# Pack-years Pack-years Status: LIVE Price: $0.005 USDC `GET /api/calc/pack_years` HTML: https://magentlab.com/docs/pack-years Markdown: https://magentlab.com/docs/pack-years.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Compute NCI pack-year smoking exposure as packs_per_day × years_smoked. Caller supplies packs per day or cigarettes per day (20 cigarettes = 1 pack) and years smoked. ## When to use When an agent already has packs per day or cigarettes per day and years smoked and must not take a smoking history interview, invent a pack size other than 20 cigarettes, or treat the product as a lung-cancer screening order. ## When not to use - Not a medical device. Not a lung-cancer screening order, COPD diagnosis, or sleep-apnea screen. magent does not take a smoking history interview. - NCI pack year is packs per day times years smoked. Does not convert cigar, pipe, or other tobacco to pack-years. - Provide packs_per_day (0-10, magent clamp) or cigarettes_per_day (0-200; 20 cigarettes = 1 pack), not both. years_smoked is 0-80 (magent clamp). NCI does not publish an input band. - Does not return years since quit or current-versus-former status. Caller supplies the two NCI factors. ## Formula ``` pack_years = packs_per_day × years_smoked ``` ## Citation [NCI Dictionary of Cancer Terms: pack year](https://www.cancer.gov/publications/dictionaries/cancer-terms/def/pack-year) National Cancer Institute NCI Dictionaries DOI: none ## Worked example ### 1 pack/day for 1 year Given: `packs_per_day=1, years_smoked=1` 1. packs_per_day = 1 2. years_smoked = 1 3. pack_years = 1 × 1 = 1.0 ### 10 cigarettes/day for 10 years Given: `cigarettes_per_day=10, years_smoked=10` 1. packs_per_day = 10 / 20 = 0.5 2. years_smoked = 10 3. pack_years = 0.5 × 10 = 5.0 ## Also searched as - pack year - pack-year - smoking pack years - cigarette pack years - packs per day years smoked - NCI pack year - tobacco pack-years - smoking exposure pack-years ## Parameters - `packs_per_day` (number, optional): Cigarette packs smoked per day (0-10, magent clamp; NCI does not publish an input band). Provide this or cigarettes_per_day, not both. NCI: 1 pack/day for 1 year = 1 pack-year. - `cigarettes_per_day` (number, optional): Cigarettes smoked per day (0-200, magent clamp). Converted as packs_per_day = cigarettes_per_day / 20. Provide this or packs_per_day, not both. - `years_smoked` (number, required): Years smoked (0-80, magent clamp; NCI does not publish an input band). NCI: 2 packs/day for 0.5 year = 1 pack-year. magent does not take a smoking history interview. ## Bulk (POST) POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/pack_years` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows. - The first invalid item fails the whole request (index in the 400 JSON). You are not charged. - HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row. - Catalog misses (empty matches, found=false) stay paid 200s inside that slot. - x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items. Example request: ```json { "items": [ { "packs_per_day": "1", "years_smoked": "1" }, { "packs_per_day": "1", "years_smoked": "1" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/pack-years Example 200: ```json { "count": 2, "path": "/api/calc/pack_years", "items": [ { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "National Cancer Institute", "id": "nci-pack-year", "source": "NCI Dictionaries", "title": "NCI Dictionary of Cancer Terms: pack year" }, "formula": "pack_years", "formula_expression": "pack_years = packs_per_day × years_smoked", "pack_years": 1.0, "packs_per_day": 1.0, "years_smoked": 1.0 }, { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "National Cancer Institute", "id": "nci-pack-year", "source": "NCI Dictionaries", "title": "NCI Dictionary of Cancer Terms: pack year" }, "formula": "pack_years", "formula_expression": "pack_years = packs_per_day × years_smoked", "pack_years": 1.0, "packs_per_day": 1.0, "years_smoked": 1.0 } ] } ``` ## Response fields - `formula` (string): pack_years - `formula_expression` (string): Exact expression used - `packs_per_day` (number): Packs per day used (cigarettes_per_day inputs converted /20) - `years_smoked` (number): Years smoked used - `pack_years` (number): NCI pack-years, 1 decimal - `citation` (object): NCI pack-year dictionary citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "National Cancer Institute", "id": "nci-pack-year", "source": "NCI Dictionaries", "title": "NCI Dictionary of Cancer Terms: pack year" }, "formula": "pack_years", "formula_expression": "pack_years = packs_per_day × years_smoked", "pack_years": 1.0, "packs_per_day": 1.0, "years_smoked": 1.0 } ``` ## Errors - HTTP 400 `invalid_pack_years`: Pack-years need packs_per_day (or cigarettes_per_day) and years_smoked as non-negative numbers. Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [GOLD spirometric grade](https://magentlab.com/docs/gold-copd) — Apply the 2017 GOLD executive summary spirometric classification: obstruction when post-bronchodilator FEV1/FVC is < 0.70, then GOLD grades 1-4 from FEV1 percent predicted. - [STOP-Bang](https://magentlab.com/docs/stop-bang) — Compute Chung 2008 Appendix 2 STOP-Bang from four STOP flags and computed BANG (BMI >35, age >50, neck >40 cm, male) and return the published 0-2 / >=3 OSA-risk band. ## Payment Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/docs/mcp ## Guarantees - HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON. - exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE. - HTTP 402 is unpaid only. Do not sign a second authorization because of a 503. - Execution is timeout-bounded and concurrency-capped. - Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.