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FactStamp Bulk Verification
x402
FactStamp Bulk Verification is a paid API for AI agents from factstamp.agentrails.workers.dev, paid per call via x402, $0.12/call, status unknown (last checked 2026-10-16).
Verify up to 12 citations or dependency packages in a single batch call at $0.12 flat, returning a verdict for each item.
Price / call$0.12
Success—
StatusUnknown
How this service works
Check a whole bibliography or dependency manifest in one round trip, before you rely on the list: up to 12 items at a flat US$0.12 — 1 cent an item, against 2 cents for the same lookups one at a time. Every item is answered by the same door that answers a single call, so the verdicts cannot disagree. Pay per call here, or redeem a prepaid pack code (one answer-pack credit per three items, up to 25 items on that rail).
Output
A JSON object with: total items count, per-item results array (each with tool name, input identifier, and verdict such as 'verified', 'retracted', or 'unreadable'), aggregate by-verdict counts, number answered, number unreadable, payment details including rail used and settlement status, and a receipt URL for the transaction.
Example use cases
Pre-submission bibliography audit
“I'm about to submit my paper and need to check all 10 citations in one go — can you verify these DOIs and tell me if any are retracted or can't be found: 10.1038/nature12373, 10.1016/j.cell.2021.05.001, 10.1126/science.aaa1028, 10.1371/journal.pone.0123456, 10.1093/bioinformatics/btaa123, 10.1101/2021.05.10.443464, 10.1002/jcc.21334, 10.1021/acs.jctc.1c00234, 10.1038/s41586-020-2649-2, 10.1145/3292500.3330919?”
Dependency manifest pre-install check
“Before I run npm install, can you check these 12 packages from my package.json for any known issues — react@18.2.0, lodash@4.17.21, axios@1.4.0, express@4.18.2, typescript@5.0.4, jest@29.5.0, eslint@8.42.0, prettier@3.0.0, webpack@5.88.0, babel-core@7.21.8, dotenv@16.1.4, and uuid@9.0.0?”
Research pipeline citation validation
“I have a batch of 11 arXiv papers my pipeline pulled in — can you verify all of them at once and give me a summary of how many are confirmed, retracted, or unreadable? The IDs are: 2106.09685, 2203.02155, 2301.07041, 2112.10752, 2005.14165, 1706.03762, 2204.02311, 2207.09069, 2302.04023, 2303.08774, 2109.01652.”
Technical details
Endpoint
POSThttps://factstamp.agentrails.workers.dev/bulk?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to verify multiple citations or packages in a single round trip rather than making individual calls — it costs half as much per item ($0.01 vs $0.02) and guarantees consistent verdicts across all items since they all go through the same verification logic. Prefer it when processing a bibliography, reference list, or dependency manifest of up to 12 items. For ongoing monitoring of a list, consider the standing re-check (watch) endpoint instead.
Side effects
- Exceeds 12-item limit per call — request rejected
- Invalid or malformed DOI/arXiv ID — item returned as unreadable
- Payment settlement failure — call not processed
- Identifier type not supported — verdict may be unreadable
- Network timeout on upstream registry lookups — partial results or error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| outputrequired | object |
Output
Schema · Response
{
"type": "json",
"example": {
"items": 3,
"results": [
{
"tool": "verify_citation",
"input": "10.1038/nature12373",
"verdict": "verified"
}
],
"answered": 3,
"paid_with": {
"rail": "x402_pay_per_call",
"settlement": {
"success": true
},
"list_price_usd": 0.12
},
"by_verdict": {
"verified": 2,
"retracted": 1
},
"unreadable": 0,
"receipt_url": "https://factstamp.agentrails.workers.dev/r/c41e77b2aa90d613"
}
}Tags
x402
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