Numbers-LE: Zero Hassle Number Extraction

Pull every number out of the current file in one keystroke
JSON, YAML, CSV, TOML, INI, and Environment files

Useful? A star or rating is how other developers find it — ★ GitHub · ★ Marketplace · ★ Open VSX

What it does

Open a file, press Ctrl+Alt+N (Cmd+Alt+N on Mac), and every numeric value in the document lands in a new editor — deduplicate and sort it from there. Works in VS Code and in VS Code–based editors like Cursor and VSCodium (installable from Open VSX).

• Data validation — pull the numbers out of a config or fixture and eyeball ranges at a glance
• Config audits — compare ports, thresholds, and limits across INI/TOML/.env files
• CSV work — extract everything, one column, or several columns into separate documents

Use it from an AI agent

The same engine runs as an MCP server, so an agent can call it directly instead of you running a command.

extract_numbers(content, format?, filename?, dedupe?, maxResults?)

Returns the values in document order, capped at 500 by default with meta.truncated. A format is optional — anything unrecognised is scanned as plain text rather than refused.

The server takes content and returns data — it reads no files and makes no network requests of its own. Published as numbers-le-mcp on npm and as io.github.nolindnaidoo/numbers-le in the MCP registry.

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

npm install -g numbers-le-mcp

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

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

Supported formats

The shared policy (one heuristics module, applied to every format): only finite numbers are extracted — NaN and inf/.inf never appear in results — and a coerced string must be numeric in full: plain decimals with optional sign, decimal point, and exponent. For unrecognized file types you can pick a format explicitly or fall back to a plain-text scan (no grammar: v1.2.3 reads as 1.2 and 0.3).

Commands

Settings

Languages

Twelve languages besides English:

German · Spanish · French · Indonesian · Italian · Japanese · Korean · Portuguese (Brazil) · Russian · Ukrainian · Vietnamese · Chinese (Simplified)

Both halves are covered — the manifest (command titles, setting names and descriptions) and everything shown while the extension runs (notifications, the status bar, quick-picks and prompts). The extension follows VS Code's display language, so it matches whatever the editor is already set to; no setting of its own.

Privacy & security

• No network access. The extension never sends data anywhere. The telemetryEnabled setting only writes events to a local Output Channel you can inspect (Numbers-LE).
• The MCP server holds the same line. It takes content as an argument and returns data: no filesystem access, no network calls, no telemetry. Your agent already has file-read tools, so duplicating them inside the server would add a path-traversal surface for no capability. check:mcp-bundle fails the build if the server ever imports something that could reach either.
• Error notifications redact home directories and credential-shaped fragments.

Development

bun install
bun run build            # esbuild bundle -> dist/extension.js
bun run typecheck        # tsc --noEmit (includes tests)
bun run test             # vitest unit suite
bun run test:integration # real VS Code extension host
bun run lint             # biome
bun run package          # VSIX into release/

Architecture and conventions live in AGENTS.md. Changes are tracked in CHANGELOG.md.

Performance

Median of 7 runs after warmup, on Apple M5 Pro, 24 GB RAM, Node 24.3.0. Inputs are generated by scripts/benchmark.ts rather than checked in, so the sizes above are exactly what was measured. Reproduce with bun run benchmark.

These are machine-specific and are not asserted in CI — a benchmark that gates a build only tells you how busy the runner was.

Testing

309 test cases across 21 files, plus an integration suite that runs in a real VS Code extension host and an end-to-end test that installs the built .vsix into a clean profile.

Generated from coverage/coverage-summary.json by scripts/coverage-readme.js; CI fails if this section drifts from a fresh run. Reproduce with bun run test:coverage.

More from the LE Family

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

All ten also ship as MCP servers — npx <name>-mcp gives any agent the same engine.

• String-LE - Extract string values for i18n from JSON, YAML, CSV, TOML, INI, and .env
• Paths-LE - Extract file paths from JS/TS imports, JSON, HTML, CSS, TOML, CSV, and .env
• EnvSync-LE - Spot missing keys across your .env files, with a markdown report
• Regex-LE - Find, test, and validate regular expressions with ReDoS screening
• Secrets-LE - Detect and sanitize credentials locally, before you commit
• Scrape-LE - Check whether a page is scrapeable before you write the scraper
• Colors-LE - Extract and analyze colors from CSS, SCSS, LESS, Stylus, HTML, JS/TS, and SVG
• URLs-LE - Extract URLs from documentation, configs, and code
• Dates-LE - Extract and analyze dates from logs, configs, and code

Also by nolindnaidoo

Rust

• pixelcoords — Freeze your screen, mark regions, get pixel-exact coordinates and crops pixelcoords.dev · crates.io · docs.rs
• pixelactions — Consume human-verified coordinates, perform the interaction, confirm it landed pixelactions.dev · crates.io · docs.rs

Contact Developer — GitHub · LinkedIn

License

MIT © nolindnaidoo