TimeStitch - Auto-Capture Billable Work from Calendar and Email

Acceptance Criteria

Calendar Sync: done when user authorizes Google Calendar and activities appear in daily digest within 30 minutes of calendar event creation. Email Detection: done when flagged or starred emails are parsed and included in digest with > 70% accuracy. Confirmation Workflow: done when user can confirm all activities with 3 clicks and data persists in Supabase. Export: done when CSV downloads and matches confirmed activities exactly. Payment: done when Stripe checkout converts free user to paid and access persists after renewal.

How to build it, step by step

1. Bootstrap: `npx create-next-app@latest timestitch --typescript --app` then `npm install @slack/bolt @supabase/supabase-js stripe ai zod node-cron resend`. 2. Supabase schema: create tables — `users (id, slack_user_id, google_refresh_token, stripe_customer_id, plan)`, `calendar_activities (id, user_id, event_id, title, start_time, end_time, client_tag, project_tag, confirmed, billable, source)`, `daily_digests (id, user_id, date, sent_at, confirmed_at)`. Enable RLS on all tables with `auth.uid() = user_id` policies. 3. Google Calendar OAuth: create `/app/api/auth/google/route.ts` using googleapis npm package — request scopes `calendar.readonly` and `gmail.readonly`, store refresh token encrypted in `users.google_refresh_token` via Supabase service role client. 4. Slack app setup: on api.slack.com create app with Bot Token Scopes `chat:write`, `im:write`, `users:read`. Enable Event Subscriptions pointing to `/api/slack/events`. Use Slack Bolt in `/app/api/slack/events/route.ts` to handle `app_home_opened` and `block_actions` events. 5. Calendar sync cron: in `/app/api/cron/sync/route.ts` use `node-cron` to schedule `0 7 * * *` — for each user with a valid refresh token, call Google Calendar API `events.list` with `timeMin=today 00:00` and `timeMax=today 23:59`, insert new events into `calendar_activities` with `confirmed=false`. Secure endpoint with `CRON_SECRET` header check. 6. Claude parsing endpoint: create `/app/api/parse/route.ts` — POST receives array of raw calendar event titles and email subjects, calls Claude API via Vercel AI SDK `generateObject()` with a Zod schema `z.object({ activities: z.array(z.object({ title: z.string(), estimated_minutes: z.number(), likely_billable: z.boolean(), suggested_client: z.string().optional() })) })`. System prompt: 'You are a billing assistant for hourly professionals. Given these calendar events and email subjects, identify which are likely billable client work, estimate duration, and suggest client name from context.' 7. Slack digest delivery: after cron sync, build a Slack Block Kit message with a `section` block per activity showing title/duration and `confirm` + `edit` buttons using `actions` blocks. Use `client.chat.postMessage` to DM each user. Store `message_ts` in `daily_digests` for later updates. 8. Block Kit confirm/edit modal: use Slack Block Kit Builder (block.kitbuilder.com) to design the edit modal with `plain_text_input` for client tag, `static_select` for project, and `timepicker` for duration override. Handle `view_submission` in Bolt to update `calendar_activities` row. 9. Stripe billing: create `/api/stripe/checkout` that calls `stripe.checkout.sessions.create` with `price_id` for $49/month solo plan. Create `/api/stripe/webhook` to handle `customer.subscription.created` and `customer.subscription.deleted` events — update `users.plan` accordingly. Test with `stripe listen --forward-to localhost:3000/api/stripe/webhook`. 10. CSV export: create `/app/api/export/route.ts` — query confirmed activities for date range, format as RFC 4180 CSV with columns `date,client,project,hours,description`, return with `Content-Type: text/csv` and `Content-Disposition: attachment` headers. 11. Basic dashboard: use shadcn/ui BarChart component (built on Recharts) to display weekly confirmed hours grouped by client — query Supabase `calendar_activities` grouped by `client_tag` and `date`. 12. Deploy: push to GitHub, connect Vercel, set env vars (`SLACK_BOT_TOKEN`, `SLACK_SIGNING_SECRET`, `GOOGLE_CLIENT_ID`, `GOOGLE_CLIENT_SECRET`, `ANTHROPIC_API_KEY`, `SUPABASE_SERVICE_ROLE_KEY`, `STRIPE_SECRET_KEY`, `STRIPE_WEBHOOK_SECRET`, `CRON_SECRET`). Add Vercel Cron Job in `vercel.json` pointing to `/api/cron/sync` at `0 7 * * *`.