Sigil MCP Server

sigil is a local signing tool and Claude Code integration that lets agentic coding tools use private keys without ever putting key material in the model's context window.

People connecting this server to Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-08-19 · ★ 3 · #285 OF 848 MAINTAINED OTHER · VERIFIED 2026-08-25

Apache-2.0 · TypeScript servers · how we verify → /methodology

01 · Install Sigil

before you install - you'll need

The README does not document required environment variables for a basic install.

Claude Code

claude mcp add cdrn-sigil -- npx -y sigild

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "cdrn-sigil": {
      "command": "npx",
      "args": [
        "-y",
        "sigild"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license Apache-2.0 - declared in the repository

npm package sigild - unscoped; check the name against the project README before installing

registry namespace io.github.cdrn is GitHub-verified and matches the repo owner

03 · What Sigil can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.0.12 · 2026-07-09

fix stale and inaccurate claims · raise default error correction L→M for scan reliability · add dependabot; refresh action pins to current releases · sigil rpc init - one-command signing-proxy setup · add ESLint +…

v0.0.11 · 2026-07-06

v0.0.10 · 2026-07-05

04 · Who maintains Sigil

sigil is maintained by cdrn. It's the only MCP server we track from this author; the repo dates to May 2026.

05 · Facts

repository: github.com/cdrn/sigil
category: other - ranked #285 of 848 actively-maintained other servers as of 2026-08-25.
release cadence: 5 releases in the last 90 days (latest 2026-07-09)
registry: io.github.cdrn/sigil (active, first published 2026-05-17 · 4 versions)
packages: npm:sigild

06 · Sigil FAQ

What is Sigil?

sigil is a local signing tool and Claude Code integration that lets agentic coding tools use private keys without ever putting key material in the model's context window.

Is Sigil still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-19 and it shipped 5 releases in the last 90 days. We re-verify nightly.

How do I install Sigil?

Run `npx -y sigild`. The README does not document required environment variables for a basic install. You can also paste the ready-made client config above.

Does Sigil run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Sigil

Alternatives to Sigil

Maintained other servers if Sigil isn't the fit.

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