Handle Arrays in Code Actions - Twenty Documentation

When working with arrays in Code actions, you may encounter two common challenges:

Arrays passed as strings — data from external systems or previous steps arrives as a string instead of an actual array
Can’t select individual items — you can only select the entire array, not specific fields within it

Both can be solved with a Code node.

Parsing Arrays from Strings

Arrays are often passed between workflow steps as strings or JSON rather than native arrays. This happens when:

Receiving data from external APIs via HTTP Request
Processing webhook payloads
Passing data between workflow steps

Solution: Add this pattern at the start of your Code action:

export const main = async (params: {
  users: any;
}): Promise<object> => {
  const { users } = params;

  // Handle input that may come as a string or an array
  const usersFormatted = typeof users === "string" ? JSON.parse(users) : users;

  // Now you can safely work with usersFormatted as an array
  return {
    users: usersFormatted.map((user) => ({
      ...user,
      activityStatus: String(user.activityStatus).toUpperCase(),
    })),
  };
};

The key line typeof users === "string" ? JSON.parse(users) : users checks if the input is a string, parses it if needed, or uses it directly if it’s already an array.

Extracting Individual Fields from Arrays

A webhook might return an array like answers: [...], but in subsequent workflow steps you can only select the entire array — not individual items within it. Solution: Add a Code node to extract specific fields and return them as a structured object:

export const main = async (params: {
  answers: any;
}): Promise<object> => {
  const { answers } = params;

  // Handle input that may come as a string or an array
  const answersFormatted = typeof answers === "string"
    ? JSON.parse(answers)
    : answers;

  // Extract specific fields from the array
  const firstname = answersFormatted[0]?.text || "";
  const name = answersFormatted[1]?.text || "";

  return {
    answer: {
      firstname,
      name
    }
  };
};

The Code node returns a structured object instead of an array. In subsequent steps, you can now select individual fields like answer.firstname and answer.name from the variable picker.

Want to loop over the array instead of extracting fields? When a Code or Logic Function step returns a top-level array, you can feed it straight into an Iterator: select the step’s Whole list option as the Iterator’s input, then reference each element with {{iterator.currentItem}} inside the loop. In that case you don’t need to restructure the array into an object.

Click the square icon at the top right of the code editor to display it in full screen — helpful since the default editor width is limited.

​Parsing Arrays from Strings

​Extracting Individual Fields from Arrays

Parsing Arrays from Strings

Extracting Individual Fields from Arrays