envsync-le-mcp

envsync-le-mcp

An MCP server that compares dotenv files and reports which keys are missing from which — names only, never values — the comparison engine behind the EnvSync-LE editor extension, exposed as a tool an agent can call.

No dependencies, no network calls, no filesystem access. Content goes in, structured results come out.

Use it

Point any MCP host at npx envsync-le-mcp.

Claude Code

claude mcp add envsync-le -- npx -y envsync-le-mcp

Anything with a JSON config — Cursor, Windsurf, Claude Desktop:

{
  "mcpServers": {
    "envsync-le": {
      "command": "npx",
      "args": ["-y", "envsync-le-mcp"]
    }
  }
}

VS Code needs nothing here. Install the extension instead — it carries this server and registers it for you: VS Code Marketplace · Open VSX

No Node? The same compare_env_files tool ships in a static Rust binary: cargo install envsync-le, then envsync-le mcp (crates.io). The two servers answer identically — one fixture corpus runs against both and CI fails if they diverge. The binary additionally offers envsync_le_check, which discovers the dotenv files in a directory; this server reads no files, which is what lets an agent call it anywhere.

Prefer a global install to npx on every launch:

npm install -g envsync-le-mcp

{
  "mcpServers": {
    "envsync-le": { "command": "envsync-le-mcp" }
  }
}

No environment variables, no API key, no configuration of its own. To check it before wiring it into anything:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | npx -y envsync-le-mcp

If that prints the tool name, the server works.

The tool

compare_env_files

argument	type
files	object[]	required. The dotenv files to compare, each { "path": ".env", "content": "…" }.
mode	string	auto (the default) compares every file against the union of all keys, so nothing can be extra; template compares every file against one.
templatePath	string	Which file is the template. Required when mode is template.
caseSensitive	boolean	Compare key names case-sensitively. Default true.
maxResults	number	Default 500, ceiling 5000.

Returns the overall status — in-sync, missing-keys, extra-keys or parse-error — each file with its key count, and the keys missing from each file (and, in template mode, extra in it) by name only. A value never leaves the tool. maxResults caps the mismatches returned, and meta.truncated says whether any were dropped.

{
  "ok": true,
  "data": {
    "status": "missing-keys",
    "files": [
      {"path": ".env", "type": "base", "keyCount": 2},
      {"path": ".env.example", "type": "example", "keyCount": 1}
    ],
    "missingKeys": [
      {
        "filepath": ".env.example",
        "keys": ["DB_HOST"],
        "reference": ".env"
      }
    ],
    "extraKeys": []
  },
  "diagnostics": [],
  "meta": {
    "tool": "compare_env_files",
    "count": 1,
    "truncated": false
  }
}

Extraction is heuristic, and what it deliberately does not match is documented as carefully as what it does — see the extension README.

Also in the MCP registry

io.github.nolindnaidoo/envsync-le — registry.modelcontextprotocol.io

Nine more like it

One tool each, same shape: content in, structured data out, no network and no filesystem. Every one is on npm as <name>-mcp and in the MCP registry as io.github.nolindnaidoo/<name>.

Package	Tool	Extracts
urls-le-mcp	extract_urls	URLs, with protocol and position
colors-le-mcp	extract_colors	colors from stylesheets and code
dates-le-mcp	extract_dates	dates and timestamps
paths-le-mcp	extract_paths	file and directory paths
numbers-le-mcp	extract_numbers	numeric values
string-le-mcp	extract_strings	string values
regex-le-mcp	extract_patterns	regexes, with a ReDoS verdict
secrets-le-mcp	detect_secrets	credentials, masked — never the value
scrape-le-mcp	analyze_robots_txt	whether a path may be crawled

Every tool in the family, one page: letools.dev

Built by

Nolin Naidoo — Chief Engineer, AI/ML & Platform Architecture. nolindnaidoo.com · GitHub · LinkedIn

Also from the same workshop

Twelve Rust tools built the same way: small, single-purpose, and driven by a machine rather than a person. pixelcoords and pixelactions make up one loop — pixelcoords answers where, pixelactions acts there. The ten LE crates are the terminal half of the extensions they sit in: the same detection, held to the extension's own corpus, and an exit code instead of a results editor.

pixelcoords	Freeze your screen, mark regions, get pixel-exact coordinates and crops	site · crates.io · docs.rs
pixelactions	Consume human-verified coordinates, perform the interaction, confirm it landed	site · crates.io · docs.rs
paths-le	Find every path in a codebase and report whether it still points at anything	crates.io
secrets-le	Find hardcoded credentials, and never print one	crates.io
urls-le	Extract every URL from a codebase, with its protocol and exact position	crates.io
regex-le	Find every regex in a codebase and report which can be driven into catastrophic backtracking	crates.io
string-le	Get every string in a codebase out where a person can read them	crates.io
numbers-le	Find every hardcoded number in a codebase so a person can check them	crates.io
envsync-le	Compare the dotenv files in a tree and say which keys are missing from which	crates.io
colors-le	Find every colour in a codebase, and say which are not in your palette	crates.io
dates-le	Extract every date and timestamp, and the exact instant each one resolves to	crates.io
scrape-le	Check whether a page is scrapeable before the scraper is written	crates.io

Licence

MIT © Nolin Naidoo