gapfill
Scholarly literature search in every discipline (Crossref: articles, preprints, books, proceedings, datasets), filtered by author, years, type or abstract, sorted by relevance, date or citations; a DOI returns that work. Each work has DOI, title, authors with ORCID, venue, date, citation counts, licence, open-access links, the abstract where CC-licensed for commercial use, and retraction, correction and concern notices. For citation checks and literature reviews. No matches: not charged.
SearchUnknowneip155:8453Exactvia cdp
LiteraturePapersScholarlyAcademicResearch
Settlements · 30d
17
No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days.
$0.07
Verified settled volume
17 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0040
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-10-26 10:38Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x91A71892231A256d69d4bf8a442234701a762AaFThe wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.004USDC≈ $0.004 USD
on Base · exact scheme
Pay 0.004 USDC on Base to 0x91A7…62AaF. The signed payment is good for 5 minutes.
- Paid to
- 0x91A7…62AaF
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 4000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x91A71892231A256d69d4bf8a442234701a762AaF",
"amount": "4000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"limit": 2,
"query": "aspirin"
},
"type": "http",
"method": "POST",
"bodyType": "json"
},
"output": {
"type": "json",
"example": {
"query": "aspirin",
"total": 33491,
"works": [
{
"doi": "10.1155/2012/626289",
"url": "https://doi.org/10.1155/2012/626289",
"issn": [
"2090-1488",
"2090-1496"
],
"type": "journal-article",
"year": 2012,
"issue": null,
"pages": "1-1",
"title": "Thrombosis and Aspirin: Clinical Aspect, Aspirin in Cardiology, Aspirin in Neurology, and Pharmacology of Aspirin",
"venue": "Thrombosis",
"issues": [
"no abstract deposited"
],
"volume": "2012",
"authors": [
{
"name": "Christian Doutremepuich",
"orcid": null,
"affiliation": "Laboratoire d'Hématologie, Université Victor Segalen Bordeaux 2, 146 Rue LéoSaignat, 33076 Bordeaux Cedex, France"
}
],
"license": "http://creativecommons.org/licenses/by/3.0/",
"updates": [],
"abstract": null,
"cited_by": 3,
"subjects": [],
"full_text": [],
"published": "2012-10-21",
"publisher": "Hindawi Limited",
"retracted": false,
"references": 0,
"open_access": true,
"authors_total": 1
},
{
"doi": "10.1201/9780203646960-13",
"url": "https://doi.org/10.1201/9780203646960-13",
"issn": [],
"type": "book-chapter",
"year": 2004,
"issue": null,
"pages": "585-616",
"title": "REYE’S SYNDROME AND ASPIRIN",
"venue": "Aspirin and Related Drugs",
"issues": [
"no authors listed",
"no abstract deposited"
],
"volume": null,
"authors": [],
"license": null,
"updates": [],
"abstract": null,
"cited_by": 0,
"subjects": [],
"full_text": [],
"published": "2004-10-28",
"publisher": "CRC Press",
"retracted": false,
"references": 1,
"open_access": false,
"authors_total": 0
}
],
"source": {
"name": "Crossref REST API",
"api_url": "https://api.crossref.org/works?query=aspirin&rows=2&select=DOI%2CURL%2Ctitle%2Csubtitle%2Ctype%2Cauthor%2Ccontainer-title%2Cpublisher%2Cpublished%2Cissued%2Cvolume%2Cissue%2Cpage%2CISSN%2Csubject%2Cabstract%2Clicense%2Clink%2Cis-referenced-by-count%2Creferences-count%2Cupdated-by%2Cupdate-to",
"licence": "Bibliographic metadata: facts deposited by publishers, served by Crossref without restriction. Abstracts: returned only when the version of record is under a Creative Commons licence in force that allows commercial use; others are withheld (their copyright can stay with the publisher). Retraction notices include the Retraction Watch database, published openly by Crossref.",
"citation": "Source: Crossref (crossref.org)"
},
"filters": {
"sort": "relevance",
"type": null,
"author": null,
"to_year": null,
"from_year": null,
"has_abstract": false
},
"returned": 2,
"retracted": 0,
"with_abstract": 0
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"required": [
"query"
],
"properties": {
"sort": {
"enum": [
"relevance",
"newest",
"most_cited"
],
"type": "string",
"description": "relevance (default), newest or most_cited"
},
"type": {
"type": "string",
"description": "Crossref work type, e.g. journal-article, posted-content (preprint), book-chapter, proceedings-article, dataset, dissertation (default: any)"
},
"limit": {
"type": "integer",
"maximum": 50,
"minimum": 1,
"description": "Maximum works to return, default 10"
},
"query": {
"type": "string",
"maxLength": 300,
"description": "Search terms, e.g. aspirin, or a DOI for that one work"
},
"author": {
"type": "string",
"maxLength": 300,
"description": "Author name, e.g. Ioannidis"
},
"to_year": {
"type": "integer",
"description": "Published in or before this year"
},
"from_year": {
"type": "integer",
"description": "Published in or after this year"
},
"has_abstract": {
"type": "boolean",
"description": "Only works whose abstract is returned (Creative Commons, in force, commercial use allowed)"
}
}
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"required": [
"query",
"total",
"returned",
"works",
"source"
],
"properties": {
"query": {
"type": "string"
},
"total": {
"type": "integer",
"description": "Works Crossref matches in all (with has_abstract, before the licence check)"
},
"works": {
"type": "array",
"items": {
"type": "object",
"properties": {
"doi": {
"type": "string"
},
"url": {
"type": "string"
},
"issn": {
"type": "array",
"items": {
"type": "string"
}
},
"type": {
"type": [
"string",
"null"
],
"description": "Crossref work type"
},
"year": {
"type": [
"integer",
"null"
]
},
"issue": {
"type": [
"string",
"null"
]
},
"pages": {
"type": [
"string",
"null"
]
},
"title": {
"type": "string"
},
"venue": {
"type": [
"string",
"null"
],
"description": "Journal, book or proceedings"
},
"issues": {
"type": "array",
"items": {
"type": "string"
},
"description": "Problems the record shows"
},
"volume": {
"type": [
"string",
"null"
]
},
"authors": {
"type": "array",
"items": {
"type": "object",
"properties": {
"name": {
"type": "string"
},
"orcid": {
"type": [
"string",
"null"
]
},
"affiliation": {
"type": [
"string",
"null"
]
}
}
},
"maxItems": 50
},
"license": {
"type": [
"string",
"null"
],
"description": "Licence URL as deposited: the one in force on the version of record where there is one"
},
"updates": {
"type": "array",
"items": {
"type": "object",
"properties": {
"doi": {
"type": [
"string",
"null"
]
},
"date": {
"type": [
"string",
"null"
]
},
"type": {
"type": "string"
},
"label": {
"type": "string"
},
"source": {
"type": [
"string",
"null"
]
}
}
},
"description": "Retraction, correction and other notices on this work"
},
"abstract": {
"type": [
"string",
"null"
]
},
"cited_by": {
"type": [
"integer",
"null"
],
"description": "Citations Crossref counts"
},
"subjects": {
"type": "array",
"items": {
"type": "string"
}
},
"full_text": {
"type": "array",
"items": {
"type": "object",
"properties": {
"url": {
"type": "string"
},
"content_type": {
"type": [
"string",
"null"
]
}
}
}
},
"published": {
"type": [
"string",
"null"
],
"description": "YYYY, YYYY-MM or YYYY-MM-DD"
},
"publisher": {
"type": [
"string",
"null"
]
},
"retracted": {
"type": "boolean"
},
"references": {
"type": [
"integer",
"null"
]
},
"open_access": {
"type": "boolean",
"description": "The version of record is under a Creative Commons licence in force that allows commercial use"
},
"authors_total": {
"type": "integer"
}
}
}
},
"source": {
"type": "object"
},
"filters": {
"type": "object"
},
"returned": {
"type": "integer"
},
"retracted": {
"type": "integer",
"description": "Returned works retracted or withdrawn"
},
"with_abstract": {
"type": "integer",
"description": "Returned works with an abstract"
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-26 10:38Z
- Last indexed by Roundhouse
- 2026-10-26 20:00Z
- Last enriched (probe, favicon, geo)
- —
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- Not probed
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GET api.roundhouseai.io/v0/endpoints
No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service gapfill and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=gapfill' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://jotowl.com/v1/literature, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.