Agent + Actions send a JSON as a string and not as an object

[chunkete]

Hi All, I am building and agent that I expect to send a JSON as an object to then handle it in other app. This is created as an Action.

The agent is working well and defining well the JSON, I asked it to write it in the chat box, the issue is when sending, it sends it as an String not as an object, see below:

{
  "input": "{\n\"tipo_registro\": \"comida\",\n\"fecha\": \"\",\n\"hora\": \"21:00\",\n\"tipo_comida\": \"cena\",\n\"alimentos\": \"arandanos\",\n\"lactosa\": \"No\",\n\"gluten\": \"No\",\n\"agua_ml\": 500,\n\"notas\": \"\"\n}"
}

I have asked the LLM for the function it is using, and it is the following:

{
    "description": "Envía un JSON al webhook de Make", 
    "name": "enviarMake_action_aG9vay5ldT", 
    "parameters": {
        "$schema": "http://json-schema.org/draft-07/schema#", 
        "additionalProperties": false, 
        "properties": {
            "input": {"type": "string"}
        }, 
        "type": "object"
    }
}

In the actions UI I cannot modify the properties, and I don't know where this function is stored to modify it.

What my app is receiving is the following:

[
    {
        "0": "{",
        "1": "\"",
        "2": "t",
        "3": "i",
        "4": "p",
        "5": "o",
        "6": "_",
        "7": "r",
        "8": "e",
        "9": "g",
        "10": "i",
        "11": "s",
        "12": "t",
        "13": "r",
        "14": "o",
        "15": "\"",
        "16": ":",
        "17": "\"",
        "18": "c",
        "19": "o",
        "20": "m",
        "21": "i",
        "22": "d",
        "23": "a",
        "24": "\"",
        "25": ",",
        "26": "\"",
        "27": "f",
        "28": "e",
        "29": "c",
        "30": "h",
        "31": "a",
        "32": "\"",
        "33": ":",
        "34": "\"",
        "35": "\"",
        "36": ",",
        "37": "\"",
        "38": "h",
        "39": "o",
        "40": "r",
        "41": "a",
        "42": "\"",
        "43": ":",
        "44": "\"",
        "45": "2",
        "46": "1",
        "47": ":",
        "48": "0",
        "49": "0",
        "50": "\"",
        "51": ",",
        "52": "\"",
        "53": "t",
        "54": "i",
        "55": "p",
        "56": "o",
        "57": "_",
        "58": "c",
        "59": "o",
        "60": "m",
        "61": "i",
        "62": "d",
        "63": "a",
        "64": "\"",
        "65": ":",
        "66": "\"",
        "67": "c",
        "68": "e",
        "69": "n",
        "70": "a",
        "71": "\"",
        "72": ",",
        "73": "\"",
        "74": "a",
        "75": "l",
        "76": "i",
        "77": "m",
        "78": "e",
        "79": "n",
        "80": "t",
        "81": "o",
        "82": "s",
        "83": "\"",
        "84": ":",
        "85": "\"",
        "86": "a",
        "87": "r",
        "88": "a",
        "89": "n",
        "90": "d",
        "91": "a",
        "92": "n",
        "93": "o",
        "94": "s",
        "95": "\"",
        "96": ",",
        "97": "\"",
        "98": "l",
        "99": "a",
        "100": "c",
        "101": "t",
        "102": "o",
        "103": "s",
        "104": "a",
        "105": "\"",
        "106": ":",
        "107": "\"",
        "108": "N",
        "109": "o",
        "110": "\"",
        "111": ",",
        "112": "\"",
        "113": "g",
        "114": "l",
        "115": "u",
        "116": "t",
        "117": "e",
        "118": "n",
        "119": "\"",
        "120": ":",
        "121": "\"",
        "122": "N",
        "123": "o",
        "124": "\"",
        "125": ",",
        "126": "\"",
        "127": "a",
        "128": "g",
        "129": "u",
        "130": "a",
        "131": "_",
        "132": "m",
        "133": "l",
        "134": "\"",
        "135": ":",
        "136": "5",
        "137": "0",
        "138": "0",
        "139": ",",
        "140": "\"",
        "141": "n",
        "142": "o",
        "143": "t",
        "144": "a",
        "145": "s",
        "146": "\"",
        "147": ":",
        "148": "\"",
        "149": "\"",
        "150": "}"
    }
]

Any idea on how to send it correctly? What am i doing wrong?

Thank you

[tnsai]

Post the OpenAPI spec for your Action and someone might be able to help you.

[chunkete]

Here you go:

openapi: 3.0.0
info:
title: Envío a Make Webhook
version: 1.0.0
servers:

• url: xxxxxx
  paths:
  /xxxxxx:
  post:
  operationId: enviarMake
  summary: Envía un JSON al webhook de Make
  requestBody:
  required: true
  content:
  application/json:
  schema:
  type: object
  additionalProperties: true
  responses:
  '200':
  description: OK

[tnsai]

Yep, your JSON was split into Make bundles at the receiving end because a) your OpenAPI spec is incorrect and b) your Make Webhook probably has 'JSON pass-through' set to Yes.

If you give your favorite LLM a curl request that you know works with your Make webhook, and ask it to generate an OpenAPI 3.0.0 from it, you should get a usable spec that you can then paste into your Action instead.

Next, make sure your Make Webhook has JSON pass-through set to No (in 'Show advanced settings' when you Edit the Webhook).

[chunkete]

Thank you for your response.

a) I have changed the OpenAPI scheme, with a different one proposed by Claude with a working curl and it still have the same behaviour.

This curl command works and send a correct object to Make

curl -X POST https://hook.eu2.make.com/xxx \
  -H "Content-Type: application/json" \
  -d '{
    "tipo_registro": "comida",
    "fecha": "",
    "hora": "",
    "tipo_comida": "comida",
    "alimentos": "2 trozos pequeños de empanada de atún, camarones, salmorejo, trozos pequeño de tarta De Santiago",
    "lactosa": "No",
    "gluten": "Sí",
    "agua_ml": 1000,
    "notas": ""
  }'

b) pass-through is deactivated

What I am able to find asking the LLM is that the description of the function requires a string:

`{
    "description": "Envía un registro variable al webhook", 
    "name": "enviarJSON_action_aG9vay5ldT", 
    "parameters": {
        "$schema": "http://json-schema.org/draft-07/schema#", 
        "additionalProperties": false, 
        "properties": {
            "input": {
                "type": "string"
            }
        }, 
        "type": "object"
    }
}`

The new OpenApi is:

openapi: 3.0.0
info:
  title: Webhook Registro Variable
  version: '1.0'
  description: >
    Endpoint para registrar diferentes tipos de eventos: resumen diario, comida o deposición.
paths:
  /:
    post:
      operationId: enviarJSON
      summary: Envía un registro variable al webhook
      requestBody:
        required: true
        content:
          application/json:
            schema:
              oneOf:
                - type: object
                  required:
                    - tipo_registro
                    - fecha
                    - dolor_abdominal
                    - hinchazon
                    - numero_deposiciones
                    - gases
                    - dolor_articular_0_10
                    - dolor_cabeza_0_10
                    - nivel_malestar_global_0_10
                    - actividad_del_dia_baja_media_alta
                    - notas
                  properties:
                    tipo_registro:
                      type: string
                      enum: [resumen_dia]
                      example: resumen_dia
                    fecha:
                      type: string
                      format: date
                      example: "2025-08-22"
                    dolor_abdominal:
                      type: integer
                      example: 0
                    hinchazon:
                      type: integer
                      example: 0
                    numero_deposiciones:
                      type: integer
                      example: 0
                    gases:
                      type: string
                      example: nada
                    dolor_articular_0_10:
                      type: integer
                      example: 0
                    dolor_cabeza_0_10:
                      type: integer
                      example: 0
                    nivel_malestar_global_0_10:
                      type: integer
                      example: 0
                    actividad_del_dia_baja_media_alta:
                      type: string
                      enum: [baja, media, alta]
                      example: media
                    notas:
                      type: string
                      example: ""
                
                - type: object
                  required:
                    - tipo_registro
                    - fecha
                    - hora
                    - tipo_comida
                    - alimentos
                    - lactosa
                    - gluten
                    - agua_ml
                  properties:
                    tipo_registro:
                      type: string
                      enum: [comida]
                      example: comida
                    fecha:
                      type: string
                      format: date
                      example: "2024-01-22"
                    hora:
                      type: string
                      pattern: "^([01]\\d|2[0-3]):([0-5]\\d)$"
                      example: "12:45"
                    tipo_comida:
                      type: string
                      example: merienda
                    alimentos:
                      type: string
                      example: cafe con leche sin lactosa
                    lactosa:
                      type: string
                      enum: [Sí, No]
                      example: No
                    gluten:
                      type: string
                      enum: [Sí, No]
                      example: No
                    agua_ml:
                      type: integer
                      example: 0
                    notas:
                      type: string
                      example: ""
                
                - type: object
                  required:
                    - tipo_registro
                    - subtipo
                    - fecha
                    - hora
                    - bristol_1_7
                    - urgencia
                    - dolor_durante
                    - incontinencia_0_1
                    - cantidad_peq_med_grande
                    - sensacion_vaciado_completo_0_1
                    - notas
                  properties:
                    tipo_registro:
                      type: string
                      enum: [deposicion]
                      example: deposicion
                    subtipo:
                      type: string
                      example: deposicion
                    fecha:
                      type: string
                      format: date
                      example: "2025-08-22"
                    hora:
                      type: string
                      pattern: "^([01]\\d|2[0-3]):([0-5]\\d)$"
                      example: "14:00"
                    bristol_1_7:
                      type: integer
                      minimum: 1
                      maximum: 7
                      example: 4
                    urgencia:
                      type: integer
                      example: 0
                    dolor_durante:
                      type: integer
                      example: 0
                    incontinencia_0_1:
                      type: string
                      enum: [Sí, No]
                      example: No
                    cantidad_peq_med_grande:
                      type: string
                      enum: [peq, med, grande]
                      example: med
                    sensacion_vaciado_completo_0_1:
                      type: string
                      enum: [Sí, No]
                      example: Sí
                    notas:
                      type: string
                      example: ""
      responses:
        '200':
          description: Registro recibido correctamente
servers:
  - url: xxxxx

Any other idea?