Esquema JSON: extraer una factura española

JSON Schema para extraer una factura española con un LLM: emisor y NIF, número, fecha, líneas, base imponible, IVA y total en euros.

Extrae los datos de la factura. Los importes son números en euros, sin símbolo. Si falta un dato, no lo inventes.

JSON Schema

{
  "type": "object",
  "required": [
    "emisor",
    "fecha",
    "total"
  ],
  "properties": {
    "fecha": {
      "type": "string",
      "format": "date",
      "description": "Fecha de expedición (AAAA-MM-DD)"
    },
    "total": {
      "type": "number"
    },
    "emisor": {
      "type": "string",
      "description": "Razón social del emisor"
    },
    "lineas": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "concepto",
          "importe"
        ],
        "properties": {
          "importe": {
            "type": "number"
          },
          "cantidad": {
            "type": "number"
          },
          "concepto": {
            "type": "string"
          }
        }
      }
    },
    "numero": {
      "type": "string",
      "description": "Número de factura"
    },
    "tipo_iva": {
      "type": "number",
      "description": "Porcentaje de IVA (21, 10 o 4)"
    },
    "cuota_iva": {
      "type": "number"
    },
    "nif_emisor": {
      "type": "string",
      "description": "NIF o CIF del emisor"
    },
    "base_imponible": {
      "type": "number"
    }
  }
}

Output example

{
  "emisor": "Imprenta Gómez S.L.",
  "nif_emisor": "B12345678",
  "numero": "F-2026-0412",
  "fecha": "2026-09-15",
  "lineas": [
    {
      "concepto": "Tarjetas de visita x500",
      "cantidad": 1,
      "importe": 80.0
    },
    {
      "concepto": "Folletos A5 x1000",
      "cantidad": 1,
      "importe": 120.0
    }
  ],
  "base_imponible": 200.0,
  "tipo_iva": 21,
  "cuota_iva": 42.0,
  "total": 242.0
}

Estimated cost

Input tokens per call : ≈ 610

Input cost only, excluding the model's answer. Providers' public standard prices (Mistral AI, DeepSeek, OpenAI, Anthropic) converted from USD to euros at the ECB rate of September 29, 2026. Estimate: 1 token ≈ 3.6 characters.

Identifier

contextetech--extraer-factura-espanola

Type

Output schemas

File

extraer-factura-espanola.schema.json

Format

JSON (application/json)

Size

1,163 bytes (1.1 KB)

Encoding

UTF-8

Estimated tokens

≈ 322

Language

Spanish

License

MIT

Commercial use

Allowed

Personal data

None

Version

1.0

Published on

October 3, 2026 at 5:20 AM

Updated on

October 3, 2026 at 5:20 AM

Storage

in database

Uses

0

Likes

0

extraer-factura-espanola.schema.json

{
  "type": "object",
  "required": [
    "emisor",
    "fecha",
    "total"
  ],
  "properties": {
    "fecha": {
      "type": "string",
      "format": "date",
      "description": "Fecha de expedición (AAAA-MM-DD)"
    },
    "total": {
      "type": "number"
    },
    "emisor": {
      "type": "string",
      "description": "Razón social del emisor"
    },
    "lineas": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "concepto",
          "importe"
        ],
        "properties": {
          "importe": {
            "type": "number"
          },
          "cantidad": {
            "type": "number"
          },
          "concepto": {
            "type": "string"
          }
        }
      }
    },
    "numero": {
      "type": "string",
      "description": "Número de factura"
    },
    "tipo_iva": {
      "type": "number",
      "description": "Porcentaje de IVA (21, 10 o 4)"
    },
    "cuota_iva": {
      "type": "number"
    },
    "nif_emisor": {
      "type": "string",
      "description": "NIF o CIF del emisor"
    },
    "base_imponible": {
      "type": "number"
    }
  }
}

Anthropic API (Python)

import json, anthropic

schema = json.load(open("extraer-factura-espanola.schema.json"))
client = anthropic.Anthropic()
resp = client.messages.create(model="claude-sonnet-5", max_tokens=1024,
    tools=[{"name": "extraire", "description": "Renvoie les données extraites", "input_schema": schema}],
    tool_choice={"type": "tool", "name": "extraire"},
    messages=[{"role": "user", "content": "your input here"}])
print(resp.content[0].input)

OpenAI format (response_format)

{
  "type": "json_schema",
  "json_schema": {
    "name": "extraer-factura-espanola",
    "schema": {
      "type": "object",
      "required": [
        "emisor",
        "fecha",
        "total"
      ],
      "properties": {
        "fecha": {
          "type": "string",
          "format": "date",
          "description": "Fecha de expedición (AAAA-MM-DD)"
        },
        "total": {
          "type": "number"
        },
        "emisor": {
          "type": "string",
          "description": "Razón social del emisor"
        },
        "lineas": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "concepto",
              "importe"
            ],
            "properties": {
              "importe": {
                "type": "number"
              },
              "cantidad": {
                "type": "number"
              },
              "concepto": {
                "type": "string"
              }
            }
          }
        },
        "numero": {
          "type": "string",
          "description": "Número de factura"
        },
        "tipo_iva": {
          "type": "number",
          "description": "Porcentaje de IVA (21, 10 o 4)"
        },
        "cuota_iva": {
          "type": "number"
        },
        "nif_emisor": {
          "type": "string",
          "description": "NIF o CIF del emisor"
        },
        "base_imponible": {
          "type": "number"
        }
      }
    },
    "strict": true
  }
}