Overview

treepeat is a tool that finds similarities in your codebase.

• Find duplicate code blocks meaningful to the language (classes/functions), not just lines (--ruleset none)
• Find near-duplicates, ignore whitespace, strings, high level AST nodes such as function and names (--ruleset default)
• Find structurally similar code, anonymizing identifiers, constants, etc (--ruleset loose)

Pull requests welcome: This is very much an proof of concept - I'm happy with it, but I haven't supported very many languages at present. PRs welcome!

Languages supported: astro, bash, css, go, html, javascript, lua, markdown, python, sql, typescript, java, kotlin, rust, yaml

Usage

Installation

pip install treepeat

detect

Scan a codebase for similar or duplicate code blocks using tree-sitter AST analysis and locality-sensitive hashing.

Key flags:

• --ruleset: Normalization ruleset to use (none, default, loose) - controls how code is normalized before comparison
• --similarity: Percent similarity from 1-100 (default: 100 for exact duplicates)
• --min-lines: Minimum number of lines for a match (default: 5)
• --diff: Show side-by-side comparisons of similar blocks
• --format: Output format - console (default) or sarif for CI integration
• --verbose: Show additional run metrics, including per-stage timing when available
• --progress: Show progress bars for long-running pipeline stages

# Find exact duplicates
treepeat detect /path/to/codebase

# Find near-duplicates with 80% similarity threshold
treepeat detect --similarity 80 /path/to/codebase

# Show diffs between similar blocks and use loose ruleset
treepeat --ruleset loose detect --diff --min-lines 10 /path/to/codebase

# Show parse progress and verbose stage timing
treepeat detect --progress --verbose /path/to/codebase

# Output results in SARIF format for CI tools
treepeat detect --format sarif -o results.sarif /path/to/codebase

--progress is intended primarily as interactive CLI feedback. The current implementation writes tqdm progress bars to stderr, leaving normal command output on stdout or --output.

Other sub commands

list-ruleset

List all rules in a ruleset, along with their descriptions. Use --language to see which rules apply to a specific language.

treesitter

Display how treepeat normalizes source code into tree-sitter tokens for similarity detection -- helpful for debugging why a certain section of a file might be similar to another. Shows the original source code side-by-side with the normalized token representation.

Dev setup

make setup
make test

Performance harness for benchmarking real repositories: tools/perf/harness.py (docs).

ADRs

Architecture Decision Records live in docs/adr.