# Coprocesseur Déterministe – Conversion d'Unités

> Coprocesseur Déterministe – Conversion d'Unités is a paid API for AI agents from x402.laboiteatubes.media, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-13).

Converts a numeric value from one physical unit to another (length, mass, volume, temperature) and returns the result with its formula, exact conversion factor, and a SHA-256 proof fingerprint.

## Facts

- Endpoint: GET https://x402.laboiteatubes.media/conversion?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/coprocesseur-d-terministe-conversion-d-unit-s-6616cee9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_grdZNzfnNmmdjj0JTSuni

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 coprocesseur-d-terministe-conversion-d-unit-s-6616cee9
```

Example prompt: Convert 100 km to miles and give me the exact conversion factor and the SHA-256 fingerprint so I can verify the result myself.

## When to prefer this

Choose this endpoint when you need a deterministic, auditable unit conversion with a cryptographic proof that the computation was performed correctly and consistently — ideal for AI agents, automated pipelines, or compliance workflows where reproducibility and verifiability matter. Prefer it over generic conversion libraries when you need a third-party signed fingerprint or an exact-definition factor (e.g. 1959 international yard/pound agreement, BIPM nautical mile).

## Known failure modes

- Missing required query parameters (valeur, de, vers) returns an error
- Incompatible unit families (e.g. converting km to kg) returns a validation error
- Unsupported unit enum value returns an error
- Payment failure via x402 protocol blocks the request
- Network timeout or service unavailability

## How this service works

Trois calculs déterministes destinés aux agents IA : amortissement de prêt, distance orthodromique, conversion d'unités.

Chaque réponse porte son résultat, la formule appliquée, ses limites, et une empreinte SHA-256 recalculable — la chaîne exacte qui a été hachée est renvoyée avec, et `POST /verifier` permet de la contrôler gratuitement. Un même appel rend toujours la même empreinte : l'horodatage est exclu du hachage.

Le paiement suit le protocole x402 (version 2), en USDC sur Base.

## Output

A JSON object containing: the converted numeric value rounded to 12 significant figures, the source and target units, the SI base-unit intermediate value, the multiplicative conversion factor applied, a human-readable formula expression and its reference standard, a SHA-256 fingerprint (with the exact canonical JSON string that was hashed, covering operation, formula version, inputs, and result), service metadata (version, timestamp), and notes on precision and exact-definition factors.

## 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": [
      "valeur",
      "de",
      "vers"
     ],
     "properties": {
      "de": {
       "enum": [
        "km",
        "m",
        "dm",
        "cm",
        "mm",
        "um",
        "nm",
        "mi",
        "yd",
        "ft",
        "in",
        "nmi",
        "t",
        "kg",
        "g",
        "mg",
        "ug",
        "lb",
        "oz",
        "st",
        "m3",
        "L",
        "dL",
        "cL",
        "mL",
        "gal_us",
        "qt_us",
        "pt_us",
        "floz_us",
        "gal_uk",
        "K",
        "C",
        "F"
       ],
       "type": "string"
      },
      "vers": {
       "enum": [
        "km",
        "m",
        "dm",
        "cm",
        "mm",
        "um",
        "nm",
        "mi",
        "yd",
        "ft",
        "in",
        "nmi",
        "t",
        "kg",
        "g",
        "mg",
        "ug",
        "lb",
        "oz",
        "st",
        "m3",
        "L",
        "dL",
        "cL",
        "mL",
        "gal_us",
        "qt_us",
        "pt_us",
        "floz_us",
        "gal_uk",
        "K",
        "C",
        "F"
       ],
       "type": "string"
      },
      "valeur": {
       "type": "number"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "notes": [
   "Résultat arrondi à 12 chiffres significatifs.",
   "Les facteurs utilisés sont des valeurs de définition exactes, pas des approximations."
  ],
  "preuve": {
   "note": "L'horodatage `calcule_le` est volontairement exclu de l'empreinte.",
   "empreinte": "110e8bee04129dd94951c2ff11d7a73c156675522ee3bc5b266f18e585eceacf",
   "algorithme": "SHA-256",
   "chaine_hachee": "{\"entrees\":{\"de\":\"km\",\"famille\":\"longueur\",\"valeur\":100,\"vers\":\"mi\"},\"formule_expression\":\"v' = v × (k_source / k_cible)\",\"operation\":\"conversion\",\"resultat\":{\"facteur_applique\":0.621371192237,\"unite\":\"mi\",\"unite_de_base\":\"m\",\"valeur_convertie\":62.1371192237,\"valeur_en_unite_de_base\":100000},\"version_formule\":\"conversion-unites@1.0.0\"}",
   "champs_couverts": [
    "operation",
    "version_formule",
    "entrees",
    "resultat",
    "formule_expression"
   ],
   "canonicalisation": "JSON à clés triées récursivement, sans espace, encodé en UTF-8"
  },
  "entrees": {
   "de": "km",
   "vers": "mi",
   "valeur": 100,
   "famille": "longueur"
  },
  "formule": {
   "reference": "Facteurs impériaux exacts de l'accord international sur le yard et la livre (1959) ; mille marin = 1852 m (BIPM/OHI).",
   "variables": {
    "v": "valeur d'entrée",
    "v'": "valeur convertie",
    "k_cible": "facteur de « mi » vers m = 1609.344",
    "k_source": "facteur de « km » vers m = 1000"
   },
   "expression": "v' = v × (k_source / k_cible)",
   "description": "Conversion multiplicative via l'unité SI de base (m)."
  },
  "service": "coprocesseur-deterministe",
  "resultat": {
   "unite": "mi",
   "unite_de_base": "m",
   "facteur_applique": 0.621371192237,
   "valeur_convertie": 62.1371192237,
   "valeur_en_unite_de_base": 100000
  },
  "operation": "conversion",
  "calcule_le": "2026-08-16T08:29:39.319Z",
  "version_formule": "conversion-unites@1.0.0",
  "version_service": "1.0.0"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coprocesseur-d-terministe-conversion-d-unit-s-6616cee9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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