Repository Analysis

FStarLang/FStar

A Proof-oriented Programming Language

5.7 Low AI signal View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of FStarLang/FStar, a F* project with 3,068 GitHub stars. SynthScan v2.0 examined 27,951 lines of code across 221 source files, recording 83 pattern matches distributed across 12 syntactic categories. The overall adjusted score of 5.7 places this repository in the Low AI signal band.

The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).

5.7
Adjusted Score
5.7
Raw Score
100%
Time Factor
2026-07-14
Last Push
3.1K
Stars
F*
Language
28.0K
Lines of Code
221
Files
83
Pattern Hits
2026-07-14
Scan Date
0.02
HC Hit Rate

What These Metrics Mean

Adjusted Score
Primary synthetic code indicator. Raw score normalised per 1,000 lines of code and multiplied by the temporal discount factor. This is the definitive comparative metric — use it to rank repositories by AI authorship density.
Raw Score
The unmodified sum of all severity-weighted, context-multiplied pattern match scores before temporal discounting. Reflects the absolute signal strength independent of when the repository was last active.
Time Factor
The temporal discount multiplier (0–100%) applied to the raw score. Repositories last updated before ChatGPT's launch (Nov 2022) receive a 5% factor. Full signal is only assigned to repositories active in the post-adoption era (Jan 2024+).
Pattern Hits
Total count of individual pattern matches across all files and categories. A high hit count with a low score may indicate a very large codebase with isolated AI snippets; a low count with a high score indicates dense, concentrated AI signatures.
HC Hit Rate
High+Critical pattern hits per file, averaged across the repository. This orthogonal signal catches repositories where a few files are densely packed with high-severity AI tells — a strong indicator even when the normalised score appears moderate due to codebase size.
Lines of Code / Files
Total lines and files analysed. The scanner examines 94 file extensions. These denominators are used to normalise the score, enabling fair comparison between repositories of vastly different sizes.

Score History

This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.

Severity Breakdown

Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.

CRITICAL 0HIGH 4MEDIUM 29LOW 50

Directory Score Breakdown

This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.

Pattern Findings

The scanner identified 83 distinct pattern matches across 12 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.

Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.

Decorative Section Separators20 hits · 60 pts
SeverityFileLineSnippetContext
MEDIUM.scripts/diff_smt2.sh44# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh46# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh62# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh64# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh80# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh82# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh153# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh155# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh210# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh212# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh300# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh302# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh434# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/diff_smt2.sh436# ──────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py30# ── Parsing ──────────────────────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py117# ── Helpers ──────────────────────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py136# ── Statistics ───────────────────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py205# ── Markdown Report ──────────────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py323# ── HTML Report ──────────────────────────────────────────────────────────────COMMENT
MEDIUM.scripts/ramon-report.py616# ── Main ─────────────────────────────────────────────────────────────────────COMMENT
Cross-Language Confusion4 hits · 20 pts
SeverityFileLineSnippetContext
HIGHtests/ide/test-incremental.py247 request = f'{{"query-id":"1", "query": "vfs-add", "args":{{"filename":null, "contents": {json_contents}}}}}\n{{"querCODE
HIGH.scripts/ramon-report.py528const sigMem = memData.filter(d => d.base > 50 || d.patch > 50);CODE
HIGH.scripts/ramon-report.py558const sigTime = timeData.filter(d => d.base > 1 || d.patch > 1);CODE
HIGH.scripts/benchmarking/run_benchmarks.py173 shell_exec('grep BENCHMARK_PRE ulib/gmake/fstar.mk || git apply %s'%args.benchmark_hook_patch)CODE
Over-Commented Block20 hits · 20 pts
SeverityFileLineSnippetContext
LOWtests/ide/test-incremental.py241 json_contents = json.dumps(contents)COMMENT
LOWpulse/pulse2rust/tests/src/lib.rs1mod pulsetutorial_algorithms;COMMENT
LOWpulse/pulse2rust/dpe/krmllib.h1#include <stdbool.h>COMMENT
LOWcontrib/CoreCrypto/ml/openssl_stub.c1/* -------------------------------------------------------------------- */COMMENT
LOWcontrib/CoreCrypto/ml/openssl_stub.c1401COMMENT
LOW.scripts/renamings.sh1#!/bin/bashCOMMENT
LOW.scripts/remove_all_unused_opens.sh1#!/usr/bin/env bashCOMMENT
LOW.scripts/runlim_diff.py1#!/usr/bin/env python3COMMENT
LOW.scripts/run_benchmark.sh1#!/bin/bashCOMMENT
LOW.scripts/diff_smt2.sh1#!/usr/bin/env bashCOMMENT
LOW.scripts/diff_smt2.sh301# Phase 6: Compare .smt2 filesCOMMENT
LOW.scripts/release.sh1#!/usr/bin/env bashCOMMENT
LOW.github/workflows/nightly-build.yml1name: F* nightly buildCOMMENT
LOW.github/workflows/build-windows.yml81 echo FSTAR_VERSION="nightly-$(date -I)" >> $GITHUB_ENVCOMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py1# -*- coding: utf-8 -*-COMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py41COMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py61# source_suffix = ['.rst', '.md']COMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py81COMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py101# Custom sidebar templates, must be a dictionary that maps document namesCOMMENT
LOWdoc/book/PoP-in-FStar/book/conf.py121latex_elements = {COMMENT
Excessive Try-Catch Wrapping7 hits · 15 pts
SeverityFileLineSnippetContext
LOWtests/ide/cleanup.py40 except Exception as ex:CODE
MEDIUM.scripts/query-stats.py420 print("Error: %s\n" % str(err))CODE
MEDIUM.scripts/query-stats.py430 print("Error: file '%s' does not exists." % a)CODE
MEDIUM.scripts/query-stats.py450 print("Error: -n/-t/--top must be >= 0.")CODE
MEDIUM.scripts/query-stats.py460 print("Error: filter not in s=v format.")CODE
MEDIUM.scripts/query-stats.py469 print("Error: unsupported output format '%s'" % a)CODE
LOW.scripts/ramon-report.py68 except Exception as e:CODE
Deep Nesting11 hits · 11 pts
SeverityFileLineSnippetContext
LOW.scripts/query-stats.py50CODE
LOW.scripts/query-stats.py96CODE
LOW.scripts/query-stats.py136CODE
LOW.scripts/query-stats.py202CODE
LOW.scripts/query-stats.py282CODE
LOW.scripts/query-stats.py405CODE
LOW.scripts/ramon-report.py54CODE
LOW.scripts/fstardoc/fstardoc.py39CODE
LOW.scripts/fstardoc/fstardoc.py114CODE
LOW.scripts/fstardoc/fstardoc.py273CODE
LOWexamples/tactics/bench/script.py72CODE
AI Slop Vocabulary4 hits · 8 pts
SeverityFileLineSnippetContext
LOWstage0/.scripts/mk-package.sh5# This will just create a tar.gz or zip out of a directory.COMMENT
MEDIUM.scripts/src-install.sh24# before it tries to copy it. This seems robust.COMMENT
LOW.scripts/mk-package.sh5# This will just create a tar.gz or zip out of a directory.COMMENT
LOW.github/workflows/nightly-schedule.yml4# nightly build. To add a new branch, just add it to the matrix below.COMMENT
Unused Imports6 hits · 6 pts
SeverityFileLineSnippetContext
LOWtests/ide/test-incremental.py3CODE
LOWtests/ide/emacs/fuzz.py28CODE
LOW.scripts/ramon-report.py27CODE
LOW.scripts/runlim_diff_old.py7CODE
LOWdoc/book/PoP-in-FStar/book/smt2_pygments.py2CODE
LOWdoc/book/PoP-in-FStar/book/fstar_pygments.py2CODE
Self-Referential Comments2 hits · 6 pts
SeverityFileLineSnippetContext
MEDIUM.scripts/advance.sh32 # Create a new version number. Fail if it is identical to theCOMMENT
MEDIUM.scripts/advance.sh119 # Create a pull request if we pushed to a different branchCOMMENT
Slop Phrases2 hits · 4 pts
SeverityFileLineSnippetContext
LOW.scripts/remove_all_unused_opens.sh13# Please do NOT trust this script and make sure to save your stateCOMMENT
MEDIUM.scripts/run_benchmark.sh16# (you can use other commands, but they should support a `-o FILE`COMMENT
Redundant / Tautological Comments3 hits · 4 pts
SeverityFileLineSnippetContext
LOW.scripts/diff_smt2.sh357 # Check if difference is only in metadata (comment lines)COMMENT
LOW.scripts/create_tag.sh21# Check if the user has provided a GitHub authentication tokenCOMMENT
LOW.scripts/create_tag.sh63# Check if the commit pointed to by that tag (if any) points to the current commitCOMMENT
Hyper-Verbose Identifiers3 hits · 3 pts
SeverityFileLineSnippetContext
LOW.scripts/benchmarking/fstar_slack_post.py155def create_slack_text_message(s):CODE
LOW.scripts/benchmarking/fstar_slack_post.py160def create_slack_attachment_message(fallback, color, text, footer):CODE
LOW.scripts/benchmarking/run_benchmarks.py87def parse_and_format_results_for_upload(fname, bench_name_prefix=''):CODE
Example Usage Blocks1 hit · 2 pts
SeverityFileLineSnippetContext
LOW.scripts/diff_smt2.sh13# Usage:COMMENT