StackSwap — $29/Month B2B Outreach Stack That Replaces Your $400 Lemlist and Apollo Subscription
Someone on r/automation just proved you can replace a $400/month outreach stack with $15 in tools and some duct tape — StackSwap packages that exact system into a $29/month SaaS so you never have to duct tape it yourself. Lead enrichment, sequenced email, reply detection, and CRM sync — all without the enterprise price tag. Built for solo founders and small agencies who are tired of paying SaaS tax.
Difficulty
intermediate
Category
Sales Automation
Market Demand
Very High
Revenue Score
7/10
Platform
Web App
Vibe Code Friendly
No
Hackathon Score
5/10
Validated by Real Pain
— sourced from real community discussions
Bootstrappers and small agencies report paying $400 or more per month for B2B outreach tool stacks while the core workflow can be replicated with $15 in API costs, creating strong demand for a packaged low-cost alternative.
What is it?
The r/automation post describing a $15/month replacement for Apollo and Lemlist got 400 upvotes because the pain is universal — B2B outreach tools are laughably overpriced for small teams. StackSwap is a productized version of that exact system: it takes a CSV of target companies, enriches contacts via Hunter.io and Apollo's free tier, runs a 3-step email sequence via Resend, detects replies and pauses the sequence automatically, and syncs outcomes to a lightweight CRM built into the app. No Zapier glue, no n8n setup, no manual hand-off between five tools. Priced at $29/month for solo founders and $79/month for agencies running multiple clients. Buildable in 2 weeks because Hunter.io, Resend, and Supabase are battle-tested APIs requiring no novel infrastructure.
Why now?
The May 2026 wave of bootstrappers cutting SaaS costs has made the r/automation DIY outreach post go viral — the market is primed for a packaged version right now.
- ▸CSV upload to enriched contact list via Hunter.io in under 2 minutes (Implementation note: Hunter.io domain search API per row)
- ▸3-step drip sequence builder with delay controls and reply-detection auto-pause via Resend webhooks
- ▸AI-generated first-line personalization using OpenAI based on company description
- ▸Lightweight CRM showing sequence status, reply rate, and meeting booked flag per contact
Target Audience
Solo founders, bootstrappers, and small B2B agencies running outreach — roughly 500,000 active Lemlist and Apollo subscribers based on published user counts, targeting the bottom 20% who do not need enterprise features.
Example Use Case
A solo B2B SaaS founder uploads a CSV of 200 target companies, StackSwap enriches emails, runs a 3-step sequence over 9 days, detects 12 replies, pauses those contacts, and logs 3 demo calls booked — all for $29/month.
User Stories
- ▸As a solo founder, I want to upload a CSV and have emails enriched automatically, so that I do not need to pay for a separate data tool.
- ▸As an agency owner, I want to manage outreach campaigns for 3 clients from one dashboard, so that I can cancel my Lemlist subscription.
- ▸As a bootstrapper, I want reply detection to auto-pause sequences, so that I do not accidentally email someone who already responded.
Done When
- ✓Enrichment: done when a 10-row CSV upload returns verified email addresses for at least 6 rows within 30 seconds.
- ✓Sequence launch: done when a 3-step sequence sends the first email and schedules step 2 for the configured delay without any manual action.
- ✓Reply detection: done when a reply to a sequence email is received and the contact status changes to Replied and no further emails are sent.
- ✓Billing gate: done when a free-tier user hitting 51 contacts sees an upgrade prompt and cannot launch the sequence until upgrading.
Is it worth building?
$29/month x 100 solos plus $79/month x 20 agencies = $4,480 MRR at month 3. Math assumes 5% conversion from cold outreach to 2,400 leads.
Unit Economics
CAC: $20 via Reddit community seeding. LTV: $348 (12 months at $29/month). Payback: under 1 month. Gross margin: 78%.
Business Model
SaaS subscription at $29/month solo and $79/month agency with 5 sender seats.
Monetization Path
Free tier allows 50 contacts per month. Paid tier required for sequences over 50 contacts and agency seats.
Revenue Timeline
First dollar: week 2 via r/automation thread response. $1k MRR: month 2. $5k MRR: month 5.
Estimated Monthly Cost
Hunter.io API: $49 starter, Resend: $20, OpenAI API: $25, Supabase: $25, Vercel: $20, Stripe fees: $20. Total: ~$159/month at launch.
Profit Potential
Viable side income at $3k MRR, full-time at $8k MRR.
Scalability
High — expand to LinkedIn step integration, AI personalization at scale, and white-label for agencies.
Success Metrics
Week 1: 50 signups from r/indiehackers post. Week 2: 15 paid. Month 2: 80 paid, $3,200 MRR.
Launch & Validation Plan
Post a side-by-side cost breakdown on r/indiehackers comparing StackSwap to Apollo plus Lemlist, collect 30 comments before writing billing code.
Customer Acquisition Strategy
First customer: reply directly to the r/automation thread about the $15 outreach stack offering StackSwap as the no-setup version. Ongoing: r/indiehackers, ProductHunt, cold email to Lemlist and Apollo churned users via public G2 reviews.
What's the competition?
Competition Level
High
Similar Products
Lemlist ($59/month, complex, overkill for solos), Instantly ($37/month, requires own SMTP warm-up), Apollo ($49/month, data tool not a sequencer) — StackSwap is the all-in-one at half the combined price.
Competitive Advantage
Radically simpler setup — zero configuration required versus the 4-hour Lemlist onboarding that triggers most churn.
Regulatory Risks
CAN-SPAM and GDPR compliance required — unsubscribe link mandatory in every email, document data processor agreements for EU users.
What's the roadmap?
Feature Roadmap
V1 (launch): CSV enrichment, 3-step sequences, reply detection, Stripe billing. V2 (month 2-3): AI personalization lines, open tracking, agency multi-client view. V3 (month 4+): custom sending domain, A/B subject testing, CRM export to HubSpot.
Milestone Plan
Phase 1 (Week 1-2): enrichment, sequence builder, and email delivery working end-to-end. Phase 2 (Week 3-4): reply detection, dashboard, Stripe billing live with 10 beta users. Phase 3 (Month 2): 80 paid users, r/indiehackers case study published.
How do you build it?
Tech Stack
Next.js, Hunter.io API for email enrichment, Resend for email sequencing, Supabase for CRM and sequence storage, Stripe for billing, OpenAI API for personalization line generation — build with Cursor for backend logic, v0 for campaign dashboard UI.
Suggested Frameworks
Resend SDK, Hunter.io REST API, Supabase JS client
Time to Ship
2 weeks
Required Skills
Resend email sequencing, Hunter.io API, Supabase cron jobs for sequence drip, Stripe billing.
Resources
Resend docs, Hunter.io API docs, Supabase edge functions docs, Stripe billing quickstart.
MVP Scope
app/api/enrich/route.ts (Hunter.io enrichment endpoint), app/api/sequence/route.ts (sequence create and start), app/api/webhook/resend/route.ts (reply detection webhook), app/dashboard/page.tsx (campaign overview), app/campaigns/new/page.tsx (sequence builder), lib/db/schema.ts (contacts, sequences, steps, events schema), lib/sequence-runner.ts (Supabase cron drip logic), app/api/stripe/route.ts (billing webhook), seed.ts (demo campaign), .env.example
Core User Journey
Upload CSV -> enrich contacts -> build 3-step sequence -> launch -> see replies detected and paused automatically in dashboard.
Architecture Pattern
CSV upload -> Hunter.io enrichment -> contacts stored in Supabase -> Supabase cron triggers Resend email per step -> Resend reply webhook pauses sequence -> CRM dashboard updated.
Data Model
User has many Campaigns. Campaign has many Contacts. Contact has one SequenceState. SequenceState has many EmailEvents.
Integration Points
Hunter.io for email enrichment, Resend for email delivery and reply webhooks, OpenAI API for personalization lines, Supabase for data and cron jobs, Stripe for billing.
V1 Scope Boundaries
V1 excludes: LinkedIn steps, custom sending domains, team collaboration, white-label, A/B testing, mobile app.
Success Definition
A solo founder finds StackSwap via a Reddit post, runs a full 3-step sequence to 100 contacts, and books a meeting — without contacting the founder.
Challenges
Competition from Instantly, Smartlead, and Apollo is intense and these tools are lowering prices — differentiation must be radical simplicity and price, not features, or StackSwap becomes a feature war it cannot win.
Avoid These Pitfalls
Do not build LinkedIn outreach in V1 — it requires browser automation that gets accounts banned and will consume 3 weeks. Finding first 10 paying customers will take longer than building — budget 3x time on community seeding. Do not compete on features with Instantly — compete on zero-setup simplicity only.
Security Requirements
Supabase Auth with Google OAuth, RLS on all campaign and contact tables, CAN-SPAM unsubscribe link injected in every email, rate limit enrichment endpoint at 20 req/min, GDPR data deletion endpoint required.
Infrastructure Plan
Vercel for Next.js, Supabase for Postgres and cron jobs, Resend for email, Sentry for errors, Vercel Analytics for traffic, no additional file storage needed at V1.
Performance Targets
Enrichment API under 3s per row. Dashboard load under 2s. Sequence cron runs within 5 minutes of scheduled send time. 80 DAU at launch.
Go-Live Checklist
- ☐CAN-SPAM unsubscribe link tested in every email.
- ☐Stripe subscription and limit enforcement tested.
- ☐Sentry live and capturing errors.
- ☐Resend reply webhook tested with real email reply.
- ☐Custom domain with SSL live.
- ☐Privacy policy and terms with data processor clause published.
- ☐5 beta users ran full sequence end-to-end.
- ☐Rollback plan documented.
- ☐r/indiehackers and ProductHunt posts drafted.
First Run Experience
On first run: dashboard shows a demo campaign with 10 pre-enriched contacts, a 3-step sequence, and simulated reply events. User can immediately browse the demo campaign and see how reply detection pauses contacts. No manual config required: demo mode fully functional without connecting Hunter.io or Resend keys.
How to build it, step by step
1. Define schema: campaigns, contacts, sequence_steps, email_events in Supabase. 2. Build CSV upload and Hunter.io enrichment endpoint with Cursor. 3. Implement sequence builder UI in app/campaigns/new using v0. 4. Write sequence runner cron in lib/sequence-runner.ts using Supabase pg_cron. 5. Integrate Resend for email delivery with reply-detection webhook at /api/webhook/resend. 6. Build campaign dashboard showing sent, opened, replied counts per campaign. 7. Add OpenAI API call for first-line personalization per contact on enrichment. 8. Set up Stripe subscription with 50-contact free tier limit enforced server-side. 9. Seed demo campaign with 10 pre-enriched contacts and fake reply events. 10. Verify: upload a real 5-row CSV, enrich, launch sequence, confirm first email sends and reply webhook pauses the contact.
Generated
May 22, 2026
Model
claude-sonnet-4-6
Disclaimer: Ideas on this site are AI-generated and may contain inaccuracies. Revenue estimates, market demand figures, and financial projections are illustrative assumptions only — not financial advice. Do your own research before making any business or investment decisions. Technology availability, pricing, and market conditions change rapidly; always verify details independently.