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Overview

When using for loop actions in Agent.ai, you might run into issues if you’re working with multi-select dropdowns. The problem usually comes down to format: for loop expects a very specific type of input, and the raw output from a multi-dropdown list might not be an exact match. This guide walks you through how to inspect your input, transform it using a built-in LLM, and successfully run a loop with multi-dropdown values.

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Required Format for for loop

Agent.ai’s for loop requires a plain list of strings in the following format: 
["item1", "item2", "item3"]
Unspecified
  • Must include square brackets []
  • Each item must be in quotes
  • Items must be separated by commas
Structured JSON (e.g., objects with ) will not work directly.

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Step 1: Inspect Multi-Dropdown Output

Multi-dropdown inputs do not return a list of strings. Instead, you’ll get a list of objects that looks like this: 
[  
  {"label": "LinkedIn", "value": "LinkedIn"},
  {"label": "Twitter", "value": "Twitter"}
]
To verify this, add a Create Output action immediately after your multi-dropdown input and display the variable. This lets you confirm the exact format before using it in a loop.

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Step 2: Transform the Input

To convert this into a usable format, insert an LLM action before the the loop action. Use a prompt that extracts only the value fields and returns a plain list of strings.

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Example Prompt

You will receive a JSON array of objects. Each object has a “label” and “value.” Your task:
  • Extract the “value” from each object
  • Return a plain Python list of strings
  • No extra text, no code block formatting, no JSON structure
  • Only output something like: [“LinkedIn”, “Twitter”]

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Step 3: Use the Transformed List

Once the LLM returns the cleaned-up list, pass it into your for loop action. The loop should now work as expected. Have questions or need help with your agent? Reach out to our support team or community.