---
name: http_get_json
kind: function
lang: go
domain: infra
version: "1.0.0"
purity: impure
signature: "func HttpGetJSON(url string, headers map[string]string, timeout time.Duration) (map[string]any, error)"
description: "GET request que espera JSON. Agrega Accept: application/json automaticamente. Retorna error con status code si >= 400. Siempre cierra body con defer."
tags: [http, json, get, client, network, stdlib, infra, pendiente-usar, extractor]
uses_functions: []
uses_types: []
returns: []
returns_optional: false
error_type: "error_go_core"
imports: ["encoding/json", "fmt", "io", "net/http", "time"]
params:
  - name: url
    desc: "URL del endpoint HTTP a consultar"
  - name: headers
    desc: "mapa de headers custom a incluir en la solicitud"
  - name: timeout
    desc: "duracion maxima para completar la solicitud"
output: "mapa con la estructura JSON decodificada del response"
tested: true
tests:
  - "httptest.Server con respuesta JSON"
  - "Status 404 → error"
  - "Timeout → error"
  - "Headers custom"
test_file_path: "functions/infra/http_get_json_test.go"
file_path: "functions/infra/http_get_json.go"
---

## Ejemplo

```go
result, err := HttpGetJSON(
    "https://api.example.com/users",
    map[string]string{"X-Api-Key": "secret"},
    10*time.Second,
)
if err != nil {
    return nil, err
}
fmt.Println(result["total"])
```

## Notas

Solo usa stdlib (net/http, encoding/json). El timeout se configura en el http.Client. El error incluye los primeros 200 bytes del body para facilitar debugging. Los headers custom se fusionan con Accept: application/json (custom tiene precedencia).