# StillCurrent Citation Check API

> StillCurrent Citation Check API is a paid API for AI agents from stillcurrent.something-agent.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-28).

Verifies whether a cited URL is live and current, and whether a quoted sentence or paraphrased claim still appears on the referenced page, with archive.org fallback.

## Facts

- Endpoint: POST https://stillcurrent.something-agent.workers.dev/check/citation?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stillcurrent-citation-check-api-e07f5803
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XXLN5ZypRkWaKOkK59TJM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stillcurrent-citation-check-api-e07f5803 -d '<json body>'
```

Example prompt: Can you check whether this source URL https://example.com/study is still live and that the quote 'global temperatures rose by 1.5 degrees' still appears on the page? If it's missing, also try the archive.org snapshot.

## When to prefer this

Use this endpoint when you need to confirm that a specific citation, quote, or statistical claim still exists on a referenced web page — especially for research, journalism, or automated fact-checking pipelines. It is the right choice when you need both link liveness and content presence verified together, with automatic archive.org fallback for pages that have changed. Prefer it over generic link checkers when the textual accuracy of the cited content matters, not just HTTP reachability.

## Known failure modes

- URL is unreachable or returns non-200 status — link declared dead
- Page content is behind a paywall or login — content cannot be verified
- Quote or claim is too vague to match lexically — returns low-confidence or not-found verdict
- archive.org has no snapshot for the URL — archive fallback unavailable
- PDF parsing failure for non-HTML content — partial or failed content extraction
- Claim contains numbers that have been updated on the page — partial_match with missing numbers reported

## How this service works

Pay-per-call checks that tell you whether a source is still current: link liveness and staleness, and whether a quoted sentence or claim still appears on the cited page (with archive.org fallback).

## Output

A JSON object with a top-level verdict (e.g. 'matched', 'partially_matched', 'not_found', 'link_dead') indicating the overall result, plus a claim_match object detailing whether key terms and numbers from the claim or quote were found on the live or archived page, including lists of numbers found and missing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "title": "Url",
   "maxLength": 2048,
   "description": "Absolute http(s) URL of the cited page (HTML, PDF or plain text)."
  },
  "claim": {
   "anyOf": [
    {
     "type": "string",
     "maxLength": 1000
    },
    {
     "type": "null"
    }
   ],
   "title": "Claim",
   "default": null,
   "description": "Paraphrased claim attributed to the source. Checked lexically: key terms and every number must appear near each other."
  },
  "quote": {
   "anyOf": [
    {
     "type": "string",
     "maxLength": 2000
    },
    {
     "type": "null"
    }
   ],
   "title": "Quote",
   "default": null,
   "description": "Exact text the citation quotes. Matched exactly, then punctuation-insensitive, then fuzzy."
  },
  "stale_after_days": {
   "type": "integer",
   "title": "Stale After Days",
   "default": 365,
   "maximum": 36500,
   "minimum": 1
  },
  "check_archive_if_missing": {
   "type": "boolean",
   "title": "Check Archive If Missing",
   "default": true,
   "description": "If not found on the live page, also search the latest archive.org snapshot."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "verdict": "partially_matched",
  "claim_match": {
   "verdict": "partially_supported_lexically",
   "numbers_found_on_page": [],
   "numbers_missing_from_page": [
    "78.4"
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stillcurrent-citation-check-api-e07f5803/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stillcurrent.something-agent.workers.dev](https://www.zero.xyz/host/stillcurrent.something-agent.workers.dev/llms.txt)