Syntax for Outputting an Array in GROQ

The issue is that you're using JavaScript template literal interpolation ('${ids}') which converts your array to a comma-separated string. Instead, you should pass the array as a GROQ parameter.

The correct syntax is:

*[_type == 'portfolio' && _id in $ids]

Then pass your array as a parameter when executing the query:

const ids = [
  '416927ba-3c52-40f9-b3eb-c41d18010b29',
  'c34dedda-4325-49c6-8270-08084c867213',
  'aff6dd72-add1-44e0-bc14-784a8f5fba98',
  'bb15831f-c31f-4020-bf20-157d97ab278f'
]

const result = await sanityClient.fetch(
  `*[_type == 'portfolio' && _id in $ids]`,
  { ids }
)

Why this happens:

When you use '${ids}' in a template literal, JavaScript converts the array to a string using .toString(), which joins array elements with commas. This creates a single string value instead of an array, resulting in the malformed query you're seeing.

Why parameters are better:

Using GROQ parameters with the $ syntax:

• Maintains proper data types (your array stays an array)
• Prevents GROQ injection vulnerabilities
• Automatically handles proper escaping
• Makes your queries cleaner and more maintainable

The Sanity client handles all the encoding automatically when you pass parameters as the second argument to fetch(), so you don't need to worry about converting the array yourself.