SheetBoard

1. Market opportunity

Small teams outgrow their tracker spreadsheet but stop at per-seat prices and setup effort of big project tools. SheetBoard keeps the sheet they already have and turns it into a shared board in a minute.

Who pays: 3–10 person teams running work in a spreadsheet

Evidence we found

• r/smallbusiness: a 5–10 person team has 'outgrown spreadsheets but don't want the complexity (and cost) of big PM suites'. — reddit r/smallbusiness
• r/smallbusiness: per-user pricing for a 6-person team reaches £50–£80+/month; the poster asks whether a flat subscription would be preferred. — reddit r/smallbusiness
• r/projectmanagement (28 upvotes, 35 comments): user likes monday.com's 'database and spreadsheet hybrid' but says per-seat pricing is not freelancer-friendly. — reddit r/projectmanagement
• Plaky: Free plan with unlimited users; Pro $3.99/seat/month annual ($4.99 monthly); every invited user occupies a paid seat. — plaky.com/pricing
• Zuuna markets spreadsheet-to-kanban import: 'Most projects start life as a spreadsheet: one row per task, a Status column, and eventually five copies.' Free plan capped at 100 cards. — zuuna.de tutorial

2. Business potential

Market gaps to win

• Auto-detected spreadsheet-to-board import (no manual mapping) as the first-run experience, not a buried feature.
• One flat workspace price with unlimited members — per-seat totals are the most repeated complaint.
• Round-trip back to Excel so teams never feel locked in.

4. Build preview — full prompt

Paste it into Lovable and try it yourself.

# SheetBoard — Prompt 1 of 4: Product foundations & architecture

Turn your team's existing spreadsheet into a shared board in 60 seconds — one flat price, unlimited teammates.

## Goal
Creates: secure sign-in, multi-team workspaces with roles and invites, the full board/card data model with row-level security, and server functions for import, moving cards and export.

Build the foundation of SheetBoard: a web app that turns a team's existing spreadsheet into a shared kanban board, billed as one flat price per workspace.

AUTH
- Use Lovable Cloud authentication (email + password and Google). Never create a users table with passwords; store profile data in `profiles(id uuid pk references auth.users, display_name, avatar_url, created_at)` filled by a signup trigger.

MULTI-TENANT DATA (all tables have RLS enabled)
- `workspaces(id, name, owner_id, plan text default 'free', card_limit int default 200, created_at)`
- `workspace_members(workspace_id, user_id, role text check in ('owner','member'), joined_at, primary key(workspace_id,user_id))`
- `workspace_invites(id, workspace_id, token text unique, created_by, expires_at, revoked_at)`
- `boards(id, workspace_id, name, source_filename, created_by, created_at)`
- `board_columns(id, board_id, name, position int, color text)`
- `cards(id, board_id, column_id, title, assignee_id null, due_date date null, position numeric, created_at, updated_at)`
- `card_fields(id, board_id, name, kind text check in ('text','number','date','select'), position)`
- `card_values(card_id, field_id, value text, primary key(card_id, field_id))`
- `import_jobs(id, board_id, filename, rows_total, rows_imported, rows_failed, mapping jsonb, created_by, created_at)`
- `activity_log(id, workspace_id, board_id, card_id null, actor_id, action text, detail jsonb, created_at)`

ACCESS RULES
- Create a SECURITY DEFINER function `is_workspace_member(ws uuid)` and use it in every policy; only members read/write rows of their workspace. Only `owner` may rename/delete the workspace, revoke invites or change plan.
- Joining via invite happens through a server function that validates token, expiry and revocation, then inserts the membership.
- On first login create a personal workspace automatically and make the user its owner.

SERVER FUNCTIONS
- `createBoardFromImport({workspaceId, name, columns[], fields[], rows[]})` inserts board, columns, fields, cards and values in one transaction, enforces `card_limit`, writes an import_jobs row and returns failed row indexes.
- `moveCard({cardId, columnId, position})` and `exportBoard({boardId})` (returns rows for XLSX download).

SCREENS (functional, minimal styling for now): sign-in, workspace switcher, empty "Import your first sheet" state, board list.


## Acceptance criteria
- A new user gets a personal workspace and owner role on first login.
- A user of workspace A cannot read any row of workspace B (verified by test).
- createBoardFromImport inserts 500 rows in one call and reports failed rows.
- No table stores passwords.

## Do NOT
- Store passwords or roles on profiles.
- Use client-side checks as the only access control.

## How to verify it is done
- Sign in as two users in different workspaces and confirm isolation.
- Call createBoardFromImport with a row over card_limit and confirm it is rejected.