Is 21st Dev safe and trustworthy?

tashan scores 21st Dev on public evidence — tashan score 79.0/100, it is currently active, no known advisories against the current release. Audit scope: OSV advisories, install-time scripts, build provenance and declared permission surface. We do not review source code or execute the capability.

How do I install 21st Dev?

In Claude Code: run `claude mcp add 21st-dev-cli -- npx -y @21st-dev/cli`. In Cursor / Claude Desktop, add it to mcp.json / claude_desktop_config.json.

‹ The Index

21st Dev

npm

The 21st CLI: search, retrieve and install 21st.dev components from your terminal, and configure the 21st MCP for your editor.

Works with: Claude Code, Cursor, Claude Desktop, Codex CLI, Gemini CLI, Cline, Windsurf, VS Code (installable)
installable: each client documents how to load an MCP server of this type — that is the client's promise, not a claim verified against this capability

Install (Claude Code):

claude mcp add 21st-dev-cli -- npx -y @21st-dev/cli

tashan score: 79.0
Adoption: 7.2k/wk
Upkeep: 100.0
Freshness: 99.0
Evidence coverage: 100% of the inputs this score can use
Health: active
License: MIT

Security audit

Every finding is shown in full — which advisory, the version that fixes it, and the exact command run at install time. Nothing in this audit is behind a licence.

No known advisoriesclearchecked against OSV for 1.16.0 — this package, not its dependency tree

No access inferred from declared dependenciesnothing it depends on reaches files, shell or network. This reads declarations only — built-in APIs are invisible to it, so absence of a declaration is not absence of access

No build provenanceno attestation — the published artifact cannot be traced to its source

What changed recently

2026-08-24 @21st-dev/cli published 1.16.0, was 1.15.1 A new release is available.

You are reading this because you came looking. tashan Pro gives tashan doctor the history behind it, so a run over your own config says which of YOURS moved.

You searched for one. Check the rest of your stack:

npx tashan-cli doctor

Reads the config already on your machine and names what is dead, deprecated or running code at install time. No account, nothing uploaded.

tashan Pro$6/mo

We recorded 1 change to 21st Dev in the last 45 days. Pro tells you on the day — for the servers in your own config, not the ones you thought to look up.

Every score since we started measuring, for any capability
The named replacement when something you run is dying — not just that it is
tashan doctor over the config you already have, on your machine

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[![tashan](https://tashan.sh/badge/pkg-21st-dev-cli.svg)](https://tashan.sh/capability/pkg-21st-dev-cli.html)

npm ↗ · source ↗ · pkg:@21st-dev/cli

Already running this? Check your whole config — free, in your browser, nothing installed. Or npx tashan-cli doctor locally, which sends nothing at all.

Measured 2026-08-25 · scorer s5 · how · something wrong here?