any-code-fingerprint

any-code-fingerprint

Deterministic source code fingerprinting, snippet hashing, and code (any programming language) similarity detection for Node.js and browsers

The package supports:

• Node.js (ESM and CommonJS)
• Browser usage (IIFE bundle)
• Pure JavaScript runtime (no native addons)
• Zero external runtime dependencies
• Language-agnostic usage across programming languages and source code formats (any code that can be read as text)

Research Note

This library is based on research work prepared for a publication currently under review for SEAA 2026.

Conference CFP link:

• https://easychair.org/cfp/SEAA2026

Installation

npm install any-code-fingerprint

Public API

Main exports:

• snippetFingerprint (alias to snippetFingerprint)
• compareFingerprints (alias to compareSnippetFingerprints)

Helpers:

• compareCodeSnippets(codeA, codeB, options?)
• findSimilarInDirectory(queryCode, rootDir, options?) (Node-only, exported from any-code-fingerprint/node)

Usage (Node.js ESM)

import {
  snippetFingerprint,
  compareFingerprints,
  compareCodeSnippets
} from 'any-code-fingerprint';

const codeA = 'function sum(a,b){ return a+b; }';
const codeB = 'function add(x,y){ return x+y; }';

const fpA = snippetFingerprint(codeA);
const fpB = snippetFingerprint(codeB);
const similarity = compareFingerprints(fpA, fpB);

console.log(similarity.score);

const direct = compareCodeSnippets(codeA, codeB);
console.log(direct);

Usage (Node.js CommonJS)

const {
  snippetFingerprint,
  compareFingerprints,
  compareCodeSnippets
} = require('any-code-fingerprint');

const result = compareCodeSnippets(
  'for(let i=0;i<10;i++){x+=i}',
  'for(let j=0;j<10;j++){sum+=j}'
);

console.log(result.score);

Directory Search (Node-only)

import { findSimilarInDirectory } from 'any-code-fingerprint/node';

const query = `
function normalize(items) {
  return items.map((x) => x.trim().toLowerCase());
}
`;

const output = await findSimilarInDirectory(query, './src', {
  topK: 20,
  minScore: 0.5,
  extensions: ['.js', '.ts'],
  excludeDirs: ['node_modules', 'dist', '.git'],
  maxFileSizeBytes: 300000,
  concurrency: 8,
  absolutePaths: false
});

console.log(output.results.slice(0, 5));

Browser Usage

Recommended with jsDelivr:

• ESM import: https://cdn.jsdelivr.net/npm/any-code-fingerprint@0.1.1/dist/index.mjs
• Global build: https://cdn.jsdelivr.net/npm/any-code-fingerprint@0.1.1/dist/index.browser.js

ES module

<script type="module">
  import { compareCodeSnippets } from 'https://cdn.jsdelivr.net/npm/any-code-fingerprint@0.1.1/dist/index.mjs';
  const result = compareCodeSnippets('const a=1', 'let b=1');
  console.log(result.score);
</script>

Global IIFE bundle

<script src="https://cdn.jsdelivr.net/npm/any-code-fingerprint@0.1.1/dist/index.browser.js"></script>
<script>
  const result = AnyCodeFingerprint.compareCodeSnippets('const a=1', 'let b=1');
  console.log(result.score);
</script>

Helper Options

compareCodeSnippets:

compareCodeSnippets(codeA, codeB, {
  fingerprintOptions: { numWindows: 4, normalize: true, filterStops: true },
  scoreOptions: { wGlobal: 0.4, wLocal: 0.3, wOrder: 0.15, wType: 0.15 },
  includeFingerprints: false
});

findSimilarInDirectory:

findSimilarInDirectory(queryCode, rootDir, {
  topK: 50,
  minScore: 0,
  extensions: ['.js', '.ts', '.py'],
  excludeDirs: ['node_modules', '.git', 'dist'],
  maxFileSizeBytes: 512000,
  concurrency: 8,
  absolutePaths: true,
  fingerprintOptions: { numWindows: 4, normalize: true, filterStops: true },
  scoreOptions: { wGlobal: 0.4, wLocal: 0.3, wOrder: 0.15, wType: 0.15 },
  includeFingerprints: false
});

Build and Test

npm install
npm run build
npm test

Build outputs:

• dist/index.mjs
• dist/index.cjs
• dist/node.mjs
• dist/node.cjs
• dist/cli.mjs
• dist/cli.cjs
• dist/index.browser.js

CLI

macOS — Homebrew (Apple Silicon)

brew tap ExeconOne/acf
brew install acf

Linux — apt (Ubuntu 20.04+ / Debian 12+)

curl -fsSL https://ExeconOne.github.io/any-code-fingerprint/gpg.key \
  | sudo gpg --dearmor -o /usr/share/keyrings/execonone-acf.gpg

echo "deb [arch=amd64 signed-by=/usr/share/keyrings/execonone-acf.gpg] \
https://ExeconOne.github.io/any-code-fingerprint stable main" \
  | sudo tee /etc/apt/sources.list.d/acf.list

sudo apt-get update
sudo apt-get install acf

Manual install (tarball)

macOS (Apple Silicon)

VERSION=0.1.13
curl -LO "https://github.com/ExeconOne/any-code-fingerprint/releases/download/v${VERSION}/acf-macos-arm64.tar.gz"
shasum -a 256 -c acf-macos-arm64.tar.gz.sha256
tar -xzf acf-macos-arm64.tar.gz
chmod +x acf-macos-arm64
sudo mv acf-macos-arm64 /usr/local/bin/acf

Linux (x64)

VERSION=0.1.13
curl -LO "https://github.com/ExeconOne/any-code-fingerprint/releases/download/v${VERSION}/acf-linux-x64.tar.gz"
shasum -a 256 -c acf-linux-x64.tar.gz.sha256
tar -xzf acf-linux-x64.tar.gz
chmod +x acf-linux-x64
sudo mv acf-linux-x64 /usr/local/bin/acf

Build binary locally

# on macOS
npm run build-mac-cli

# on Linux
npm run build-linux-cli

Artifacts are generated under artifacts/cli/v<version>/.

Commands

acf compare <fileA> <fileB> [options]
acf find <queryFile> <rootDir> [options]
acf fingerprint <file> [options]

find — search for similar files

Default output is one path per line, sorted by similarity (most similar first):

acf find snippet.js ./src

/home/user/project/src/utils.js
/home/user/project/src/helpers/string.js
/home/user/project/src/lib/parse.js

Pipe-friendly — works with standard Unix tools:

acf find snippet.js ./src | head -5
acf find snippet.js ./src | xargs grep "TODO"
acf find snippet.js ./src --min-score 0.8 | wc -l

Use --format table for the full scored breakdown:

acf find snippet.js ./src --format table

scanned: 142  matched: 38  errors: 0

rank  score      sim_global  sim_local   sim_order   sim_type    sim_bigram  path
----  ---------  ----------  ----------  ----------  ----------  ----------  ----
1     0.921034   0.998122    0.991450    0.843200    0.812300    0.764100    /home/user/project/src/utils.js
2     0.876541   0.987300    0.954200    0.801100    0.776400    0.712300    /home/user/project/src/helpers/string.js

Score components:

column	description
score	weighted average of all components
sim_global	global image similarity (whole-file token encoding)
sim_local	local window alignment similarity
sim_order	token type ordering pattern similarity
sim_type	token type distribution similarity
sim_bigram	token bigram distribution similarity

Available options:

--top-k <n>              return at most N results (default: 20)
--min-score <n>          minimum score threshold 0..1 (default: 0)
--ext .js,.ts,.py        file extensions to scan
--exclude dir1,dir2      directory names to skip
--max-file-size <bytes>  skip files larger than this (default: 512000)
--concurrency <n>        parallel workers (default: 8)
--relative               output relative paths instead of absolute
--format paths|table|json  output format (default: paths)
--weights g,l,o,t[,b]   custom metric weights (default: 0.4,0.3,0.15,0.15,0.2)

compare — compare two files directly

acf compare fileA.js fileB.js --format table

metric               value
-------------------  ----------
score                0.876541
sim_global           0.987300
sim_local_alignment  0.954200
sim_order            0.801100
sim_type             0.776400
sim_bigram           0.712300

fingerprint — inspect a file's fingerprint

acf fingerprint file.js

fingerprint summary
-------------------
tokens:        42
numWindows:    4
global shape:  64x64x3
order bins:    16
type bins:     16
bigram bins:   64

Quick Performance Benchmark

A local benchmark script is included to measure directory search speed:

npm run benchmark

Optional parameters:

npm run benchmark -- --files 2000 --runs 7 --concurrency 12 --topK 30

What it does:

• generates a synthetic recursive corpus of JavaScript snippets,
• performs one warm-up pass,
• runs findSimilarInDirectory multiple times,
• reports latency and throughput.

Reference Benchmark Results

Reference run date: April 26, 2026

Environment:

• Node.js: v20.19.0
• Platform: darwin arm64
• CPU: Apple M3 Max (16 cores)

Benchmark config:

• corpus size: 1200 files
• runs: 5
• concurrency: 8
• topK: 25

Measured results:

• average latency: 2854.471 ms
• p50 latency: 2854.459 ms
• p95 latency: 2856.994 ms
• throughput: 420.4 files/sec
• top hit score: 1.0

Notes:

• these values are reference numbers from this specific machine and dataset,
• real-world results depend on file sizes, language mix, storage speed, and CPU.

Notes

• The comparison API is deterministic for identical inputs.
• findSimilarInDirectory depends on fs, so it is not available in browsers.