# Parkland Archives: 1900 Sears Catalog Price Modern Value Converter

> Parkland Archives: 1900 Sears Catalog Price Modern Value Converter is a paid API for AI agents from history.parklandarchives.com, paid per call via x402, $0.06/call, status unknown (last checked 2026-09-16).

Looks up a 1900 Sears catalog item by item number or raw price and returns its inflation-adjusted modern USD equivalent using Federal Reserve CPI data.

## Facts

- Endpoint: GET https://history.parklandarchives.com/api/catalog-prices/modern-value
- Price: $0.06/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/parkland-archives-1900-sears-catalog-price-modern-value-converter-0aff3211
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LS-FSQ03DeGYFQdcyFbbz

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 parkland-archives-1900-sears-catalog-price-modern-value-converter-0aff3211
```

Example prompt: What would Sears catalog item 3T400 cost in today's dollars? Look it up in the Parkland Archives 1900 catalog and give me the inflation-adjusted modern value.

## When to prefer this

Choose this endpoint when you need inflation-adjusted modern dollar values for specific 1900 Sears catalog items, or to convert any arbitrary 1900 USD price to its 2025 equivalent using academically-grounded CPI methodology. Prefer this over generic inflation calculators when you also want structured product metadata (category, materials, source page) alongside the conversion.

## Known failure modes

- Item number not found in catalog — returns found: false
- Neither price_usd nor item_number provided — missing required query parameter
- Invalid item number format — no matching record
- Price value of 0 or negative — may produce unexpected results
- Payment failure via x402 micropayment — call not processed

## How this service works

Structured historical data from verified primary sources — 1900 Sears catalog prices, World Almanac statistics, and more. Queryable by AI agents via x402 micropayments on Base.

## Output

Returns a JSON object with: the found flag, a full product record (item number, product name, category, original USD price, source page, catalog year, materials, and data quality flags), the inflation multiplier (e.g. 38.7x), the original year, modern year, and the calculated modern USD value. Also includes the authoritative source citation (Federal Reserve Bank of Minneapolis CPI).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "price_usd": {
       "type": "number"
      },
      "item_number": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "found": true,
  "record": {
   "id": 44,
   "category": "books",
   "priceUsd": 0.6,
   "createdAt": "2026-07-14T21:51:18.595Z",
   "materials": "cloth",
   "uncertain": false,
   "flagReason": null,
   "itemNumber": "3T400",
   "sourcePage": 130,
   "catalogYear": 1900,
   "productName": "Practical Blacksmithing, Volume I",
   "catalogSeason": null,
   "sourceIdentifier": "catalogueno11200sear"
  },
  "source": "Federal Reserve Bank of Minneapolis, Consumer Price Index 1800- (official BLS CPI from 1913, academic estimates before)",
  "modernYear": 2025,
  "multiplier": 38.7,
  "originalYear": 1900,
  "modernValueUsd": 23.22,
  "originalPriceUsd": 0.6
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/parkland-archives-1900-sears-catalog-price-modern-value-converter-0aff3211/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from history.parklandarchives.com](https://www.zero.xyz/host/history.parklandarchives.com/llms.txt)