codex vs mdBook
codex and mdBook share 5 technologies: axum, Tokio, pulldown-cmark, tracing, and tracing-subscriber. Both are written in Rust.
LinkedInWhat they share and what sets them apart
openai
codex
Lightweight coding agent that runs in your terminal
Rust133.1kRead on November 4, 2026, at commit 021fccbWhat is codex built with?Only in codex
In common
- axum
- Tokio
- pulldown-cmark
tracing
rust-lang
mdBook
Create book from markdown files. Like Gitbook but implemented in Rust
Rust22.3kRead on November 5, 2026, at commit 7fb5bc8What is mdBook built with?Only in mdBook
- handlebars
- html5ever
- listenfd
Side by side
codexmdBook
SizeLines written by people and agents, without generated ones; code files, without tests.
codex2,320,674 lines written4,216 code files
mdBook20,533 lines written66 code files
Who writes itA commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
codex2.8% of its commits signed by AIWith Codex, Claude Code, and GitHub Copilot
mdBook0.1% of its commits signed by AIWith Codex
ActivityFrom GitHub and its history, on the day SeeRepo read it.
codexLast push November 4, 202613,099 commits133,103 stars
mdBookLast push November 2, 20262,281 commits22,266 stars
TestsThe files that test the code, and the share of code files a test imports.
codex2,448 test files51.6% of its code files have a test that imports them
mdBook73 test files10.6% of its code files have a test that imports them
Frequently asked questions
Which is bigger, codex or mdBook?
codex, with 2,320,674 lines written; mdBook has 20,533.
The proof: openai/codex's code at commit 021fccb
Which has more GitHub stars, codex or mdBook?
codex, with 133,103 stars; mdBook has 22,266.
The proof: openai/codex on GitHub
Which has more tests, codex or mdBook?
codex, with 2,448 test files; mdBook has 73.
The proof: openai/codex's code at commit 021fccb
Which was updated more recently, codex or mdBook?
codex: its last push was on November 4, 2026, and mdBook's on November 2, 2026.
The proof: openai/codex's commits on GitHub
Which has more commits signed by AI, codex or mdBook?
codex: an AI signed 2.8% of its commits, with Codex, Claude Code, and GitHub Copilot; in mdBook, 0.1%.
The proof: the commits each tool signed in openai/codex
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