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

Infura Developer Tutorials

Tutorials

Getting Started With Infura

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 [https://twitter.com/PalmNft] 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
[https://palm.io/studio/damien-hirst-currency-nft-updates/], DC
[https://palm.io/studio/creating-a-sustainable-future-for-digital-fandoms/], 
Niftys and Warner Brothers
[https://palm.io/studio/niftys-launches-the-matrix-resurrections-nft-project-on-the-palm-network/] 
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 [http://infura.io/login] to your Infura account and select an existing
Ethereum project (or create a new Ethereum project
[https://docs.infura.io/infura/create-a-project] if you have not yet). 

2. Click on the settings of the project to view the Palm API endpoints
[https://docs.infura.io/infura/networks/palm/getting-started/accessing-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 [https://docs.infura.io/infura/networks/palm] for
more information, as well as links to helpful tutorials
[https://docs.infura.io/infura/networks/palm].

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 [/minting-nfts-with-infura-and-replit/], based on his 
EthDenver 2022 [https://www.youtube.com/watch?v=kim7T4GDFOM] presentation. 

Let us know how you are using NFTs in our Discord and feel free to ask questions
in our community [https://community.infura.io/]. 

Just getting started with Infura? Our docs will get you building
[https://docs.infura.io/infura/].

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) [/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
[https://www.scalablepath.com/blog/using-quill-js-build-wysiwyg-editor-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 2020October 2021Web3.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
[https://github.com/ChainSafe/web3.js/pulse/monthly] and ethers.js 3,100
[https://github.com/ethers-io/ethers.js/pulse/monthly] as of Oct. 14, 2021. 
Web3.js is used by 112,849 repositories
[https://github.com/ChainSafe/web3.js/network/dependents?package_id=UGFja2FnZS0xNTA1NzY4MA%3D%3D]
, compared with 65,519 for ethers.js
[https://github.com/ethers-io/ethers.js/network/dependents?package_id=UGFja2FnZS0xNjEzMjI4Ng%3D%3D]
.

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

LibraryCommits to Main BranchClosed IssuesActive IssuesMaintainersweb3.js2060107
10ethers.js217391
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
[https://medium.com/chainsafe-systems/the-future-of-web3-js-v3-0-0-release-ecc9feecb2de] 
(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 [https://chainsafe.io/] is the lead maintainer of the web3.js library, 
having received a grant from the Ethereum Foundation to “continue the
maintenance and further development”
[https://medium.com/chainsafe-systems/chainsafe-receives-grant-from-ef-for-web3js-9e4376f5f36a] 
of web3.js in September 2020. ChainSafe’s outline of the future plans for
web3.js
[https://medium.com/chainsafe-systems/the-future-of-web3-js-v3-0-0-release-ecc9feecb2de]
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 [https://ethers.org/] 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 [https://docs.ethers.io/v5/#features]. 


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

LibraryDependent RepositoriesDependent Packagesweb3.js113,0184,685ethers.js
66,9503,505

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 [https://docs.ethers.io/v5/testing/]. The documentation of
the
testing is very impressive [https://docs.ethers.io/v5/testing/]. Check it out.

Web3.js has added test documentation
[https://github.com/ChainSafe/web3.js/blob/1.x/TESTING.md] 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
[https://npm-stat.com/charts.html?package=web3&from=2015-01-01&to=2021-10-15] 
and ethers.js has 24,284,490 downloads
[https://npm-stat.com/charts.html?package=ethers&from=2015-01-01&to=2021-10-15].
Compare that with May 20, 2020, when we first looked at this statistic, when
web3.js had 14,703,432
[https://npm-stat.com/charts.html?package=web3&from=2015-01-01&to=2020-05-20] 
downloads and ethers.js had 8,500,336
[https://npm-stat.com/charts.html?package=ethers&from=2015-01-01&to=2020-05-20]
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 [https://www.npmjs.com/package/web3] and ethers.js at 339,318
[https://www.npmjs.com/package/ethers]. 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 [https://www.npmjs.com/package/web3] and
ethers.js at 184,798 [https://www.npmjs.com/package/ethers].

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 [https://www.npmjs.com/package/web3] 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
[https://www.npmjs.com/package/ethers] 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
[https://medium.com/@moqod_development/understanding-open-source-and-free-software-licensing-c0fa600106c9]
,” 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 [https://twitter.com/web3_js] 
(1,250 followers) and @ethersproject [https://twitter.com/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
[https://medium.com/chainsafe-systems] 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)
[/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
[https://github.com/NoahZinsmeister/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 [https://infura.io/register] 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
[https://consensys.net/blog/teku/teku-and-infura-team-up-to-make-the-fastest-ethereum-2-0-client-sync/]
. 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
[https://github.com/ConsenSys/teku/issues/4090].

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
[https://docs.teku.consensys.net/en/latest/Reference/CLI/CLI-Syntax/#validators-early-attestations-enabled]
.

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
[https://blog.ethereum.org/2020/08/21/validated-why-client-diversity-matters/] 
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 [https://infura.io/register] 
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 [https://caddyserver.com/]. Once that’s downloaded, check
out their Getting Started guide here
[https://caddyserver.com/docs/getting-started]. 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
[https://caddyserver.com/docs/quick-starts/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
[https://caddyserver.com/docs/caddyfile/directives/reverse_proxy#load-balancing] 
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 [https://github.com/FiloSottile/mkcert],
and it’s incredibly easy to install by following these steps
[https://web.dev/how-to-use-local-https/]. 

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
[https://infura.io/customers/maker]. 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
[https://docs.infura.io/infura/networks/polygon-pos]. 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
[https://consensys.net/blog/developers/how-to-save-time-on-devops-and-scale-with-infura-lessons-from-leading-ethereum-dapps/] 
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
[https://infura.io/register] 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 [https://infura.io/product/ethereum] to connect your app instantly
with a single line of code. Simplify your transaction management with Infura
Transactions (ITX)
[/why-you-should-use-infura-transactions-instead-of-building-your-own-in-house-relayer/] 
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”
[https://www.youtube.com/watch?v=EgbzVFfdZyg] at EdCon 2021.

Interested in building on Ethereum? Contact us [https://infura.io/contact]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
[https://www.trufflesuite.com/] 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 [https://infura.io/register] 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
[https://courses.consensys.net/courses/bootcamp-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
[https://docs.github.com/en/github/authenticating-to-github/keeping-your-account-and-data-secure/removing-sensitive-data-from-a-repository] 
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
[https://discord.gg/ADWNDYVb8b] if you want to continue the conversation, share
projects, ideas, and join the community!

Start here with a free Infura account > [https://infura.io/register]

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
[https://trufflesuite.com/boxes/optimism] 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
[https://github.com/ethereum-optimism/optimism-tutorial/pull/60/files] 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
[https://remix-optimism-compiler-plugin.readthedocs.io/en/latest?xgtab&] 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?

We’re excited to continue the expansion of our multi-chain ecosystem
[https://infura.io/networks] that supports the needs of all developers, from
those working on side hustles to the developer teams at the biggest Web3
companies. Our goal has been and always will be to grow the entire ecosystem in
as many industries as possible. Supporting multiple networks is critical to that
future.

Today, we’re thrilled to announce our 12th supported network – Celo
[https://infura.io/networks/celo] – a truly unique community of “developers,
designers, dreamers, and doers” laser-focused on building an interoperable
ultra-light mobile identity client to help anyone with a smartphone move value
anywhere in the world. 

As part of ConsenSys, Infura, along with developer tools such as Truffle and
Diligence, offer a one-stop shop for developers, that includes complementary
Web3 tools and services for all supported networks. Now it’s easier than ever to
build for the over six billion smartphone users worldwide on Celo.

The Celo Ecosystem
Celo’s mission of prosperity for all – particularly the financially underserved
– as well as their focus on regenerative finance (ReFi), or “DeFi for good,”
resonates with many of us at Infura. ReFi utilizes the power of blockchain and
Web3 to address climate change, support conservation and biodiversity, and
create a more equitable and sustainable financial system.

Celo makes it easier for billions of smartphone users worldwide to send money,
with the ability to have transaction fees paid using tokens or a variety of
stablecoins. Perhaps most compellingly, Celo allows users of Celo dapps and
wallets (including MetaMask, Opera, Valora and others) to send or receive money
using only their mobile phone number – a far more simple identity tag than a
42-character randomized wallet address. The simplicity of use coupled with
virtually zero fees make Celo one of the most accessible protocols out there,
reducing the complexity of financial transactions to the ease of sending a text
message.

Celo uses a Byzantine Fault Tolerant consensus mechanism (Proof of Stake) for
its decentralized, secure and permissionless carbon negative blockchain
transactions. The reduced amount of data needed to sync to the Celo blockchain
with the ultra-light client mobile identity client lowers the barrier to
participation.

Why build on Celo with Infura
For Infura developers, Celo offers full EVM-compatibility and a broad codebase
including Solidity, making the inspiring task of building for 6 billion
smartphones surprisingly familiar and accessible. Plus, working with Infura
means no syncing or complex setups, 10x faster request response times than
self-hosted solutions and 99.99% uptime.

At Infura, the networks we offer aim to meet our developer communities where
they most want to be. As such, you’re not limited to one network – signing up
for an account [https://app.infura.io/register] with Infura to build on Celo or
any single network gets you access to all 12 networks (and counting) through a
simple, single line of code. A bonus: get access to free archive data with your
Infura plan [https://www.infura.io/pricing] and exceptional developer resources.

Looking for inspiration on what you could do with Infura and Celo? Some notable
DeFi projects in the Celo ecosystem include Ubeswap and Moola, a mobile-first
platform for borrowing and lending assets on Celo. The Celo Ecosystem Venture
Fund [https://celo.org/community] helps developers build on Celo, with over
US$77.6M in grants given out so far. 

See what kind of impact you could make on the future of decentralized,
regenerative, socially inclusive finance by getting started today
[https://app.infura.io/register].

Start building with Celo + Infura
Getting started with Celo on Infura is easy. Follow the few simple steps below,
to start building today!

Step 1: Login in or sign up
Login to your Infura account or sign up for a free account and check out our 
Infura quickstart guide
[https://blog.infura.io/post/getting-started-with-infura-28e41844cc89]!

Step 2: Create a new key
Once you are logged in click CREATE NEW KEY.

From the “CREATE NEW KEY” pop-up:

 * Select Web3 API (Formerly Ethereum) in the NETWORK dropdown list.
 * Provide a NAME for your project and click CREATE

Your new project's settings page has all the information you need to connect to
the network.

Step 3: Connect to the Celo network
Use the Celo card Mainnet or Alfajores endpoints to send JSON-RPC requests to
the Celo network.

Never expose your key secret. It must never be human-readable in your
application.  We suggest using a .env file
[https://blog.infura.io/post/how-to-use-dotenv-to-enhance-basic-security-within-your-dapp]

Step 4: Make requests

Celo supports EVM JSON-RPC methods to interact with the Celo network.

Call a CELO JSON-RPC method

Use HTTPS to call a JSON-RPC method. In this example, we use curl
[https://curl.se/] to make the HTTPS request to obtain the latest block number.

Ensure that you replace <YOUR-KEY-ID> with a project ID from your Infura
dashboard: [https://infura.io/dashboard]

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc": "2.0", "id": 0, "method": "eth_blockNumber", "params": []}' "https://celo-mainnet.infura.io/v3/<YOUR-KEY-ID>"

The result should look similar to the following:

{"jsonrpc":"2.0","id":0,"result":"0xdde9f2"}

Step 5: Choose a network
Use one of the endpoints below, as your Celo client provider.
Ensure that you replace YOUR-KEY-ID with a KEY ID from your Infura dashboard.
[https://infura.io/dashboard]

Celo Mainnet
Network: Celo Mainnet
Description: JSON-RPC over HTTPS
URL: https://celo-mainnet.infura.io/v3/YOUR-KEY-ID

Celo Testnet
Network: Celo Alfajores
Description: JSON-RPC over HTTPS
URL: https://celo-alfajores.infura.io/v3/YOUR_KEY_ID

Step 6: Add Celo Network to MetaMask
From MetaMask, select Settings > Networks > Add Network.

Add the Celo network details to MetaMask (shown below).

Celo Mainnnet

 * Network Name: Celo (Mainnet)
 * New RPC URL: https://celo-mainnet.infura.io/v3/<API-KEY>
 * Chain ID: 42220
 * Currency Symbol (Optional): CELO
 * Block Explorer URL (Optional): https://explorer.celo.org

Celo Testnet

 * Network Name: Celo (Alfajores Testnet)
 * New RPC URL: https://celo-alfajores.infura.io/v3/<API-KEY>
 * Chain ID: 44787
 * Currency Symbol: CELOBlock Explorer URL (Optional):
   https://alfajores-blockscout.celo-testnet.org

Step 7: Fund Your Testnet Account
Create an account on Celo Alfajores with the Celo Faucet
[https://celo.org/developers/faucet] and your account will automatically be
topped up with the CELO token. You’re ready to go!

For more guidance, see Infura’s Celo documentation
[https://docs.infura.io/infura/networks/celo].

Celo x Infura: Continuing our multi-chain expansion with social, regenerative DeFi

Avalanche is a proof-of-stake (PoS), Layer 1 chain that supports
Solidity-compatible dapps running on an Ethereum Virtual Machine (EVM). Infura
supports the Contract Chain (C-Chain), which is an instance of the EVM. It
enables the creation of smart contracts using the C-Chain’s API. Developers can
write decentralized applications (dapps) that use Infura to call Avalanche
C-Chain via JSON-RPC endpoints.

This tutorial shows how developers can use Avalanche to deploy an ERC721 smart
contract and then mint a series of NFTs with links to metadata that represent
double-entry accounting transactions.

In an example use case, a company wants to create a decentralized record of its
financial performance for a given year. At the start of that year, and again at
the end of every quarter, the company mints a series of NFTs whose metadata
shows changes to its balance sheet. Those changes are a permanent record that
can be accessed by a bank in support of a loan package.


Prerequisites

A MetaMask wallet [https://metamask.io/]

An Infura account [https://docs.infura.io/infura/getting-started]

Node.js (version 16 or later), and npm
[https://docs.npmjs.com/downloading-and-installing-node-js-and-npm] or yarn
[https://yarnpkg.com/getting-started] installed

An IDE such as Microsoft Visual Studio Code [https://code.visualstudio.com/]





 1. Prepare your MetaMask wallet

We will use the Avalanche FUJI C-Chain testnet, so we need to fund our wallet
with test AVAX tokens. Our first step is to add the FUJI C-Chain to MetaMask by
defining a custom network:

Log into MetaMask, click the network dropdown, and select “Add a network” and
fill in the following information:

Network Name: Avalanche FUJI C-Chain

New RPC URL: https://api.avax-test.network/ext/bc/C/rpc

ChainID: 43113

Symbol: AVAX

Explorer: https://testnet.snowtrace.io/

2. Add wallet address to config file





Copy the wallet address to clipboard.


As described below, paste the wallet address into the WALLET_ADDRESS field in
src/config.tsx, replacing the placeholder string (“xxxxxxx”).





3. Add private key to config file





Click “Export private key,” and then enter browser password to enable copying. 


As described below, paste the private key into the PRIVATE_KEY field in
src/config.tsx, replacing the placeholder string (“xxxxxxx”).


NOTE: As described below, DO NOT commit config.tsx to the repo after you have
filled in actual values. The private key is most critical because exposure
completely removes your protection against hacking.

4. Get AVAX tokens from the Avalanche Fuji Faucet


Next, we visit https://faucet.avax.network/ to request 2 AVAX, the maximum
available in any 24-hour period. Click the Connect button to copy the address of
your MetaMask wallet into the form, then press REQUEST 2 AVAX. Given the speed
of the Avalanche chain, the balance should quickly appear in your wallet. 





5. Create an ERC721 contract with the Open Zeppelin wizard


We use the Open Zeppelin wizard to create our ECR721 contract. Visit 
https://wizard.openzeppelin.com/ and select the ERC721 tab. 


Create a name and symbol. We will leave the Base URI field blank for this
example.


Choose Mintable and Auto increment ids, Burnable and URI Storage.




When you have done this, click the “Open in Remix” button. Your browser will
open a tab with this view of the code.



Click the “Compile Contract” button to compile the contract in Remix, which
should display the correct compiler version.




Click the “ABI” icon to copy the ABI from Remix. As described below, paste it
into the empty file src/abi.json” in the GitHub repo referenced below.




Deploy the contract to the Avalanche Fuji C-Chain. On the left side of the Remix
panel, go to the first dropdown “Environment,” and be sure the Injected Provider
is set to Metamask, which should already be set to the Fuji C-Chain.


Copy the contract address from Remix.


Visit the Fuji Snowtrace block explorer at https://testnet.snowtrace.io/.


Paste the contract address into the search bar and you will see the deployed
contract. 




As described below, paste the contract address into the CONTRACT_ADDRESS field
in src/config.tsx, replacing the placeholder string (“xxxxxxx”).


6. Create an Avalanche project in Infura 


Go to your Infura dashboard and click the “Create New Key” button.


Choose “Web3 API” in order to see the Avalanche endpoints.



Choose the Avalanche C-Chain Fuji testnet endpoint.





Copy the endpoint. This is your project’s URL, which will display in this
format:


https://avalanche-fuji.infura.io/v3/xxxxxxxxxxxxxxxxxxxxxxx


As described below, paste this into the INFURA_FUJI_PROVIDER field in
src/config.tsx, replacing the placeholder string (“xxxxxxx”).



7. Create an IPFS project in Infura


An NFT contains metadata that describe images and other related resources that
are stored off-chain, typically on the IPFS decentralized file storage network.
In order to mint Avalanche NFTs, we need to create an IPFS project in your
Infura account. 


Under “Create an IPFS Project”, click “Get Started”


Name your IPFS project.


Enable dedicated gateways.


As described below, paste PROJECT ID and API KEY SECRET into the
INFURA_IPFS_PROJECT_ID and INFURA_IPFS_API_KEY_SECRET fields in src/config.tsx,
replacing the placeholder strings (“xxxxxxx”).

Create a subdomain name that is unique to your project.


Add the string “/ipfs/” to the Subdomain Name that you have created, then paste
the entire name (https://your-name.infura-ipfs.io/ipfs/) into the
INFURA_IPFS_GATEWAY field in src/config.tsx, replacing the placeholder string
(“xxxxxxx”).



8. Visit the GitHub repo to clone this project


https://github.com/ConsenSys/avalanche-tutorial-accounting


Before building and running the application, you need to finish these two steps:

 1. As described above, copy the contents of the ABI from Remix intp the
    src/abi.json file.
 2. Fill in the values contained in src/config.tsx, replacing the placeholder
    strings (“xxxxx”)”
    

const config = {

INFURA_FUJI_PROVIDER: "xxxxxxxxxx",

INFURA_IPFS_PROJECT_ID: "xxxxxxxxxx",

INFURA_IPFS_API_KEY_SECRET: "xxxxxxxxxx",

INFURA_IPFS_GATEWAY: "xxxxxxxxxx",

CONTRACT_ADDRESS: "xxxxxxxxxx",

WALLET_ADDRESS: "xxxxxxxxxx",

PRIVATE_KEY:"xxxxxxxxxx",

};


NOTE: If you are doing additional commits, instead of writing these values
directly to config.tsx, create a file called “config_local.tsx” in the src
directory. You can store these values there, and then copy the entire config
structure into config.tsx before running the application. Since the .gitignore
file has an entry for config_local.tsx, you should avoid accidentally committing
the actual values for everyone to see. Before any additional commits, remove the
changes to config.tsx, so the file reverts to the placeholder strings.


To build the application, run npm install or yarn install.


To run the application, run npm start or yarn start.



Summary

This application enables a user to mint a group of NFTs containing metadata that
represent a series of double entries in an accounting system. Starting with an
empty balance sheet, we follow three steps to record each double entry:


 1. Entry - Show the changes in each account affected by the double entry.
 2. IPFS - Upload a JSON object representing those changes to IPFS.
 3. Mint - Mint an NFT with a URI containing the IPFS file identifier
    

The application roadmap below shows the steps to connect your MetaMask wallet,
and four transactions that generate entries:

 1. Initial equity investment
 2. Purchase manufacturing equipment
 3. Purchase inventory from supplier
 4. Sell the product to customer
    

For each step, we show changes in the accounts, based on mock data included in
the application. As each NFT is minted, the balance of AVAX test tokens in our
MetaMask wallet decreases by the amount of the transaction fee. The 2 tokens you
get from the Avalanche C-Chain Fuji test faucet should be enough to run this
application many times.


The Entry, IPFS and Mint buttons are disabled after the fourth NFT is minted.


The user can reset the application to start another series of four entries by
reloading the page.



After launching the application

Click the Entry button to post the first accounting entry.


After Entry 1

Click the “IPFS” button to upload a JSON object representing the entry.


After IPFS 1

Click the “Mint” button to begin minting the NFT.


Minting 1

Wait for the progress indicator to indicate that minting has finished.












After Entry 2

Click the “Entry” button when it is enabled again to repeat the process for the
second entry.


After Entry 3

Click the “Entry” button when it is enabled again to repeat the process for the
third entry.


After Entry 4

Click the “Entry” button when it is enabled again to repeat the process for the
fourth entry.


After Minting 4

The “Entry”, “IPFS” and “Mint” buttons will be disabled after minting the fourth
NFT.


Snowtrace Block Explorer - Contract

After each series of entries, the transactions will appear in the contract shown
in the Snowtrace Block Explorer. https://testnet.snowtrace.io/






Snowtrace Block Explorer - Transaction

In this view of Transaction Details, we see that the most recently minted NFT
has a TokenID of 74. The metadata for this NFT should show the state of the
accounts after the fourth entry.




Remix - call tokenURI

In Remix, we can enter that TokenID in the field for the tokenURI call. Clicking
the “call” button will show the IPFS URL under which the metadata is stored.


tokenURI output in browser

Pasting that URL into a browser displays the JSON object that represents the
fourth entry.



Using external data feeds

In this tutorial, we used placeholder data to mint a series of NFTs that
represent changes in a company’s financial state. Live data from a company’s
accounting systems can be fed into  a decentralized oracle network like
Chainlink to provide a deterministic view of its performance. This can provide
an end-to-end audit solution that companies can share with financial
institutions and other interested parties.

ethereum

Deploy an ERC721 Smart Contract and Mint Accounting NFTs with Infura and Avalanche C-Chain

We launched the private beta
[https://blog.infura.io/post/infura-now-supports-the-avalanche-c-chain?utm_source=twitter&utm_medium=organicsocial&utm_campaign=2022_Jul_avalanche-C-chain-blog_content_content] 
of our Avalanche Contract Chain (C-Chain) endpoints in July this year, and have
seen strong usage, with great feedback from our community. Now, we are ready to
offer Infura’s API for Avalanche C-Chain
[https://infura.io/networks/avalanchecchain] to all users for free! 


With this addition, Infura now supports 11 networks (and will continue to add
more networks) including Ethereum, IPFS, Filecoin, Polygon, Arbitrum, Optimism,
StarkNet, Palm, NEAR and Aurora. 


Avalanche has become one of the leading Layer 1 platforms since launching in
September 2020, making transactions cheaper, faster and more reliable.
Developers of smart contracts may find the Avalanche C-Chain interesting, as it
focuses entirely on smart contracts to boost performance, rather than spreading
its focus over multiple functions like most other blockchains. The C-Chain is
one of three chains comprising Avalanche's Primary Network
[https://docs.avax.network/overview/getting-started/avalanche-platform], and is
also EVM-compatible, allowing for easy Ethereum dapp migration to Avalanche for
scale. Furthermore, it’s poised to become a major network for facilitating DeFi
protocols, because of its advanced scalability with a throughput of 4,500
transactions per second, lower transaction costs that are a fraction of
Ethereum's, sub-second finality, and robust security. 


Infura has always put the developer at the center of everything we do. The first
to bring easy Ethereum access to developers with a standard JSON-RPC API, Infura
removes the complexity and high cost associated with self-hosting an Ethereum
node. Our mission is to grow the ecosystem for everyone and make it easy for
developers to build the next innovative application. Over the past year, we have
focused our efforts on expanding our multi-chain offerings, so that we can
provide value for developers wherever you are building. 


That’s why we’re working with Avalanche to create a powerful solution that
enables the next wave of DeFi dapps in the marketplace. Through Infura’s C-Chain
API, you’ll have instant access to all of Avalanche C-Chain’s benefits - high
throughput, fast transaction speed, consistent uptime, high programmability,
compatibility with all your favorite Ethereum tools, decentralization, and sound
security, with substantially lower costs. 


With Infura's C-Chain APIs, you can seamlessly access and communicate with
Avalanche C-Chain with a few clicks in the same familiar Infura developer
portal. With only one API key, you can access multiple networks beyond Avalanche
C-Chain on your Infura plan, without paying a premium for add-ons. As part of
the ConsenSys family, Infura developers also have access to the leading Web3
development stack that includes the Truffle development framework, Diligence
security tools, and MetaMask wallet to help you build, test, deploy, and secure
your dapps.


Start building with Avalanche + Infura. Sign up [https://infura.io/register] for
a free Infura account today.

Infura Makes Layer 1 Network, Avalanche C-Chain, Available to All Users

After a successful private beta, Infura, the No. 1 blockchain development
platform, is excited to announce that StarkNet
[https://infura.io/networks/ethereum/starknet] is now available to all
developers. 

We invite builders to experience the ease of the fast transactions, low gas
fees, and Ethereum-level security of StarkNet on Infura. 

Eli Ben-Sasson, co-founder of StarkNet, co-invented the technology behind
ZK-STARKs and ZK-SNARKs, the two leading technologies underpinning the prominent 
ZK-rollups
[https://ethereum.org/en/developers/docs/scaling/zk-rollups/#:~:text=A%20ZK%2Drollup%20chain%20is,an%20on%2Dchain%20rollup%20contract.] 
today. 


The benefits of building with StarkNet

When you build with StarkNet and Infura, you have the assurance of building with
the Web3 pioneers. StarkNet brings many benefits, including:

 * Scalability: Increased scalability with high throughput, as the result of the
   efficiency of STARK technology. The innovative zero-knowledge proof system
   uses cryptography to efficiently and transparently verify and prove
   transaction integrity.  StarkNet bundles data and processes transactions
   off-chain with STARK proofs that require very little computational power to
   verify, enabling scaling by orders of magnitude greater than other scaling
   solutions.
 * Security: Verification of dapp transactions takes place on the Ethereum
   mainnet.
 * Simplicity: Easier builds and seamless user experience. Build any dapp you
   want, with any business logic, across multiple protocols, with the first
   ZK-rollup to have general-purpose smart contracts on a fully composable
   network.
 * Speed: StarkNet provides fast finality, potentially exceeding existing
   throughput levels by up to 3 times transactions per second (TPS). Withdrawals
   take minutes, not days.
 * Permissionless: StarkNet is non-custodial, involving none of the cost, risks
   and effort involved in maintaining a traditional custodial system.
   

New cases with an improved developer experience

Using StarkNet on the Infura platform makes new use cases possible. For example,
developers with an Ethereum dapp using Solidity-based contracts can leverage
Infura to route transactions to StarkNet. They use and compile the pre-defined
Cairo contract that can be passed as input to Infura to deploy on StarkNet and
interact with Ethereum from there. With the Infura StarkNet API, developers can
leverage Infura standard JSON-RPC endpoints to communicate seamlessly with
StarkNet. 


Infura supports a multi-chain future


As an infrastructure provider of high-availability Web3 APIs for a variety of
networks, Infura believes in a multi-chain future. We not only support Ethereum
and IPFS, but also Polygon, Arbitrum, Optimism, Palm, Avalanche, NEAR, Aurora,
Filecoin, and now StarkNet, giving flexibility to developers, and allowing for
maximum scale and performance of their decentralized applications. 


Start building today

To get started, create a free account [https://infura.io/register] to experience
building on StarkNet with Infura. 


For more details on the Infura and StarkNet integration, visit our StarkNet
product page [https://infura.io/networks/ethereum/starknet]. 


Learn more about how the ConsenSys suite of tools work with StarkNet, read the
blog “ConsenSys and StarkWare expand existing partnership for complete Web3
tech
stack development
[https://consensys.net/blog/news/ConsenSys-and-StarkWare-expand-existing-partnership-for-complete-Web3-tech-stack-development]
". 


Seeking inspiration? Learn how to build an NFT with our tutorial, “Mint Your
First NFT with Infura and StarkNet
[https://blog.infura.io/post/mint-your-first-nft-with-infura-and-starknet].”

Network

Ethereum Network Updates, Upgrades, Hard Forks

Celo x Infura: Continuing our multi-chain expansion with social, regenerative DeFi

Deploy an ERC721 Smart Contract and Mint Accounting NFTs with Infura and Avalanche C-Chain

Infura Makes Layer 1 Network, Avalanche C-Chain, Available to All Users

ZK-Rollup StarkNet Now Available to All Infura Users

Mint Your First NFT with Infura and StarkNet