Auxiliar

Unified MCP capability index so your agent stops picking the wrong tool.

New contributor? See ONBOARDING.md for the fast path into the project — 30-second / 5-minute / 30-minute tours, architecture map, glossary, and links to every proposal + retro.

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, that Neon moved to usage-based pricing, or that an auxiliar-nfs-e + Surya parser hits 100% field accuracy on Brazilian invoices. This MCP server fixes that — one find_capability query searches across cloud services, ClawHub skills, MCP servers, plugins, parsers, and public-data lookups.

80+ Capabilities indexed (71 cloud services + skills, MCPs, plugins, parsers, public-data sources). Chrome-verified pricing. Reproducible eval scores on real-world corpora. 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

Twelve tools your agent can call. Four unified Capability tools (preferred for new agents — search across every kind of indexed thing) plus eight legacy single-purpose tools (still wired for backward-compat).

Unified Capability tools (v0.11.0+): `` find_capability → Ranked search across services / skills / MCPs / plugins / parsers / data Filter by jtbd, element_type, agent_context. Pass a query or jtbd tag. get_capability → Full record by stable slug — pricing tiers, risks, install spec, deps, eval records, distribution surfaces. list_capabilities → Filtered enumeration. element_type / category / jtbd / agent_context. compare_capabilities → 2–5 ids → aligned row-per-field comparison structure. ``

Legacy single-purpose tools (still work; will be removed in a future version once consumers cut over): `` recommend_service → Best cloud service for your constraints get_pricing → Verified pricing tiers + hidden costs get_risks → Gotchas, breaking changes check_compatibility → 31 rules for known conflicts (Turso+Prisma, Better Auth+Workers, etc.) setup_service → CLI commands, env vars, signup URLs list_services → Cloud-service catalog by category solve_task → Per-task ranked tool recommendations (PDF OCR, NFS-e extraction, …) list_solve_tasks → Available /solve/ task rankings ``

Example (unified find_capability)

Agent: "I need to extract structured fields from Brazilian NFS-e invoices"

→ find_capability(query="Brazilian NFS-e invoice extraction", jtbd=["nfs-e-extraction"])

{
  "total_matches": 3,
  "results": [
    {
      "id": "nfs-e-parser",
      "element_type": "skill",
      "name": "nfs-e-parser",
      "score": 35,
      "page_url": "https://auxiliar.ai/skill/nfs-e-parser/",
      "install_command": "openclaw skills install tlalvarez/nfs-e-parser",
      "eval_score": 10.0,
      "jtbd_tags": ["nfs-e-extraction", "brazilian-invoice-parsing", "bookkeeping", ...]
    },
    {
      "id": "auxiliar-nfs-e",
      "element_type": "parser",
      "score": 30,
      "eval_score": 10.0,
      ...
    },
    ...
  ]
}

Example (legacy recommend_service)

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 cloud-service pricing page verified by actually browsing it in Chrome (not scraping or WebFetch — many are JS-rendered)
• Every Capability record validated against a Pydantic schema (Python) and a Zod schema (TypeScript) on every build — drift fails fast, never silently
• 1061 MCP TypeScript test assertions + 482 Python test assertions
• /solve/ task rankings backed by reproducible eval harnesses on real-world corpora — see /solve/pdf-text-extraction-mcp/ and /solve/nfs-e-extraction/ on auxiliar.ai
• Tested with 50+ agent runs across 8 iterations, scoring 9/10 on recommendation accuracy
• Each Capability has a last_verified 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