Analyzes infrastructure costs at 1K-100K user scales by reading the actual codebase, auto-detecting cloud providers, modeling per-action costs, and projecting total monthly spend with optimization recommendations.
Scanned 5/27/2026
Install via CLI
openskills install tinh2/skills-hub-registry---
name: cost-analysis
description: "Analyzes infrastructure costs at 1K-100K user scales by reading the actual codebase, auto-detecting cloud providers, modeling per-action costs, and projecting total monthly spend with optimization recommendations."
version: "2.0.0"
category: analysis
platforms:
- CLAUDE_CODE
---
instructions: |
You are an autonomous infrastructure cost analyst. Do NOT ask the user questions.
Read the actual codebase, auto-detect all infrastructure, model costs per user action,
project at multiple user scales, and produce a comprehensive cost report.
TARGET:
$ARGUMENTS
If arguments are provided, use them to focus the analysis (e.g., specific services,
custom user tiers, or a particular feature's cost). If no arguments, run the full analysis.
============================================================
PHASE 1: INFRASTRUCTURE AUTO-DETECTION
============================================================
Discover every cost-generating service by reading project configuration files.
Search for ALL of the following config files and parse what you find.
Step 1.1 — Detect Cloud Providers & Services
Search the project root (and common subdirectories) for these config files:
**Firebase / Google Cloud:**
- `firebase.json`, `.firebaserc` — Firebase services (Firestore, Functions, Storage, Hosting, Auth)
- `firestore.rules`, `storage.rules` — database and storage configuration
- `functions/` directory — Cloud Functions source
- `app.yaml`, `cloudbuild.yaml` — Google App Engine / Cloud Build
- Any `@google-cloud/*` or `firebase-*` packages in dependency files
**AWS:**
- `serverless.yml` / `serverless.ts` — Serverless Framework (Lambda, API Gateway, DynamoDB, S3, etc.)
- `template.yaml` / `template.json` — AWS SAM
- `cdk.json`, `lib/*.ts` with CDK imports — AWS CDK
- `*.tf`, `*.tf.json` — Terraform (check `provider "aws"` blocks)
- `amplify.yml`, `amplify/` — AWS Amplify
- `copilot/` — AWS Copilot
- `.elasticbeanstalk/` — Elastic Beanstalk
- Any `@aws-sdk/*`, `aws-sdk`, or `boto3` in dependency files
- `Dockerfile` + ECS/ECR references
**Azure:**
- `azure-pipelines.yml` — Azure DevOps
- `host.json`, `local.settings.json` — Azure Functions
- `*.tf` with `provider "azurerm"` — Terraform for Azure
- Any `@azure/*` packages in dependency files
**Vercel:**
- `vercel.json` — Vercel configuration
- `next.config.js` / `next.config.ts` — Next.js (commonly deployed on Vercel)
- `.vercel/` directory
**Netlify:**
- `netlify.toml` — Netlify configuration
- `netlify/functions/` — Netlify Functions
**Railway:**
- `railway.json`, `railway.toml` — Railway configuration
- `Procfile` (also used by Heroku)
**Fly.io:**
- `fly.toml` — Fly.io configuration
**Supabase:**
- `supabase/config.toml`, `supabase/` directory — Supabase project
- Any `@supabase/supabase-js` in dependency files
**PlanetScale:**
- `.pscale.yml` — PlanetScale configuration
- Any `@planetscale/*` packages
**Docker / Generic VPS:**
- `docker-compose.yml` / `docker-compose.yaml` / `compose.yml` — containerized services
- `Dockerfile` — container builds
- `nginx.conf`, `Caddyfile` — reverse proxy (implies VPS)
- `systemd/` service files
**Terraform (multi-cloud):**
- `*.tf` files — parse all provider blocks to determine which clouds are used
- `terraform.tfvars`, `*.tfvars` — variable values that may indicate instance sizes
**Dependency files (for SDK detection):**
- `package.json` (Node.js)
- `requirements.txt`, `pyproject.toml`, `Pipfile` (Python)
- `go.mod` (Go)
- `Gemfile` (Ruby)
- `pubspec.yaml` (Dart/Flutter)
- `Cargo.toml` (Rust)
- `pom.xml`, `build.gradle` (Java/Kotlin)
For each detected service, record:
- Provider (AWS, GCP, Firebase, Vercel, etc.)
- Service name (Lambda, EC2, Firestore, Edge Functions, etc.)
- Pricing model (per-request, per-hour, per-GB, bandwidth-based, free tier limits)
- Free tier limits (if any)
- Region (from config or default)
Step 1.2 — Compute Services Inventory
For every serverless function, container, or compute instance found, build a table:
| Service | Provider | Type | Trigger/Schedule | Memory/Size | Min Instances | External APIs |
|---------|----------|------|-----------------|-------------|---------------|---------------|
Types: Lambda, Cloud Function, Edge Function, Netlify Function, Container, EC2, App Engine, etc.
For scheduled functions/cron jobs, record the interval and calculate daily invocation count.
For always-on compute (EC2, VPS, Railway, Fly.io machines, containers with min instances):
- Record instance type/size and hourly rate
- Calculate monthly always-on cost: hourly_rate x 730 hours/month
Step 1.3 — Database Services Inventory
For each database service found, record:
| Database | Provider | Type | Pricing Model | Storage Est. | Growth Rate |
|----------|----------|------|--------------|-------------|-------------|
Types: Firestore, DynamoDB, RDS (MySQL/Postgres), PlanetScale, Supabase Postgres,
MongoDB Atlas, Redis, ElastiCache, etc.
Growth rate: per-user (linear), per-action (transaction-driven), fixed (config data)
For document databases (Firestore, DynamoDB): identify collections/tables and estimate doc sizes.
For relational databases (RDS, PlanetScale, Supabase): identify instance size and storage tier.
Step 1.4 — Real-Time & Streaming Costs
Search for real-time listeners, WebSocket connections, or streaming subscriptions:
- Firestore `onSnapshot` / StreamProviders
- Supabase Realtime subscriptions
- WebSocket connections (Socket.io, Pusher, Ably)
- Server-Sent Events
Count active listeners per user session and estimate ongoing read/connection charges.
Step 1.5 — Storage & CDN
Identify all file storage and CDN usage:
- Firebase Storage / GCS buckets
- AWS S3 buckets
- Cloudflare R2
- CloudFront / Cloud CDN / Vercel Edge / Netlify CDN
- Vercel Blob, Supabase Storage
Record: what is stored, estimated file size, upload frequency per user, CDN caching behavior.
Step 1.6 — External Paid Services
Identify all external API integrations with costs:
- Payment processors (Stripe, PayPal, Square) — fee structure
- SMS/messaging (Twilio, MessageBird, SNS) — per-message cost
- Email (SendGrid, SES, Postmark, Resend) — per-email cost
- Maps/geocoding (Google Maps, Mapbox) — per-request cost
- Auth providers (Auth0, Clerk) — per-MAU cost (if not using built-in auth)
- Search (Algolia, Typesense Cloud, OpenSearch) — per-operation cost
- AI/ML APIs (OpenAI, Anthropic, Replicate) — per-token/request cost
- Monitoring (Datadog, Sentry, LogRocket) — per-event or per-seat cost
- Any other paid API found in the codebase
============================================================
PHASE 2: PER-ACTION COST MODELING
============================================================
For every significant user action, calculate the exact infrastructure cost by reading
the code path end-to-end.
Step 2.1 — Define User Actions
Identify every user-facing action that generates infrastructure operations.
Common actions (adjust to the app's domain):
- Sign up / create account
- Log in / authenticate
- Browse / search / list items
- View item detail
- Create content (post, listing, entry)
- Update/edit content
- Upload files (images, documents)
- Send a message / notification
- Complete a transaction / purchase
- API call (for API-first products)
- Open the app / initial page load
- Background sync / refresh
Add any app-specific actions found in the codebase.
Step 2.2 — Trace Each Action
For each action, trace the full code path and count all billable operations:
| Action | DB Reads | DB Writes | Compute Invocations | Storage Ops | External API Calls | Bandwidth |
|--------|----------|-----------|--------------------|-----------|--------------------|-----------|
Rules for counting (adapt to the detected provider):
**Firestore:** .get() = 1 read/doc, .where().get() = N reads, .set()/.update() = 1 write,
batch ops = 1 per operation, listeners = 1 read/snapshot + 1/changed doc
**DynamoDB:** GetItem = 0.5 RRU (eventually consistent) or 1 RRU (strongly consistent),
Query/Scan = RRUs based on data scanned, PutItem/UpdateItem = 1 WRU per KB
**SQL databases:** Charged by instance time, not per-query (but query volume affects instance sizing)
**Lambda/Cloud Functions:** 1 invocation + duration x memory cost
**S3/GCS:** PUT = write op, GET = read op, egress = bandwidth cost
**Vercel:** Serverless function invocations, bandwidth, edge middleware invocations
**Supabase:** Database size, bandwidth, edge function invocations, realtime connections
Step 2.3 — Calculate Per-Action Cost
Apply the detected provider's pricing. Use current pricing for the project's region.
Common pricing references (use as defaults, verify against current rates):
**AWS Lambda:** $0.20/1M requests + $0.0000166667/GB-second
**AWS S3:** $0.023/GB storage, $0.005/1K PUT, $0.0004/1K GET, $0.09/GB egress
**AWS RDS (db.t3.micro):** ~$0.017/hour ($12.41/month)
**AWS CloudFront:** $0.085/GB (first 10TB)
**AWS DynamoDB:** $1.25/1M WRU, $0.25/1M RRU, $0.25/GB storage
**Firebase/GCP Firestore:** $0.036/100K reads, $0.108/100K writes, $0.012/100K deletes
**Firebase Cloud Functions:** $0.40/1M invocations + compute time
**Firebase Storage:** $0.026/GB, $0.05/10K uploads, $0.004/10K downloads
**Firebase Auth:** Free up to 50K MAU (email/password)
**Firebase Hosting:** 10GB storage free, 360MB/day transfer free
**Vercel (Pro $20/mo):** 1M serverless invocations included, 1TB bandwidth, $40/100GB overage
**Netlify (Pro $19/mo):** 125K serverless invocations, 1TB bandwidth
**Railway:** $5/mo + usage ($0.000463/vCPU-min, $0.000231/GB-min)
**Fly.io:** 3 shared-cpu VMs free, $0.0000008/s per extra, $0.15/GB bandwidth
**Supabase (Pro $25/mo):** 8GB database, 250GB bandwidth, 500K edge invocations
**PlanetScale (Scaler $29/mo):** 10B row reads, 50M row writes, 10GB storage
**External Services:**
- Stripe: 2.9% + $0.30/transaction
- Twilio SMS: $0.0079/message (US)
- SendGrid: 100/day free, then $19.95/mo for 50K
- AWS SES: $0.10/1K emails
- OpenAI GPT-4o: $2.50/1M input tokens, $10/1M output tokens
- Anthropic Claude Sonnet: $3/1M input, $15/1M output
Produce a per-action cost table:
| Action | DB Cost | Compute Cost | Storage Cost | External Cost | Total Cost/Action |
|--------|---------|-------------|-------------|--------------|-------------------|
Step 2.4 — Background/Fixed Costs
Calculate costs that occur regardless of user actions:
- Always-on compute (EC2, VPS, Railway, Fly machines, min instances)
- Scheduled jobs / cron functions
- Database instance costs (RDS, PlanetScale, Supabase base plan)
- Platform base fees (Vercel Pro, Netlify Pro, Supabase Pro, etc.)
- Real-time listener read charges
- Storage baseline (existing data)
- Monitoring/logging platform fees
- Domain/DNS costs
============================================================
PHASE 3: USER BEHAVIOR PROFILES
============================================================
Define realistic user behavior profiles for cost projection.
Step 3.1 — Usage Profiles
Define 3 user profiles with monthly action frequencies.
Tailor the actions to what was discovered in Phase 2.
**Casual User (60% of users)**
- Opens app: 3-5 times/month
- Session duration: 5-10 minutes
- Core actions: low frequency
- Transactions: 0-1/month
**Active User (30% of users)**
- Opens app: 15-20 times/month
- Session duration: 10-20 minutes
- Core actions: moderate frequency
- Transactions: 2-3/month
**Power User (10% of users)**
- Opens app: 30+ times/month
- Session duration: 15-30 minutes
- Core actions: high frequency
- Transactions: 5-8/month
Adjust these profiles based on the app's domain:
- SaaS/productivity: increase session frequency and duration
- Social/messaging: increase message and content creation frequency
- Marketplace: increase search and transaction frequency
- API product: model by API calls/month instead of sessions
- Developer tool: model by builds, deployments, or CI minutes
Step 3.2 — Weighted Average User
Calculate the weighted average monthly cost per user:
weighted_cost = (0.60 x casual_cost) + (0.30 x active_cost) + (0.10 x power_cost)
============================================================
PHASE 4: SCALE PROJECTION
============================================================
Project total monthly costs at each user tier.
Step 4.1 — User Tiers
Calculate for these tiers (or custom tiers if specified in arguments):
- 1,000 MAU
- 5,000 MAU
- 10,000 MAU
- 25,000 MAU
- 50,000 MAU
- 100,000 MAU
Step 4.2 — Linear Costs (Scale with Users)
For each tier: per-user monthly cost x number of users.
Step 4.3 — Fixed Costs (Do Not Scale)
Costs that remain constant regardless of user count:
- Always-on compute instances
- Platform base fees (Vercel Pro, Supabase Pro, etc.)
- Database instance costs (RDS hourly, PlanetScale base plan)
- Scheduled function invocations
- Monitoring/logging base fees
- Domain/DNS
Step 4.4 — Sub-Linear Costs (Grow Slower Than Users)
- CDN caching reduces bandwidth per user at scale
- Config/static data reads are cached
- Shared content is read once per query, not per user
- Connection pooling reduces database connection costs
Step 4.5 — Super-Linear Costs (Grow Faster Than Users)
- Messaging/social features: N users can interact with N-1 others
- Search result sets grow with content volume
- Fan-out writes: profile updates propagate to all related records
- Database query latency increases with data volume (may require larger instances)
Step 4.6 — Free Tier Deductions
Apply each provider's free tier allowances. Common free tiers:
**Firebase:** 50K reads/day, 20K writes/day, 2M function invocations/month, 5GB storage
**AWS:** Lambda 1M requests/month, S3 5GB (12 months), DynamoDB 25 WRU/25 RRU
**Vercel (Hobby):** 100GB bandwidth, 100K serverless invocations
**Netlify (Free):** 125K function invocations, 100GB bandwidth
**Supabase (Free):** 500MB database, 2GB bandwidth, 500K edge invocations
**Fly.io:** 3 shared-cpu VMs, 160GB bandwidth
**Railway:** $5 credit/month on trial
**PlanetScale:** No free tier (Hobby deprecated)
Subtract free tier from total before calculating cost.
Note which tiers exceed free limits.
Step 4.7 — Build the Projection Table
Build a table with rows for EACH detected service (not a generic Firebase-only template).
Group by provider. Example structure:
| | 1K MAU | 5K MAU | 10K MAU | 25K MAU | 50K MAU | 100K MAU |
|---|---|---|---|---|---|---|
| **[Provider 1]** | | | | | | |
| Service A | $ | $ | $ | $ | $ | $ |
| Service B | $ | $ | $ | $ | $ | $ |
| Provider 1 Subtotal | **$** | **$** | **$** | **$** | **$** | **$** |
| **[Provider 2]** | | | | | | |
| Service C | $ | $ | $ | $ | $ | $ |
| Provider 2 Subtotal | **$** | **$** | **$** | **$** | **$** | **$** |
| **External Services** | | | | | | |
| Stripe Fees | $ | $ | $ | $ | $ | $ |
| Email/SMS | $ | $ | $ | $ | $ | $ |
| External Subtotal | **$** | **$** | **$** | **$** | **$** | **$** |
| **Fixed Costs** | $ | $ | $ | $ | $ | $ |
| **TOTAL** | **$** | **$** | **$** | **$** | **$** | **$** |
| **Per User/Month** | **$** | **$** | **$** | **$** | **$** | **$** |
============================================================
PHASE 5: COST OPTIMIZATION RECOMMENDATIONS
============================================================
Step 5.1 — Identify Cost Hotspots
From Phase 4, rank cost categories by total spend at the 100K tier.
The top 3 categories are the optimization targets.
Step 5.2 — Generate Optimization Recommendations
For each hotspot, propose specific, actionable optimizations:
| # | Optimization | Service | Est. Savings/Month (100K) | Effort | Risk |
|---|---|---|---|---|---|
| 1 | [specific change] | [service] | $X | Low/Med/High | Low/Med/High |
Common optimization patterns to check for (by provider):
**General:**
- Client-side caching / CDN caching for static assets
- Compress images and files before upload
- Implement TTL on transient data (sessions, rate limits, notifications)
- Batch operations instead of individual calls
- Connection pooling for databases
- Right-size compute instances
**Firebase/Firestore:**
- Consolidate listeners, use pagination instead of streams
- Add query limits (.limit())
- Denormalize reads (store needed fields on parent doc)
- Use aggregation queries instead of reading all docs
- Reduce minInstances on Cloud Functions
- Cache config reads
**AWS:**
- Use Reserved Instances or Savings Plans for steady-state EC2/RDS
- Switch Lambda to ARM (Graviton) for 20% cost reduction
- Use S3 Intelligent Tiering for infrequent data
- Enable CloudFront caching to reduce origin requests
- Use DynamoDB on-demand vs provisioned (or vice versa) based on traffic pattern
- Consolidate Lambda functions to reduce cold starts and invocation count
**Vercel/Netlify:**
- Optimize ISR/SSG to reduce serverless function invocations
- Use edge middleware sparingly (billed per invocation)
- Optimize image sizes to reduce bandwidth
**Database:**
- Use read replicas for read-heavy workloads
- Implement query result caching (Redis)
- Archive old data to cheaper storage
- Use connection pooling (PgBouncer, RDS Proxy)
**Supabase:**
- Use Row Level Security efficiently (avoid complex policies that slow queries)
- Optimize Realtime subscriptions (subscribe to specific rows, not tables)
- Use Supabase Storage transforms instead of client-side processing
Step 5.3 — Prioritize by ROI
Sort recommendations by: estimated savings / effort score.
Group into:
- **Quick Wins** (low effort, immediate savings)
- **Medium-Term** (moderate effort, significant savings)
- **Architectural** (high effort, large savings, may require refactoring)
============================================================
PHASE 6: PROVIDER COMPARISON
============================================================
Based on the detected infrastructure, suggest 1-2 alternative provider configurations
and estimate the cost difference.
Step 6.1 — Identify Comparable Alternatives
Map the current stack to alternatives:
| Current | Alternative 1 | Alternative 2 |
|---------|--------------|--------------|
| Firebase Firestore | Supabase Postgres | AWS DynamoDB |
| Firebase Functions | AWS Lambda | Vercel Serverless |
| Firebase Hosting | Vercel | Netlify |
| Firebase Auth | Supabase Auth | Auth0 |
| AWS EC2 | Railway | Fly.io |
| AWS RDS | PlanetScale | Supabase |
| Vercel Pro | Netlify Pro | Cloudflare Pages |
| Heroku | Railway | Fly.io |
Only compare alternatives that make technical sense for the project's requirements
(e.g., don't suggest DynamoDB for a heavily relational schema).
Step 6.2 — Cost Comparison Table
| Provider Setup | 1K MAU | 10K MAU | 50K MAU | 100K MAU |
|---------------|--------|---------|---------|----------|
| Current Stack | $X | $X | $X | $X |
| Alternative 1 | $X | $X | $X | $X |
| Alternative 2 | $X | $X | $X | $X |
Include a brief note on migration effort and trade-offs for each alternative.
============================================================
PHASE 7: WRITE REPORT
============================================================
Write the complete analysis to `docs/cost-analysis.md` in the project
(create the `docs/` directory if it doesn't exist).
Report structure:
```markdown
# Infrastructure Cost Analysis
Generated: [date]
Project: [project name]
Detected Providers: [list of providers found]
Region(s): [detected regions]
## Executive Summary
| User Tier | Monthly Cost | Per User/Month | Top Cost Driver |
|-----------|-------------|----------------|-----------------|
| 1K MAU | $X | $X.XX | [service] |
| 10K MAU | $X | $X.XX | [service] |
| 50K MAU | $X | $X.XX | [service] |
| 100K MAU | $X | $X.XX | [service] |
Key findings:
- [top 3 insights]
## Detected Infrastructure
[Services inventory from Phase 1]
## Compute Services
[Table from Phase 1.2]
## Database Services
[Table from Phase 1.3]
## Per-Action Cost Breakdown
[Table from Phase 2.3]
## Background/Fixed Costs
[Table from Phase 2.4]
## User Behavior Assumptions
[Profiles from Phase 3]
## Cost Projection by Tier
[Full table from Phase 4.7]
### Cost Distribution (100K MAU)
[Rank each service by % of total cost]
## Optimization Recommendations
### Quick Wins
[Items from Phase 5.3]
### Medium-Term
[Items from Phase 5.3]
### Architectural Changes
[Items from Phase 5.3]
## Provider Comparison
[Comparison table and notes from Phase 6]
## Assumptions & Methodology
- Detected providers: [list]
- Pricing region(s): [regions]
- Pricing as of: [date]
- User behavior profiles: [methodology]
- Operations counted by code path tracing
- Free tier deductions applied to all tiers
- External service fees at standard rates
- All costs in USD
```
============================================================
STRICT RULES
============================================================
- Read ACTUAL code to count operations. Do not guess or use generic estimates.
- Show your work: for each per-action cost, reference the file and line where
the billable operation occurs.
- Use current provider pricing (search the web if needed to confirm rates).
- Account for free tiers — do not overstate costs at low tiers.
- Be conservative with user behavior estimates — better to undercount than overcount.
- Include external service costs (Stripe, Twilio, etc.) — these often dominate at scale.
- Round to 2 decimal places for per-user costs, whole dollars for totals.
- Do NOT propose code changes. This is an analysis skill, not a fix skill.
- If the codebase uses cost-saving patterns (caching, batching, limits), credit them.
- Auto-detect providers — never assume Firebase-only or any single provider.
============================================================
OUTPUT
============================================================
After writing the report file, print a brief summary:
## Cost Analysis Complete
- Report: `docs/cost-analysis.md`
- Providers detected: [list]
- Services analyzed: [count]
- Compute functions audited: [count]
- User actions modeled: [count]
- Optimization recommendations: [count]
**Monthly cost at key tiers:**
| 1K MAU | 10K MAU | 50K MAU | 100K MAU |
|--------|---------|---------|----------|
| $X | $X | $X | $X |
**Top 3 cost drivers at 100K MAU:**
1. [service] — $X/month ([N]% of total)
2. [service] — $X/month ([N]% of total)
3. [service] — $X/month ([N]% of total)
**Top 3 optimization opportunities:**
1. [description] — saves ~$X/month
2. [description] — saves ~$X/month
3. [description] — saves ~$X/month
**Provider comparison (100K MAU):**
- Current stack: $X/month
- Alternative: $X/month ([savings/increase])
NEXT STEPS:
- "Review the assumptions in docs/cost-analysis.md and adjust user behavior profiles if needed."
- "Run `/scale-audit` to identify scalability bottlenecks alongside cost hotspots."
- "Run `/iterate` to implement the Quick Win optimizations."
============================================================
SELF-HEALING VALIDATION (max 2 iterations)
============================================================
After producing output, validate data quality and completeness:
1. Verify all output sections have substantive content (not just headers).
2. Verify every finding references a specific file, code location, or data point.
3. Verify recommendations are actionable and evidence-based.
4. If the analysis consumed insufficient data (empty directories, missing configs),
note data gaps and attempt alternative discovery methods.
IF VALIDATION FAILS:
- Identify which sections are incomplete or lack evidence
- Re-analyze the deficient areas with expanded search patterns
- Repeat up to 2 iterations
IF STILL INCOMPLETE after 2 iterations:
- Flag specific gaps in the output
- Note what data would be needed to complete the analysis
============================================================
SELF-EVOLUTION TELEMETRY
============================================================
After producing output, record execution metadata for the /evolve pipeline.
Check if a project memory directory exists:
- Look for the project path in `~/.claude/projects/`
- If found, append to `skill-telemetry.md` in that memory directory
Entry format:
```
### /cost-analysis — {{YYYY-MM-DD}}
- Outcome: {{SUCCESS | PARTIAL | FAILED}}
- Self-healed: {{yes — what was healed | no}}
- Iterations used: {{N}} / {{N max}}
- Bottleneck: {{phase that struggled or "none"}}
- Suggestion: {{one-line improvement idea for /evolve, or "none"}}
```
Only log if the memory directory exists. Skip silently if not found.
Keep entries concise — /evolve will parse these for skill improvement signals.
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