Install guide · 2026-04-30

The MCP install shortlist — 19 community servers that earn an A in our 101-repo audit (April 2026)

If you're an indie developer or small team picking a Model Context Protocol server to drop into Claude Code, Cursor, Windsurf, or Codex this week, you do not need to read all 101 audit pages on our public board. Of the 101 most-installed community MCP servers in our April 2026 corpus, exactly 19 earned an A grade — clean across all six axes, no high-severity findings, no credential echoes, no SSRF in tool handlers. Here are all 19, grouped by what they actually do, with the trade-offs an indie buyer cares about.

How the shortlist was built

SkillAudit v0.2.1 clones every audited repo at its default branch HEAD into an ephemeral sandbox, walks the source tree, and runs six static checks over the .js / .ts / .py sources: SSRF, command-exec, credential handling, permissions hygiene, maintenance signals, and documentation completeness. It also runs an LLM-assisted prompt-injection probe against the MCP tool surface — though that probe is currently gated on ANTHROPIC_API_KEY availability and is reported separately when active. Each axis gets a 0–100 score; the overall grade is the worst-axis floor (security-prioritised). A repo earns an A when every axis lands at 90 or above, no production-source findings exceed warn-level, and metadata signals (declared runtime, recent push, present README) check out. The methodology page at skillaudit.dev/methodology documents every cap and deduction.

The corpus is 101 of the most-installed community MCP servers as of April 2026 — sourced from the official modelcontextprotocol/servers registry, the punkpeye/awesome-mcp-servers list, the mcp-server-list aggregators, vendor-official releases (Cloudflare, Stripe, Heroku, GitHub, MongoDB, AWS, Azure, Anthropic, etc.), and the indie-author repos most cross-linked across the above. The roster is not "the top 101 by install count" — there is no public install counter for MCP — but it is the 101 a buyer in 2026 is most likely to encounter when searching "MCP server for X".

Of those 101: 19 A, 0 B, 30 C, 10 D, 42 F. The full grade distribution is visible on the public audit board. The 19 below are the entire A-grade set as of this scan.

Vector and embedding databases (5)

The largest A-grade category. Vector databases are typically narrow-surface MCPs — a tool to upsert, a tool to query, a few namespace and index management tools. Narrow surface means a small attack surface, which means it's easier to write correctly, which is why this category dominates the A grades. If you are building a RAG pipeline or agent memory, your safe-by-default vector backend is on this list.

Operational databases (4)

The four A-grade operational databases all share a careful pattern: connection strings live in environment variables (never logged), tools wrap parameterised queries (no string-concat SQL), and the surface area is intentionally narrow (a few schema-introspection tools plus an execution tool that the host application is expected to authorise). If your agent needs to read or write to a real database, these four are the safe-by-default picks.

Search and web fetch (5)

This is the category most likely to fail an audit — fetching arbitrary URLs the LLM hands you is the canonical SSRF anti-pattern, and "give the agent a browser" is one of the broadest attack surfaces in the MCP ecosystem. The five A grades below all handle the URL-trust problem deliberately: either by restricting traffic to a vendor-managed search endpoint, by sandboxing browser execution, or by being honest about being a generic fetcher and documenting the operational expectation that you don't pipe LLM output to it without a layer in between.

Backend platforms and files (3)

Three A grades for "the agent needs to talk to a real product backend or file store" use case. Each one wraps a managed service whose own API surface defines the trust boundary, and each handles credentials with the careful pattern (env-var reads not echoed back into tool responses).

Voice and audio (1)

Frameworks and adapters (1)

Three indie-dev install scenarios — which to pick

The shortlist is most useful when you start from your actual use case rather than the catalogue. Three common indie shapes and the safe-by-default picks for each:

You're building a RAG agent for a Claude Code project

You need a vector backend, a web-fetch tool, and probably a search tool. The A-grade default stack is Qdrant or Pinecone for vectors (Pinecone if you don't want to run infrastructure, Qdrant if you do), FireCrawl for converting web pages to clean markdown, and Exa for high-quality search retrieval. All three pair well; none have overlapping responsibilities. If you also need a memory layer for cross-session context, drop Redis in for working memory and reserve the vector DB for long-term embeddings.

You're letting an agent query a data warehouse

You almost certainly already know which warehouse — pick the matching A-grade MCP. Snowflake, ClickHouse, Couchbase are all on the shortlist. Pair with FastAPI-MCP if you're standing up a thin API layer in front of the warehouse to let the agent run named queries instead of arbitrary SQL — that's the more conservative pattern for agent-data integration in 2026 and it pulls two A grades into the same stack.

You're building a research-and-summarise agent

The agent needs to navigate the web, scrape JS-rendered pages, and store its working notes. The A-grade default stack is Microsoft Playwright for browser automation, FireCrawl or fetch-mcp for direct HTTP fetches (Playwright handles JS-rendered pages, FireCrawl handles markdown conversion, fetch-mcp handles raw HTTP — they complement rather than compete), and Pinecone or Qdrant for the agent's note store. DuckDuckGo covers free web search. Vectara is a single-MCP alternative if you'd rather have managed RAG instead of assembling vector + retrieval + reranker yourself.

What's NOT on this list (and why)

Several MCPs you might expect to see here didn't land at A. The honest reasons:

Honest caveats

Three things to keep in mind when using this shortlist as a buying signal.

First, the rubric is calibrated toward MCP-shape risk: SSRF in tool handlers, command-exec primitives, credential echo on return paths, prompt-injection susceptibility on the tool-output channel. It does not certify that the underlying service is bug-free, that the MCP is feature-complete, or that the upstream product is well-priced. A repo can earn an A and still be the wrong tool for your use case; that's a feature-fit decision the audit doesn't make for you.

Second, grades are time-bound. This list reflects the April 2026 scan of the corpus. A botched maintainer commit can drop a repo from A to D in a single week — it has happened in the corpus already. The install-gate post recommends a 30-day re-scan cadence; for an indie dev installing once and living with it for months, sanity-checking the audit page before each upgrade is a 30-second hygiene step.

Third, the engine has a known calibration question. The current pass over a repo treats a finding in examples/ or scripts/ the same way it treats a finding in src/, with one exception (the tests/ down-weight). Engine v0.3 will subdivide further — runtime tool surface vs examples vs scripts vs benchmarks — at which point a handful of repos at the C / D edges will likely move. The 19 A grades on this list are unaffected by the calibration update because they have no high-severity findings anywhere in the source tree, in any context. The shortlist is the most stable corner of the rubric.

FAQ

Why are there only 19 A grades and zero B grades?

Score-distribution property of the current rubric. A repo with no high-severity findings on any axis lands at 90+ across the board (= A). A repo with a single high-severity finding takes a -30 on that axis and lands at 70 on it (= C). The intermediate case (high finding plus successful mitigation evidence) is rare in the corpus. v0.3 is expected to introduce more B grades; until then, B-and-up is functionally equivalent to A-and-up.

Is the shortlist exhaustive — could a great MCP not be on it?

Yes — the corpus is 101 repos, not the entire MCP ecosystem. Submit any MCP you'd like to see audited via the audit form and we'll add it to the next scan. If you're an MCP author, embed the badge on your README so future visitors see the grade at install time.

Should I just install all 19?

No. Each MCP added to a Claude Code or Cursor session expands the tool surface the LLM has to reason about, which dilutes prompt quality and increases the prompt-injection blast radius. Pick the smallest set that covers your use case — the three indie scenarios above suggest 3–5 MCPs is usually the right number. The audit is a "safe to install if needed" signal, not a "you should install this" signal.

How often is the corpus re-scanned?

Currently re-scanned on demand — when a maintainer flags a fix, when a new repo is submitted, or when the engine itself is updated (v0.2.1 → v0.3 forthcoming). The public board shows the scan date for each report card. A cron-driven weekly re-scan is on the roadmap; for now, treat April 2026 as the snapshot date for everything on this list.

Can I trust the grade for my own use case?

The grade summarises six axes that matter for most agent use cases. For specialised contexts (regulated finance, healthcare PHI, government workloads), pair the audit grade with whatever vendor-side compliance attestations you require — SOC 2, HIPAA BAAs, FedRAMP. The audit doesn't speak to those; it speaks to the source-code shape the MCP's tool handlers actually have. Both signals matter.

Is this list paid placement?

No. SkillAudit's free tier audits any public repo, the rubric and methodology are open, and grade placement is mechanical from the engine's score. The 19 entries above earned A grades because their source code passed the rubric — not because anyone paid for the placement. The same engine ran on the 42 F grades, with the same deductions.

Related posts and pages

Picking an MCP server this week? Start with the public board.

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