## Overview

This article covers how to retrieve data via GET requests, transform and manipulate arrays (including editing specific items), and submit the updated data through POST requests in Assembled workflows.

## Core Concepts

### Variables and Data Flow

- Variables are the key to passing data between workflow steps
- Data from GET requests can be stored as variables and referenced throughout your workflow
- Use the `{{variable_name}}` syntax to reference variables in subsequent steps

### The "Analyze case" Step

The "Analyze case" step is your most powerful tool for data manipulation. It can:

- Extract specific values from API responses
- Transform data structures
- Edit array items
- Parse complex JSON objects
- Create new variables from existing data

## Step-by-Step Implementation

### 1. GET Request - Retrieve Data

Set up a Custom API step to fetch your data:

- Configure your GET endpoint
- Map the response to output variables

**Note:** If you want to capture the full response, use JSON path "." to return the entire payload as a single variable.

### 2. Analyze Case - Transform and Edit

Use an Analyze case step to manipulate your data

**Variable configuration**

- Variable Name: Something descriptive and meaningful
- Variable Type: Text
- Description: Clear, specific instructions for the transformation you want to perform

**Example variable descriptions**

Edit single array item:

```auto
Using the data from {{api_response}}, find the artist with id: 2 and update their role_ids to [1, 3, 5]. Keep all other artists unchanged. Return the complete updated artists array.
```

Transform keys + edit array:

```auto
Using {{api_response}}:
1. Rename 'role_ids' to 'assigned_roles' in all artist objects
2. Find the artist named "Artist A" and change their status to "featured"
3. Add a new field 'updated_at' with {{todays_date}} to all artists
4. Return the complete transformed array
```

Multiple array operations:

```auto
Transform {{api_response}} by:
1. Remove any artists where status = "inactive"
2. For all remaining artists, add role_id 99 to their existing role_ids
3. Sort the array by artist name alphabetically
4. Return the final updated artists array
```

Conditional transformations:

```auto
Using {{api_response}}:
- If artist has role_ids [1,2], change to [1,2,3,4]
- If artist name contains "Senior", add role_id 99
- Otherwise, keep existing role_ids unchanged
Return the updated artists array
```

Data type conversions:

```auto
Transform {{api_response}} by:
1. Convert all id fields from strings to numbers
2. Change date fields from "YYYY-MM-DD" to "MM/DD/YYYY" format
3. Ensure role_ids is always an array (convert single values)
4. Return the converted data
```

**Tips for array manipulation**

- Be specific about which item to edit (use ID, name, or position)
- Provide an example of the expected output format
- You can edit multiple items in a single step
- Text variables can return complex JSON structures

### 3. POST Request - Submit Updated Data

Create another Custom API step for your POST request. In the body, reference your transformed variable, for example:

```auto
{
 "artists": "{{updated_artists}}"
}
```

## Testing Your Transformations

Use the **Preview** button in the workflow toolbar and run the workflow with a previous case ID, test email, or test chat. This lets you check how data flows step by step:

1. Verify that `{{api_response}}` contains the expected data
2. Confirm that `{{updated_data}}` reflects the correct transformations
3. Validate the POST payload

**Common validation checks:**

- Array structure is preserved
- Required fields aren't accidentally removed
- Data types match API expectations
- IDs and references remain valid

## Best Practices

**Writing clear instructions**

- Be specific about what to modify
- Use examples of expected output
- Break complex changes into steps
- Call out required data types if the API is strict

**Variable naming**

- Use descriptive names (`updated_artists` not `data`)
- Match your API terminology
- Use multiple variables for more complex transformations

**Error handling**

- Add conditional branches after API calls
- Validate data exists before transforming
- Include fallbacks for missing/malformed data

## Troubleshooting Common Issues

**Variable not found**

- Ensure variable names match exactly between steps
- Check that the GET request completed successfully

**JSON format errors**

- Be explicit about expected format in variable descriptions
- Use the preview feature to validate the outputted structure

**Array reference issues**

- Use unique identifiers (ID, email) rather than array positions
- Handle cases where target items might not exist

## Getting Help

For complex transformations or specific use cases not covered here, reach out to your AI Deployment Strategist team for personalized guidance and implementation support.