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What It Does

The JavaScript Code node executes a JS snippet in an isolated environment with no access to the network or file system. Use it when data transformations become too complex for {{ }} expressions, or when you need conditional logic, iteration, or string manipulation that other nodes do not cover natively. Typical use cases:
  • Transform the structure of a JSON returned by an external API
  • Validate fields and throw descriptive errors when data is missing
  • Calculate derived values (discount, due date, hash)
  • Combine data from multiple upstream nodes into a single object
  • Format strings: masked IDs, localized dates, URL slugs

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Input and Output

Variables available in the code scope:
VariableTypeDescription
inputanyOutput of the immediately preceding node ($json)
triggerobjectFull trigger payload (body, headers, query, method)
varsobjectWorkflow variables defined by Set Variable nodes
Output: the value returned via return is exposed as $json to downstream nodes. It can be an object, array, string, number, or boolean.

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Configuration

1

Add the node to the flow

In the component palette, select Actions > JavaScript Code and drag it onto the canvas.
2

Write the code in the editor

The editor accepts modern JavaScript (ES2020+). Use return to define the node’s output.Auto-generated starter template:
// Access input data via 'input'
// Return the result with 'return'

const data = input;

const result = {
  processed: true,
  original:  data,
  timestamp: new Date().toISOString()
};

return result;
3

Reference flow variables

Do not use {{ }} expressions inside JS code — access data through the global variables:
// Correct
const nome = trigger.body.cliente.nome;
const plano = vars.plano_selecionado;

// Incorrect — {{ }} is not interpolated inside the JS editor
const nome = "{{ $trigger.body.cliente.nome }}";
4

Use console.log for debugging

console.log() is available and logs appear in the node’s execution panel during tests. In production, logs are discarded.
5

Test the node

Click Test in the node panel. The runtime executes the code with the pinned output data from upstream nodes and displays the result and execution duration.

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Available APIs

The runtime is isolated — there is no access to the network, file system, or environment variables. The available JavaScript APIs are:
APIAvailable
JSON.parse() / JSON.stringify()yes
Math.*yes
Dateyes
RegExpyes
Array.* / Object.* / String.*yes
console.log()yes (debug only)
fetch() / XMLHttpRequestno
fs / path / Node.js modulesno
setTimeout / setIntervalno
require() / importno

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Examples

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Transform API response structure

The external API returns a format different from what downstream nodes expect. 
{
  "status": 200,
  "body": {
    "data": {
      "customer_id":    "C-4821",
      "full_name":      "Ana Lima",
      "contact_email":  "ana@empresa.com",
      "is_premium":     true,
      "created_at":     "2025-01-15T10:30:00Z"
    }
  }
}

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Format and validate a CPF

const cpfRaw = trigger.body.cpf || '';
const numeros = cpfRaw.replace(/\D/g, '');

if (numeros.length !== 11) {
  return { valido: false, cpf: null, erro: 'CPF deve ter 11 dígitos' };
}

const cpfFormatado = numeros.replace(
  /(\d{3})(\d{3})(\d{3})(\d{2})/,
  '$1.$2.$3-$4'
);

return { valido: true, cpf: cpfFormatado, erro: null };
The downstream Condition node checks {{ $json.valido }} and routes to the error path when false.

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Calculate a due date

const diasParaVencer = vars.prazo_dias || 30;
const hoje = new Date();
hoje.setDate(hoje.getDate() + Number(diasParaVencer));

return {
  vencimento_iso: hoje.toISOString().split('T')[0],
  vencimento_br:  hoje.toLocaleDateString('pt-BR'),
  dias_restantes: Number(diasParaVencer)
};

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Combine data from multiple nodes

When you need to assemble an object with fields coming from different nodes (HTTP, LLM, and trigger), use the JavaScript node as a consolidation point before sending. 
// Data from the trigger
const cliente = trigger.body.cliente;

// Output of the HTTP node (saved to a variable via Set Variable node)
const pedido = vars.dados_pedido;

// Output of the LLM node (output of the preceding node)
const classificacao = input.result;

return {
  cliente_nome:   cliente.nome,
  cliente_email:  cliente.email,
  pedido_id:      pedido.id,
  pedido_valor:   pedido.valor,
  intencao:       classificacao.intencao,
  prioridade:     classificacao.confianca > 0.8 ? 'alta' : 'normal',
  gerado_em:      new Date().toISOString()
};

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Filter and sort an array

const itens = input.body.itens || [];

const ativos = itens
  .filter(item => item.ativo === true)
  .sort((a, b) => b.valor - a.valor)
  .slice(0, 5);

return {
  total_recebidos: itens.length,
  total_ativos:    ativos.length,
  top5:            ativos
};

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Error Handling

If the code throws an uncaught exception, the node marks the execution as failed and the error appears in the execution logs. To handle errors in a controlled way, use try/catch: 
try {
  const dados = JSON.parse(trigger.body.payload_raw);
  return { sucesso: true, dados };
} catch (err) {
  return { sucesso: false, erro: err.message, dados: null };
}

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Limits

ParameterValue
Execution timeout10 seconds
Network accessNot allowed
File system accessNot allowed
require() / external modulesNot supported
Maximum script sizeNo documented limit
Maximum output size10 MB
Infinite loops or very heavy synchronous operations cause a timeout after 10 seconds. Prefer array processing with Array.map() and Array.filter() instead of while loops without a clear exit condition.

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Next Steps