ReplayIQ - MCP Server That Injects Live PostHog Session Replay Context Into Claude for Instant UX Diagnosis
You can watch session replays in PostHog all day but Claude has no idea what your users are actually doing. ReplayIQ is an MCP server that pulls live PostHog session replay metadata, event sequences, and rage-click hotspots into Claude's context so you can ask it to diagnose UX failures in plain English. It's like giving Claude eyes on your product.
Difficulty
intermediate
Category
MCP & Integrations
Market Demand
High
Revenue Score
7/10
Platform
MCP Server
Vibe Code Friendly
No
Hackathon Score
🏆 8/10
What is it?
PostHog has session replays. Mixpanel has funnels. But neither can tell you in plain English why users are dropping off at step 3 of your onboarding. ReplayIQ exposes a set of MCP tools that Claude or Cursor can call to fetch recent session replay summaries, event sequences for specific user cohorts, rage-click hotspot data, and funnel drop-off points from PostHog's API. Claude can then synthesize across dozens of sessions and answer questions like 'why are users abandoning the pricing page?' in seconds. This is the missing AI reasoning layer on top of analytics data that every indie founder needs but that PostHog will never build natively.
Why now?
Anthropic's MCP ecosystem hit critical mass in early 2026 with Claude Desktop's tool use becoming mainstream, and PostHog's public API is stable and well-documented — this combination makes a usable MCP server shippable in under 2 weeks.
- ▸get_session_replays tool: fetches recent session replay summaries filtered by page, event, or user cohort from PostHog.
- ▸get_rage_clicks tool: returns rage-click hotspot data with element selectors and frequency counts.
- ▸get_funnel_dropoff tool: fetches funnel step conversion rates and identifies the highest drop-off step.
- ▸ask_ux_question prompt: pre-built Claude prompt that synthesizes session data into a plain-English UX diagnosis.
Target Audience
Indie SaaS founders and solo PMs using PostHog, estimated 50k+ active PostHog OSS users and 10k+ cloud users.
Example Use Case
Tom, a solo SaaS founder, installs ReplayIQ, connects his PostHog project, then asks Claude in plain English 'why are users rage-clicking on the upgrade button?' and gets a synthesized diagnosis across 40 sessions in 30 seconds.
User Stories
- ▸As a solo SaaS founder, I want to ask Claude why users are dropping off my onboarding flow, so that I get a synthesized answer from real session data instead of watching 30 replays manually.
- ▸As a PM, I want rage-click hotspot data surfaced in Claude's context, so that I can diagnose UI friction without switching between tools.
- ▸As a PostHog user, I want a one-command MCP server setup, so that I can start querying my analytics through Claude in under 10 minutes.
Acceptance Criteria
get_session_replays: done when Claude receives structured session summaries for a specified page URL within 3 seconds. get_rage_clicks: done when rage-click data returns element selectors and frequency counts for the last 7 days. get_funnel_dropoff: done when funnel step conversion rates return correctly for a named funnel. UX Diagnosis Prompt: done when Claude produces a plain-English diagnosis citing specific session data without hallucinating metrics.
Is it worth building?
$49 one-time x 100 buyers = $4,900 in month 1. Hosted tier $19/month x 50 users = $950 MRR at month 3. Math: PostHog's 50k OSS user base is the distribution channel — 0.2% conversion is realistic.
Unit Economics
CAC: $5 via PostHog community organic. LTV: $220 (one-time $49 + 9 months hosted at $19/month). Payback: immediate. Gross margin: 92%.
Business Model
One-time purchase plus optional hosted SaaS tier
Monetization Path
$49 one-time for self-hosted MCP config. $19/month for hosted version with auto-sync and multi-project support.
Revenue Timeline
First dollar: week 1 via GitHub launch. $1k MRR: month 2 via hosted tier. $5k MRR: month 8.
Estimated Monthly Cost
PostHog API: free tier sufficient at launch, Vercel: $20, Supabase: $25 for hosted config, Stripe fees: $10. Total: ~$55/month at launch.
Profit Potential
Side income at $2k–$5k MRR.
Scalability
Medium — can expand to Mixpanel, Amplitude, and FullStory connectors.
Success Metrics
Week 1: 50 installs. Week 2: 10 paid purchases. Month 2: 40 hosted subscribers.
Launch & Validation Plan
Post a demo video on Twitter showing Claude diagnosing a real rage-click issue using the MCP server, link to GitHub repo and one-time purchase page.
Customer Acquisition Strategy
First customer: post the demo video in PostHog's official Slack community and GitHub discussions, offer first 20 buyers a free onboarding call. Ongoing: PostHog community, Anthropic MCP marketplace when available, Twitter developer community, ProductHunt.
What's the competition?
Competition Level
Low
Similar Products
PostHog's own AI features are basic and not Claude-integrated. Heap has no MCP server. Mixpanel has no Claude integration — ReplayIQ fills the gap for PostHog users specifically who already use Claude Desktop.
Competitive Advantage
No existing MCP server exposes PostHog session data. This is the only way to give Claude live product analytics context without copy-pasting CSV exports.
Regulatory Risks
Low regulatory risk. Session replay data may contain PII — must document that no user PII is sent to Claude API without anonymization, and provide a scrubbing option.
What's the roadmap?
Feature Roadmap
V1 (launch): session summaries, rage clicks, funnel drop-off, UX diagnosis prompt. V2 (month 2-3): Mixpanel connector, PII scrubbing toggle, multi-project support. V3 (month 4+): Amplitude connector, automated weekly UX digest to Slack, team config sharing.
Milestone Plan
Phase 1 (Week 1-2): three MCP tools + README ship, 10 beta PostHog users test live. Phase 2 (Week 3-4): Stripe purchase flow live, first paid buyer. Phase 3 (Month 2): ProductHunt launch, 50 one-time buyers and 20 hosted subscribers.
How do you build it?
Tech Stack
MCP SDK (TypeScript), PostHog API, Claude Desktop, Supabase for config storage, Vercel for hosted version — build with Cursor for MCP server logic
Suggested Frameworks
MCP SDK (TypeScript), PostHog JS Client, Zod for schema validation
Time to Ship
2 weeks
Required Skills
MCP SDK TypeScript, PostHog API, Claude tool use schemas, Zod validation.
Resources
Anthropic MCP SDK docs, PostHog API docs, Model Context Protocol spec.
MVP Scope
src/index.ts (MCP server entry), src/tools/get-sessions.ts, src/tools/get-rage-clicks.ts, src/tools/get-funnel.ts, src/prompts/ux-diagnosis.ts, src/lib/posthog.ts, claude_desktop_config.json example, README with setup guide.
Core User Journey
Install MCP server -> connect PostHog API key -> ask Claude a UX question -> receive session-backed diagnosis in 30 seconds -> upgrade to hosted tier.
Architecture Pattern
Claude Desktop calls MCP tool -> ReplayIQ MCP server -> PostHog API fetches session data -> structured JSON returned to Claude context -> Claude synthesizes diagnosis -> user receives plain-English answer.
Data Model
Config has one PostHogProject. PostHogProject has many SessionSummaries. SessionSummary has many Events. RageClickReport belongs to one PageURL.
Integration Points
PostHog API for session and funnel data, MCP SDK for Claude tool exposure, Stripe for one-time purchase and subscription, Supabase for hosted config storage.
V1 Scope Boundaries
V1 excludes: Mixpanel or Amplitude connectors, team multi-user config, mobile SDK events, custom event schema mapping, white-label.
Success Definition
A PostHog user installs ReplayIQ, asks Claude a UX question, receives an accurate diagnosis from real session data, and purchases the hosted tier within 7 days without any founder help.
Challenges
The hardest non-technical problem is discoverability — MCP servers are still niche in April 2026 and most PostHog users don't know Claude tool use exists. Must embed distribution inside the PostHog community directly via their Slack and forum.
Avoid These Pitfalls
Do not try to stream raw video from session replays into Claude — PostHog's API returns metadata and events only, not video, and that scope is out of reach for v1. Do not skip PII scrubbing documentation or the PostHog community will reject the tool on privacy grounds. Finding first 10 buyers requires showing a live demo not a README — ship the video before the product.
Security Requirements
PostHog API key stored encrypted in Supabase with RLS, no raw PII forwarded to Claude API, input validation via Zod on all tool schemas, GDPR: API key deletion endpoint required.
Infrastructure Plan
Vercel for hosted MCP server endpoint, Supabase for encrypted config storage, GitHub Actions for CI, Sentry for error tracking — total infra under $60/month at launch.
Performance Targets
200 tool calls/day at launch, PostHog API response cached for 5 minutes per project to reduce rate limit hits, MCP tool response under 2 seconds, no page load target (CLI-first product).
Go-Live Checklist
- ☐Security audit complete
- ☐Payment flow tested end-to-end
- ☐Sentry live
- ☐PostHog API rate limit handling tested
- ☐Custom domain with SSL
- ☐Privacy policy covering session data published
- ☐5 beta users signed off
- ☐Rollback plan documented
- ☐Twitter demo video and ProductHunt draft ready.
How to build it, step by step
1. Run npx @modelcontextprotocol/create-server replayiq --type tools. 2. Install posthog-node, zod, stripe. 3. Build get_session_replays tool that calls PostHog /api/projects/{id}/session_recordings with filters. 4. Build get_rage_clicks tool that calls PostHog /api/projects/{id}/insights/trend with rage click event filter. 5. Build get_funnel_dropoff tool that calls PostHog /api/projects/{id}/insights/funnel. 6. Add Zod schemas for all tool inputs and outputs. 7. Build ux-diagnosis prompt template that instructs Claude to synthesize across tool results. 8. Write claude_desktop_config.json example and detailed README. 9. Add Stripe payment link for one-time purchase gating the hosted config endpoint. 10. Deploy hosted version to Vercel and test end-to-end with a real PostHog project.
Generated
April 11, 2026
Model
claude-sonnet-4-6