# Paper & Print Calc – Envelope Fit Checker

> Paper & Print Calc – Envelope Fit Checker is a paid API for AI agents from paper-print-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-03).

Given a card or folded sheet's dimensions, returns which standard envelopes (#10, A2, A7, C5, DL, C6, etc.) it will fit into, along with the margin left on each side.

## Facts

- Endpoint: GET https://paper-print-calc.x402tookit.com/envelope-fit?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-03
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/paper-print-calc-envelope-fit-checker-13f16597
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IwLZc2KPk2DbSIzMX9NtB

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 paper-print-calc-envelope-fit-checker-13f16597
```

Example prompt: I have a folded card that's 4.25 inches wide by 5.5 inches tall — which standard envelopes (#10, A2, A7, etc.) will it fit in, and how much margin will be left on each side?

## When to prefer this

Use this endpoint when you need to programmatically determine which off-the-shelf standard envelopes (#10, A2, A7, C5, DL, C6, etc.) can hold a specific card or folded sheet, including margin clearance data. Ideal for print-production workflows, stationery design tools, direct-mail campaign planning, or any scenario where you need to match a physical piece to a standard envelope size without manual lookup tables.

## Known failure modes

- Missing required width or height query parameters returns an error
- Non-numeric width/height values cause a validation failure
- Extremely small or large dimensions outside any standard envelope range return an empty fits array
- Invalid unit value (not 'in' or 'mm') may produce unexpected behavior

## How this service works

Which standard envelopes (#10, A2, A7, C5, DL, C6 and more) hold a card or folded sheet, with the margin left over.

## Output

Returns an array of matching envelope names (e.g. #10, A7, C5) with their dimensions in both inches and mm, the margin per side in inches for each, the snuggest-fitting envelope, a plain-English summary verdict, reasons why certain envelopes were excluded, the total number of envelopes checked, and the clearance used.

## 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": [
      "width",
      "height"
     ],
     "properties": {
      "unit": {
       "type": "string",
       "description": "in (default) or mm"
      },
      "width": {
       "type": "number",
       "description": "Width of the flat or folded piece"
      },
      "height": {
       "type": "number",
       "description": "Height of the piece"
      },
      "clearance": {
       "type": "number",
       "description": "Minimum gap on every side, in the same unit (default 0.125 in, or 3 mm)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "fits": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "sizeMm": {
          "type": [
           "array",
           "null"
          ],
          "items": {
           "type": "number"
          }
         },
         "envelope": {
          "type": [
           "null",
           "string"
          ]
         },
         "sizeInches": {
          "type": [
           "array",
           "null"
          ],
          "items": {
           "type": "number"
          }
         },
         "marginPerSideInches": {
          "type": [
           "null",
           "number"
          ]
         }
        }
       }
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "di
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/paper-print-calc-envelope-fit-checker-13f16597/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from paper-print-calc.x402tookit.com](https://www.zero.xyz/host/paper-print-calc.x402tookit.com/llms.txt)