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Comparing NFT Standards - ERC-721 vs ERC-721a vs ERC-1155

Wanna be in the same league as Damien Hirst, DC, and Niftys? Then build your NFT on the Palm network!

Infura and Palm NFT Studio are excited to announce that the Palm network is now available to all users of Infura. Nearly 430,000 developers now have access to create NFTs on the Palm network.

The Palm NFT Studio

The Palm network is an Ethereum sidechain dedicated to selling, purchasing, and trading NFTs that are associated with real-world and digital assets. Palm provides low gas costs and fast transaction finality. The network is over 99% more energy efficient than Proof of Work-based blockchain networks, providing artists with a more sustainable solution today, while Ethereum upgrades to Proof of Stake in the Merge, tentatively scheduled for release in July 2022.

The Palm NFT Studio has collaborated with Damien Hirst, DC, Niftys and Warner Brothers and other artists in minting NFTs on the Palm network.

How to mint an NFT on Palm

For users looking to mint NFT projects, the Palm network provides an effective solution to create NFTs that are able to be bridged back to Ethereum.

To access the Palm mainnet or testnet endpoints, here’s how to get started:

1. Login to your Infura account and select an existing Ethereum project (or create a new Ethereum project if you have not yet).

2. Click on the settings of the project to view the Palm API endpoints.

Using Palm mainet and testnet is free as part of all Infura plans, and requests sent to the API count as part of your existing plan. No action is required to activate Palm, and the availability of Palm testnet allows you to have an environment to begin developing and testing your NFT project before going live.

See our documentation on Palm for more information, as well as links to helpful tutorials.

Get in touch and start building

Interested in creating your own NFTs, but do not know where to start?

Learn more from Infura’s Director of Engineering, Kris Shinn, on minting NFTs using Infura and Replit, based on his EthDenver 2022 presentation.

Let us know how you are using NFTs in our Discord and feel free to ask questions in our community.

Just getting started with Infura? Our docs will get you building.

Ethereum Network Updates, Upgrades, Hard Forks

Infura - Ethereum Network Updates

Network

The Palm network is now available for all NFT creators on Infura

Last July, we published Ethereum JavaScript Libraries: web3.js vs. ethers.js (Part I) to provide “a comparison of web3.js and ethers.js, focusing on their similarities and differences, so that you can better understand the nuances of the libraries.”

To recap, we dove into the documentation of both libraries. We then used a modified version of a software evaluation framework Andres Canal established in his article “Using Quill,js to Build a WYSIWYG Editor for your Website” to guide the reader toward making the best decision in choosing which library to use.

The article was “written with the intent of educating developers to understand the tradeoffs between the two libraries to be able to make a decision of which library to use for their particular use case.”

How have the conclusions from that article changed over the course of the past year?

Table 1: Comparison of Conclusions about Web3.js and Ethers.js




July 2020
October 2021




Web3.js has a community of users and maintainers associated with the Ethereum Foundation. Web3.js has a good API reference and has been around since 2015. Many projects are using it and the library has been the go-to in many "Build Your First dApp" tutorials.
Web3.js is best for those who prefer the most-used Ethereum javascript library that is also maintained by a blockchain-focused firm. Web3.js's strengths are its tests and community. Documentation is currently modest in design and scope and can definitely be improved.


Ethers.js is excellent because it is a small, compact library with a large number of test cases. It has good “Getting Started” documentation, making it accessible to new users. Developers find ethers.js simple and intuitive and the library has gained in popularity over the past two years, seeing increased downloads and usage by projects.
Ethers.js is best for those who prefer lightweight, user-friendly libraries with robust testing and documentation. Ethers.js’s strengths are its documentation, tests and community. It could have more maintainers in order to create some redundancy in the development team - currently a single individual.







Let’s dive into the updated data and explain why these conclusions have changed.


1) How important is the popularity of the library?

To use Andres Canal’s definition,

“A popular project on Github means exactly what you expect it to. Namely, that there are lots of people questioning, contributing, and supporting it. This activity tends to result in more reliable software. You can check the popularity of any project by looking at how many stars it has, how many issues are opened, how many pull requests are pending, and how many contributors worked on the project.”

Web3.js has about 11,600 stars and ethers.js 3,100 as of Oct. 14, 2021. Web3.js is used by 112,849 repositories, compared with 65,519 for ethers.js.

Looking back to July 2020, Web3.js had nearly 8,800 stars while ethers.js had nearly 1,500. Web3.js was used by 51,300 repositories on GitHub, compared with 18,500 for ethers.js.

Web3.js remains the more popular library, but impressively for both libraries, their dependencies have at least doubled over this time period. Web3.js remains more popular, but the overall pie of dependent projects has grown from about 69,800 to 178,368. We will dive more into the dependencies in question 3.


2) How important is the maintenance of the library?

To quote ourselves from the last article,

“We want to use libraries that are updated frequently, so that bugs are squashed and new features are added. Though it is not perfect, looking at a month (or two) of commits, closed issues, active issues, and the number of maintainers over that time period can give a sense of the strengths and weaknesses of an open source project. This also reveals patterns of maintenance, giving some insight to the user of a library when updates and bug fixes are generally addressed, which can be used as a proxy metric for maintenance of the library.”

Using the same metrics from our last article, we see the following for both libraries.

Table 2: GitHub Monthly Pulse for Sept. 14, 2021 to Oct. 14, 2021




Library
Commits to Main Branch
Closed Issues
Active Issues
Maintainers




web3.js
20
60
107
10


ethers.js
2
17
39
1






GitHub Pulse now reveals some additional useful information about the libraries, which gives us even more context of why we are seeing what we are seeing.

For web3.js, we can see that a single individual is responsible for the majority of the commits, though there are three individuals that have 10 or more commits. This is something I see as a plus. This means there is redundancy built into the development team, in case someone were to stop contributing to the project. Web3.js has 121 commits to branches other than the main branch, as web3.js is transitioning off of the 1.x version as outlined in this blogpost the roadmap for web3.js (which we will reference again in the next section). This indicates a lot of work is going into the future releases.

For ethers.js, Richard Moore continues to be the sole maintainer of the library, but there are many more people contributing to the project by opening and closing issues on the GitHub repository, indicating that there is a community of individuals committed to the health of the library. By virtue of a single maintainer, it is not surprising to see fewer overall commits.


3) Who is responsible for the development of the library and how many projects use it?

ChainSafe is the lead maintainer of the web3.js library, having received a grant from the Ethereum Foundation to “continue the maintenance and further development” of web3.js in September 2020. ChainSafe’s outline of the future plans for web3.js reveals major changes coming, such as the deprecation of web3-bzz and web3-shh packages in version 3.x and an eventual move to Typescript in version 4.x. These are exciting additions, but the tradeoff is that ChainSafe will need time to realize these while maintaining the existing library.

Ethers is the lead maintainer of the ethers.js library, which is Richard Moore’s project, so we can think of Richard Moore = Ethers. Ethers has been the lead maintainer of the project since the inception of it. This can be a risk for some projects, but in this case, it has made ethers.js very quick in adding features and capabilities. For example, ethers.js is fully TypeScript-ready with “definition files and full TypeScript source” according to the documentation.


Table 3: Dependent Repository and Package Counts, October 15, 2021




Library
Dependent Repositories
Dependent Packages




web3.js
113,018
4,685


ethers.js
66,950
3,505







Web3.js, likely due to the longer existence of the project, has more repositories and packages that are dependent upon it. When compared with metrics from our last article, ethers.js is closing the gap with web3.js when it comes to dependent packages.


4) How important is it that the library has tests?

Answer: Very important to any dApp developer worth their salt. Luckily for us, both libraries have gotten even better since our last article.

Ethers.js has a test suite API documented for the current v5 release on their GitHub repository. The documentation of the testing is very impressive. Check it out.

Web3.js has added test documentation since our last article. This documentation, based on my personal inspection, appears robust and clearly written.

I believe ethers.js has the lead, but web3.js has done a great job catching up in terms of its tests and their documentation, and I feel both have great coverage when it comes to tests. Tests are a strength for both libraries now.


5) How important is the number of downloads of the library?

As of Oct. 15, 2021, web3.js has 30,767,910 downloads and ethers.js has 24,284,490 downloads. Compare that with May 20, 2020, when we first looked at this statistic, when web3.js had 14,703,432 downloads and ethers.js had 8,500,336 downloads. The overall pie has grown, but the difference in downloads is surprisingly close: a difference in total downloads of 6,484,420 on Oct. 15, 2021 compared with a difference of 6,203,096 in late May of 2020.

When we look at weekly downloads, the two libraries are practically even: web3.js at 330,102 and ethers.js at 339,318. Weekly downloads of both libraries have nearly doubled since we last checked this statistic (May 20, 2020, for those following along): web3.js at 175,661 and ethers.js at 184,798.


6) How important is web performance?

Web performance is indirectly measured by comparing the size of the libraries, as we are assuming smaller libraries take less time to load in the browser.

Both libraries are small. Web3.js has decreased the size of the library to 7.28 MB unpacked (unpacked refers to the size of the library when published) from 10.6 MB when we last checked. Ethers.js touts its very small size, which has increased to 322 kb uncompressed from 284 kb uncompressed over the same time period. It’s unclear what occupies 322 kb within ethers.js. NPM shows ethers.js 10.2 MB unpacked, and I confirmed this when I downloaded to my personal machine and calculated the size of the ethers.js package using the Finder application on Macs. So we have to take ethers.js's word that it is small in size, which is a big plus, though I do need to do further research to confirm this claim is valid.


7) How important is the quality of the documentation?

Ethers.js is the clear winner when it comes to the quality of the documentation of the library and it stands out for three key reasons.

 1. Ethers.js has an extensive “Getting Started Guide,” which helps a user orient themselves to both the library and the vocabulary of Ethereum.
 2. Ethers.js has useful call outs and additional information provided as part of the documentation, giving the end user visual cues, convenient links, and other helpful user experience features that make reading and using the documentation an enjoyable experience.
 3. Ethers.js documentation has an extremely useful feature - a toggle to single page view, in which all documentation is provided on a single page. This makes using “Ctrl + f” in the documentation a breeze, and helps with finding the method you are looking for quickly.

Web3.js has not had many visible changes to the documentation since our last article and could use an update to make the user experience more pleasant.

An indirect additional comment on the documentation - ethers.org provides a very helpful “playground,” where you can try out the library in browser: https://playground.ethers.org/. This useful feature lets a user get started playing around with the library quickly and easily. While it could be argued that remix.ethereum.org provides a similar playground experience for web3.js, this is not the goal of remix, and remix support ethers.js as well.


8) How important is the overall usage of the library?

The last time we looked at the numbers, web3.js was the clear winner in overall usage, with ethers.js gaining users at a rate that appeared that it would only be time before ethers.js caught up to web3.js. The results today show that both have healthy ecosystems and a large number of users. My personal belief is that the overall growth of the ecosystem shows that both libraries have been adopted by a significant number of projects and users. So, while web3.js has more downloads, stars, and overall metrics, ethers.js is competitive to web3.js in its usage. It’s fair to say both have been widely adopted.


9) How important is the license?

This is one area that has not changed since we last reported. Web3.js still has the LGPLv3 license and ethers.js the MIT license. I am not a lawyer, and so this is the hardest area for me to pick a winner. It is worth reviewing Slava Todavchich’s article “Understanding open-source and free software licensing,” which we suggested in our July 2020 blogpost.

But wait... there is a new category!


10) How important is the community and community experience?

Yes, I am adding a new way to evaluate the two libraries, based on my experience in Developer Relations and Software Community. I am personally looking for robust channels where developers using the software can interact with one another, find information about updates and hotfixes, share their use cases and help each other debug their code. The best software projects provide this for their users and it is a differentiating factor.

Web3.js and ethers.js have both embraced Discord as a means to communicate directly with their community of developers. Web3.js lives within the ChainSafe Discord Server, in the channel #web3js-general. Web3.js has used this channel not just to interact with developers, but  as of September 2021, to promote a web3.js developer survey to help drive the direction of changes for version 4.x of web3.js. Ethers.js utilizes the EF JavaScript Team Discord Server, in the #ethers channel. Both are active channels with communication on a daily basis.

Both also use Twitter to communicate changes to their audiences, though both have relatively light follower counts. @web3_js (1,250 followers) and @ethersproject (1,279 followers) only tweet to announce updates and changes to the libraries, serving as another way for notifications about updates to get through to developers.

ChainSafe also uses their Medium account to post some updates about web3.js, though not a regular cadence.  

GitHub continues to be a source of discussion for communities of both libraries, though the shift to Discord by both reflects a growing trend in the Ethereum community, as well as in software communities in general, to commit to this tool for a mix of synchronous and asynchronous communication.

The verdict is that both take development and interaction with their communities seriously.

What’s the next step?

You should go ahead and test out the libraries themselves with Infura, and we created a tutorial for just this purpose: Ethereum JavaScript Libraries: web3.js vs ethers.js (Part II). The best way to see if my evaluation is valid is to kick the tires on both libraries.

In conclusion, instead of declaring a winner, it seems that Ethereum itself is benefitting from having two leading JavaScript front-end libraries. More libraries being built that can utilize the features of web3.js and ethers.js will push them to be even better (like web3-react, for example). In updating this article, I have been struck by the growth of downloads and dependencies of both libraries, making me of the opinion that you can choose either and feel comfortable with the decision. I hope this illuminated some ways you can evaluate both to choose what works best for you.

Get started building on Infura for free today.

Ethereum JavaScript Libraries: Web3.js vs Ethers.js: An Update

As the clock ticks down to the Merge, the Teku and Infura teams have continued refining their collaboration. In case you missed it, these two teams have created an eye-poppingly fast Ethereum 2.0 client sync experience. Since then, they have continued refining their integration and made some important discoveries and improvements.


Attestations with Teku

One of those discoveries was that validators linked to a remote beacon node could have significant performance issues: specifically, a lot of missed attestations. Obviously, this is a pretty crucial issue. It turned out to be not just a problem with a remote beacon node, but specifically a remote beacon node behind load balancers, including Infura’s load balancers.

If you’re interested in the blow-by-blow, check out the Github issue here.

The solution the team came to was to implement an option to disable early attestation publishing when the block is received:

--validators-early-attestations-enabled[=<FALSE>]

Find the full Teku documentation on this issue here.

This option allowed validators connecting to Infura beacon nodes to have performance equivalent to validators connected to a local beacon node, which in and of itself is impressive. It would appear that this is a fix not just for nodes connecting through Infura, but for any context where Teku validators are using load-balanced beacon nodes.

The second innovation the team has made surrounding attestations is batch attestations. This consists of sending all attestations produced for a given slot to the beacon node in a single batch. In the context of Infura, this allows running a lot more validators without hitting rate limits.


The future of history

Another feature that the team has been working on, which isn’t quite ready yet for a full release, is an innovative way to store historical state without having a hard drive the size of the Library of Alexandria.

With increasing adoption of decentralized technology, there is more and more demand, and even novel use cases, for historical chain data. The most top-of-mind for many in the space is tax compliance. Institutions and even individuals are increasingly in need of solutions for being able to query, quickly and cheaply, historical chain data.

Like most great things in this space, the solution being developed uses Merkle tries. Without getting too deep into the woods (pun intended), as it’s not finished yet, the technique essentially takes the difference between slots and stores the branch updates. The applicability for this is tremendous, so watch this space for more updates.


Safety through Diversity

As we approach the reality of Ethereum 2.0, more and more voices are calling out a topic of vital importance: client diversity. The Ethereum Proof of Work consensus mechanism is, at this point, venerable and battle-tested, at least in blockchain terms, and is resistant to 51% of attacks. As the network transitions to Proof of Stake, the threat remains that a single Ethereum client will be running on a majority of validator nodes. This opens the door not only for a malicious attack, but also for single points of failure bringing down the entire network.

For more explanation, check out this very readable primer that should bring a lot of issues into focus. There are so many reasons to make the move to a Proof-of-Stake consensus model, and the network is on track to do so. It would be a stunning failure of vision and quite simply, wildly unsafe to move Ethereum to a PoS network that has a majority of any Ethereum client.

Even if we were to assume that all clients were going to act in the best interests of the network as a whole, which in and of itself is a leap most aren’t willing to take, the Ethereum network is a sprawling global entity with external dependencies. No client should be able to be a single point of failure for the entire network.

As we build the Beacon Chain and validators up and out, client diversity must be included as an essential consideration.

Learn more about Infura’s Eth2 API here and sign up for a free account.

Teku + Infura to 2.0: How to Handle Attestations

SoK: Validating Bridges as a Scaling Solution for Blockchains

So, why would you need a hybrid infrastructure model alongside Infura?

Let’s think about how your database is set up. You probably have your own database, which is great. What happens if that database goes down? Would your app continue to run seamlessly, delivering the experience you want your customers to get? Or, would your database shutdown cause outages and crashes in your app?

If the dataset you’re hosting is a public dataset, you have a new paradigm for making your infrastructure much more resilient and reliable by integrating Infura into your overall strategy. Infura implements a reverse proxy pattern internally and can be a highly reliable and performant node in your infrastructure stack, allowing you the ability to have a portion (or all) of your traffic routed to Infura.

You can choose to keep your database as your primary database with Infura as a backup, or vice versa. In this way, Infura will act as an always-on backup for your database, providing a level of flexibility previously not available with a single database running.

You also have the opportunity to use Infura as a stats comparison tool to make sure your performance is up to par. Alternatively, you may need to handle more load (request traffic) than your infrastructure can currently handle. You can route the overflow to an Infura project ID to handle spikes in traffic so your service stays up and running.

There are many opportunities for you to use Infura alongside your own in-house node infrastructure to improve your user experience. Let’s dive a little deeper on how we accomplish this.


What does it mean when Infura implements a reverse proxy pattern?

Let’s review what a normal proxy is first, and then we’ll flip it and reverse it, a la Missy Elliott, to talk about the reverse proxy. A proxy server (or web proxy or forward proxy) is a server located in front of a group of client machines (computers). When those computers make requests, the proxy server intercepts those requests and communicates with the target web servers on behalf of those clients. Basically, a proxy is a fancy word for a request/response middleman.

If you’re a visual learner, here’s a diagram from Cloudflare that shows just where that forward proxy sits:


What is a reverse proxy?

A reverse proxy is a server that typically sits on the edge of your infrastructure. It is responsible for receiving requests from web clients and subsequently routing them to one or more backend web servers.

Here’s another great diagram from Cloudflare to show how the reverse proxy fits in to the whole flow:




One of the main reasons to use a reverse proxy server is load balancing, ensuring the flow of traffic between clients and servers remains smooth. This is one of the main advantages of using both your own node and Infura. In addition, it allows you to cache content and provides web acceleration for improved performance. Lastly, reverse proxies allow for more efficient, secure SSL encryption and protection from DDoS attacks and related security issues.

As we previously mentioned, Infura can be used as a reverse proxy to assist with ensuring the flow of traffic for your clients and servers stays as smooth as possible, making for a more enjoyable user experience.


Some examples of a reverse proxy in action

Let’s first look at how we can set up a very simple reverse proxy using Caddy.

We will use our localhost and a backend HTTP service running on 127.0.0.1:9000 to make sure we’re getting our reverse proxy working correctly.

First, download Caddy. Once that’s downloaded, check out their Getting Started guide here. Or, follow along to learn how to set up a simple reverse proxy!


At this point, you may be running your own node, but since it takes too long to sync one for this article, we can substitute with a simple NodeJS stub to check that our reverse proxy is working correctly. I simply named mine main.js.


const http = require('http');

const hostname = '127.0.0.1';
const port = 9000;

const server = http.createServer((req, res) => {
   res.statusCode = 200;
   res.setHeader('Content-Type', 'text/plain');
   res.end('Reverse proxy success!\n');
});

server.listen(port, hostname, () => {
   console.log(`Server running at http://${hostname}:${port}/`);
});



This sets up a backend HTTP service running on 127.0.0.1:9000 mentioned earlier and will display a “Reverse proxy success!” message if our proxy is working correctly. To start this, run `node main.js` in a different terminal window and leave that connection open!

Next, we will want to create a Caddyfile (literally create a new text file in whatever directory you’re working in and name it Caddyfile). Once you have that set up, we will set up our simple reverse proxy itself inside the Caddyfile with just two lines:

localhost 

reverse_proxy 127.0.0.1:9000



In this instance, reverse_proxy is where we want to get our information from (the original site), and localhost is where we are redirecting to using our reverse proxy.

Now, from the same directory as your Caddyfile in a new terminal window from your `node main.js`, run:  

caddy run



This will start the caddy server and will allow your reverse proxy to work! Now, you’ll notice when you run this that you don’t see the “Reverse proxy success!” message popping up.

That’s because this just started the server. You now need to make a request to “https://localhost” and you’ll see the message. To do this, open another terminal window (that makes three now, for those of us keeping track), and simply run:

curl https://localhost



Running this command will give you the “Reverse proxy success!” message we were looking for, and now you know you’ve successfully set up a simple reverse proxy.


Enter Infura!

Now that we’ve gotten a basic reverse proxy up and running, let’s try one using an Infura endpoint. We will keep our overall setup of using a Caddyfile the same, but we won’t need the backend HTTP service running in the background, as that will be switched to an Infura endpoint.

We’re going to change up how our Caddyfile looks:

localhost 

reverse_proxy https://rinkeby.infura.io {
   header_up Host {/v3/<YOUR_PROJECT_ID>}
}



You will notice that we’ve added in a “header_up Host” inside the reverse_proxy section. This allows us to include our Project ID to both the Rinkeby endpoint and the localhost endpoint we are proxying to.

To test this out, we will need to send a request, so I used web3_clientVersion as an example:

curl https://localhost/v3/<YOUR_PROJECT_ID> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"web3_clientVersion","params": [],"id":1}'



When we run this, we get the following output:

{"jsonrpc":"2.0","id":1,"result":"Geth/v1.10.8-omnibus-aef5bfb3/linux-amd64/go1.16.7"}



Cool! But how do I know my reverse proxy is working? Well, if you switch out `localhost` in our curl command to `rinkeby.infura.io`, you get the same output, which shows that our reverse proxy is running properly.


How do you use Infura as a backup for your own node?

We’re going to set things up initially the same as we did in the previous example but with two upstreams, one to our localhost and the other to the Infura node.

Next, we’re going to set up load balancing. Now, what’s load balancing? Load balancing acts like a traffic cop sitting in front of your application servers, routing client requests across all the servers that can fulfill those requests quickly and efficiently.

So how do we set that up?

Since we’re using Caddy, we can refer to their docs for the basics of how to use more than one upstream. When we look at lb_policy, there are many ways to determine which upstream Caddy will use first. Caddy will default to using the first listed upstream and will move down the list if the servers stop responding. In our example, we want to have localhost:9000 from our main.js file be the first upstream, meaning we want our reverse proxy to send the data through our localhost first, so we will identify that by putting it first in our list of upstreams (we will leave our Infura Rinkeby endpoint in as the second upstream):

localhost

reverse_proxy localhost:9000 https://rinkeby.infura.io {
   header_up Host {/v3/66172ed429624788ac264604755ba42c}
}



Since we are using the localhost:9000 port, we want to get that server back up and running. In another terminal window, start the Node server with node main.js.

To make sure everything is set up correctly, let’s run our request through by running the same request from earlier but with the :9000 port included, expecting to get the “Reverse proxy success!” message:

curl http://localhost:3000/v3/<YOUR_PROJECT_ID> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"web3_clientVersion","params": [],"id":1}'



and we get the following output:

Reverse proxy success!



Excellent! Now, how do we incorporate the Infura endpoint to be a fallback?

You’ll notice we left the Infura endpoint in our Caddyfile where it originally stood and we asked our proxy to load balance using the first upstream (our localhost), which was how we got that “Reverse proxy success!” message.

Now that we confirmed that we set everything up correctly on our end, we’re going to kill the localhost server, mimicking what would happen if your private node went down. Once we do that, our requests should automatically start routing to the Infura node and we should get something similar to the below output:

{"jsonrpc":"2.0","id":1,"result":"Geth/v1.10.8-omnibus-aef5bfb3/linux-amd64/go1.16.7"}* Closing connection 0



But wait! We don’t get that! Instead, we get an error message.

This is because Caddy only allows us to use either two HTTP or two HTTPS endpoints - in our case, localhost is HTTP and our Infura endpoint is HTTPS.

Luckily, there is a tool we can use to make this work with localhost that will create a TLS certificate and sign it with a CA trusted locally by your device and browser. That tool is called mkcert, and it’s incredibly easy to install by following these steps.

Keep in mind if you’re doing this with your own private HTTPS node, you likely will not need this additional step.

If you are following our tutorial step-by-step (using localhost), be sure to follow all the steps, including updating your main.js file to the below to include the HTTPS requirement and the options constant.

const https = require('https');
const fs = require('fs')
const options = {
   key: fs.readFileSync('<PATH_TO_CERTIFICATE-KEY_FILE>.pem'),
   cert: fs.readFileSync('<PATH_TO_CERTIFICATE_FILE>.pem')
};

const hostname = '127.0.0.1';
const port = 9000;

const server = https.createServer(options, function(req, res) {
   res.statusCode = 200;
   res.setHeader('Content-Type', 'text/plain');
   setTimeout(() => {res.end('Reverse proxy success!\n');}, 1000)
});

server.listen(port, hostname, () => {
   console.log(`Server running at https://${hostname}:${port}/`);
});



When you run the mkcert localhost command from the tutorial, the certificate key file and certificate file used in the code above will be created.

Now that we have our localhost running with HTTPS, we can continue! Since we are running everything with HTTPS, we need to update our Caddyfile to reflect those changes.

localhost:3000 

reverse_proxy https://localhost:9000 https://rinkeby.infura.io {
   header_up Host {/v3/66172ed429624788ac264604755ba42c}
}



Now that we have all our files in order, let’s make sure our Node.js server is running and send that request again.

curl http://localhost:3000/v3/<YOUR_PROJECT_ID> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"web3_clientVersion","params": [],"id":1}'



What do we get?

Reverse proxy success!



Perfect! That’s exactly what we want to get, as we have asked our reverse proxy to go to https://localhost:9000 first.

Now, what happens if we kill the Node server and send our request again? Remember last time we did this, we got an error message. This time we should be getting the result from our Infura Rinkeby node:

{"jsonrpc":"2.0","id":1,"result":"Geth/v1.10.8-omnibus-aef5bfb3/linux-amd64/go1.16.7"}



Success!

Our reverse proxy is, in essence, ignoring the localhost node, as it’s not functioning, and is defaulting to the Infura Rinkeby node!

Super easy, right? Now you know how to use Infura as a backup node to keep your services up and running smoothly!


Where can I learn more about reverse proxies?

Take a look at our client story from MakerDAO. They currently use Infura for a multitude of reasons, including using us as a backup node solution to ensure all developers can use the MakerDAO toolkit!

Another great example is the Polygon PoS network. We initially began working with Polygon to share some traffic load for their network, allowing users to access the Polygon networks via Infura endpoints and effectively ensuring their network remains fast and functional, regardless of traffic spikes they may see. We have since increased our partnership so we are now handling 100% of their network traffic.

Check out this blog post highlighting multiple companies across all verticals using a hybrid infrastructure model of their own nodes plus Infura. Get some ideas on how we can help you accomplish your needs, from verifying transactions to providing backup database services!

If you would like to run an Infura node in addition to your own, sign up for a free trial today.

How to Run Your Own Node AND an Infura Node

When enterprise developers build dapps on Ethereum, they often have to consider the entire tech stack and development process. The list of considerations range from application features such as Web2 interfaces to deployment, which is usually on a permissioned network hosted by a preferred cloud provider. Since most full-stack software engineers build off of SDKs and API calls, it’s important to establish the value of the application with consideration of the deployment network.



Get the best of both Web2 and Web3 worlds

Many enterprise blockchain business cases build on the principles of traditional Web2 development. Web2 focuses on operating with a fluid user experience with attention to detail on scalable and responsive code on multiple devices. A valuable decentralized application (dapp) in Web3 redesigns the economics and industry roles while building on complementary existing systems -- instead of fully replacing those systems with analogous Web3 features.

Say you would like to reinvent a syndicated loans issuance platform such as IPREO. This effort would require significant IT resources to spin up a minimum viable product from the ground up if you’re recreating features like tranche issuance calculations or calendar date exceptions. Instead, consider a path to lesser resistance: blockchain modules that connect these digital assets to new liquidity networks. The functionality is a re-issuance of an existing financial instrument to ABC network with a listing on XYZ automatic market maker rather than the full end-to-end dashboard.

To connect to pockets of liquidity, an enterprise developer must deploy with the same smart contract language that is compatible with the Ethereum Virtual Machine (EVM) and look to bridge the assets to networks with the desired investor and issuer markets.


Why build on public Ethereum?

Until now, publishing enterprise dapps on Ethereum requires significant system integration, executive buy-in and high set-up costs. Recently, we have seen more public blockchains working with enterprises to cover non-functional technical needs in order to meet minimum requirements of security audits and performance. However, the relatively tribal nature of the blockchain developer subculture means that mainstream enterprises are still conservative when it comes to building on Ethereum.

If you are an enterprise developer, consider the following advantages of building on public Ethereum vs. permissioned networks:

1. Faster setup and lower total cost of ownership

2. Immutability and longevity of the data stored with thousands of independent nodes

3. Composability and low barrier of entry to decentralized finance (DeFi)




1. Faster set-up and lower total cost of ownership

This is a standard private blockchain journey for a consortium:

After you develop your dapp, a lot of time is focused on node deployment adhering to enterprise software standards. On the business side, you are also trying to build a consortium to agree on the benefits and adoption before the tech is tested.

The consortium model usually chooses a separate tech vendor that does not have single ownership from one consortium member to prevent conflicts of interest. The tech vendor determining deployment and long-term support likely runs the Ethereum nodes on behalf of participants. This will get the product to market faster and focus on the business benefits.

The last step involves time and licenses for adding more nodes and mutualizing infrastructure costs across participants. Compared with private networks that remove tokens from their operation, public networks require ownership of native tokens to fund transactions. This gas cost pays for the infrastructure -- third parties running full nodes and running operations for mining/validating. In my time building enterprise projects, we have never seen this happen.

The public journey is much more straightforward. After you develop your dapp, the deployment is a choice between public networks with updated configurations on your Truffle setup. The added complexity is the gas costs for funding and running your transactions on this network.

To simplify connectivity to EVM-compatible networks, you can use Infura’s Ethereum API to connect your app instantly with a single line of code. Simplify your transaction management with Infura Transactions (ITX) using prepaid accounts without holding ETH on your balance sheets. ITX is a transaction relayer that manages your transactions to prevent dropped or stuck transactions.

You will also likely want to work with a team such as Diligence that can audit your contracts and monitor them when they’re live.

Public Ethereum has an overall lower total cost of ownership when you compare the operational cost of running a system on mainnet rather than focusing on the ownership and maintenance of the network itself.

A consortium may have more control in the private chain and face less security and treasury reviews at first. However, your infrastructure overhead and negotiations on consortium network matters tend to outweigh the convenience and added features of connecting to mainnet.


2. Immutability and Longevity

The Ethereum mainnet is secured by the interaction of thousands of independent nodes run by individuals and miners throughout the world. Private chains typically have a small number of nodes controlled by one or a few organizations. Those nodes can be tightly controlled, but only a few need to be compromised in order to rewrite the chain or commit fraudulent transactions.

At ConsenSys, we’ve recommended public networks to enterprise developers for their resilience of replicated data as you are able to recover more quickly with a larger network of more than 15,000 independent nodes. The more peers you have, the easier it is to find a seed and fully recover your recorded transactions. In consensus decisions, the more blockchain validators there are to verify transactions, the more difficult it is to coordinate a majority decision that may lead to an attack.

In a permissioned network, the security is governed by the node with the least security. Your network is only as secure as the weakest link. Any added nodes to the network may also increase the surface area of attack. Most institutions will recommend a base software security test in order to join as a full node owner. The node owner will have to pass standard penetration testing to prevent any hacking on the node in case it is a bad actor to the entire network.


3. Composability and Low Barrier to Entry on DeFi


The Ethereum network powers a vibrant ecosystem of third party applications and technology including DeFi and NFTs. A highly composable and interoperable system allows you to connect to DeFi to build financial products that enable and combine multiple apps to match specific user needs. The Ethereum mainnet offers enterprise developers the ability to gain access to market liquidity and provide innovative ways for users to participate in the exchange, trading or growth of that liquidity.

When we say composable, it’s much more than just an open banking API. It’s a set of open source live protocol contracts that can be called and extended. We’ve seen pure forks of open source code like with Uniswap to get sushiswap. The market has seen countless copies of DeFi models such as Compound and Aave, and it doesn’t look like things are slowing down anytime soon.

There’s more and more real value happening in DeFi leading us to believe that cryptocurrencies are not a fad. It is here to stay.

Watch Clemens’ presentation “Pitching Public Ethereum to Enterprises” at EdCon 2021.

Interested in building on Ethereum? Contact us to get support on starting your enterprise project.

3 things enterprise developers should consider when deploying on Ethereum

Are you excited by blockchain but don’t have a great deal of experience coding? It can be easy to fall down a rabbit hole of technical tutorials that make assumptions regarding your initial development knowledge. A particularly important topic to grasp is basic security within your code.

As you begin to build out your very own dApp, you will have to include information such as an Infura API key, along with a mnemonic.

If you are new to coding, this is the equivalent of giving a stranger your social security number and keys to your home. Once this information is public, there is no definitive way to ensure it hasn’t been captured by a person or web crawler, which could result in malicious behavior.

So, how can we address this?

Thankfully, we can use dotenv along with git to protect our sensitive information within our project when / if we push to github.

Dotenv is a zero-dependency module that loads environment variables from a .env file into process.env, storing configuration in the environment separate from the code. It is often a convention for environment variables to be stored in a .env file or other mechanisms based on the server you are using.

Note: This article will focus on building out a project using Truffle and Infura.

In our project, we will need to run the following command:

npm i dotenv


Once the process in our terminal has been completed, we will want to make sure we have the dependency successfully installed. Head over to your package.json file and check to ensure that dotenv has been added under dependencies.

Next, at the root of our project, let’s create a .env file:

Here is where you will add all of the sensitive information that should not be shared.

We will make sure we can access our .env information in our truffle.config file. At the top of the truffle.config file, add the following:

require("dotenv").config


This will tell your project to load anything that is in the .env into an environment variable, granting you access to it.

Now, instead of having to put our Infura api key or mnemonic in an exposed file, we can import that information from our .env file.

When it comes to gaining access to our project key we are going to use, sign up to Infura and create a project. In your dashboard, you should see something similar to this:

The following code is an example between the usage of .env and exposed information within truffle.config:

const HDWalletProvider = require('@truffle/hdwallet-provider');

const infuraURL = 'https://rinkeby.infura.io/v3/<project id here>'

const mnemonic = "Your mnemonic here"


rinkeby: {

provider: () => new HDWalletProvider (mnemonic, infuraURL),

network_id: 4,

gas: 5500000,

confirmations: 2,

timeoutBlocks: 200,

skipDryRun: true

},


Imagine if you pushed this up to github. Anyone would have the ability to open your truffle.config file could take advantage of your exposed mnemonic and project id from Infura.

Let’s take a look at that same code and implement better security practices.

Notice how we are calling upon the information without having to directly add to our file.

One important detail, as of now even with an .env file: if you push this project to github, it will show the .env file, which would defeat the purpose!

Take a look for yourself.

This is where .gitignore comes into play. We will need to create a .gitignore file, so we can push this project up to github.

Without getting into git, a quick summary could be git is version control software that keeps track of all of your files and the versions of them. What .gitignore does is it tells git not to keep track of this file along with everything it contains.

If you want to dive deeper into git along with other foundational material, have a look at our Basic Training, a free course that helps ensure you have the fundamental tools when developing.

At our root (similar to the level our .env file lives), we will create a .gitignore. Inside of that file, we will add .env along with any other files you would rather not be pushed to github.

We can now push our project up to github and notice that our .env file is no longer exposed. Our sensitive information is now much more secure.

If you are experimenting with this, make sure you add your .env file to your .gitignore before pushing.

If you are running into issues, remember gitignore ignores only untracked files. If your files were committed in the past, they are now tracked by git. To ignore them, you first need to delete said files, git rm them, commit and then ignore.

Otherwise, you can delete the .env file and run

Git rm .env --cached


Here is a helpful link discussing the removal of sensitive data from a repo if it was previously committed and discusses how to clean the git history. Savvy attackers don't just look at the most recent repository info, they'll look at the history of it as well.

Note: If you come across it in documentation, a question you might have is
“What is env. example”

An env. example file, on the contrary to this tutorial, is actually included in the repository, it is used as an example file for you to know what KEY=VALUE pairs you need for your project. Most often, it is used to copy the .env file and then change the values.

Example of execution:
Enter to the project root directory using your terminal.

Check if .env the file exists or not.

If the file does not exist then create a file named .env.

Now execute the command

cp .env.local .env.


So the .env.sample file has all the ENV declarations defined but without their values. It helps other developers establish/set up the project without having to reverse-engineer the codebase.

So after git clone, you usually execute the command `cp .env.sample .env` and fill in the values with the Infura credentials as we saw in the example above.

Note: When you create a new repo using github, if you scroll down you should see the option to include a .gitignore file so you don’t have to create one yourself in the future.

Hopefully, you found this article on basic security practices helpful as you begin to develop your very own projects. Feel free to join our Discord if you want to continue the conversation, share projects, ideas, and join the community!

Start here with a free Infura account >

How to Use .env to Enhance Basic Security Within Your DApp

Optimistic Ethereum is a rollup scaling solution that allows users to submit transactions on the Ethereum network and get them executed faster for a much lower gas cost. From the perspectives of users and developers, this is a "parallel universe" called Layer 2, or L2, where users typically have the same addresses as they do on the Ethereum blockchain (also called Layer 1 or L1). There are gateways that allow messages and assets to be transferred between the universes.

The Optimism network API largely uses the same JSON-RPC specification as Ethereum and Infura supports all the necessary API methods for building a fully functional application on the Optimistic Ethereum network.


Why are transactions cheaper on Optimism?

On L1 Ethereum, thousands of nodes run your transaction to verify that the proposed block that includes it is valid. This process is expensive and has to be paid for. Unlike on L1 Ethereum, Optimistic roll ups provide faster and cheaper transactions because it allows users to perform most of their tasks off-chain in a "layer 2" protocol. On Optimistic Ethereum, the smart contract has only two tasks: deposits/withdrawals and verifying proofs of transactions on chain. This makes the process more efficient and a lot cheaper.


Why is this safe?

The great thing about decentralization is you can trust that transactions are executed correctly because there are thousands of computers executing them. Honest miners would reject such a transaction. With rollups, you don't have that level of redundancy.

The answer, in the case of optimistic rollups, is incentives. Every node in the network has to put up a stake before it can propose a new block with the execution results of a transaction. Every other node can check up on those results, and if it thinks they are incorrect, dispute them. The dispute is resolved on L1, so it is as trustworthy as anything else in Ethereum. Whichever node lies, either proposer or disputer, loses its stake and most of it goes to the other node involved.

Of course, the whole point is to avoid running transactions in L1. This system achieves that by making it pointless to cheat. Any proposer who attempts to cheat is going to be caught by the other nodes, lose its stake, and not get the invalid transaction result accepted as valid. A disputer can force a single transaction to go into L1 arbitration as a denial of service attack, but the stake is high enough that it wouldn't be worth doing.


How does Infura work with Optimism?

Infura exposes endpoints for Optimistic Ethereum (the production network) and Optimistic Kovan (the test network). You use them the same way you use any other network, by selecting them from the menu and using the specified endpoint.

There are a few small differences between building on Layer 1 Ethereum and Optimism:

1. You must use the JSON-RPC API as we do not support Websockets yet.
2. Search filters are not yet supported


How to Get Started on Optimism...



The main difference between Optimism and regular L1 Ethereum (other than the cost) is the access point URL.

| Network          | RPC URL |


… If you are using the Truffle development environment

Infura users can add the free Truffle Optimism add-on directly on their Infura dashboard. The Truffle Optimism box also contains the configuration definitions required to use Infura. Currently, you will need to manually add the gas costs of transactions when you use Truffle to run deployments or tests on Optimistic Kovan or the main Optimistic Ethereum network.


… If you are using Hardhat

To use Optimistic Ethereum or Kovan, edit hardhat.config.js's modules.export.networks to add these definitions:

"optimistic-kovan": {
    url: 'https://optimism-kovan.infura.io/v3/<Infura Project ID>',
    accounts: { mnemonic: <your account mnemonic goes here> },
    gasPrice: 15000000,
    ovm: true // This sets the network as using the ovm and ensure
                      // contract will be compiled against that.
},
"optimistic-ethereum": {
  url: 'https://optimism-mainnet.infura.io/v3/<Infura Project ID>',
  accounts: { mnemonic: <your account mnemonic goes here> },
  gasPrice: 15000000,
  ovm: true // This sets the network as using the ovm and ensure
                    // contract will be compiled against that.
}



Then you simply run:

npx hardhat --network optimistic-<kovan or ethereum> <command>



… If you are using Remix

When you use the Remix Optimism plugin to develop for Optimism, network connections are created through the wallet. If you use MetaMask, you can select the network Custom RPC and fill in the details:

What is Optimistic Ethereum?

Power-Up Your App Using JS with Infura!

Featuring:
Coogan Brennan, Ethereum Technical Trainer
Sean Brennan, Infura Dev Rel Lead
Ian Lapham, Uniswap Software Engineer

In this webinar tutorial, developers from Infura and Uniswap walk you through best practices of developing responsive React frontends that take advantage of real-time Ethereum data and transactions. They guide you through using the combination of Javascript, web3-react, and Infura; using code examples and recent lessons from Uniswap's frontend team.

Check out the recording below:

Get the most out of this session by getting started on Infura for free.

Tutorial: State and Payment- Power Up Your App Using Javascript & Infura

In the previous post on frontend development, we ended with a website that allowed a user to connect via MetaMask and it displayed their account balance of Ether. Yet many Ethereum use-cases such as DeFi involve sending and receiving ERC20 tokens, which are tracked differently than native Ether. In this guide, we’ll show how to track a deployed contract’s transactions, and display and update those numbers in the frontend as they can potentially update in each new confirmed block. For this example, let’s track the Dai<>Eth trades on Uniswap.


To do this, we’ll use a library called Subspace from the Embark team at Status. Our preferred way to track real-time data is using React Hooks, so we’ll walk through setting up a frontend with Ethereum data streaming by working through Embark’s example code found here.  So in total this frontend uses Infura, React (with helper libraries), and Subspace.

 * This tutorial is a separate website from the prior frontend tutorial.  We’ll go through the important pieces of code but not all of it, so it’s recommended to clone the example repository and then run npm install and npm start in the root directory (or alternatively use yarn) which will get your website up on localhost:3000 . From there, we’ll see how adding more data tracking is easy with Hooks and useEffect().  
   

There’s only 3 important files to go over. To start, look in the short file of src/index.js, in it we have <SubspaceProvider> wrapping the entire App, which gives every component access to the web3 object, which is our connection to Ethereum through Infura as the web3 provider. We’ll set that up later in App.js to use Infura for the web3 connection.

const rootElement = document.getElementById('root')
ReactDOM.render(
  <SubspaceProvider web3={web3}>
    <App />
  </SubspaceProvider>,
  rootElement
);

In contracts/exchange_abi.json we have the ABI of Uniswap, which is a specification for the deployed Uniswap contract of every function that we have Subspace track. The ABI is specified in JSON, and we’ll use it for web3’s Contract object to interact with Uniswap throughout the dapp. Every deployed contract on Ethereum has an ABI, so you could add any existing contract to this frontend and track it’s transactions by knowing it’s ABI and the deployed contract’s address.


    {
        "name": "TokenPurchase",
        "inputs": [
            {
                "type": "address",
                "name": "buyer",
                "indexed": true
            },
            {
                "type": "uint256",
                "name": "eth_sold",
                "indexed": true
            },
  ... and a lot more

In App.js, we start by initializing the web3 object with our Infura connection. If you don’t have an API key, you can get one for free by signing up. Next, create a Contract object by combining the ABI and contract address of that ABI. This address is Uniswap’s contract that holds the Dai in its liquidity pool.

 * Note, you can now go back to index.js to add this same Infura URL as the Web3 provider there.

const web3 = new Web3("wss://mainnet.infura.io/ws/v3/806ce35b64344f04a9a7e47379d9ca41");
const dai = new web3.eth.Contract(exchangeABI, '0x2a1530C4C41db0B0b2bB646CB5Eb1A67b7158667');

In this next part, we set up the React state variables that Subspace will use. The subspace object is created from useSubspace(), and we pass in the Contract object we just created. Then a couple definitions for helping work with values in wei coming from the transactions.

function App(props) {

    const subspace = useSubspace();
    const daiContract = subspace.contract(dai);

    const [txnObserver, setObservable] = useState();
    const [last5Observable, setlast5Observable] = useState();
    const [latestBlock, setBlock] = useState();
    const [last5, setLast5] = useState([]);

    //Trade details object for calculating exchange rate
    function TradeDetails(tokensSold, ethBought) {
        this.tokensSold = web3.utils.fromWei(tokensSold);
        this.ethBought = web3.utils.fromWei(ethBought);
        this.exchangeRate = this.tokensSold / this.ethBought;
    }

These next 3 code blocks are the Hooks that are the magic of the dapp and give us the real-time streaming we want. We’ll set it up so that we look at the last 50 mined blocks, and show the 5 most recent Eth->Dai trades that happen in those blocks, which will continuously update as more blocks are mined and trades happen.  

useEffect(() => {
        web3.eth.getBlockNumber().then((block) => setBlock(block));
        if (typeof(latestBlock) != "number") 
            return;

        const EthPurchased$ = daiContract.events.EthPurchase.track({
            fromBlock: latestBlock - 50
        });
        const last5$ = EthPurchased$.pipe($latest(5));
        setObservable(EthPurchased$);
        setlast5Observable(last5$)
    },[latestBlock])

The above useEffect() sets up the Hook that gets the last 5 EthPurchase events from the latest 50 Ethereum blocks. Importantly, the setObservable(EthPurchased$) is every trade event we are tracking, and we restrict it to five events shown in the frontend by using the pipe operator (imported from RxJS) and creating an Observable of those five.

Next, we have another  useEffect() Hook that subscribes to all transactions fitting the requirements we defined above for EthPurchase, and just puts them in console.log

   useEffect(() => {
        if ((txnObserver === undefined) || (typeof latestBlock != "number")) {
            return;
        }
        txnObserver.subscribe((trade) => {
            console.log(trade);
        });
    
        return () => { txnObserver.unsubscribe(); }
    }, [txnObserver, latestBlock]);

From the last5Observable created in our first Hook, we get the transaction details of those here:

  useEffect(() => {
        if (last5Observable === undefined) {
            return;
        }
        last5Observable.subscribe((fiveTrades) => {
            const prices = fiveTrades.map(trade => {
                const txnDetails = new TradeDetails(trade.tokens_sold, trade.eth_bought);
                return {'block': trade.blockNumber, 'rate': txnDetails.exchangeRate}
            });
            setLast5(prices);
        });
    
        return () => { last5Observable.unsubscribe(); }
    }, [last5Observable]);

Lastly, we have some React UI code and than you can see the frontend!  Here's a gif showing it. This was recently started, and there have been 3 trades so far.  In the developer console, we can see the additional transaction details of each of those trades. As the trades we are watching stream in, the oldest will fall off the stack.

We hope this was a useful explanation of the Subspace library, which really makes frontend development for dapps simple and easy, especially when it uses Infura for web3 data! So clone this boilerplate repo here, use Subspace, and if you have any questions on this please discuss it with us here For more tutorials, visit the Tutorials section in our Community.

Tutorial: Real-time Frontend Data with Embark's Subspace and Infura

Building a dapp frontend, using React & Network.js, that can connect and request data from the Ethereum mainnet using Infura & Metamask

Developing a service or business on Ethereum can be difficult, due to the intricacies of working with a blockchain and the novel UX / UI issues to solve. This series of guides aims to serve as a quickstart to Ethereum dapp development, with a focus on front-end solutions. Thankfully, you don’t need to reinvent the chain. There are many pre-existing tools and services that can be leveraged to get a dapp running quickly, including:

 * Infura as a JSON-RPC connection to the mainnet or testnets;
 * MetaMask to serve as the user’s wallet and web3 provider;
 * OpenZeppelin for contracts and Network JS, a javascript library for web3 (i.e. blockchain development). This code tutorial is inspired by their dapp creation guide.

Using these products together has the benefit of replacing database setup and user credential management, resulting in a quick-to-start blockchain infrastructure. In this tutorial, we’ll create a React dapp using Network JS that can interact with MetaMask, which uses Infura as its connection to the Ethereum mainnet.

Environment Setup

Before we start you should have Node.js with npm installed. Let’s begin by creating a new project...

mkdir web3-infura && cd web3-infura

npm init -y

...and installing Network JS by OpenZeppelin to get library methods for working with web3:

npm install @openzeppelin/network

Now we’re ready to create a Dapp

Using a common React boilerplate called create-react-app we create the initial version of our dapp. This is easy to setup with npx (npm’s package runner). One line and we’ll have the scaffolding files for our dapp:

npx create-react-app client

In order to use Infura inside your dapp, you’ll need to register to set up an account and create a Project.

In the client/src/App.js file, we find the react project and look for the placeholder code written in App.js. We replace the placeholder code with the following:

import React from 'react';
import './App.css';
import { useWeb3 } from '@openzeppelin/network/react';
const infuraProjectId = '<YOUR_INFURA_PROJECT_ID';
function App() {
const web3Context = useWeb3(`wss://mainnet.infura.io/ws/v3/${infuraProjectId}`);
const { networkId, networkName, providerName } = web3Context;
return (
<div className="App">
	<div>
	<h1>Infura/MetaMask/OpenZeppelin Dapp</h1>
		<div>
    	Network: {networkId ? `${networkId} – ${networkName}` : 'No connection'}
		</div>
		<div>
		Provider: {providerName}
		</div>
	</div>
</div>
);
}
export default App;



Our dapp will now reveal which Ethereum network (mainnet or a testnet) it is currently connected to, and the web3 provider it’s using.

Let’s test this out by saving and starting the browser by running npm start from within the /client directory. Test it out by replacing the mainnet in the Infura websocket URL to rinkeby. If MetaMask is already installed, disable the extension here as you will see it takes precedence.

How this works is that in the above code we import useWeb3 from the React implementation of Network JS (@openzeppelin/network/react) in order to get a web3Context. This is a Javascript hook that will attempt to retrieve an injected web3 provider which, by default, is MetaMask. If no provider is injected, it will use the Infura URL set as web3Context.  The term injected means code or data that comes from a user's browser and is available for the website to use.

Please note there are a variety of Ethereum web3 libraries available in many languages, and while the implementation specifics differ, they all implement creating a web3 connection through a ‘provider’ or ‘signer’ so this step is important to understand.

The useWeb3 hook attempts to obtain an injected web3 provider first, before falling back to a network connection. Alternatively use useWeb3Injected for an injected web3 provider or useWeb3Network for a network provider such as Infura or a private node.

Add a React Component

Our next goal is to move the display of the current Ethereum network to a component and see how components are re-rendered when changes are made, such as the network.

To do this, the first step is to select a web3 provider to be injected, and install it. We’re going to use MetaMask as our web3 provider in this tutorial, so head to metamask.io to install it.

In the code below, the Web3Data component expects a web3Context. The networkId, networkName and providerName are obtained from the web3Context and displayed in the component.

We then create a components directory in the client/src directory, and create a Web3Data.js file with the code below:

import React from 'react';
export default function Web3Data(props) {
const { web3Context } = props;
const { networkId, networkName, providerName } = web3Context;
return (
<div>
	<h3> {props.title} </h3>
	<div>
    Network: {networkId ? `${networkId} – ${networkName}` : 'No connection'
	</div>
	<div>
	Provider: {providerName}
	</div>
</div>
);
}



Now back inside App.js, we’ll add the Web3Data component to provide a web3Context. In the client/src/App.js file, add this import for the Web3Data component:

import Web3Data from './components/Web3Data.js';

Then replace the entire contents of the App function in App.js with the following code:

const web3Context = useWeb3(`wss://mainnet.infura.io/ws/v3/${infuraProjectId}`);
return (
<div className="App">
	<div>
	<h1>Infura React Dapp with Components!</h1>
	<Web3Data title="Web3 Data" web3Context={web3Context} />
	</div>
</div>
);



Let's run npm start from within the client directory to start the dapp again to see how React components are re-rendered by Network JS when changes are made to accounts, connection type or network. You can test this out by changing networks in MetaMask.

Requesting Access to Account Address

Requesting a user’s account address and displaying it is one of the most common patterns among dapps. However, injected web3 providers don’t give the dapp access to a user’s address until that user has given permission. This bit of friction has been intentionally designed to protect user privacy and prevent bad actors from using an account address to track the user around the internet. You can learn more about this communication protocol here.

In our Web3Data.js file, we replace the contents of the component with the following code:

import React, { useCallback } from 'react';
export default function Web3Data(props) {
const { web3Context } = props;
const { networkId, networkName, accounts, providerName } = web3Context;
const requestAuth = async web3Context => {
try {
	await web3Context.requestAuth();
	} catch (e) {
	console.error(e);
	}
};
    
const requestAccess = useCallback(() => requestAuth(web3Context), []);

return (
<div>
<h3> {props.title} </h3>
	<div>
    Network: {networkId ? `${networkId} – ${networkName}` : 'No connection'}
	</div>
	<div>
	Your address: {accounts && accounts.length ? accounts[0] : 'Unknown'}
	</div>
	<div>
	Provider: {providerName}
	</div>

	{accounts && accounts.length ? (
	<div>
	Accounts & Signing Status: Access Granted
	</div>
	) : !!networkId && providerName !== 'infura' ? (
	<div>
	<button onClick={requestAccess}>Request Access</button>
	</div>
	) : (
	<div></div>
	)}
</div>
);
}



Here’s what the above code is doing:

 * Accounts are pulled from the web3Context and, if available, the user’s address is displayed in the dapp;
 * If the accounts we have requested are not available, the dapp will produce a button that enables the user to give the dapp access to their address;
 * When the user presses that button, the requestAuth function in web3Context is called and the injected web3 provider can display a dialog to the user to request access. Using React functionality, useCallback is used to set up the callback for account request access.

Now, we start the dapp again by running npm start from within the client directory.

In the browser, we press ‘Request Access’ to request access to the user’s address, and then accept the request in the Metamask popup (or extension if no popup). The user’s address will then be displayed. To restart the process, logging out of Metamask will make the user request access again.

Account Balance

Finally, our third goal is to add to the React component to display the account balance.

In the code below, we get the lib object, which contains the blockchain data we want, from the web3Context, which is an initialized instance of web3.js (a library that Network.js relies upon).

We use lib for the method getBalance to request the balance of an account, which returns the balance as in value in units of wei. It’s easier to work with in units of ether, so we convert it with the method fromWei.

Since we want to track the state of the account balance, we use a React-specific function called useState. We also use useEffect to watch for if the account address or networkId has changed, and update accordingly.

To get our dapp to display the account balance, we replace the contents of the component in our Web3Data.js file with the following code:

import React, { useState, useEffect, useCallback } from 'react';
export default function Web3Data(props) {
const { web3Context } = props;
const { networkId, networkName, accounts, providerName, lib } = web3Context;
const [balance, setBalance] = useState(0);
const getBalance = useCallback(async () => {
	let balance = accounts && accounts.length > 0 ? lib.utils.fromWei(await lib.eth.getBalance(accounts[0]), 'ether') : 'Unknown';
	setBalance(balance);
}, [accounts, lib.eth, lib.utils]);
    
useEffect(() => {
getBalance();
}, [accounts, getBalance, networkId]);

const requestAuth = async web3Context => {
	try {
		await web3Context.requestAuth();
	} catch (e) {
		console.error(e);
	}
};
const requestAccess = useCallback((web3Context) => requestAuth(web3Context), []);
return (
<div>
<h3> {props.title} </h3>
	<div>
    Network: {networkId ? `${networkId} – ${networkName}` : 'No connection'}
    </div>
	<div>
    Your address: {accounts && accounts.length ? accounts[0] : 'Unknown'}
    </div>
	<div>
    Your ETH balance: {balance}
    </div>
	<div>
    Provider: {providerName}
    </div>
	{accounts && accounts.length ? (
	<div>
    Accounts & Signing Status: Access Granted
    </div>
	) : !!networkId && providerName !== 'infura' ? (
	<div>
	<button onClick={requestAccess}>Request Access</button>
	</div>
	) : (
	<div></div>
	)}
</div>
);
}



We start the dapp again by running npm start from within the client directory and ta-da! The dapp should now display the account balance.

What you have now built is a dapp frontend (using Network.js) that can connect to the Ethereum mainnet and request data from it (using Infura). Users “login” (using Metamask), and the dapp displays the information the user cares about and reacts to state changes.  

Keep Learning

Our next tutorial will show you how to display the ERC20 balance of a user and let them transfer it. Further web3 development guides will include topics such as building with Ethers.js, using OpenZeppelin’s Starter Kits, and more complex integrations such as setting up Eth Log filters with Truffle’s Drizzle framework to react in real time to blockchain data changes on the frontend.


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Building Dapp Frontends with React & Network.js

Deciding whether to run your own Ethereum node (or nodes), outsource your infrastructure to a Web3 provider like Infura, or deploy a hybrid node solution really depends on your API workload. To help developers evaluate their options, we’ve built Versus: an open source API benchmarking tool. Versus compares your API workload across different node implementations and Web3 providers so you can make data-based decisions.

Tests run using the Versus tool are 99% reproducible. In this post we step through a sample test to demonstrate how the tool works, and share the test parameters and results so others can follow the same method and reproduce them.


Getting Started

This project lives here. Simply grab the latest release binary for your platform, extract it, put it in your $PATH and you’re ready to roll.


How it Works

Versus is a command-line tool that reads lines of JSON-RPC requests from STDIN and concurrently sends them to multiple endpoints. It validates that the same results are returned, and compares the time to retrieve them, across each endpoint.

For example: let’s say we have a file queries.json with lines of the types of queries that our application performs:

$ cat queries.json

{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber"}

{"jsonrpc":"2.0","id":1,"method":"eth_getBalance","params" ["0x49318b3970C8a82275B440900bE45f27bf682108","latest"]}

{"jsonrpc":"2.0","id":1,"method":"eth_getCode","params":["0x2a0c0dbecc7e4d658f48e01e3fa353f44050c208","latest"]}




We can send those queries to our local node: `cat queries.json | versus "http://127.0.0.1:8545"


The results would be returned super fast. That's because these are fairly simple queries – and there are only three of them. If we want to run a few thousand queries, it’s going to take a bit more time. We can bump up the concurrency of versus with the --concurrency=20 flag. Add --verbose once or twice to get more output as the process is going.

We can also run the same queries against multiple endpoints at the same time:

$ export INFURA_API_KEY=”... grab this from your https://infura.io/dashboard”
$ cat many-queries.json | versus -vv --concurrency=50 \
"http://geth-node:8545" \
	"http://parity-node:8545" \
	"https://mainnet.infura.io/v3/${INFURA_API_KEY}"



Some responses may be mismatched, but that’s to be expected. Geth and Parity don’t always agree on the exact output that certain types of queries should generate. Note that Websocket support is not implemented yet - pull requests are welcome!


Generating Realistic Queries

Not many of us have a juicy many-queries.json sitting around on our hard drive - and even if we do, these queries get stale really fast. The performance of a node on queries that touch recently-mutated state will vary from state that is super old.

To generate realistic queries, we can use Ethspam - another handy open source tool. Ethspam generates an infinite stream of realistic queries, based on the typical pattern of RPC methods that Infura receives. It’s not perfect, but it’s very useful in combination with Versus. After grabbing a binary release, we can pipe it directly:

$ ethspam | versus -vv --concurrency=50 --stop-after=10000 \
"http://geth-node:8545" \
	"http://parity-node:8545" \
	"https://mainnet.infura.io/v3/${INFURA_API_KEY}"




Output

Below is an example of the output you can expect, once you’ve piped your query into Versus:

In this example, we’ve used Infura (Core Tier) as the Web3 provider, and a local “anonymous” node on an i3.xlarge EC2 instance, and ran a test to compare the two.


Results

In this test, the local node was quite limited. Despite many optimizations (high-IO storage, high memory with increased cache size, etc), requests were bottlenecked. By comparison, Infura’s concurrency proved to be unbounded (i.e., there was no limit to how many requests Infura could respond to, per second).
Some requests were very fast to serve from the local node, which resulted in a lower minimum latency time -- however, the average and maximum latency was significantly and consistently lower for requests through Infura (0.1291s standard deviation for Infura vs 3.2035s for the local node).


Key Learnings

 1. The mismatched responses presented above were predominantly due to the local node disagreeing with Infura about what the latest block number was. If Versus is run with the --verbose flag, it will print mismatched results. Ethspam included some queries that required an archival node to retrieve. Neither the local node nor the Infura Core plan had access to archive-tier data, so these particular results matched up;
 2. Ethspam input is random, which means that if you’re using Versus to compare separate runs, your results won’t be consistent. When comparing nodes, make a single Versus run against multiple endpoints. A single run will confirm that the results match. Only make multiple Versus runs against each single endpoint if you’re using the exact same input;
 3. When running Versus against a single node, make sure that node is fully synced and functional. Nodes like geth will happily respond with an empty non-error response, even when it’s not synchronized, without doing any actual work. Running simultaneously against a known functioning node helps ensure that results are not mismatched.
 4. When running with high concurrency, make sure there are enough samples to reach consistent performance. At minimum, we suggest at least x100 requests per unit of concurrency. Higher is better!


Get Testing!

Though Versus was built by Infura, it’s intended to be an impartial and open source project. We encourage ideas and pull requests from the Ethereum community that seek to make Versus a better, more objective tool that anyone can run.

You can start playing around with Versus now to compare different node implementations and Web3 providers. Compare a light node to a full node, compare different kinds of nodes against each other, or compare Infura against other Web3 providers in high load/concurrency situations.

Our hope is that developers will find Versus a useful tool to help them evaluate what’s out there and ultimately find the best solution to power their DApp.

Want more Web3 tools? Check out this post for open source tools that help you interact more seamlessly with IPFS. Ready to test out Infura? Sign up to start building for free!

Engineering

Compare Ethereum API Performance with Versus

JSON RPC, methods, calls, requests - what does it all mean?! When you start building a dapp on the Ethereum blockchain, you’re introduced to a host of new concepts, request methods and naming conventions to employ - it can be overwhelming. The Infura team are experts in web3 infrastructure. We build open source tools and materials to help more developers interact with Ethereum and IPFS. In this tutorial, we leverage the collective experience of our team to bring you an in-depth guide to reading and writing requests to the Ethereum blockchain, using Infura.


Key Terms and Concepts

Before jumping into the meat of this tutorial, let’s clarify some key terminology. Below is a list of important terms and their corresponding definitions that you need to get familiar with.


Request

A developer interacts with Infura by sending a request through JSON RPC either over HTTP or WebSocket; as a single request or as a batched array. Requests follow this format:

{"id":1234, "method": "eth_foo", "params":[...] }

Because you should be posting this to an endpoint that has your v3 key in it, we can always associate these requests with a key or a project.


Method

The method is essentially what function we are asking an Ethereum node to execute. This will either request data from the node, execute an EVM function and return a response, or transmit data to the Ethereum network (send a transaction). Currently there are 65 methods which are supported by the popular Ethereum clients (Geth, Parity, Besu, Nethermind):

The most commonly used methods are highlighted in bold and comprise the vast majority of Infura’s traffic:

These methods can be grouped into the following categories:

i) Block Data Related

 * eth_getBlockByHash: retrieves a block's details by its hash (a string representing the 32-byte hash of a block);
 * eth_getBlockByNumber: retrieves a block's details by its number (an integer block number, or the string "latest", "earliest" or "pending");
 * eth_blockNumber: retrieves the current block number.

These methods retrieve static data about a particular block in the blockchain. This data is contained in the blockchain headers and could include information like block number or transactions mined, for example.

ii) Per User (address) Data

 * eth_getTransactionCount: retrieves the nonce of an address (i.e: how many transactions have already been mined, per user, for that address). This is needed because when you go to send a new transaction, there’s a field called ‘the nonce’ which is intended to prevent you from accidentally rebroadcasting transactions and sending them out in an order that you didn’t intend.

This method retrieves the simple state data for addresses. It doesn’t matter whether that address is a user or a smart contract. Any address can have an ETH balance.

iii) Reading Existing Smart Contract Data

The concept of smart contracts, and interacting with them, is what makes Ethereum different from other blockchains. A smart contract is two things:

 1. It’s a bit of code, usually written in Solidity, that compiles down into byte code - which is understood by the Ethereum Virtual Machine (EVM);
 2. It’s a means of storage. Think of it as halfway between ‘disc storage’ and ‘ram.’

Below are the most common methods for interacting with smart contracts:

 * eth_call: retrieves a constant EVM method on a Smart Contract and is the primary way to retrieve already mined data from the blockchain about a particular smart contract;
 * eth_getLogs: retrieves events published by smart contract transactions. Smart contracts can emit logs that are really user defined, so when you’re creating this smart contract you can decide the format of these log events. These dapps can then see when your smart contract has emitted these events, and respond accordingly;
 * eth_getStorageAt: retrieves raw state storage for a smart contract;
 * eth_getCode: retrieves the compiled EVM code for a smart contract. There is no copy of a smart contract’s source code on the blockchain itself. So, for example, when you search an address on Etherscan and the verified code of that smart contract is returned, that all happens off chain.


Using eth_call

ERC20 is one standard for how developers can create a token. Almost all wallet software understands this standard, so if you want to create a token and make it easier for people to interact with it, ERC20 is a good place to start.
Eth_call is the most commonly used method for interacting with smart contracts, particularly ERC20 contracts. A typical eth_call request looks like this:

At first glance, it’s not clear what any of this information represents. Let’s break it down:

The "id":1 field is an identifier string which is set by the requester, and helps make sure the client and server are communicating in the same context.

The "jsonrpc":"2.0" field specifies the version of the protocol and must be exactly “2.0”, which the protocol expects.

The from field is the data requester, which could be any wallet address or smart contract. This field is optional.

The to field is always a smart contract. There are two ways to find out what that smart contract is:

 1. You can make a request on the blockchain using eth _getCode, but that would give you the compiled code. Unless you have tools to reverse-engineer the EVM byteCode, you’re not going to immediately know what that means.
 2. You can type the smart contract address into Etherscan.
    Searching Etherscan is the most common way to find out what type of smart contract you’re dealing with. Let’s take the smart contract address 0x6B175474E89094C44Da98b954EedeAC495271d0F and type it in to see what happens:

Etherscan tells us that this smart contract is for the ‘Dai Stablecoin (DAI)’. At this point, we also have the opportunity to inspect the original Solidity code for this contract and confirm that it’s verified:

Great! Now we know that this address represents an ERC20 contract.


Deep-Dive into ERC20

Created in 2015, ERC20 is a relatively simple token standard and the most common contract type on Ethereum. Within this standard, an ERC20 token has to implement the following functions:

 * function totalSupply() public constant returns (uint);
 * function balanceOf(address tokenOwner) public constant returns (uint balance);
 * function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
 * function transfer(address to, uint tokens) public returns (bool success);
 * function approve(address spender, uint tokens) public returns (bool success);
 * function transferFrom(address from, address to, token uint) public returns (bool success).

At certain times, an ERC20 token also has to emit the following events:

 * event Transfer(address indexed from, address indexed to, uint tokens);
 * event Approval(address indexed tokenOwner, addressed indexed spender, uint tokens).

You can view the standard on GitHub for more detail about how these functions work and when to emit these events. For now, let’s try to request the balance for some of the DAI tokens.

We know that our address is 0xDfBaf3E4c7496DAd574a1B842bC85B402BDC298D.

We also know that the DAI contract address is 0x6B175474E89094C44Da98b954EedeAC495271d0F.

To query our balance using eth_call, we use the balanceOf function of the token contract. The JSON-RPC format expects eth_call to have a specific data field format that requires normalizing the contract function balanceOf to a short Function Selector. To do this, we take out the names and the type of inputs it takes, and take that as a string. We then run it through Ethereum’s sha3 keccak hash:

web3_sha3(“balanceOf(address)”)[0..4]-> 0x70a08231

The first four bytes of this hash comprise it’s 4-byte signature. We then take this 4-byte signature, pad it with zeros, add our address as an input and send the eth_call:

This is a hexadecimal number, padded to a 32-byte length with zeroes. If we want to, we can convert this output to a decimal number by using a hex-to-decimal converter. This would return the result 3.890227426645114e+24, which is scientific notation for 3.890227426645114 * 10^24. This is the contract’s balance of Dai in wei, a standard unit of 10^18.

So finally, divide 3.890227426645114 * 10^24 by 10^18, and ta-da! Now we know the balance of the wallet address 0xDfBaf3E4c7496DAd574a1B842bC85B402BDC298D in this contract is 3,890,227.426645114 Dai.


Sending Transactions

Eth_calls are commonly used to read data from a smart contract. But what if you want to write data to a smart contract?

Let’s say we wanted to call the transfer function. Again, we would need to normalize the function first. We take the string transfer(address to, uint tokens) and hash it to get the 4-byte signature. Again, we take that 4-byte signature, pad it with zeros, insert the address and the amount of tokens, and package this information into a data string. We then sign the transaction and send it using eth_sendRawTransaction.

At this point, nodes start broadcasting our transaction out to the rest of the network. Eventually a miner will get a copy of it, go through all their proof-of-work stuff, get lucky and find a hash that matches the proof-of-work and broadcast a block that contains our transaction. Every node that receives this block reads the transactions within it, re-executes them, and holds our ERC20 token transaction in the EVM to update.  

Gas is sent along with any other values, and is spent running the EVM code. The miner gets the block reward, plus all the gas spent in transactions. If you’d like to learn more about how Ethereum mining works, these EthHub docs are a great start.


Mined Transactions

When a transaction is mined, two important things happen: the on-chain Ethereum state is changed via contract interactions, and Event Logs are published for public viewing. Once the Event Logs are published, we can execute JSON-RPC requests for eth_getLogs to investigate what changed, relative to the events that we care about, and react to them.

For example: an event ticketing service that wants to issue off-chain tickets based on crypto payments, could use eth_getLogs to find payments to their address, and react to these events by processing some logic in their backend servers to issue tickets to users.


Using eth_getLogs

In the above sample request, we use the parameters "from block" and "to block" to specify the hexadecimal block number that we are interested in retrieving logs from. Note that if this information is omitted, the method will return information from "block 0" to "block latest" by default (the entire chain history) and that’s not ideal. Infura has a cap on requests of 10,000 events per query. Best practice is to request a single block, as we’ve done in this example, and do that for each mined block.

What this request is saying to the blockchain is “hey, I want event logs relating to address 0x6B175474E89094C44Da98b954EedeAC495271d0F emitted in block 0x91F37C (hexadecimal for block 9565052) that matches topics 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000ee25e1ba53c225d250861c8e5a9a3e0fe19c790e and  0x000000000000000000000000dfbaf3e4c7496dad574a1b842bc85b402bdc298d.

The response returned for this request is an array of events. In the example we’re using, only one event for one address matched the specified topics.

Topics

Topics are events emitted by smart contracts. If we take a look at the original DAI ERC20 Solidity contract again 0x6B175474E89094C44Da98b954EedeAC495271d0F, we can see two event signatures that could be associated with it:

 * 94    event Transfer(address indexed from, address indexed to, uint tokens);
 * 95    event Approval(address indexed tokenOwner, address indexed spender, uint tokens).

How do we find out which topic (event) it actually was? You guessed it: we have to create the Function Selector of the Event and take the hash of it. Let’s try the event on line 94:

web3.sha3('Approval(address,address,uint256)')

The resulting hash is 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925. This doesn’t match the hash provided in the initial request response. Now let’s try the event on line 95 of the contract:

web3.sha3('Transfer(address,address,uint256)')

Bingo! The resulting hash is 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, which matches the hash provided in the initial request response. Now we know that 0xddf25 is the Transfer event.


More Event logs

You might be wondering what the data provided in the request response means:

In this context, data refers to all the ‘non-indexed stuff’ that’s captured in the events. In our example, for the Transfer topic, data represents the number of tokens that were transferred. That is, that 0x41f900d25d6693623a6 or 19471.6949921 Dai tokens were transferred from ee25e1ba53c225d250861c8e5a9a3e0fe19c790e to dfbaf3e4c7496dad574a1b842bc85b402bdc298d.

This completes our investigation 🎉

View our developer documentation to explore different ways to interact with Infura to read and write Ethereum data. New to Infura? Sign up and get started for free!

Tutorials

Infura product tips and Web3 tutorials for developers building decentralized applications.

Tutorial: State and Payment- Power Up Your App Using Javascript & Infura

Tutorial: Real-time Frontend Data with Embark's Subspace and Infura

Building Dapp Frontends with React & Network.js

Compare Ethereum API Performance with Versus

Ethereum RPCs, Methods and Calls