Auxiliar

MCP server so your agent stops picking the wrong cloud services.

Your AI coding agent recommends services based on stale training data. It doesn't know SendGrid killed its free tier, that Auth.js is in maintenance mode, or that Neon moved to usage-based pricing. This MCP server fixes that.

74 cloud services. 16 categories. Manually verified pricing. 31 compatibility rules. No signup, no API key.

Install

# Claude Code
claude mcp add auxiliar -- npx auxiliar-mcp

# Cursor (add to .cursor/mcp.json)
{ "auxiliar": { "command": "npx", "args": ["auxiliar-mcp"] } }

# Any MCP client
npx auxiliar-mcp

What agents get wrong today

What your agent says	What's actually true
"Use SendGrid — it has a free tier"	Free tier removed March 2025. 60-day trial only.
"Use Auth.js for your Next.js app"	Maintenance mode. Core team joined Better Auth Sept 2025.
"PlanetScale has a generous free tier"	Free tier removed April 2024.
"Neon Launch is $19/month"	Now usage-based, starting from ~$0.
"Clerk free tier is 10K MAU"	Restructured to 50K MRU (Feb 2026).
"Use Turso with Prisma"	Prisma needs @prisma/adapter-libsql. Use Drizzle instead.

How it works

Five tools your agent can call:

recommend_service  → Best service for your constraints (budget, GDPR, edge, framework, lock-in)
get_pricing        → Verified pricing tiers and hidden costs
get_risks          → Gotchas, breaking changes, and things that will bite you
check_compatibility → 31 rules for known conflicts (Turso+Prisma, Better Auth+Workers, etc.)
setup_service      → CLI commands, env vars, signup URLs

Example

Agent: "I need a free database for Cloudflare Workers"

→ recommend_service(need="database", budget="free", constraints="edge, zero cold starts")

{
  "provider": "turso",
  "reason": "Edge-native SQLite with zero cold starts and embedded replicas",
  "pricing": { "free_tier": "5 GB storage, 100 databases" },
  "risks": ["Not PostgreSQL — limited ORM support"],
  "warnings": ["Migration note: SQLite-based — switching to Postgres later requires rewrite"],
  "key_features": ["SQLite/libSQL", "embedded replicas", "zero cold starts"],
  "cli_available": true,
  "cli_install": "brew install tursodatabase/tap/turso",
  "alternatives": [
    { "provider": "cloudflare-d1", "trade_off": "Cloudflare-only, limited tooling" },
    { "provider": "neon", "trade_off": "Has 350ms cold starts on free tier" }
  ]
}

Services covered

Database: Neon, Supabase, Turso, PlanetScale, Render Postgres, AWS RDS, Railway Postgres, Cloudflare D1 Email: Resend, Postmark, SendGrid, AWS SES, Mailgun, Listmonk Auth: Better Auth, Clerk, Auth0, Firebase Auth, Supabase Auth, Auth.js Payments: Stripe, Lemon Squeezy, Paddle, RevenueCat Deploy: Vercel, Railway, Render, Fly.io Search: Algolia, Typesense, Meilisearch, PostgreSQL FTS CMS: Sanity, Contentful, Strapi, Payload, Keystatic, Directus, Ghost Monitoring: Sentry, Datadog, PostHog, Grafana Cloud, BetterStack, Highlight.io Storage: Cloudflare R2, AWS S3, Uploadthing, MinIO Cache: Upstash Redis, Momento, Dragonfly Queues: BullMQ, Inngest, Trigger.dev, AWS SQS, CloudAMQP Vector DB: Pinecone, Weaviate, Qdrant, Chroma LLM APIs: OpenAI, Anthropic, Google AI, Groq, Together AI, Ollama SMS: Twilio, Vonage, MessageBird Feature Flags: LaunchDarkly, Statsig, Flagsmith, Unleash Cron: Inngest, Trigger.dev, QStash, Vercel Cron, Cloudflare Cron

Constraints

Constraint	Example
Framework	framework: "nextjs", "sveltekit", "fastapi", "express"
Budget	budget: "free", "cheap", "enterprise"
Region	region: "eu"
GDPR	constraints: "GDPR"
Edge	constraints: "edge, zero cold starts"
Lock-in	constraints: "no vendor lock-in"
Open source	constraints: "open source"
Features	constraints: "branching, webhooks, inbound email"

Category aliases work too: "llm-api", "file-storage", "vector-db", "background-jobs", etc. (47 aliases total).

Data quality

• Every pricing page verified by actually browsing it in Chrome (not scraping or WebFetch — many are JS-rendered)
• 307 automated test assertions
• Tested with 50+ agent runs across 8 iterations, scoring 9/10 on recommendation accuracy
• Each entry has a last_reviewed date. Re-verified monthly.

Privacy

The server sends anonymous usage pings (service names and query parameters, no project code or file paths) to help prioritize which services to verify next. Disable with:

AUXILIAR_TELEMETRY=off

Data is bundled in the npm package. No network calls needed for recommendations.

Links

• npm
• auxiliar.ai — comparison site with full service entries
• MCP server source

License

MIT