ObserverLib
ModTracks block changes across an area for other mods.
Why gradeA
How grades workStrengths
Points lost
All 11 criteria
Maintenance
5 points lost22 / 27Last releaseHow long ago the newest file came out, or an existing file was marked as working on a new Minecraft version.2 months ago (24 Aug 2026) 12 / 12Supports popular versionsWhether the project has a file for a Minecraft version that 15% or more of the popular mods updated in the last 6 months also support. A version many modpacks use, like 1.20.1 or 1.21.1, also counts after a release in the last 12 months.1.21.1 on NeoForge, 1.18.2 on Forge. 15% or more of the popular mods updated in the last 6 months also have files for 1.21.1. Latest Minecraft: 26.3. 9 / 9Regular releasesIn how many of the last 24 months a new file came out. Full points at 8 months.Releases in 1 of the last 24 months 1 / 6Stability
Full points15 / 15Removed from modpacksHow many modpacks removed it in a later version of the pack. We can only see this in modpacks with two or more versions. A pack that swaps it for another edition of the same project, or that is rebuilt from scratch, does not count.13 of the 368 modpacks with two or more versions removed it in a later one (4%) 10 / 10Quick fixesHow often a release needed a quick fix: a new release within 3 days to fix a problem in it.Not measured yet.Known conflictsHow many projects say they do not work with it, compared with how widely it is used. Packs, small projects, forks, ports, add-ons, alternatives and old versions do not count.None 5 / 5Transparency
Full points7 / 7Source codeWhether the project page links to its source code, so anyone can read what it does.GitHub · HellFirePvP/ObserverLib 7 / 7Place to report problemsWhether the project page links to a place where players can report problems: an issue tracker.Does not apply. CurseForge links are not in our data.Popularity
Full points4 / 4DownloadsDownloads on Modrinth and CurseForge. Full points from 5 million.18,388,744 4 / 4Track record
Full points8 / 8AgeHow long the project has existed. It counts less when no new file came out recently.7.4 years, 16 releases 8 / 8Security
PassedFile checksThis check adds no points. It can only take points away.Our checks found nothing harmful in the latest file for recent Minecraft versions. See Security
55.8 of the 61 points that apply = 91 out of 100. The points above are rounded to whole numbers.
About
ObserverLib is a library for tracking changes to blocks within a specified area, allowing other mods to observe that area without repeatedly scanning it. A mod registers an observer and receives relevant world changes to interpret, such as whether a structure remains complete or valid. Its change notifications are designed to support large areas, including areas spanning unloaded chunks, without needing to load chunks just to recheck their blocks. One example implementation tracks only positions whose blocks do not match a structure’s expected layout, rather than checking every component on each validation.
Written from CurseForge . How we write it
In-game changes
Changes the game's code in 1 area, as a library other mods build on: Chunk loading and storageChanges 1 game code file in this area: how the game loads, tracks, saves and unloads chunks..
Keeps all of vanilla Minecraft's textures, models and sounds.
Often used with it
See all 29Details
- Creator
- HellFirePvP
- License
- Not known
- Downloads
- 18.4M
- Created
- 30 May 2019
- Official page
- CurseForge
- Links
- Source code
Security
No harmful code found
We checked its files and read their code, without running it.
Why we show this: a mod runs on your computer like any program, so harmful code in it can take your accounts or files. Our checks look for known signs of harm. They cannot prove that a file is harmless. In the grade: malware means no grade, and a Warning in a latest file for a recent Minecraft version lowers it.
How we checked
- FilesWe download the files from Modrinth or CurseForge and look at what is inside them and what their code can do, without running them. Fixed rules tell what is harmful.7 latest files: the newest file for each Minecraft version and loader. The answer above is about the one for a recent version. Recent versions: those released in the last 2 years, plus 1.20.1 and 1.21.1, among the most played in modpacks. See each file in Releases
- Their codeWe turn the code of the files back into readable code and follow what it does, without running it. This shows what it downloads, what it sends and where your login goes.Read without running it
- Looked for, not foundWe looked for these in the file and did not find them.The internet, folders outside the game, other programs, updating itself, the webcam or microphone, an AI service.
Privacy
We found nothing it sends
We read its code without running it: it contacts no web address while you play.
Why we show this: a mod can send things about you over the internet, like your player name or your login. Contacting an address to check for updates or download files sends nothing about you. Not in the grade: sending data can be normal for what a mod does.
How we checked
- Files readWe read the code without running it. We list each web address the code contacts while you play, and what it sends. Code that is never used is left out.The code of its one file, for recent Minecraft versions. See each file in Releases
AI
No sign that AI was used to make it
We looked for AI tools in its texts, files, images and code history and found none.
No sign of AI in the game
We found no AI service, AI library or AI model file in its code.
Why we show this: some players and servers avoid projects made with AI, and AI in the game can send what you write to an online service. Not in the grade: using AI does not tell whether a project works well or is kept up to date.
How we checked
- Author on ModrinthThe disclosure form on Modrinth. Since 13 Aug 2026, Modrinth's rules require it when a substantial part of the code is AI output, when an asset is mainly AI output, or when the project or its page relies on generative AI.Not on Modrinth.
- Code historyThe public code on GitHub: who made each change, credit lines such as "Co-authored-by", and its files.Nothing found
- Description and changelogsThe description, project page and newest changelogs: sentences saying an AI tool was used, and text pasted from an AI chat.Nothing found2 of 32 changelogs read
- Its filesFiles that AI coding tools leave behind (like AGENTS.md), and the texts inside the files you download.Nothing found
- Images in its filesHidden data in the images of the files you download, where AI image tools write their name and settings.Nothing found1 image read
- Code of the modThe code and files of the mod, read without running it: addresses of AI services, AI libraries, AI model files and a place for your own AI key.No AI service, AI library or AI model file68 code files read
Compatibility
See all 16 filesPoint at or tap a version to see its loaders.
Related projects
Projects that need ObserverLib to work.
Modpacks using this project
Find modpacks with it| Oct 2024 | 37 |
|---|---|
| Nov 2024 | 23 |
| Dec 2024 | 24 |
| Jan 2025 | 18 |
| Feb 2025 | 18 |
| Mar 2025 | 17 |
| Apr 2025 | 22 |
| May 2025 | 17 |
| Jun 2025 | 12 |
| Jul 2025 | 12 |
| Aug 2025 | 13 |
| Sep 2025 | 11 |
| Oct 2025 | 12 |
| Nov 2025 | 17 |
| Dec 2025 | 11 |
| Jan 2026 | 7 |
| Feb 2026 | 7 |
| Mar 2026 | 4 |
| Apr 2026 | 4 |
| May 2026 | 3 |
| Jun 2026 | 8 |
| Jul 2026 | 6 |
| Aug 2026 | 9 |
| Sep 2026 | 9 |
Fewer modpacks put it in their new versions than a year ago: 7 a month now, 15 a year agoThe average of the last 6 months, compared with the same 6 months a year before. We say it only when the change is large..
3,344 modpacks include ObserverLib in at least one of their versions. Here are the 30 most downloaded.
All the Mods 10 - ATM1022.5M downloadslast version with it 15 Oct 2026
All the Mods 6 - ATM66.5M downloadslast version with it 24 Jan 2024
All in One [Modded One Block]4.3M downloadslast version with it 3 Sep 2023
Valhelsia 33.6M downloadslast version with it 21 Mar 2022
Valhelsia 22.8M downloadslast version with it 11 Dec 2021
Enigmatica 6 - E6 - 1.16.51.6M downloadslast version with it 13 Aug 2025
All the Mods 6 - To the Sky - ATM6sky - Skyblock1.1M downloadslast version with it 27 Apr 2022
All the Magic Spellbound - ATMS892K downloadslast version with it 15 Nov 2022
All the Mods 5 - ATM5693K downloadslast version with it 10 Dec 2021
OccultCraft615K downloadslast version with it 25 Jul 2022Often in the same modpacks
Mods that modpacks often add together with ObserverLib. Share: how many of the modpacks with ObserverLib also have that mod.
BotaniaAModin 74% of the modpacks with ObserverLib
Immersive EngineeringCModin 66% of the modpacks with ObserverLib
Mekanism GeneratorsBModin 62% of the modpacks with ObserverLib
BlueprintAModin 61% of the modpacks with ObserverLib
Blood MagicAModin 60% of the modpacks with ObserverLib
Ars NouveauAModin 59% of the modpacks with ObserverLib
Thermal FoundationCModin 57% of the modpacks with ObserverLib
Thermal ExpansionCModin 56% of the modpacks with ObserverLib
Ice and FireCModin 55% of the modpacks with ObserverLib
Mekanism ToolsBModin 55% of the modpacks with ObserverLibLatest files
The newest file for each Minecraft version and loader. The files for recent versions come first. Recent versions: those released in the last 2 years, plus 1.20.1 and 1.21.1, among the most played in modpacks.