Hi r/lua — I’m working on lua-grpc, a native gRPC implementation for Lua.

It provides:

• Pure-Lua gRPC runtime over HTTP/2
• Protocol Buffers through lua-protobuf
• Unary, server-streaming, client-streaming, and bidirectional-streaming RPCs
• Lua server support
• A protoc-gen-lua-grpc generator for Lua client/service bindings
• Hello World examples for all four gRPC call types

The project uses lua-http for HTTP/2 and is packaged for LuaRocks. The generator is a small Go executable, while generated bindings and the runtime are Lua.

It’s still early-stage. Compression, interceptor execution, and connection pooling are the main gaps I’m planning to address next.

I’d really appreciate feedback from Lua developers—especially around API ergonomics, Lua version support, and real-world gRPC interoperability.

Repo: https://github.com/Protocol-Lattice/lua-grpc

Made by the owners of Boronide, we are releasing for a limited time for free!

https://discord.gg/wnB3Pmmxd7

https://ironbrew3.com

Release notes and downloads here: Release v5.5.1.0 · OneLuaPro/OneLuaPro

Technical Baseline

Compiled for dynamic dispatch (automatic runtime detection for AVX2/AVX-512) using:

• Visual Studio Build Tools 2022 17.14.39
• Intel oneAPI Toolkit 2026.1.0.191
• National Instruments NI-488.2 2026 Q3 and NI-DAQmx 2026 Q3

New Features

• Added lyaml: This extension library enables Lua programs to process yaml files with both a high-level and a low-level API. This add-on closes feature request #4.
• Upgraded to Lua 5.5.1: Lua v5.5.1 is the latest bugfix release of the Lua scripting language.

Core Module Updates (latest git/stable)

Various. See here for details.

Minimum Requirements

• Intel: 2nd Gen Core (Sandy Bridge, 2011) or newer
• AMD: Bulldozer-based (FX-series, 2011) or newer
• OS: Windows 7 SP1, 10, or 11 (required for AVX state management)

Note: Older CPUs (e.g., Core 2 Duo, 1st Gen i7/i5) are not supported and will result in an "Illegal Instruction" error.

I've been learning Lua and found that most programming exercise platforms aren't quite what I wanted.

A lot of them teach programming through problems: implement a palindrome, solve a number problem, build an algorithm, etc. That's useful for learning problem-solving, but it doesn't necessarily help you understand the language itself.

So I made LuaLings:

https://github.com/ShyamendraH/lualings

It's inspired by Ziglings — the idea of learning a language by working through small, focused programs and fixing them yourself.

LuaLings focuses specifically on Lua concepts and semantics rather than generic programming problems.

The exercises cover things such as:

• values, types and nil
• tables and their behavior
• multiple assignment and multiple return values
• functions, closures and upvalues
• iterators
• metatables and metamethods
• modules and environments
• error handling
• coroutines
• Lua's standard libraries
• other Lua-specific behavior that is easy to miss when coming from another language

The intended workflow is:

run → inspect → experiment → fix → understand → move on

The goal is to make it useful both for someone learning Lua for the first time and for someone coming from another language who wants to understand how Lua actually works rather than spend a lot of time on beginner programming exercises.

It's open source, and feedback is welcome — particularly if you find an exercise confusing, technically incorrect, too trivial, or missing an important Lua concept.

Repository:
https://github.com/ShyamendraH/lualings

decided to share because why not :3

this was NOT MADE BY AI WHATSOEVER i made it in a few minutes

average playlist thingy

the playlist files are literally just lua files that return a table of filepaths to music/sound files

also github repository because... something

https://github.com/hanerathestupidplanet/average-playlist-thingy

okay bye!!!

Hey everyone,

I'm trying to pick up Lua mainly for general scripting and embedding into Rust projects for things like config files. If I end up liking it as much as Rust, I'll probably dive deeper into it.

The main thing tripping me up is how many versions and runtimes exist out there (Lua 5.1, 5.4, LuaJIT, Luau, ...).

If anyone has experience embedding Lua in Rust (maybe using `mlua`), which version should I actually focus on learning? Also, are there any weird compatibility traps or gotchas I should watch out for?

Appreciate any advice or resources 🙏

Hey r/lua!

Wanted to share a project I've been building called LuaDB: a lightweight, zero-dependency embeddable database system written in pure Lua.

Why pure Lua? Cross-platform embedding without needing C bindings or compiling native SQLite shared libraries (great for LÖVE, Roblox, OpenResty, or embedded devices).

What it includes:

• Full B+Tree index engine on 4KB slotted binary pages
• Write-Ahead Logging (BEGIN, COMMIT, ROLLBACK)
• Native PostgreSQL wire protocol gateway (run luajit bin/luadb_server.lua and connect with psql)
• Native JSONB operators (details->'address'->>'city')
• Foreign Keys with ON DELETE CASCADE and ALTER TABLE migrations
• Master-master cluster replication with hinted handoff

Check out the GitHub repo: https://github.com/jncastilho/luadb

Would love to hear your thoughts and feedback!

Hey r/lua!

I’ve been working on lua-utcp, a Lua implementation of the Universal Tool Calling Protocol:

https://github.com/universal-tool-calling-protocol/lua-utcp

The goal is to let Lua applications discover and call tools through their native transports without requiring an additional wrapper server. Providers expose a UTCP manual, lua-utcp builds a canonical tool registry, and applications invoke tools using stable names and schemas.

local result, err = client:call_tool("echo", {
  message = "hello from Lua"
})

assert(result, err)

Current features include:

• Lua 5.3 and 5.4 support
• HTTP, SSE, Streamable HTTP, TCP, UDP, CLI, Text, GraphQL, and MCP transports
• Remote discovery and locally registered provider manuals
• Streaming tool calls
• Structured tool and transport errors
• A small, embeddable Lua API
• Unit and transport integration tests

It also includes CodeMode, a constrained Lua execution layer for LLM-generated tool workflows:

local execution = assert(codemode:call_tool_chain([[
  local sum = codemode.call_tool("calculator.add", {
    a = 10,
    b = 20
  })

  return sum
]]))

The model generates Lua orchestration code, while lua-utcp handles tool discovery, validation, registry lookup, and native transport execution. There are working examples for OpenRouter and other OpenAI-compatible APIs.

I think Lua is particularly well suited to this kind of orchestration because it is small, embeddable, and easy to generate and inspect.

The project is open source under MPL-2.0. I’d especially appreciate feedback on the API ergonomics, transport extension design, and whether CodeMode would be useful in your Lua projects.

I made a C++17 Lua engine/wrapper around an embedded Lua runtime

I've been working on LuaPP, a C++17 Lua engine built around an embedded Lua runtime.

The goal is to make embedding Lua and exposing C++ functionality less painful than working directly with the Lua C API everywhere.

Some of the stuff it currently supports:

• LTValue abstraction for Lua values
• Numbers, integers, strings, booleans, nil, userdata, tables, functions, and threads
• Table manipulation and pairs / ipairs
• Registering C++ functions with Lua
• Function upvalues
• C++ objects stored as Lua userdata with automatic __gc destruction
• Metatables
• Loading/executing Lua strings and files
• Custom Lua readers and writers
• Lua bytecode dumping
• Error handlers and tracebacks
• Global and registry access

The project embeds the Lua runtime directly and currently builds against Lua 5.5. It requires Lua 5.3+, C++17, and CMake 3.16+.

It's still a work in progress, so I'm mainly interested in feedback on the API design, implementation, and anything that looks questionable.

GitHub: https://github.com/anatinesquire40/Lua-CPP-API

I have been building a lua color library project lately that supports multiple operations on multiple supported color-spaces.

Originally my plan was to create in C then import in Lua, but then I thought how about a native library that is missing or not found by me in lua and everyone have to re-create their own for any color related projects.

It's initial version is published in github and luarocks recently.

Please have a look and try all the features it provides. This is in active development. Report any missing functions/features, those would be added asap.

Use it in your own projects as a utility library and test scenarios.

Please send your suggestions, raise issues and pull requests to make changes.
Your contributions are heartly welcomed.

Cheers.

I’ve been working on lua-mongodb, a MongoDB driver written in Lua without binding or wrapping libmongoc (most Lua drivers are no longer maintained but took this approach).

It supports stock Lua 5.4 and 5.5 with a 64-bit lua_Integer. Network operations run through Copas, so the driver works well in coroutine-based services, tools, and long-running Lua applications.

The driver currently covers CRUD, aggregation, index and Search index management, GridFS, sessions, transactions, read and write concerns, retryable operations, change streams, client bulk writes, authentication, TLS, SRV discovery, wire compression, and client-side operation timeouts. It works with standalone servers, replica sets, sharded clusters, and load-balanced deployments.

A small example looks like this:

local mongodb = require("mongodb")

mongodb.run(function()
  local client = assert(mongodb.client(
    "mongodb://localhost:27017/example"
  ))

  local reply = assert(client:database("admin"):run_command(
    mongodb.bson.document({ { "ping", 1 } })
  ))

  print(reply:get("ok"))
  assert(client:close())
end)

What it isn’t:

• It is not an official MongoDB driver.
• It does not support LuaJIT or OpenResty.
• It does not implement all MongoDB client functionality (as defined in the MongoDB specifications) such as client-side encryption, OCSP, or SOCKS5 proxy transport.

I’m looking for feedback on:

• Bugs.
• API choices that feel unnatural or could be improved.
• Missing operations that block an actual project.
• Installation or usage problems (only tested on Linux and macOS at the moment)
• Scripts and applications willing to test it out and share feedback
• Feedback on what might make something like this more useful to you/your workload

Repository: https://github.com/alexbevi/lua-mongodb
LuaRocks: https://luarocks.org/modules/alexbevi/mongodb

Been working on this for a while. It's a Scratch-style block editor for Studio — you drag blocks onto a canvas and it generates an ordinary Script or ModuleScript in your place. Not a runtime or a sandbox, just code you can open and read.

702 blocks covering events, instances, properties, players, DataStores, RemoteEvents, rounds and game state, GUI, camera.

The part I actually care about: you can make your own blocks. Write the Luau once, mark the inputs with %NAME, use %BODY for a nested stack, pick a colour. Takes about a minute, and it sits in the palette next to the built-ins. Export a set as JSON and share it.

Generated code is tagged with block ids so a runtime error points at the block that wrote the line.

Free on the Creator Store: BlockForge - Creator Store

If a block you need doesn't exist, tell me and I'll add it.

Sharing a Lua project I made. It's a module for adding LLM-powered NPCs to Roblox games, but the part I care about is the design: it's 'correct by default'.

Instead of leaving the caller to get concurrency right, it ships per-player cooldown (state keyed by user id, not a global lock), retry with exponential backoff, and a small response cache built in. So the naive usage is also the correct usage — a talking NPC with per-player memory is about five lines.

Source (MIT): https://github.com/cortex-rbx/roblox-ai-kit

It targets Roblox's Luau, but the patterns port to plain Lua. Curious what people here think about the correct-by-default approach for a small API wrapper.

I was trying to execute this code in my CachyOS (arch-based) installation using "sudo chmod +x /route/to/file.lua", but it does not print anything, in fact, does nothing. I am new to lua and this is a training exercise, so, sorry if I am asking something obvious.

--Movements
attack1_cost = 3
attack2_cost = 5
attack3_cost = 11
heal_cost = 6
concentrate_cost = 0


--System
x = (attack1_cost + attack2_cost + attack3_cost + heal_cost) / 4


--Player 
energy = 15
player_hp = 70


--Enemy
enemy_hp = 120
enemy_attack = 8


function _enemydostuff()
    player_hp = player_hp - enemy_attack  
    _movement()
    print("player hp =", player_hp)
end

function _movement()
    local id = tonumber(io.read())
    if id == 1 then
        enemy_hp = enemy_hp - 4
        energy = energy - attack1_cost
    elseif id == 2 then
        enemy_hp = enemy_hp - 7
        energy = energy - attack2_cost
    elseif id == 3 then 
        enemy_hp = enemy_hp -12
        player_hp = player_hp + 3
        energy = energy - attack3_cost
    elseif id == 4 then 
            player_hp = player_hp + 16 
        energy = energy - heal_cost
    elseif id == 5 then 
        energy = energy + 17 - concentrate_cost
    else
        print("???")
    end
    print("energy =", energy)
    print("enemy hp =", enemy_hp)
    _enemydostuff()
end


--This starts the program
_movement()--Movements
attack1_cost = 3
attack2_cost = 5
attack3_cost = 11
heal_cost = 6
concentrate_cost = 0


--System
x = (attack1_cost + attack2_cost + attack3_cost + heal_cost) / 4


--Player 
energy = 15
player_hp = 70


--Enemy
enemy_hp = 120
enemy_attack = 8


function _enemydostuff()
    player_hp = player_hp - enemy_attack  
    _movement()
    print("player hp =", player_hp)
end

function _movement()
    local id = tonumber(io.read())
    if id == 1 then
        enemy_hp = enemy_hp - 4
        energy = energy - attack1_cost
    elseif id == 2 then
        enemy_hp = enemy_hp - 7
        energy = energy - attack2_cost
    elseif id == 3 then 
        enemy_hp = enemy_hp -12
        player_hp = player_hp + 3
        energy = energy - attack3_cost
    elseif id == 4 then 
            player_hp = player_hp + 16 
        energy = energy - heal_cost
    elseif id == 5 then 
        energy = energy + 17 - concentrate_cost
    else
        print("???")
    end
    print("energy =", energy)
    print("enemy hp =", enemy_hp)
    _enemydostuff()
end


--This starts the program
_movement()

Im new to the world of programming and Lua. I've seen a lot of discussions about what version of the language people prefer and most of them seem pretty divided. So I wanted to know, which one do you think is the best to start learning? And also what's the difference between Lua and LuaJIT?

Is anyone here familiar with the ReturnOfModding Lua framework? If so, can you help me out?

LuaCAD models solids in Lua rather than the OpenSCAD language, with operator overloading for CSG (a + b, a - b, a * b). It ships with a CLI and a desktop app, including a preview area and a text editor.

It’s fully open source and you can find the repo here: https://github.com/ad-si/LuaCAD

I've always been a big fan of OpenSCAD, but the SCAD language itself is unfortunately quite cobbled-together and is a very poorly designed programming language.

LuaCAD takes all the good parts of OpenSCAD and combines them with Lua. It has now completely replaced OpenSCAD for me, and I think it provides a better experience than OpenSCAD for all use cases. I'd love to hear any reasons why LuaCAD won't fully replace OpenSCAD for you!

Tech stack:

• It's implemented in Rust and uses mlua (https://github.com/mlua-rs/mlua) to execute the Lua code.
• Uses OpenCSG (https://opencsg.org) for fast and correct rendering of the 3D models (like OpenSCAD)
• Uses Manifold (https://github.com/elalish/manifold) to create the manifold triangle meshes
• Native support for all BOSL2 functions (i.e. implemented in Rust for better performance)