Review and approve Lemlist openers before anyone gets enrolled

Build me an app for staging and quality checking a batch of prospects before anyone gets enrolled in a Lemlist campaign. Today that review happens in a spreadsheet with a research tab open beside it. The human approval gate is the whole product here: a reviewer reads and okays every opener before it can be sent, so do not build an auto push path or any way for a row to reach a campaign without a person approving it.

The main screen is a staging table with one row per prospect and columns for name, company, email, opener, status, and campaign. A Load batch control brings prospects in two ways. From Google Sheets, the reviewer picks a spreadsheet and range and maps columns to name, company, and email, and the handler reads it with Get Values. From HubSpot, the reviewer filters a contact search by properties such as lifecycle stage, owner, or created date, and the handler reads it with Search Contacts. Store every loaded batch along with its source so the same list never gets loaded twice: dedupe incoming rows by email address against prospects already staged, and report a count of skipped duplicates after each load.

A Draft openers button kicks off an embedded background agent over the rows the reviewer has selected. For each prospect the agent researches the person and their company on the web, then writes a single personalized one line opener into that prospect's opener column and sets the row status to drafted. Have the agent write each row back as it finishes so the table fills in progressively rather than all at once, and have it save a short note of what it found so the reviewer can sanity check the claim behind the opener. If the agent cannot ground an opener in a real finding, it should leave the opener blank and flag the row rather than invent something.

The reviewer then works the table like a queue: edit any opener inline, then mark the row approved or rejected. The target is a 30 to 60 second review per opener, so keep rows compact and put the opener text, the research note, and the approve and reject controls all within reach without opening a modal. Show running counts of drafted, approved, and rejected across the batch. Approving is what unlocks a prospect for sending, and nothing else in the app may set that status.

A Push approved button enrolls only the approved rows. The reviewer first picks a target campaign from a dropdown populated by List Campaigns. For each approved prospect, check Get Lead by Email first and skip anyone already present in that campaign, then call Create Lead in Campaign with their name, email, and company, populating Lemlist's built in icebreaker field with the approved opener. Icebreaker is a reserved lead field alongside email, firstName, lastName, phone, linkedinUrl, companyName, and companyDomain, so the opener belongs there rather than in a custom variable. Any extra personalization columns the batch carries go through Add Lead Variables as custom variables. Custom variable names cannot collide with a reserved name or with an existing custom variable, so validate the names before creating them.

Track a status on every prospect of drafted, approved, rejected, or pushed. Move a row to pushed only after Lemlist confirms the lead was created, and store the campaign name so the table shows which campaign each prospect landed in. Enforce the approval gate in the handler and not just in the UI: the push handler must refuse any prospect whose status is not approved, and editing an opener after approval should knock the row back to drafted so the new wording gets read before it can go out. Rejected and pushed rows stay visible for the record and are never eligible to be pushed again.

If the batch came from a Google Sheet, offer an optional write back that uses Update Values to put the final status and the approved opener into columns on the source sheet, so the spreadsheet the team already keeps stays in sync with what actually got enrolled.