RepLens — AI Sales Call Analyzer for Diarized Transcripts

Q: Who can build RepLens — AI Sales Call Analyzer for Diarized Transcripts?

This is a intermediate level project. Sales managers at SMBs with 3–15 reps, sales coaches charging $200–$500/session, and RevOps leads at seed-to-Series A startups who can't justify Gong pricing.

Paste or upload any diarized sales call transcript and get a Claude-powered breakdown of rep performance, objection handling, talk ratios, and next-step recommendations in under 30 seconds. Built specifically for sales managers and coaches who are drowning in call recordings but need actionable intel fast.

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Difficulty

intermediate

What is it?

RepLens accepts diarized transcripts (from Fireflies, Otter, Gong exports, or manual uploads) and runs them through Claude to produce a structured scorecard: talk-to-listen ratio per speaker, objection patterns, buying signals detected, competitor mentions, and a prioritized coaching checklist. Sales managers stop re-listening to 45-minute calls and instead read a 1-page AI summary with timestamps. The product integrates with Zapier so new transcripts from Fireflies or Otter auto-trigger analysis and email the scorecard to the manager. Monetized on a per-seat SaaS model targeting small-to-mid sales teams of 3–15 reps where Gong is overkill at $1,200/seat/year.

Why now?

Claude's 200k context window means a 45-minute diarized transcript (typically 8–12k tokens) fits in a single API call with room for detailed instructions — this wasn't cost-effective or reliable with GPT-3.5 era models. Fireflies and Otter have also normalized transcript exports, so the raw material is already sitting in inboxes waiting to be analyzed.

▸Diarized transcript ingestion: paste raw text or upload .txt/.docx from Fireflies, Otter, or Gong exports — Claude identifies speakers automatically even without labels
▸Structured scorecard output: talk-to-listen ratio, top 3 objections raised, buying signals detected, competitor mentions, and a 5-point coaching checklist with exact transcript timestamps
▸Manager email digest: after each analysis, Resend fires a formatted HTML scorecard to the manager's inbox so they never need to log in to stay informed
▸Zapier webhook trigger: connect Fireflies or Otter so every new transcript auto-queues for analysis — zero manual upload needed after setup

Target Audience

Sales managers at SMBs with 3–15 reps, sales coaches charging $200–$500/session, and RevOps leads at seed-to-Series A startups who can't justify Gong pricing.

Example Use Case

Sarah manages 6 SDRs and uploads their Monday call transcripts every Tuesday. RepLens emails her a coaching digest by 9am — she identifies that 4 of 6 reps never ask for a next meeting, fixes it in her 1:1s, and closes 2 more deals that month.

User Stories

▸As a sales manager, I want to paste a Fireflies transcript and get a talk-ratio and objection breakdown in under 60 seconds, so that I can coach my rep in tomorrow's 1:1 without re-listening to a 40-minute call.
▸As a sales coach, I want to upload a client's call transcript and receive a timestamped coaching checklist, so that I can deliver higher-value sessions and justify my $400/hour rate with concrete AI-backed evidence.
▸As a RevOps lead, I want new Fireflies transcripts to auto-trigger analysis via Zapier and email me the scorecard, so that I get a weekly digest of team call quality without any manual work.

Done When

✓Core analysis: done when a pasted 5,000-word diarized transcript returns a valid scorecard JSON (talkRatio, min 2 objections, min 1 buying signal, 5-item coaching checklist) rendered in the UI within 45 seconds.
✓Auth: done when Google OAuth login redirects to /dashboard and displays the authenticated user's email and transcript history.
✓Payment: done when Stripe checkout processes a $29/month subscription, Supabase updates the team's plan tier, and the user can submit their 6th transcript without hitting the free limit gate.
✓Email digest: done when a completed analysis triggers a Resend email to the manager's address within 60 seconds, containing the full scorecard rendered in HTML with speaker labels and timestamps.

Is it worth building?

$79/month x 40 Growth teams + $29/month x 30 Starter teams = $4,030 MRR at month 4.

Unit Economics

CAC: ~$15 via LinkedIn cold outreach (1 hour at founder rate) or $0 via organic Reddit. LTV: $948 (12 months at $79/month Growth). Payback: under 1 month. Gross margin: ~90% (API costs ~$8/customer/month at average usage).

Business Model

SaaS subscription — $29/month Starter (3 seats, 50 calls/mo), $79/month Growth (10 seats, unlimited calls)

Monetization Path

Free tier: 5 transcript analyses forever, no credit card. Upgrade prompt hits after call #3. Target 15% free-to-paid conversion driven by the 'you've used 3 of 5 free analyses' nudge email via Resend.

Revenue Timeline

First dollar: day 10 (beta user converts). $1k MRR: month 2. $5k MRR: month 6.

Estimated Monthly Cost

Claude API (claude-3-5-sonnet at ~3k tokens/call, 500 calls/month): ~$45, Vercel Pro: $20, Supabase: $25, Resend: $10. Total: ~$100/month.

Profit Potential

Full-time viable at $5k MRR. Infrastructure costs stay under $150/month until 500+ daily analyses.

Scalability

High — add Slack digest delivery, CRM push to HubSpot/Salesforce, team leaderboards, and white-label for sales coaching agencies at $299/month.

Success Metrics

Week 1: 50 signups, 15 analyses run. Month 2: 20 paying teams, 80% still active, avg 8 analyses/team/month.

Launch & Validation Plan

Post in r/sales asking 'how do you currently review call recordings?' to validate pain. DM 20 LinkedIn sales managers offering free analysis of one real transcript. Build landing page on day 3 with email capture. Recruit 8 beta testers before writing any backend code.

Customer Acquisition Strategy

First customer: post in r/salestechniques offering free transcript review, then DM 20 VP of Sales on LinkedIn with a cold loom showing a sample scorecard. Then: ProductHunt launch, SEO targeting 'sales call transcript analysis' and 'Fireflies transcript review', and a YouTube short showing the Zapier automation.

What's the competition?

Competition Level

Medium

What's the roadmap?

Feature Roadmap

V1 (launch): transcript paste + scorecard + email digest + Zapier webhook + Stripe billing. V2 (month 2–3): HubSpot/Salesforce deal note push, Slack scorecard delivery, team leaderboard by talk ratio. V3 (month 4+): white-label for sales coaching agencies, bulk CSV upload for historical call batches, trend dashboards across 30/60/90 day periods.

Milestone Plan

Phase 1 (Week 1–2): Supabase schema live, Claude analysis route returning valid JSON, Scorecard UI rendering, Google Auth working, deploy to Vercel — done when founder can analyze a real transcript end-to-end. Phase 2 (Week 3–4): Stripe billing gating free tier, Resend email digest live, Zapier webhook tested, landing page with clear pricing — done when first paying stranger completes full flow. Phase 3 (Month 2): 20 paying teams, Slack delivery shipped, ProductHunt launched — done when MRR hits $1,000.

How do you build it?

Tech Stack

Next.js 14 App Router, Claude API (claude-3-5-sonnet), Stripe, Supabase — build with Cursor

Suggested Frameworks

Anthropic SDK, pdf-parse or plain text ingestion, Resend for email delivery, Zod for schema validation

Time to Ship

2 weeks

Required Skills

Claude API prompt engineering for structured JSON output, Next.js file upload handling, Stripe billing, Supabase RLS.

Resources

Anthropic prompt engineering docs, Fireflies transcript export format docs, Stripe subscription billing guide, Supabase Row Level Security quickstart.

MVP Scope

app/page.tsx (landing + paste box), app/dashboard/page.tsx (history list), app/api/analyze/route.ts (Claude call + scorecard), app/api/webhook/route.ts (Zapier trigger), lib/db.ts (users, transcripts, scorecards schema), components/Scorecard.tsx (formatted result UI)

Core User Journey

Paste transcript -> see scorecard in 30s -> share scorecard link with rep -> hit free limit -> enter card to upgrade.

Architecture Pattern

User uploads transcript -> Next.js API route -> Claude API returns structured JSON scorecard -> saved to Supabase -> Resend fires email to manager -> Stripe gates volume above free tier.

Data Model

User has many Teams. Team has many Transcripts. Transcript has one Scorecard. Scorecard has JSON fields: talkRatio, objections[], buyingSignals[], competitorMentions[], coachingChecklist[].

Integration Points

Claude API for analysis, Stripe for subscriptions, Resend for scorecard emails, Supabase for auth + storage, Zapier webhook for Fireflies/Otter auto-trigger.

V1 Scope Boundaries

V1 excludes: audio/video file upload (text transcripts only), CRM integrations, Slack delivery, team leaderboards, mobile app, white-label, and direct Fireflies/Otter OAuth (Zapier webhook is the V1 integration path).

Success Definition

A paying sales manager uploads a transcript, receives a scorecard email, and uses it in a 1:1 with their rep — all without contacting the founder.

Challenges

Distribution is the hard part — sales managers don't browse ProductHunt. First 20 customers must come from cold DMs on LinkedIn to VP of Sales titles at 20–200 person SaaS companies, plus Reddit posts in r/sales and r/salestechniques.

Avoid These Pitfalls

Don't let Claude return free-form prose — enforce a strict JSON schema in the system prompt and validate with Zod before saving, or scorecards will be inconsistent and unrenderable. Don't target enterprise on launch — Gong owns that space. Stay laser-focused on the 10–50 person SaaS company where the sales manager is also doing RevOps and needs a $29 tool, not a $50k contract.

Security Requirements

Supabase Auth + Google OAuth on all routes, Row Level Security ensuring users only read their own transcripts and scorecards, transcript text encrypted at rest via Supabase, rate limiting 20 analyses/hour per team to prevent API cost abuse, no transcript data shared across accounts.

Infrastructure Plan

Vercel for Next.js hosting (serverless functions for API routes), Supabase for Postgres DB + auth + storage, GitHub Actions for CI running Zod schema tests before deploy, Sentry for error tracking on the /api/analyze route specifically.

Performance Targets

Target 200 DAU at month 3. Claude API call must return within 30 seconds for a 10k-token transcript. Dashboard page load under 2 seconds. Scorecard email delivered within 60 seconds of analysis completion. CDN for static assets via Vercel Edge.

Go-Live Checklist

☐Claude prompt tested against 10 real diarized transcripts with consistent valid JSON output.
☐Stripe payment flow tested end-to-end: free tier blocks at call 6, upgrade unlocks immediately.
☐Supabase RLS policies verified: user A cannot access user B's transcripts via direct API call.
☐Sentry error tracking live and firing alerts to founder's email on any /api/analyze failure.
☐Custom domain with SSL configured on Vercel (replens.io or similar).
☐Privacy policy and data retention policy (90-day auto-delete) published on /privacy.
☐5 beta users have completed the full flow and confirmed scorecard usefulness in a 10-minute Loom review.
☐Rollback plan documented: Vercel instant rollback to previous deployment + Supabase point-in-time restore.
☐ProductHunt launch post drafted and scheduled, LinkedIn cold outreach sequence of 20 VP Sales targets queued.

First Run Experience

On first load, a pre-loaded demo transcript (fictional SaaS sales call, clearly labeled) is already in the paste box. User clicks 'Analyze' and sees a real scorecard in 30 seconds with no signup required. After viewing the result, a modal prompts 'Sign up free to save this and analyze 4 more calls.'

How to build it, step by step

1. Define Supabase schema in lib/db.ts (users, teams, transcripts, scorecards). 2. Set up Supabase project, run migrations, enable RLS policies. 3. Build /api/analyze route: accept transcript text, call Claude with structured JSON prompt, validate response with Zod. 4. Build Scorecard.tsx component to render JSON as visual scorecard. 5. Build dashboard page showing transcript history and scorecard links. 6. Add Supabase Auth with Google OAuth. 7. Add Stripe subscription checkout for Starter and Growth plans with usage gating at 5 free analyses. 8. Wire Resend to send scorecard email on every successful analysis. 9. Add Zapier-compatible webhook endpoint at /api/webhook/zapier. 10. Deploy to Vercel, walk the full end-to-end journey as a new user before announcing.

Generated

April 25, 2026

Model

Claude Haiku

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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.