--- title: Plugins case study: mdBook preprocessors | daily.dev description: mdBook's preprocessor plugin mechanism is examined as a case study in plugin infrastructure design. Preprocessors are arbitrary programs registered in... canonical: https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Plugins case study: mdBook preprocessors | daily.dev og:description: mdBook's preprocessor plugin mechanism is examined as a case study in plugin infrastructure design. Preprocessors are arbitrary programs registered in... og:url: https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb og:image: https://api.daily.dev/og/posts/qK5ppofwb.png og:image:alt: Plugins case study: mdBook preprocessors og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Plugins case study: mdBook preprocessors **[Planet Python](https://daily.dev/sources/planetpython)** · 4 min read · 0 upvotes · 0 comments ## Summary mdBook's preprocessor plugin mechanism is examined as a case study in plugin infrastructure design. Preprocessors are arbitrary programs registered in book.toml that receive the entire book as JSON via stdin, modify it, and return the result via stdout — making them language-agnostic. The post walks through discovery (explicit config), registration (two-phase invocation), hooks (coarse-grained whole-book JSON), and API exposure (Rust-only via the Preprocessor trait). Sample implementations in both Python and Rust are provided, along with a brief look at mdBook's renderer/backend plugin mechanism. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Plugins case study: mdBook preprocessors](https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-d1rmt4oui) · Eli Bendersky · 0 upvotes · 0 comments - [Plugins case study: Pluggy](https://daily.dev/posts/plugins-case-study-pluggy-1wqotugye) · Eli Bendersky · 0 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#rust](https://daily.dev/tags/rust) [View this post on daily.dev](https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Plugins case study: mdBook preprocessors","url":"https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb"},"datePublished":"2026-06-07T01:46:39.668Z","dateModified":"2026-06-07T01:47:01.906Z","description":"mdBook's preprocessor plugin mechanism is examined as a case study in plugin infrastructure design. Preprocessors are arbitrary programs registered in...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/52db1ae87ad6af123d1c0a79f0eab17f?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/52db1ae87ad6af123d1c0a79f0eab17f?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Planet Python","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Planet Python","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/eac3cc584cb043b5a242d13752bd3d0c","url":"https://daily.dev/sources/planetpython"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/plugins-case-study-mdbook-preprocessors-qk5ppofwb","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"python,rust","timeRequired":"PT4M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Planet Python","item":"https://daily.dev/sources/planetpython"},{"@type":"ListItem","position":3,"name":"Plugins case study: mdBook preprocessors"}]} ```