Socket.dev alternative
A Socket.dev alternative for Claude skills and MCP servers
Socket.dev grades the npm package you're installing. SkillAudit grades the MCP server's tool-handler code that runs after you install it. The two scanners cover different halves of the same install decision — and the dangerous code in MCP usually lives on the half Socket doesn't model.
TL;DR
Socket is excellent at catching supply-chain risk: typo-squatted packages, install-script malware, suspicious behaviors injected into a postinstall, sudden permission expansions in a transitive dep. It treats the registry as the threat surface. An MCP server's risk is mostly different and downstream: an SSRF written into server.tool('fetch', async ({url}) => await fetch(url)), a credential echoed back through tool output, a prompt-injection payload smuggled in a tool response. None of that lives in package.json; it lives in tools/*.ts. We scanned 101 of the most-installed MCP servers: 50% had SSRF, 38% had credential-handling findings, 19% earned an A. Socket is genuinely useful — and most of those repos pass it cleanly.
Why teams look for a Socket.dev alternative when adopting MCP
Socket's core thesis is "package authors are sometimes adversaries." A new package version can quietly add an install-script that exfiltrates ~/.aws, a maintainer transfer can flip a 50-million-download dependency into a payload, a typo-squat can mimic a popular name and ride autocomplete into someone's npm install. That model is real, and Socket's behavioural feed is the right product for it.
An MCP server is usually a different shape. The repos on our public board are vendor-official releases or first-party indie projects with clean transitive trees. The package.json imports @modelcontextprotocol/sdk and a small handful of HTTP clients; Socket flags nothing because there's nothing supply-chain-shaped to flag. The risk is in the handler code the developer wrote this quarter — code that calls fetch(template_url) without validating the host, returns process.env.STRIPE_SECRET_KEY in a debug field, or trusts the LLM-supplied tool argument to be a clean string instead of a prompt-injection payload.
Three reasons buyers and authors look for a Socket alternative for MCP specifically:
- The dangerous surface is in tool handlers, not in the registry. Socket's behavioural model — install scripts, network at install time, environment access in postinstall — doesn't fire on a clean
npm installof a vendor-official MCP that ships SSRF in tool code. A scanner that reads the package source for the MCP-specific antipatterns is what's missing. - Buyers want a single buyer-readable grade for the install decision. Socket's package report is detailed, scoped to one package, and presented as a risk feed. A team lead deciding "do we let agents install this MCP server" wants A or F and a one-paragraph reason. SkillAudit's report cards are written for that decision.
- Prompt injection is a first-class threat for LLM tool use. Socket doesn't model it — that's not what Socket is for. SkillAudit runs an LLM-assisted prompt-injection probe against extracted tool handlers as a separate axis.
How SkillAudit is different
SkillAudit is a six-axis static + LLM-assisted scanner built specifically for Claude skills and MCP servers. The six axes — security, permissions hygiene, credential exposure, maintenance, client compatibility, documentation — were chosen by reading the actual source of vendor-official MCP releases that shipped vulnerabilities, not by porting a generic supply-chain taxonomy. The output is a single A–F grade plus a public report card at a stable URL the author can embed as a badge on their README.
Where Socket runs continuously against the npm registry feed, SkillAudit runs against any public GitHub repo, npm package, or uploaded ZIP — and it reads the tool-handler bodies, not just the manifest. Different layer of the install decision; complementary use cases.
Side by side
| Socket.dev | SkillAudit | |
|---|---|---|
| Threat model focus | Supply-chain risk: typo-squat, install-script malware, sudden permission expansion, maintainer takeover | MCP tool-handler SSRF, prompt injection, credential echo, permission scope |
| What it reads | Package manifests, install scripts, behavioural metadata, registry-wide telemetry | Tool-handler source code, env-var usage, fetch/exec call sites, README + manifest |
| Catches malicious npm publishes? | Yes — primary use case | No — explicitly out of scope |
Catches SSRF in fetch(url) tool handlers? | Generally no — it's not source code SAST | Yes — pattern-based static check tuned to MCP idioms |
| LLM-assisted prompt-injection probe | No | Yes — extracts tool handlers, red-teams them via Claude Haiku 4.5 |
| Credential-echo detection (env var → tool response) | No (different threat layer) | First-class axis; flags process.env.X in handler return paths |
| Single A–F buyer grade | Per-package risk score (0–100) | One letter grade + per-axis pass/warn/fail |
| Public per-repo report card URL | Yes (per package on socket.dev) | Yes (e.g. /audits/owner-repo/) |
| Public embed badge for authors | Yes (Socket badge — supply-chain framed) | Yes (skill-grade badge — written for marketplace listings) |
| Free tier scope | Free for public repos and personal use; usage-tiered | 3 audits/month on public repos; unlimited public reports |
| Starting paid price | Tiered self-serve; enterprise pricing for orgs | $19/mo (Pro), $99/mo (Team, 10 seats) |
| CI integration | Mature: GitHub App + checks, GitLab, Bitbucket | GitHub Action with min-grade gate (Pro) |
| Coverage outside npm | npm primary; PyPI, Go, Rust expanding | Any GitHub repo + npm + ZIP regardless of language; checks tuned to MCP/skill conventions |
What the data says
We ran SkillAudit against 101 of the most-installed Claude skills and MCP servers — the full live board is public and growing. The corpus includes vendor-official releases (Stripe, PayPal, MongoDB, Redis, Cloudflare, AWS, Azure, GCP, Heroku, Notion, Snowflake, Pinecone, Couchbase, Auth0, Resend, Brave, Vectara, Meilisearch, plus the nine official Anthropic MCP language SDKs), popular indie frameworks (FastMCP, mcp-use, mcp-agent), and community releases. Most of these packages would not raise a Socket flag — clean transitive trees, no install scripts, no maintainer drama.
Results: 50% (50/101) shipped SSRF findings, 38% (38/101) had credential-handling findings, 10% (10/101) had command-exec findings, and only 19% (19/101) earned an A grade. Full grade distribution: 19 A · 30 C · 10 D · 42 F. Methodology and per-repo grades are written up in our research post: The state of MCP server security, 2026.
The relevant point for the Socket comparison: a healthy supply chain at the registry level — which Socket measures — does not imply a safe tool surface at the handler level. The two failure modes are nearly disjoint, and the buyer's decision needs both signals. Socket says "the package wasn't published by a typo-squatter and didn't ship a malicious install script." SkillAudit says "the tools registered by this server, when invoked by an LLM, are unlikely to leak credentials or fetch attacker-controlled URLs." Both true, both useful, neither sufficient.
When Socket.dev is still the right choice
Socket is the right scanner for plenty of work — even for MCP authors. Specifically:
- You're worried about supply-chain attacks across your full dependency graph. Socket is the leader on that surface. SkillAudit doesn't model registry behaviour at all and never will.
- You install many third-party npm packages outside the MCP/skill world. A Node service that pulls in 600 transitive deps gets more value from Socket's registry telemetry than from SkillAudit's MCP-tuned static checks.
- You want continuous monitoring of new package versions. Socket's GitHub App watches every PR that bumps a dependency and surfaces behavioural changes between versions. That's a posture SkillAudit doesn't compete with.
- Your priority is catching malicious maintainer takeovers and typo-squats before they're installed. That is precisely what Socket was built for. Use it.
The most useful framing: Socket guards the registry; SkillAudit grades the handlers. They sit alongside each other in CI, not in opposition.
Switching cost
SkillAudit isn't a replacement for Socket — it's the second scanner you add when you ship MCP. Both can coexist in CI. A typical adoption path for an indie MCP author:
- Keep Socket's GitHub App (or self-serve install) on for supply-chain telemetry. Don't remove it.
- Add the SkillAudit GitHub Action with a minimum-grade gate (e.g. fail PR if grade falls below B).
- Drop the SkillAudit badge into your MCP server's README so reviewers and team buyers can read your handler-grade at a glance before installing.
Indie developers publishing skills to a public marketplace can use both at zero cost: Socket's free tier covers your supply-chain posture; SkillAudit's free tier covers your skill grade up to three audits a month.
Try SkillAudit on your repo — free
Paste any GitHub URL on the home page, get a graded report card in 60 seconds. Your repo joins the public board only if you opt in; private repos audit through a single-repo OAuth scope, never org-wide.