--- title: Valkey · Valkey Modules 101 | daily.dev description: A hands-on walkthrough of building Valkey modules to extend the in-memory data store with new commands and data types without touching its core code. Covers... canonical: https://daily.dev/posts/valkey-valkey-modules-101-az0beln0y twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Valkey · Valkey Modules 101 | daily.dev og:description: A hands-on walkthrough of building Valkey modules to extend the in-memory data store with new commands and data types without touching its core code. Covers... og:url: https://daily.dev/posts/valkey-valkey-modules-101-az0beln0y og:image: https://api.daily.dev/og/posts/Az0beLn0y.png og:image:alt: Valkey · Valkey Modules 101 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. # Valkey · Valkey Modules 101 **[Valkey](https://daily.dev/sources/valkey-blog)** · 4 min read · 0 upvotes · 0 comments ## Summary A hands-on walkthrough of building Valkey modules to extend the in-memory data store with new commands and data types without touching its core code. Covers writing a minimal 'Hello World' module in C, then the same module in Rust using the Valkey Module Rust SDK, compiling each as a shared library, loading them via valkey.conf or at runtime with MODULE LOAD/UNLOAD, and verifying custom commands via valkey-cli. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I create a basic Valkey module in C that adds a custom command? Define a command function that returns a reply, then call ValkeyModule_Init and ValkeyModule_CreateCommand inside the required ValkeyModule_OnLoad function. For example, a hello function returning a simple string is registered as module1.hello via ValkeyModule_CreateCommand(ctx,"module1.hello", hello,"",0,0,0), then compiled into a shared library with make inside src/modules. _Developers extending Valkey with custom commands can track module tutorials like this on daily.dev._ ### How do I build a Valkey module in Rust instead of C? Create a library crate with cargo new --lib, add the valkey-module crate as a dependency, and set crate-type to cdylib in Cargo.toml so cargo builds a shared library. Use the valkey_module! macro to define the module name, version, data types, and commands, implementing each command as a Rust function returning a ValkeyResult. _Teams choosing between C and Rust for Valkey extensions can follow comparisons like this on daily.dev._ ### How do I load and unload a Valkey module without restarting the server? Set enable-module-command yes in valkey.conf, restart valkey-server once, then use MODULE LOAD and MODULE UNLOAD from valkey-cli to add or remove modules at runtime. This lets you recompile module code and reload it without a full server restart, and MODULE LIST shows currently loaded modules with their name, version, and path. _Developers iterating on Valkey module code can keep up with runtime workflows like this via daily.dev._ ## Similar posts on daily.dev - [Valkey just had a 17x year. 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