The Scenario
You are a CRM analyst. You have a Google Sheet with 200 rows mapping Resend contact emails to segment names. Column A is email, column B is segment name.
The marketing team set up the segments in Resend last week. Now every contact needs to be placed in its correct segment before the targeted campaign goes out Friday.
The bad version:
- You ask the developer to write a script to look up contact IDs and segment IDs from Resend, then add each contact to the right segment
- She estimates two hours. It takes four because the Resend API requires the contact ID, not the email, to add someone to a segment
- The script looks up all 200 contact IDs, then all the segment IDs, then iterates through the mapping
- Halfway through, it errors out on a segment name that has a trailing space in the sheet
- You go into the weekend with half the contacts in the wrong place and no time to fix it.
The fast version is one prompt.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent inside your Google Sheet that reads the mapping, looks up the IDs in Resend, and assigns every contact in one pass.
Open the SheetXAI sidebar and type:
For each row in the SegmentAssignments sheet (A=contact email, B=segment name), look up the contact ID and segment ID in Resend and add the contact to that segment. Write "added" or the error message into column C for each row.
SheetXAI iterates through all 200 rows, resolves the contact and segment IDs from Resend, fires the assignment for each one, and logs the result in column C. Two hundred assignments, one prompt, column C filled with "added" for every clean row and the exact error for anything that did not work.
What You Get
A completed sheet with:
- Column A — emails, untouched
- Column B — segment names, untouched
- Column C — "added" or the Resend error message for each row
The error column tells you exactly what broke and why, so you are not guessing at 200 rows. If one segment name was misspelled, the error in column C says "segment not found" for that row and the rest succeed.
The segments are populated and ready for the Friday campaign. You do not need to check the Resend dashboard; the sheet tells you what happened.
What If the Data Is Not Quite Ready
Segment mapping sheets are rarely clean. SheetXAI handles the data issues and the assignments in the same prompt.
When segment names in the sheet do not exactly match Resend segment names
Some rows say "Early Adopters," others say "early adopters" or "Early adopters." Resend's API is case-sensitive.
Normalize the segment names in column B to title case before looking them up in Resend. For each row in SegmentAssignments, match the normalized name to the Resend segment, add the contact, and write the result in column C.
When some contacts do not exist in Resend yet
A few emails in column A are new and were never added to the Resend contact list.
For each row in SegmentAssignments, look up the contact in Resend. If the contact does not exist, create it first using the email in column A. Then add the contact to the segment in column B and write the result in column C.
When you only want to assign contacts to high-priority segments first
Column C has a priority flag ("high" or "normal") and you want to run the high-priority assignments first as a test.
Filter the SegmentAssignments sheet to rows where column C equals "high". For each filtered row, look up the contact and segment IDs in Resend and add the contact to the segment. Log the result in column D.
When the sheet has duplicates, missing segments, and unregistered contacts all mixed together
The mapping came from three different sources and was never cleaned. You want everything handled in one go.
Look at the SegmentAssignments sheet. Remove duplicate rows where both column A and column B are identical. For each unique row, look up the contact in Resend by email. If the contact does not exist, create it. Then look up the segment by name in column B. If the segment does not exist, write "segment not found" in column C and skip. Otherwise add the contact to the segment and write "added" in column C.
The pattern: the lookup, the error handling, and the assignment all happen in one prompt. No script required.
Try It
Get the 7-day free trial of SheetXAI and open any sheet with email-to-segment mappings, then ask it to run the Resend assignments. The Resend integration is included in every SheetXAI plan. See also how to bulk-remove contacts from segments or the Resend in Google Sheets overview.