List of Solidity libraries in the wild

You probably know by now that I like making lists :slight_smile:
This one is about keeping track of Solidity libraries that are used by projects out there in the wild.

:warning: This is not an endorsement of any kind.
Unless it is mentioned specifically, OpenZeppelin haven’t audited any of these libraries and you should assess their quality and extensively test your integrations with them before using them in production.

A side effect of the list is that we can discuss about including the strongest and more popular building blocks into OpenZeppelin Contracts, so they are reviewed and maintained by our community.

This is a wiki, and comments are open. Please add the libraries you have used, and let us know about your experience using them.

OpenZeppelin Contracts is a library for secure smart contract development. Build on a solid foundation of community-vetted code.

When you are looking for a library, we always recommend to search for it first in OpenZeppelin Contracts. The list below is for contracts that are not part of the OpenZeppelin library.


Integer Arithmetic

Floating Point Arithmetic

Fixed Point Arithmetic





Type conversion





Data Structures










Hi @elopio, great list!

We’ve got a bunch of libraries we’ve done ourselves, which might be of use for some people. We try to make them simple but top quality, following your lead.

Our goal is to show how common business use cases can be implemented, but sometimes that leads us to develop basic building blocks as well.

Please have a look at our repo.

AccessControl - This is a similar approach to your own 3.0 access control libraries (we are helping you :D), but some people might appreciate the extra context.
Classifieds - How to implement a simple classifieds board, like Craigslist.
Exchange - We grabbed the Uniswap code and ported it back to Solidity. It’s a great pattern to create decentralized exchanges and markets.
Issuance - A simpler version of Crowdsale, intended to explain how issuance or ICO processes work at a contract level. It has some interesting reuses.
Lists - Implementations of Linked Lists, Doubly Linked Lists, Sorted Sets and so on.
State - A simple implementation of a State Machine. We find it very useful to manage contract state in a consistent manner across projects.
Token - Among others, there is an implementation for a dividend-bearing ERC20 token.
DAO - A demo of how to build a DAO, in this case for a Venture Capital Fund. Reuses the contracts above for a very clear implementation.
Energy - A demo of how to use the uniswap market pattern (not the contract yet) to build an energy trading market.

I’m also the guy that implemented the FixidityLib library. Those were fun times. We’ve forked it to our repo since unfortunately it seems that CementDAO are not maintaining it. We are happy to receive PRs.


Nice @albertocuestacanada! Thanks for sharing and the great work.
I have some problems understanding what is a library and what is a demo. I think this list should only have generic building blocks, what do you think?

Feel free to edit the post and add the ones you think that will be useful and fit the format. I can go through them later in the week.

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We aim to produce implementation patterns, and during that process a few building blocks have appeared.

If you are just interested in directly reusable contracts you should check these ones:

And as mentioned by yourself:

Our driving concern is that we often have to code a number of recurrent solutions. The patterns are repetitive but we are not sure that coding them into reusable packages would make sense due to their complexity.

We prefer to provide simple examples that just show how things work, and then build the contracts from scratch but customized to a high degree. These might interest some other people in this forum:

  • Classifieds - Simplest implementation of an ERC721 DEX.
  • Exchange - Simplest implementation of an ERC20 DEX.
  • Issuance - An ICO, as well as share issuance.
  • DAO - We are having lots of fun coding a DAO, which reuses 4 of the projects above (Issuance, Voting, Dividends and State Machine). We don’t plan to compete with Aragon, though.
  • Energy - Yet another DEX, this time to trade energy.
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Great! I’ve added the ones you mentioned as reusable.

I’m not sure the Dividend Bearing ERC20 is as generic as the others in the list On the other hand, I think your Roles implementation should be in the list.
But I like that the guidelines to bootstrap the list are blurry. Let’s give this a try and some time. When more people join and leave their libraries and their comments it will be clearer what’s useful to keep in here.

About your other contracts that are more like a demo, I think having topics for some on them in the showcase category would be awesome.

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Thanks for pointing out your showcases section, we will definitely be contributing!

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