Numbers-LE: Zero Hassle Number Extraction

Pull every number out of the current file in one keystroke
JSON/JSONC, YAML, CSV/TSV, TOML, INI, Environment files, and twelve source languages

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

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

Install

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.

Python, Rust, Go, Java, Kotlin, C#, C, C++, JavaScript, TypeScript, SQL and shell are read by a numeric-literal extractor that understands hex 0xFF, binary 0b1010, octal 0o755 and legacy 0755, digit separators 1_000_000 and 1'000, and suffixes 123n, 1.5f, 10u32, 100L — and that knows u32 is a type name, not the number 32. A dialect changes an answer: 0755 is 493 in C, C++, Go and Java, and 755 in Rust, Python 3, Kotlin and C#.

Every finding carries the notation it was written in — decimal, hex, binary, octal, scientific, bigint. For anything left over 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).

The CLI

The same extraction runs from a terminal or a shell pipeline: a Rust CLI in crate/, sharing one corpus with the extension — crate/fixtures/ — so the two can never read a document differently.

numbers-le .                     # every number in the tree, as JSON
numbers-le --values config/      # just the numbers, one per line
numbers-le mcp                   # the same extraction over MCP on stdio

# the point of the whole thing:
numbers-le --values --dedupe src/ | sort -n > after.txt
diff before.txt after.txt        # what constants moved this release

Somebody has to verify that the rate in the code is the rate in the specification. A tax percentage, a retention window, a rounding boundary. In a regulated setting that check is a deliverable, and the person doing it usually has no checkout and never has the editor open.

Numbers are printed exactly as JavaScript prints them — 1e+21, not Rust's 1000000000000000000000. This tool's whole output is numbers as text, so the rendering is the contract, and the corpus pins it.

Exit codes follow grep — 0 numbers found, 1 none found, 2 the question was malformed.

Commands

Settings