## TL;DR

Make sure the outer JSON uses double quotes and every inner quote is escaped: build the body as {"query": "mutation { create_item (...) { id } }"} with proper escaping. Fix the nesting and the same mutation returns the new item id. The 500 came from malformed quote nesting in the mutation string.

## The error

```text
Creating a monday.com board item with cURL fails with a 500 error
```

## Fix

1. Make sure the outer JSON uses double quotes and every inner quote is escaped: build the body as {"query": "mutation { create_item (...) { id } }"} with proper escaping.
   Expected: You get the expected result; the problem is gone.
2. Fix the nesting and the same mutation returns the new item id.
   Expected: You get the expected result; the problem is gone.
3. Re-run the original operation and confirm the error is gone.
   Expected: no error, normal output.

## When to use

- You hit this exact error.
- The symptom matches: Creating a monday.com board item with cURL fails with a 500 error.

## When NOT to use

- A different error message; the cause here is specific to this error.
- Unrelated issues with a different cause.
- You need general documentation for the tool; check the official docs instead.

## Compatibility

Reported per the linked source.

## Variant phrasings

### Creating a monday.com board item with cURL fails with a 500 error

## Why it happens

Stack Overflow question: a cURL POST to the monday.com API v2 endpoint with a create_item mutation returns a 500 Internal Error; the mutation JSON was hand-built.

## Edge cases

- If your error message differs even slightly, this is probably a different issue; search the exact text.
- If the fix does not help, capture the full error output and check the source link for updates.