Decentralized Reddit

Transcript

[Music] hello my name is Connor and I am a developer at consensus um I've been working on a uh platform for having threaded discussions that are difficult to censor um they are built using ethereum ipfs and Whisper and I'm the first part of my talk I'm going to explain how you could use this as a a foundation for building a decentralized Reddit really like an ecosystem more than like one particular app um and later I'll give a demo and

explain some more technical details um so the working title right now is nonsense like not easy to censor um and why would we want a decentralized Reddit so many people here probably uh Venture into the r Bitcoin sometimes and have noticed that they generally the moderators receive a lot of heat for um questionable uh moderation policies um and I personally noticed that as the community grew during the rise of Bitcoin um that the quality of the content on the Moder on the site actually uh suffered more and more due to the moderators um expressing their own agendas so this even applies to um to people who are uh deeply involved in

the Bitcoin space where we're not being able to voice their their own uh opinions so uh that that's one reason but that that same uh thing applies to pretty much any uh open public uh online Forum uh you can you can see the same ways that uh companies or investors or corporations or uh organizations with like legal agendas May uh censor certain voices on on on the internet and uh I think that that we should change the Paradigm and and look for ways to have uh censorship to be hard by default um so how could you do this on ethereum uh what I've built uses the the middle

pieces ipfs whisper and ethereum to to structure a very basic U threaded discussion system but one of the benefits of building on a public blockchain uh Julian alluded to this earlier in the the game uh panel the game uh developer panel uh that on ethereum it's it's unrestricted for any third party to build services on top of uh content that is on the blockchain or on ipfs and and so that is that is one way I I could definitely see uh a Reddit type of ecosystem developing serving see all of these pieces uh permissions moderation notification search and and so on are currently done by uh the the

centralized Reddit or Facebook or Twitter organizations and uh on ethereum we can actually have competing services in each of those areas uh offering different uh services for a uh discussion platform so the colors mean just briefly that the blue is like stuff that has to be on Shain and trustless and you have to pay for it but the the purple is a combination of onchain and or offchain or both and uh ipfs swarm whisper notifications are offchain services that could be provided um so that's that's how I see that evolving um I I'll go ahead and talk about what I'm what I built and how um onchain storage works so there's two ways you could do this uh one is

with contract structs uh that we all know and love but the other way is logs and I'll describe the trade-offs between those so for onchain storage uh basically there's two two methods that are important add and edit when you add a a post you are designating a parent that that post will be referenced to as a child um and a string of data which could be anything I like I like using strings there because they could be a ipfs hash a URL or uh potentially just raw text so then uh the the that will create a struct which will be saved in this array right here um it it just expands uh with each new post and that that index of the array is implicitly

the ID of the post which is used in this mapping of uh post to children and edit is is a method I wanted to add so um if you if you submit a post you can you can edit the content of it if you are the owner and so that is checked from this address uh and I'll go through the the other data types so we have uh two U for for timestamps for when the post is created and when it is edited um we also have a number of children which makes lookups easy if you're looking up an array you you would like to know how big it is um you don't want to look up 10 if there's only two objects in in the children uh and then the data type so uh just to point out something uh I wanted to cast these to un 32s they're U on the

as environment variables to contracts and would make sense to store time stamps as un and I was able to save a storage slot by doing that but it does limit me to uh to 90 years so maybe you'd want to go with un 40s but um that's worth considering if you're developer also uh yeah I already mentioned data strings are very flexible uh so what's what's the upside of events why would you use events instead of uh stru events are much cheaper they um they require uh a lot less gas to use they're pended only logs and uh the the other upside is that they're very light client friendly so the the downside of using a a log though is that they're more difficult to edit so you with the the

struct for posts it you you store the owner in one of the fields and the contract can look that up and verify that only the the message sender that equals that owner can actually change the data but for uh a post event or log uh the contract doesn't have any way to read the the data from from past log so it can't verify uh that the message sender is equal to the owner of a particular log so what you can do maybe to get around this is have an event for editing and let the front end uh filter through the the edits to to find the ones where the owner matches the original log ID but um that that that seems a little bit annoying and uh it just kind of depends I guess on what

your use case is if you're an application that doesn't want to allow edits then logs would probably be the way to go if if you do want to allow them you you may have to consider the trade-offs there post count is necessary here so that each each event would have its own ID um right and those are the guas cost trade-offs for logs versus uh s stores uh where each log is uh 375 plus 375 per topic which I think you can go up to three or four topics and then eight gas per bite all right so I'll show you a very Alpha demo of of what I've built so far um this is a video so we'll start by adding a couple of accounts that I

already generated with these seeds that uh I was able to get using uh cooworker Christian lonquist Library e Das light wallet um so this is how you would create one in the app um but I'll just go ahead and import an existing one uh these seeds have been pre-loaded with some ether I'll add a password to uh to encrypt them in my browser so I can uh unencrypt them when I need to sign transactions and you can see my initials CK under the accounts um comes from the the uport Persona schema that's saved an ipfs I I use that to associate names and images with ether addresses so we'll add the the second account to demonstrate one without a

Persona and you'll see see that in in the next videos so that is adding an account um and this is the identity schema for um the ort uh where we have name and content URL are really the the important Fields there but but this is cool because it's just a a Json so you could add other schemas for different use cases and they they could all be derived from one the same ether address um so now I'll create a couple threads right so I'll use my my named account and write an enter in a thread name this is going to use a string data type so I found the exact gas cost per character count on the right you'll see

that transaction price increases with each character that I add so this is going to be half a Cent and I'll make a random one and a meta one and this bubble on the left means that the transaction is pending it hasn't been received in a block real quick I'll do a Refresh on the browser just to prove that I keep that data around associated with the transaction before it gets received in Block so um that tends to be something that users like to do when they don't understand what's going on they'll refresh the page and and if I don't if it's just blank because the the data is not on chain yet then uh I wanted to prevented that scenario so it'll get received and I have uh another method that that you can use to wrap components that that use that mechanism for TR tracking State uh to to determine

based on the current block which which they'll all they'll receive as it updates what the the percentage of confirmation is given some confirm count so this will this will increment up to um the height of the div and I'll just skip through so this is that utility I mentioned it it it's a way to keep track of transaction State um you add transaction hashes and you associate some data with those hashes and you can filter through uh that data to match those transactions to components on your front end and select to receive any updates from these St from transactions that match that filter um so for this I'm just using pending and received but the arrows indicate the different

directions that those transitions can happen um and that's that's been really helpful so let's do um some chat and comment example so we'll go into the random thread and with the CK account we'll write some uh yeah so this is 7 cents at current cost so yeah first post um sign the transaction and it will do the same thing and you see uh a picture that's associated with that account there um and now we're going to send a whisper message while that's waiting to get received in Block because this is much faster and it's free so some people might find a use for that um if they if they don't have any ether or don't want

their message to live forever so I'll demonstrate how this wizzywig editor can can throw in some arbitrary HTML that my front end will uh will sanitize when it picks it up and I'll also add um an array of files just one for this demo but you can add multiple um you can rename the file name add a description to the Moon um and so you actually also sign these whisper messages with your same uh light wallet accounts so that signature gets appended to the payload so the front end can derive the The Ether address of the sender otherwise it's it's stored on the client it's not really usable for for these types of apps so I switch accounts I'm going to reply very cool I'm going

to save this and you see how there's a jenton associated with that because it doesn't have a Persona and I just saved the other accounts whisper message into ipfs and stored that that ipfs hash on chain and the front end was able to to figure that out that that this was a whisper object looks at the signature deres the sender address and uses CK as the as the center of that comments even though even though 3 1 D is the owner of of that post object um so yeah offer a thank you and that's pretty much the meat of this the the rest is I'll just go through and show that you can chat and comment on on any

of these uh onchain posts or whisper messages but uh yeah so we'll move on this is a schema of the ipfs content that I save pretty straightforward just an HTML string and an array of uh file descriptions uh and IP Fest hashes and then on the right is the whisper object that I've modified a little bit uh with the signature recovery pram and the hash uh the topic that I use for whisper is a hash of the the contract address and the post ID that you're whispering to and these are the libraries that I Ed that that were really helpful for me obviously web 3 um the the ipfs teams I

know IPS API exposes pretty much every ipfs command to http so that was really helpful hooked web 3 provider Tim couter wrote uh it's a super easy way to sign transactions in your browser uh E Light wallet um is what Christian wrote and that's uh a key store and man key manager for for signing transactions those that and hooked web 3 go go really easily together um and then finally reflex TX is the transaction manager I wrote um so that's all if there are any questions I have uh few minutes two minutes yeah we have time for one

question so I think one of the bigger problems with Reddit and any tread is the the matter of how do you get reputation how do you count Karma or in any sort of system on how do how do you fight spam while keeping good content to on the top how do you want how do you plan to solve that in a system where without having single single user single person yeah so I think uh that is a really hard problem and uh I don't claim to know the answer but I I think that we should all anybody interested should should try to build something like that and and I'd Advocate using some of these tools to do so um I'll also be working

on that unfortunately we do not have any more time for questions thank you so much Conor and your decentralized