--- title: "Cancel a citation check" method: POST path: "/api/v1/citechecks/{citecheck_id}/cancel" tags: ["Citecheck"] --- # Cancel a citation check `POST /api/v1/citechecks/{citecheck_id}/cancel` ## Request - Base URL: `https://lenz.io` - URL: `https://lenz.io/api/v1/citechecks/{citecheck_id}/cancel` - Auth: HTTP bearer Stop a citation check. Returns the check as it stands afterwards, `status: cancelled`. You are charged only for the citations it checked before the cancel; the rest are refunded. A check that had already finished is returned unchanged (`completed` or `failed`); cancelling again is safe. **Versions.** 200: `2026-10-11` receives `CitecheckOut`, `2026-05-13` receives `CitecheckOutLegacy`; 403: `2026-10-11` receives `CitecheckErrorOut`, `2026-05-13` receives `CitecheckErrorOutLegacy`; 404: `2026-10-11` receives `CitecheckErrorOut`, `2026-05-13` receives `CitecheckErrorOutLegacy`; 410: `2026-10-11` receives `CitecheckErrorOut`, `2026-05-13` receives `CitecheckErrorOutLegacy`; default: `2026-10-11` receives `ErrorOut`, `2026-05-13` receives `ErrorOutLegacy`. ## Path parameters - `citecheck_id` string, required ## Headers - `X-Lenz-API-Version` string ## Response `200` OK - CitecheckOut - `citecheck_id` string, required - `status` 'queued' | 'checking' | 'completed' | 'failed' | 'cancelled', required: cancelled: you cancelled it (POST /citechecks/{citecheck_id}/cancel). Only citations it checked before that are charged. - `outcome` 'clean' | 'issues_found' | 'incomplete' | 'unchecked', nullable, required: Null until terminal. incomplete: a citation could not be checked for a reason of ours. - `created_at` string, required - `completed_at` string, nullable, required - `language` string, required: The language the reasoning is written in, as the review envelope echoes it. - `poll_after_seconds` integer, nullable, required - `policy` CitecheckPolicyOut, required - `max_citations` integer, nullable, required: How many citations the check selects: for text, the limit (default 20); for pairs, the number of pairs checked. - `summary` CitecheckSummaryOut, required - `citations_found` integer, nullable: Citations with a URL or DOI in the text, or the pairs sent; null until read. - `citations_selected` integer, nullable - `citation_limit` integer, nullable - `citation_limit_exceeded` boolean, nullable: True when citations_found is more than citation_limit: the rest are in more_citations, found and not checked. False when every citation found was selected, exactly citation_limit included. Null until the text is read. - `citation_checks` ReviewCitationCountsOut: Three disjoint counts; once every check has ended they add up to citations_selected. - `checked` integer, required: A finding other than unchecked. - `unchecked` integer, required: Could not be checked, for a reason of the page or the draft. - `failed` integer, required: No finding, for a reason of ours. - `citation_issues` integer - `citation_limit_reached` boolean, nullable: Sent only to callers on `2026-05-13`; use `citation_limit_exceeded`. - `credits` ReviewCreditsOut, required - `charged` integer, required: Net credits this review cost the account, read from the ledger. Authoritative once no deep check is running. - `citations` ReviewCitationOut[] - `index` integer, required - `reference` string, nullable, required - `cited_url` string, nullable, required - `doi` string, nullable, required - `statement` string, nullable, required - `quotes` string[] - `position` PositionOut, required - `start` integer, nullable, required: Where the passage starts in `text` as you sent it, in Unicode code points (not UTF-16 units or bytes). Half-open with `end`. `null` when `text` was a URL: the page is not returned, so there is nothing to index, and `text` carries the passage instead. - `end` integer, nullable, required: Where the passage ends, exclusive; `null` as for `start`. - `text` string, nullable, required: The passage itself, as it appears in the text. `null` on a citation position, whose row already carries the statement. - `result` ReviewCitationResultOut, required - `finding` 'doi_not_found' | 'page_not_found' | 'contradicted' | 'quote_not_in_source' | 'not_in_source' | 'partly_supported' | 'metadata_mismatch' | 'supported' | 'unchecked', required - `source` 'doi' | 'page' | 'support' | 'quote' | 'metadata', nullable, required - `is_issue` boolean, required: True for every finding except partly_supported, supported and unchecked. partly_supported is reported, with its snippet, but is not an issue. - `check` ReviewCitationCheckOut, required - `status` 'pending' | 'running' | 'completed' | 'failed', required - `page_read` 'full' | 'partial' | 'not_found' | 'none', nullable: What reading the source gave: full, partial (cut short, a teaser or an abstract alone), not_found, none. - `page_title` string, nullable - `page_published_date` string, nullable - `page_language` string, nullable: The language of the page that was read, as an ISO 639-1 code (e.g. `en`, `uk`); null when unknown. - `source_url` string, nullable: Where the text was actually read from. - `source_version` 'published' | 'accepted' | 'submitted', nullable - `support` 'supported' | 'partly_supported' | 'contradicted' | 'not_in_source' | 'unchecked', nullable - `snippet` string, nullable: The passage from the source the support answer rests on, checked against the page text. - `rationale` string, nullable: The reviewer's sentence: reasoning, not a checked source. - `quote` 'matched' | 'not_in_source' | 'unchecked', nullable - `missing_quote` string, nullable: The first of quotes the source does not contain; null unless quote is not_in_source. - `doi_registered` boolean, nullable - `metadata` 'consistent' | 'mismatch' | 'unchecked', nullable - `metadata_differences` ReviewMetadataDifferenceOut[] - `field` 'title' | 'authors' | 'year' | 'journal', required - `cited` string, nullable - `registered` string, nullable - `registered` ReviewRegisteredOut - `title` string, nullable - `authors` string[] - `year` integer, nullable - `journal` string, nullable - `unchecked_reason` string, nullable: Why the finding is unchecked; an extensible string. - `hint` string, nullable - `failure` FailureOut: Why an item failed, and what to do next. The same block everywhere an item fails: a verification, an /assess row, a review, a review's claim rows and citation checks. ``code`` is what failed, ``detail`` one sentence on it (the same sentence for the same code on every endpoint), ``hint`` what to send next (null when there is nothing to change), ``failure_class`` why, ``retryable`` whether sending the same request again can succeed, ``docs_url`` where that class is explained. API version ``2026-05-13`` sends each endpoint's earlier fields instead (flat ``error`` / ``failure_reason`` on a verification, ``error_code`` / ``hint`` on an /assess row, ``failure.failure_reason`` on a review). - `code` string, required: What failed, one vocabulary everywhere: `no_checkable_claim`, `page_unreadable`, `upstream_unavailable`, `internal`, `cancelled`, `no_citations`, `insufficient_credits` (a verification only ever says the first, the third, the fourth and `cancelled`). Branch on `retryable` for whether to resend, and on the input codes for what to say; fall through on a value you do not know. `no_checkable_claim`: no claim in the input could be checked against public evidence (an opinion, a forecast, a claim about a private person, a statement whose only source is unidentified; on a review, also claims found that could not be traced back to the text); `hint` says which. `page_unreadable`: the link /review was sent could not be read. Version `2026-05-13` spells `no_checkable_claim` as `no_claim` (/assess, /review) or `not_a_claim` (/extract, a verification), and keeps the earlier causes as codes (`timeout`, `framing_failed`, `assessment_failed`, `citation_check_failed`, `invalid_input`). - `detail` string, required: The cause, in one sentence (out of time, no row could be assessed, ...); the same sentence for the same cause everywhere. - `hint` string, nullable: What to send next; null when there is nothing to change. - `failure_class` 'upstream_unavailable' | 'invalid_input' | 'cancelled' | 'internal', required - `retryable` boolean, required - `docs_url` string, nullable, required - `citation_issues` ReviewCitationIssueOut[]: Citations whose source does not say what the draft says, the most serious first; partly_supported rows are not issues and are only in citations[]. - `citation_index` integer, required - `reference` string, nullable, required - `cited_url` string, nullable, required - `doi` string, nullable, required - `statement` string, nullable, required - `quotes` string[] - `position` PositionOut, required - `start` integer, nullable, required: Where the passage starts in `text` as you sent it, in Unicode code points (not UTF-16 units or bytes). Half-open with `end`. `null` when `text` was a URL: the page is not returned, so there is nothing to index, and `text` carries the passage instead. - `end` integer, nullable, required: Where the passage ends, exclusive; `null` as for `start`. - `text` string, nullable, required: The passage itself, as it appears in the text. `null` on a citation position, whose row already carries the statement. - `finding` 'doi_not_found' | 'page_not_found' | 'contradicted' | 'quote_not_in_source' | 'not_in_source' | 'partly_supported' | 'metadata_mismatch' | 'supported' | 'unchecked', required - `source` 'doi' | 'page' | 'support' | 'quote' | 'metadata', nullable, required - `snippet` string, nullable, required: Set only when source is support. - `rationale` string, nullable, required: Set only when source is support. - `metadata_differences` ReviewMetadataDifferenceOut[] - `field` 'title' | 'authors' | 'year' | 'journal', required - `cited` string, nullable - `registered` string, nullable - `missing_quote` string, nullable: Set only when finding is quote_not_in_source. - `page_title` string, nullable, required - `failure` FailureOut, required: Why an item failed, and what to do next. The same block everywhere an item fails: a verification, an /assess row, a review, a review's claim rows and citation checks. ``code`` is what failed, ``detail`` one sentence on it (the same sentence for the same code on every endpoint), ``hint`` what to send next (null when there is nothing to change), ``failure_class`` why, ``retryable`` whether sending the same request again can succeed, ``docs_url`` where that class is explained. API version ``2026-05-13`` sends each endpoint's earlier fields instead (flat ``error`` / ``failure_reason`` on a verification, ``error_code`` / ``hint`` on an /assess row, ``failure.failure_reason`` on a review). - `code` string, required: What failed, one vocabulary everywhere: `no_checkable_claim`, `page_unreadable`, `upstream_unavailable`, `internal`, `cancelled`, `no_citations`, `insufficient_credits` (a verification only ever says the first, the third, the fourth and `cancelled`). Branch on `retryable` for whether to resend, and on the input codes for what to say; fall through on a value you do not know. `no_checkable_claim`: no claim in the input could be checked against public evidence (an opinion, a forecast, a claim about a private person, a statement whose only source is unidentified; on a review, also claims found that could not be traced back to the text); `hint` says which. `page_unreadable`: the link /review was sent could not be read. Version `2026-05-13` spells `no_checkable_claim` as `no_claim` (/assess, /review) or `not_a_claim` (/extract, a verification), and keeps the earlier causes as codes (`timeout`, `framing_failed`, `assessment_failed`, `citation_check_failed`, `invalid_input`). - `detail` string, required: The cause, in one sentence (out of time, no row could be assessed, ...); the same sentence for the same cause everywhere. - `hint` string, nullable: What to send next; null when there is nothing to change. - `failure_class` 'upstream_unavailable' | 'invalid_input' | 'cancelled' | 'internal', required - `retryable` boolean, required - `docs_url` string, nullable, required - `citation_failures` ReviewCitationFailedRowOut[] - `citation_index` integer, required - `reference` string, nullable, required - `cited_url` string, nullable, required - `doi` string, nullable, required - `failure` FailureOut, required: Why an item failed, and what to do next. The same block everywhere an item fails: a verification, an /assess row, a review, a review's claim rows and citation checks. ``code`` is what failed, ``detail`` one sentence on it (the same sentence for the same code on every endpoint), ``hint`` what to send next (null when there is nothing to change), ``failure_class`` why, ``retryable`` whether sending the same request again can succeed, ``docs_url`` where that class is explained. API version ``2026-05-13`` sends each endpoint's earlier fields instead (flat ``error`` / ``failure_reason`` on a verification, ``error_code`` / ``hint`` on an /assess row, ``failure.failure_reason`` on a review). - `code` string, required: What failed, one vocabulary everywhere: `no_checkable_claim`, `page_unreadable`, `upstream_unavailable`, `internal`, `cancelled`, `no_citations`, `insufficient_credits` (a verification only ever says the first, the third, the fourth and `cancelled`). Branch on `retryable` for whether to resend, and on the input codes for what to say; fall through on a value you do not know. `no_checkable_claim`: no claim in the input could be checked against public evidence (an opinion, a forecast, a claim about a private person, a statement whose only source is unidentified; on a review, also claims found that could not be traced back to the text); `hint` says which. `page_unreadable`: the link /review was sent could not be read. Version `2026-05-13` spells `no_checkable_claim` as `no_claim` (/assess, /review) or `not_a_claim` (/extract, a verification), and keeps the earlier causes as codes (`timeout`, `framing_failed`, `assessment_failed`, `citation_check_failed`, `invalid_input`). - `detail` string, required: The cause, in one sentence (out of time, no row could be assessed, ...); the same sentence for the same cause everywhere. - `hint` string, nullable: What to send next; null when there is nothing to change. - `failure_class` 'upstream_unavailable' | 'invalid_input' | 'cancelled' | 'internal', required - `retryable` boolean, required - `docs_url` string, nullable, required - `more_citations` ReviewMoreCitationOut[], nullable: Citations found in the text past the ones selected (up to 100): found but not checked; send them in a later request to check them. Null until the text is read; [] for pairs. - `index` integer, required - `reference` string, nullable - `cited_url` string, nullable - `doi` string, nullable - `sentence` string, required: The draft sentence around the citation, at most 1,000 characters. - `position` PositionOut - `start` integer, nullable, required: Where the passage starts in `text` as you sent it, in Unicode code points (not UTF-16 units or bytes). Half-open with `end`. `null` when `text` was a URL: the page is not returned, so there is nothing to index, and `text` carries the passage instead. - `end` integer, nullable, required: Where the passage ends, exclusive; `null` as for `start`. - `text` string, nullable, required: The passage itself, as it appears in the text. `null` on a citation position, whose row already carries the statement. - `failure` FailureOut, required: Why an item failed, and what to do next. The same block everywhere an item fails: a verification, an /assess row, a review, a review's claim rows and citation checks. ``code`` is what failed, ``detail`` one sentence on it (the same sentence for the same code on every endpoint), ``hint`` what to send next (null when there is nothing to change), ``failure_class`` why, ``retryable`` whether sending the same request again can succeed, ``docs_url`` where that class is explained. API version ``2026-05-13`` sends each endpoint's earlier fields instead (flat ``error`` / ``failure_reason`` on a verification, ``error_code`` / ``hint`` on an /assess row, ``failure.failure_reason`` on a review). - `code` string, required: What failed, one vocabulary everywhere: `no_checkable_claim`, `page_unreadable`, `upstream_unavailable`, `internal`, `cancelled`, `no_citations`, `insufficient_credits` (a verification only ever says the first, the third, the fourth and `cancelled`). Branch on `retryable` for whether to resend, and on the input codes for what to say; fall through on a value you do not know. `no_checkable_claim`: no claim in the input could be checked against public evidence (an opinion, a forecast, a claim about a private person, a statement whose only source is unidentified; on a review, also claims found that could not be traced back to the text); `hint` says which. `page_unreadable`: the link /review was sent could not be read. Version `2026-05-13` spells `no_checkable_claim` as `no_claim` (/assess, /review) or `not_a_claim` (/extract, a verification), and keeps the earlier causes as codes (`timeout`, `framing_failed`, `assessment_failed`, `citation_check_failed`, `invalid_input`). - `detail` string, required: The cause, in one sentence (out of time, no row could be assessed, ...); the same sentence for the same cause everywhere. - `hint` string, nullable: What to send next; null when there is nothing to change. - `failure_class` 'upstream_unavailable' | 'invalid_input' | 'cancelled' | 'internal', required - `retryable` boolean, required - `docs_url` string, nullable, required ## Other responses - `403`: Forbidden - `404`: Not Found - `410`: Gone - `default`: An error --- [API](https://skmtc.dev/lenz/apis/lenz-ai-fact-checking-api.md) · [All operations](https://skmtc.dev/lenz/apis/lenz-ai-fact-checking-api/llms.txt) · [OpenAPI document](https://skmtc.dev/lenz/apis/lenz-ai-fact-checking-api/revisions/6150947324bf?raw)