# Working with JSON in Custom Actions

When configuring a Custom Action that expects a response, Adalo requires the response body to be valid **JSON**. If the JSON is not structured correctly, Adalo will not parse it into outputs and may instead display the entire response as a text blob.

#### ✅ JSON Rules

1. **Content Type**\
   The response must be returned with the header:

   ```
   Content-Type: application/json
   ```
2. Responses must always start with `{` and end with `}`.
3. Each key must be wrapped in double quotes:

   ```json
   { "key": "value" }
   ```
4. Multiple key/value pairs are separated by commas:

   ```json
   {
     "image_url": "https://example.com/image.jpg",
     "status": "ok"
   }
   ```
5. The last key/value pair should **not** end with a trailing comma.

***

#### **🧠 General JSON Formatting Rules**

When building a Custom Action body, make sure your data types are written correctly. JSON is strict about which values need quotes.

1. **Strings and Dates**\
   Use **double quotes** around all text and date values.

   ```json
   { "name": "Taylor", "city": "Denver", "date_joined": "2025-10-28" } // ✅ Correct  
   { name: Taylor, city: Denver } // ❌ Missing quotes  
   { "date_joined": 2025-10-28 }  // ❌ Dates must be strings
   ```
2. **Numbers and Booleans**\
   Do **not** use quotes around numbers or true/false values.

   ```json
   { "age": 32, "isMember": true } // ✅ Correct  
   { "age": "32", "isMember": "true" } // ❌ Incorrect — numbers and booleans should not be quoted
   ```
3. **Null Values**\
   Use `null` (without quotes) when a property has no value.

   ```json
   { "nickname": null } // ✅ Correct  
   { "nickname": "null" } // ❌ Incorrect — this is a string, not null
   ```

***

#### ⚡ Common Pitfalls

1. **Escaped JSON**

   ```json
   "{ \"image_url\": \"https://example.com\" }"
   ```

   This looks correct, but it’s actually a JSON *string* containing escaped characters. Adalo will not parse this.

   ✅ Fix: remove the wrapping quotes and escapes.
2. **Missing or Extra Commas**

   ```json
   { "a": 1 "b": 2 }   // ❌ Missing comma
   { "a": 1, "b": 2, } // ❌ Trailing comma
   ```

   Both will cause parsing errors.
3. **Incorrect or Missing Quotes**\
   JSON requires that property names and string values are enclosed in **double quotes**. Using single quotes or missing quotes will cause the request to fail.

   ```json
   { name: "John" }   // ❌ Missing quotes around key  
   { 'name': 'John' } // ❌ Single quotes not valid in JSON  
   { "name": "John" } // ✅ Correct format  
   ```

   Always use **double quotes** for both keys and string values.
4. **Improper Nesting or Unclosed Brackets**\
   Ensure every opening bracket `{` or `[` has a matching closing one.

   ```json
   { "user": { "name": "John", "email": "john@example.com" } } // ✅ Correct  
   { "user": { "name": "John", "email": "john@example.com" }   // ❌ Missing closing bracket  
   ```

***

#### 📌 Best Practices

* Always test the response in a JSON validator before using it in Adalo.
* Keep keys simple and use lowercase with underscores (e.g., `image_url`, `ok`, `message`).
* Configure matching **Outputs** in Adalo with the same names and types as the JSON keys.

***

✨ In short: Adalo will only recognize outputs if the response is valid JSON with proper formatting and the correct Content-Type header.