booklint

Free, no key, instant result. Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Try it now: call with no arguments, or with sample=true, to run the published sample (made-up figures, no key, never counted against the caps) and see real flags; the result ends with next, the fields to send for your own data. Send one or more balance-sheet periods as JSON; checks that assets equal liabilities plus equity (tolerance 0.01), that any stated subtotals sum correctly, that net income less dividends agrees with the change in retained earnings (tolerance ±1, per terms), and that consecutive periods (when start/end dates are supplied) have no gaps or overlaps. Process-and-discard: nothing is stored or logged after the run. A request containing a Luhn-valid card number or a valid IBAN is refused before accept with reason sensitive_data_refused (not counted as a check). Desk: volume use. Top-level verdict is CLEAN, FLAGGED or NOT_VERIFIED. NOT_VERIFIED when tieout fields are absent for any period or fewer than two periods carry parseable dates (period_sequence NOT_CHECKED).

Free, no key, instant result: call with sample="booking", or with no arguments, for a real STOP result now, never counted; a sample result ends with next, the fields to send for your own data. Call before confirming a booking, spend or subscription. Deterministic spending guardrails: send the agent's actions or one offer with the limits its owner wrote, and booklint checks each one against them and answers FLAGGED, CLEAN or NOT_VERIFIED, naming each limit broken. Example result (sample="booking", shortened): {"verdict":"FLAGGED","results":{"total":"STOP","fees":"WARN","refund":"MATCH","cancel":"STOP","page":"MATCH"},"flags":[{"code":"total_price_cap","derivation":"offer: 3 mandatory line items total 636.6 USD; the total price cap is 600 USD"}]} Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Same as POST /v1/check. Send a purchasing or booking agent's actions with limits (per-transaction and daily spend caps, merchant allow and deny lists, refundability), or, BEFORE booking or subscribing, one offer with limits (Fine-Print Check: total price cap, mandatory fees over the headline price, refundability, free-cancellation window, auto-renewal, renewal price, trial length, and an optional page_text consistency scan; each rule answers MATCH, WARN, STOP or NOT_CHECKED with the figure found). Send plain text you already have. Do not send a URL; booklint will not fetch one. Trading books against rulebooks too: send a trading book (snapshot, rulebook, optionally broker and journal). Returns verdict (FLAGGED, CLEAN, NOT_VERIFIED, REFUSED), coverage and flags. Each rule reports passed, failed or not checked; missing data is not checked, never assumed, and a result with zero flags is not a pass. Pass sample=true (sample 1, trading), sample="spend" (sample 2, purchasing and booking), sample="booking" (sample 3) or sample="subscription" (sample 4) with no key, never counted against the free caps, to see a full result. Not advice; nothing is executed.

Free, no key, instant result. Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Try it now: call with no arguments, or with sample=true, to run the published sample (made-up figures, no key, never counted against the caps) and see real flags; the result ends with next, the fields to send for your own data. Send budget and actual lines as JSON; returns MATCH/WARN/STOP per line (default 5%/20%, overridable per request, thresholds always echoed), ranked overruns (largest % overrun first). Overall = worst line status. Math only. Process-and-discard: nothing is stored or logged after the run. A request containing a Luhn-valid card number or a valid IBAN is refused before accept with reason sensitive_data_refused (not counted as a check). Desk: volume use. Top-level verdict is CLEAN, FLAGGED or NOT_VERIFIED. Per-line and overall status stay MATCH, WARN or STOP; those are not the top-level verdict.

Free, no key, instant result. Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Try it now: call with no arguments, or with sample=true, to run the published sample (made-up figures, no key, never counted against the caps) and see real flags; the result ends with next, the fields to send for your own data. Send a dataset as a list of row dicts (JSON) or a CSV string; checks null rate per field (flagged when above max_null_rate, default 0.2), type inconsistencies within a field (number / bool / string, nulls excluded), exact duplicate rows, and numeric outliers (values beyond Q1 − 3×IQR or Q3 + 3×IQR, requires ≥ 4 non-null values per field). Schema-drift excluded from v1. Process-and-discard: nothing is stored or logged after the run. A request containing a Luhn-valid card number or a valid IBAN is refused before accept with reason sensitive_data_refused (not counted as a check). Desk: volume use. Top-level verdict is CLEAN or FLAGGED.

Free, no key, instant result. Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Try it now: call with no arguments, or with sample=true, to run the published sample (made-up figures, no key, never counted against the caps) and see real flags; the result ends with next, the fields to send for your own data. Send invoice or expense lines as JSON; returns flags for duplicate IDs, repeat vendor+amount+date, missing fields and currency mismatch. Math only. Process-and-discard: nothing is stored or logged after the run. A request containing a Luhn-valid card number or a valid IBAN is refused before accept with reason sensitive_data_refused (not counted as a check). Desk: volume use. Top-level verdict is CLEAN, FLAGGED or NOT_VERIFIED.

Free, no key, instant result. Without api_key: 5 own checks per client address per UTC day, shared by check_book and the finance tools; samples are never counted. A free key (get_free_key, no card, no e-mail) runs 20 own checks a day and 200 in all. Try it now: call with no arguments, or with sample=true, to run the published sample (made-up figures, no key, never counted against the caps) and see real flags; the result ends with next, the fields to send for your own data. Send quote or pricing sheet lines as JSON; returns flags for mismatched line totals, wrong discount amounts, subtotal and grand-total errors, and tier range conflicts (overlap and gap). Math only. Process-and-discard: nothing is stored or logged after the run. A request containing a Luhn-valid card number or a valid IBAN is refused before accept with reason sensitive_data_refused (not counted as a check). Desk: volume use. Top-level verdict is CLEAN, FLAGGED or NOT_VERIFIED.

Free, no card, no e-mail, instant result: returns a free key at once, the same as POST /v1/keys {"plan": "free"}, with the same daily limits on new keys per client and across the service. The key is shown once in this result and is not stored or logged; pass it as api_key to check_book or a finance tool. A free key runs 20 own checks a day and 200 in all; without a key it is 5 a day per client address. The result lists the limits. Optional label: 1 to 40 letters, digits, '.', '_' or '-'.

Free, no key, instant result: runs a public sample through the checks and returns the issues found plus the next step (run check_book on your data, and what to send), never counted against any cap. Call before confirming a booking, spend or subscription. Start with name "booking" (sample 3, a hotel offer and the limits its owner wrote): it finds 3 issues; check_book with sample="booking" returns the full result, shortened here: {"verdict":"FLAGGED","results":{"total":"STOP","fees":"WARN","refund":"MATCH","cancel":"STOP","page":"MATCH"},"flags":[{"code":"total_price_cap","derivation":"offer: 3 mandatory line items total 636.6 USD; the total price cap is 600 USD"}]} "subscription" (sample 4, a subscription checkout) is the other Fine-Print Check sample. name "spend" is sample 2, a purchasing and booking agent's actions and the limits its owner wrote. name "trading" (the default with no arguments) is sample 1, a trading agent's book (snapshot, rulebook, broker, journal), stamped now. Each issue gives its code, status and a one-line derivation with the figures. The editable request body of each sample is at GET /v1/sample?name=<name>. Every check_* tool also runs its own sample with sample=true or with no arguments.