needed — to verify the endpoint before paying. Equivalent to sending the \"X-2s-Trial: 1\" request header. Works on every endpoint.","schema":{"type":"integer","enum":[1]}}},"securitySchemes":{"x402Payment":{"type":"apiKey","in":"header","name":"PAYMENT-SIGNATURE","description":"x402 protocol v2: base64-encoded PaymentPayload. Call any paid endpoint without auth to receive a 402 with a multi-network PaymentRequirements envelope. Sign for either rail: EIP-3009 transferWithAuthorization (Base USDC) OR a partial SPL token transfer (Solana USDC). Retry with PAYMENT-SIGNATURE header. X-PAYMENT is also accepted for v1 buyer clients. See https://x402.org."}},"schemas":{"Source":{"type":"object","description":"Provenance of the data: upstream provider, source URL, and license.","properties":{"provider":{"type":"string","description":"Upstream data provider."},"url":{"type":"string","description":"Source URL or documentation link."},"license":{"type":"string","description":"License / usage terms for the data."}}},"CallMeta":{"type":"object","description":"Per-call meta envelope — endpoint id, cost, caller kind, settlement details."},"X402PaymentRequiredV2":{"type":"object","description":"x402 v2 PaymentRequired envelope. Pick any entry from accepts[], sign for that rail, retry with the PAYMENT-SIGNATURE header.","required":["x402Version","accepts"],"properties":{"x402Version":{"type":"integer","const":2},"error":{"type":"string","description":"Human-readable reason payment is required."},"resource":{"type":"string","description":"The resource URL being purchased."},"accepts":{"type":"array","description":"Payment requirement options, one per supported network (Base USDC, Solana USDC).","items":{"type":"object","required":["scheme","network","amount","asset","payTo","maxTimeoutSeconds"],"properties":{"scheme":{"type":"string","enum":["exact"]},"network":{"type":"string","description":"CAIP-2 network id, e.g. \"eip155:8453\" (Base) or \"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp\"."},"amount":{"type":"string","description":"Price in atomic asset units (USDC has 6 decimals)."},"asset":{"type":"string","description":"Asset contract address / mint."},"payTo":{"type":"string","description":"Treasury address to pay."},"maxTimeoutSeconds":{"type":"integer"},"extra":{"type":"object","description":"Rail-specific extras (EVM: EIP-712 domain name/version; Solana: feePayer).","additionalProperties":true}}}},"extensions":{"type":"object","description":"Optional discovery metadata (e.g. bazaar input/output schemas).","additionalProperties":true}}}}},"paths":{"/api/paper/doi-lookup":{"get":{"tags":["paper"],"summary":"Resolve a DOI to authoritative bibliographic metadata via...","description":"Resolve a DOI to authoritative bibliographic metadata via Crossref. Accepts bare DOI (10.1038/nature12373) or full DOI URL (https://doi.org/10.1038/nature12373). Returns work type, title, container (journal/conference), publisher, issued/published dates, abstract, authors (with ORCID + affiliations), page range, volume/issue, ISBN + ISSN lists, canonical URL, reference + citation counts, license blocks, and subject classifications. ~160M works in Crossref. Best authoritative DOI → bibliographic resolver. Metadata is CC0.","operationId":"paper_doi-lookup","deprecated":false,"security":[{"x402Payment":[]}],"responses":{"200":{"description":"Normalized envelope: items = [Crossref bibliographic record] for the DOI; total = 1.","content":{"application/json":{"schema":{"type":"object","required":["data","meta"],"properties":{"data":{"type":"object","properties":{"ok":{"type":"boolean","enum":[true]},"items":{"type":"array","items":{"type":"object","properties":{"doi":{"type":"string"},"type":{"type":"string","nullable":true},"title":{"type":"string","nullable":true},"containerTitle":{"type":"string","nullable":true},"publisher":{"type":"string","nullable":true},"issued":{"type":"string","nullable":true},"publishedPrint":{"type":"string","nullable":true},"publishedOnline":{"type":"string","nullable":true},"abstract":{"type":"string","nullable":true},"authors":{"type":"array","items":{"type":"object","properties":{"given":{"type":"string","nullable":true},"family":{"type":"string","nullable":true},"orcid":{"type":"string","nullable":true},"affiliation":{"type":"array","items":{"type":"string"}}},"required":["given","family","orcid","affiliation"],"additionalProperties":false}},"pageRange":{"type":"string","nullable":true},"volume":{"type":"string","nullable":true},"issue":{"type":"string","nullable":true},"isbn":{"type":"array","items":{"type":"string"}},"issn":{"type":"array","items":{"type":"string"}},"url":{"type":"string","nullable":true},"referenceCount":{"type":"integer","nullable":true},"isReferencedByCount":{"type":"integer","nullable":true},"license":{"type":"array","items":{"type":"object","properties":{"url":{"type":"string"},"contentVersion":{"type":"string","nullable":true}},"required":["url","contentVersion"],"additionalProperties":false}},"subjects":{"type":"array","items":{"type":"string"}}},"required":["doi","type","title","containerTitle","publisher","issued","publishedPrint","publishedOnline","abstract","authors","pageRange","volume","issue","isbn","issn","url","referenceCount","isReferencedByCount","license","subjects"],"additionalProperties":false}},"total":{"type":"integer","nullable":true,"description":"Total matching rows upstream; null when unknown."},"source":{"$ref":"#/components/schemas/Source"}},"required":["ok","items","total","source"],"additionalProperties":false},"meta":{"$ref":"#/components/schemas/CallMeta"}}}}}},"400":{"$ref":"#/components/responses/BadRequest"},"402":{"$ref":"#/components/responses/PaymentRequired"},"405":{"$ref":"#/components/responses/MethodNotAllowed"},"500":{"$ref":"#/components/responses/ServerError"},"502":{"$ref":"#/components/responses/UpstreamError"}},"x-2s-id":"paper.doi-lookup","x-2s-version":null,"x-2s-price":{"usd":0.003},"x-2s-accepts":["x402"],"x-2s-response-shape":"normalized","x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.003000"},"protocols":[{"x402":{}}]},"parameters":[{"name":"doi","in":"query","required":true,"description":"DOI.","schema":{"type":"string","minLength":7,"maxLength":300}},{"$ref":"#/components/parameters/TrialMode"}]}}}}