Numbers-LE

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

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What it does

Open a file, run Numbers-LE: Extract Numbers, 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, each with the notation it was written in and — for JSON, source code and plain text, where the position is exact — its 1-based line and column; a parsed format (YAML, TOML, CSV, INI, dotenv) carries no position rather than a guessed one. 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.

Configuring it by hand — any host with an MCP config file

Most hosts read a JSON config. Add one entry:

{

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

-y skips the install prompt on first run. Pin a version if you would rather not track releases — numbers-le-mcp@2.5.0.

Prefer not to go through npx on every launch? Install it once and point at the binary instead:

npm install -g numbers-le-mcp

{

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

It speaks MCP over stdio and needs no environment variables, no API key and no configuration of its own. To check it before wiring it into anything:

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

That prints the tool list and exits — if you see extract_numbers, the server works.

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. Install it from npm with npm install -g numbers-le (or run it with npx numbers-le) or from crates.io with cargo install numbers-le. Both install the same command and are held to the same output byte for byte, apart from the words a parser uses to refuse a broken document.

numbers-le .                     # every number in the tree; JSON on stdout when piped

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

Install it from npm (numbers-le) or from crates.io (numbers-le). Both install the same numbers-le command.

npm install -g numbers-le   # or run it once: npx numbers-le

cargo install numbers-le

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

No command is bound to a key by default. Give any of them one under Keyboard Shortcuts in the editor.

Settings

Languages

Twelve languages besides English:

German · Spanish · French · Indonesian · Italian · Japanese · Kore