Bitcoin was created to reduce the level of trust required for the operation of monetary systems.
Everytime I see another centralized interface to Bitcoin it depresses me. Centralized interfaces on top of Bitcoin are sort of a worst of all worlds, gaining all of the disadvantages of both centralized and decentralized approaches.
The difference here is that with Bitcoin, it is impossible for any centralized service to monopolize the space or take away a user's power to manage their own money. Unlike banks and so forth, if you want to make a transaction or take the reins on the management of your own finances, you can, and nothing and nobody can stop you, nor can they take your money from you.
Introducing new paradigms are not always as simple as changing the playing field in one step. These centralized services are a good thing. They introduce to the playing field an entry point for the layperson who doesn't want to deal with the headaches, learning curve and stresses of doing things themselves. When they feel a burning need to take the reins, they will be able to, and will take the time to learn how, and no bank or government will be able to stop them.
It's surprising to me that this project can get so much positive attention from developers, and even investors (according to their website). It is pretty critical that the people building the future Bitcoin ecosystem learn what sort of services they should stay away from.
Also, I wonder how much they paid for that domain.
I see it differently. To me there's a parallel between open source software and decentralized systems. Both have two sides. On one side you'll have the low-profile hackers and early/autonomous adopters who act as the driving forces executing and developing the innovative ideas of the project. On the other side, service-oriented companies provide consultancy and their experience to help other companies or individuals adopt the project.
Open source, decentralized, don't mean service-less. As long as your service provides some value, then there will be a market.
Sometimes companies need enterprise support, service level agreements, and outsourced business processes in order to focus on their core businesses. We will be seeing lots of non-currency related Bitcoin startups who sell services related to the blockchain. Either crawling it, or utilizing it for contracts / trades.
It takes a lot more skill and capability to be a creator than a consumer. I would like someone to make a movie about two time travelers who chase each other through time like a car chase. However I have zero filmmaking skill and I don't really know how to even start such a thing. My skills are best applied elsewhere, that doesn't mean I can't cross my fingers and hope that a talented filmmaker makes that movie.
Maybe because he is to busy. Or maybe because of a 100 different other reasons. Whatever his excuse, the fact that someone could be to busy to implement some software doesn't mean they can't critique something they don't like, or suggest ideas for things they do.
Because nobody wants to store and maintain a local copy of the blockchain. Simple as that. That's why I use blockchain.info for everything and not bitcoind.
Works fine for me right now. When someone creates a competitor to BCI that provides SPV proofs in an API, I'll be the first to include fully validating support into pybitcointools. Until then, sorry, convenience and zero loading time (yes, even SPV clients are not instant) win out.
Having worked with the Blockchain.info API, I am quite disappointed that Chain.com (great domain name!) haven't put much effort into building a better, more developer-friendly API. I mean returning variables named "n" and some awkwardly abbreviated to "reqSigs" ?
C'mon we need better than this. You can do better than this!
We are just getting started (day 2!), so stay tuned, and hopefully we will turn you into a fan! And thank you for sharing those links, we love those as role models as well.
If you're serious about building a Bitcoin service, you don't need an extra layer between you and bitcoind (or bitcoinj). If you find it too hard to deal with the blockchain on your own via those apis, you probably should think twice about developing a Bitcoin service.
I put together balancebadge.com, a simple bitcoind related app. If I didn't use the chain.com API I would have had to run a server with bitcoind (~20GB of data), a server that indexes data from bitcoind (recall that a simple address balance is not exposed in bitcoind), and stores the data in an alternate database (~200GB). There is no way that I would have built balancebadge if I had to setup and maintain 3 servers with 100s of gigabytes of data.
Also, should developers who don't want to run a PostgreSQL server think twice about building web apps? I believe that general purpose software that requires server maintenance and state management should be run as a service. App developers should be focusing on the details of their product –not how to keep general purpose infrastructure alive and well.
edit
Full disclosure: I am one of the creators of chain.com
Does one really need to keep the whole blockchain to perform basic things like tracking account balance?
I'm not really savvy on the details, but from the overall understanding of how Bitcoin works I believe one should receive data, keep it until consensus is confirmed (blocks had matured for good, so unless the network went into really weird split-brain situation no "valid" branches would grow out from those blocks), then aggregate and throw data away.
Keeping the whole transaction history up to genesis block seems nearly pointless to me.
Not sure whenever bitcoind can do those, though. Seems that it keeps the whole blockchain, at least for seeding purposes.
And, indeed, one would still need a database and running daemon that'd leech data from Bitcoin network. So, no way to have a badge on static HTML site. That's valid use case.
Chain.com is something I have been hoping to see for quite some time now, personally.
I run a "Bitcoin service", it calculates the future difficulty level[0], it's just not all that important to require the constant running of a full bitcoind node.
After I completed the Bitcoin version using the blockchain.info API, I realized there was literally no stable API for Namecoin and was forced to place the namecoin difficulty estimator on hold.
The minute that Chain.com implements their namecoin API, I will be subscribing.
Not because I don't have the competance to build and run a crypto coin daemon 24 hours a day, 7 days a week. I simply know that it's a waste of resources for my current needs.
For me, it defeats the vision of Bitcoin as being decentralized. I know some high level API is of warrant nowadays, but we need something that's independent from someone's profits from it.
If you're serious about building a prototype as fast as you can, you don't need to build something someone else has built for you. If you find it to hard to imagine using that service in the long term, you might be right, but you can just replace it if your product goes anywhere.
bitcoind does not index addresses. It only (if you use the `txindex` switch) indexes transactions. You can't query arbitrary addresses using the bitcoind RPC API.
Because you're paying a huge price for a small amount of convenience: you are trusting a third party so you don't have to deal with a lightweight server and a few gigabytes of data.
It's not like they are providing access to the Twitter firehose or the Google Search Index, which you couldn't have otherwise.
Edit: people are really downvote-happy on HN lately. You should not put a reasonable comment in the negative just because you disagree.
> Because you're paying a huge price for a small amount of convenience: you are trusting a third party so you don't have to deal with a lightweight server and a few gigabytes of data.
Can you point me to a ready-to-use address indexer for the blockchain, that can run on a lightweight server and only consumes a few gigabytes of data?
Well for me I can try some ideas without going all-in to setting up a bitcoind server. blockchain.info seems to have a half-hearted attempt at an API too.
Anybody working with Bitcoin should really avoid services like this just for their own sanity. You've a wealth of freely accessible data in the form of the 20GB blockchain, why rely on trusting a third party for their uptime, privacy and security?
It sort of already shows in the Bitcoin ecosystem, every time Blockchain.info (the biggest API provider) glitches up, all of the services relying on it die as well. Last time it went down there were people complaining that their ATMS could no longer work without Blockchain.info functioning.
Last year it was a 10GB large blockchain. Next year it will be a 40GB large blockchain. I think the argument is that no normal user considers it reasonable that you have to download tens of gigabytes of data to every single client, with at least another gigabyte every month to "keep up", in order to get relatively basic functionality. Many devices don't even have 20GB of storage in the first place :/.
> You've a wealth of freely accessible data in the form of the 20GB blockchain, why rely on trusting a third party for their uptime, privacy and security?
Except an address index, which is the added value that most of these types of services provide (balance of an address, transactions associated with a particular address, etc.).
Nobody except for people running block explorers really needs this information. If you think you need it then you're probably using Bitcoin completely wrong. Address based indexes don't scale, which is why it doesn't create or even need one.
Playing around on archive.org, this domain name seems to have never been used for anything, so it was probably just a matter of obtaining enough money to purchase it.
I also found http://blockcypher.com to be quite nice. In addition to the blockchain API, they also have APIs for creating transactions and even provide web sockets and web hooks. They do not host the wallet so you do not have to share your private key with them. They will create a transaction for you and you can then sign it with your private key. This is a good gateway for developers into the bitcoin system. The alternative is running bitcoind to download the 17 gig blockchain and then start coding. This provides instant gratification for developers to get started.
I'm am extremely excited about Chain.com, and the other tools being build up around the Bitcoin ecosystem. The power of giving developers simple tools and building blocks is often underestimated - but it often results in radical innovations.
A case in point is Stripe's API, and the ecosystem that has been subsequently built around it. Yes, it's possible to send CC auths/settlements and ACH transactions yourself - but the barrier to entry stifles innovation. Often the most interesting innovations in tech occur when there's an innovation in tooling.
I'm particularly interesting in Chain.com though, because I think currency is only the tip of the iceberg when it comes to Blockchains. I wouldn't be surprised if we see a number of other use-cases for Blockchains soon. [1]
To be honest I do not understand why this made it to the HN top posts when there are already other more complete APIs out there such as the Biteasy.com API. Good domain name though. Maybe that's why it made it up here?
I was just looking at the Blockchain.info transaction API yesterday, and I'm in love with its simplicity. It doesn't even require an account, and it's one endpoint.
You just call it with a destination address and a URL, and it returns a source address. Whenever any funds reach the source address, it forwards them to the destination and calls your webhook once for every confirmation it sees.
So simple, and so brilliant. I'm trying to brainstorm things to build with it, but so far I've come up short.
Would it really be that hard to reimplement this yourself if you needed to? The idea seems to be that this is a service: it isn't doing anything that difficult to accomplish, it is just doing something that happens to be resource intensive.
That's the wrong repository: that's a front-end (a UI written using angular); the backend repository (which could be said to be an open-source implementation of chain.com) is the one I link below. All this package does is provide a node.js wrapper for the bitcoind API. Almost all of the code (in both repositories) is project boilerplate or data marshaling: everything even remotely difficult is just "run bitcoind". I maintain it would be difficult to get locked in to a service like this just because it isn't open source: it isn't that difficult to rewrite.
As for "resource intensive", I was thinking memory, disk space, and network connectivity: the reason these services are valuable is because the blockchain is 18GB at this point, so downloading it to clients or even storing it at all on some clients, is at minimum "egregiously painful" and sometimes "pretty much impossible". If you want to be able to answer tons of different kinds of questions about transactions with low latency you are likely going to be storing this information with a number of specialized indexes, further increasing the database size requirement.
However, "people" is also a valuable point, but no: having an open source project doesn't solve that; if you make a program that uses bitcoin, you either have to download and manipulate the blockchain locally (which sounds awesome, and is arguably half the point of bitcoin to many reasonable people, but in practice is not realistic or even possible in many if not most interesting situations) or use a service. You can either run your own service or use someone else's. I enjoy running services: I accept that most people do not ;P. Instead, they would rather use a hosted API such as this one (or any of the numerous existing alternatives to this one) so they don't have to have people maintaining servers.
The reality though is that most people will never, ever need this sort of information. Unless you have a particular desire to run a block explorer or other lookup service, you are only going to be interested in addresses that you own and not those of the rest of the network. You don't need to store extended lookup tables and indexes for an ever increasing amount of information, doing so is foolish as it doesn't scale at all with the size of the network.
If a service needs to have a wallet connected to the network without the resources for storing the entire blockchain, they can just use a SPV [0] client like BitcoinJ to set bloom filters on their peers. They then get a stream of trustless information that's only relevant to the wallet at hand. You end up with a local service that's faster, completely under your control, and has a tiny resource footprint. You could happily run that a device like an iPhone, no problem.
So, this is the first I'd heard of the bloom filter feature: the descriptions I've seen of SPV allowed the client to only store a subset of the data, but still needed to download everything at least once in order to have any semblance of trust in the data it was seeing. The web page you link you also has a "See Also" to a page that makes bitcoinj sound horribly insecure, but maybe that's no longer the case with the bloom filter extension? This was all written before this bloom filter feature existed (which was late October of 2012); despite that being a little over a year and a half ago, there is almost no mention anywhere of it... I will have to spend more time learning about this feature and see how it changes things. (Maybe you are then correct: having a service like this is totally useless. However, I would then argue that it should be a really big priority to make people understand that this feature exists, is deployed, is practical, and is secure, as otherwise people are going to keep going about their lives as I have assuming this is all impossible with the current implementation of Bitcoin.)
Ugh, yeah the documentation for anything related to Bitcoin is terrible. Originally it didn't use bloom filters, they're a new thing as of Bitcoin client version 0.8 and above.
> the descriptions I've seen of SPV allowed the client to only store a subset of the data, but still needed to download everything at least once in order to have any semblance of trust in the data it was seeing.
With bloom filters you don't need to bother with all of that. The headers of the blocks are separate from the transaction data itself (that's in the merkle tree), so the SPV client can download all of the headers up to the current date and verify their difficulty in a few seconds. As the wallet gains addresses it sets bloom filters with it's peers, when they announce a new block on the network they send the SPV client the block header and also a trimmed merkle tree with only the transactions relevant to the client left in it. The SPV client can verify that the transaction is in the block by following up the tree to the block header, without ever needing to download the entire thing.
Privacy is gained by setting false positives in the filter, the more junk results the less likely it in the peer can discover what the SPV client is really interested in and what is being discarded. The SPV client ultimately doesn't need to store anything but the outputs that are unspent, and transaction history if this is required. There's no trust in the peers as at worst they can withhold blocks from us that contain transactional data, to counter this we can connect to multiple peers with the same filters set and compare the difference.
> However, I would then argue that it should be a really big priority to make people understand that this feature exists, is deployed, is practical, and is secure, as otherwise people are going to keep going about their lives as I have assuming this is all impossible with the current implementation of Bitcoin
This is a problem really, we have lots of awesome crypto features but everybody just insists on using solutions that don't scale like blockchain.info. The original whitepaper describes some of the scaling features but doesn't mention bloom filters specifically I don't think.
Rubbish. Write a thin abstraction layer between your app and the Chain API and should you wish to switch in the future, change the implementation of the abstraction layer to point at your bitcoind server or something else.
Would love if you guys added Nxt to this, it's completely different from bitcoind (it's based on java and a completely new codebase). If we had an API that would work across completely different systems, it would add great value.
I am wanting to use it for my site's difficulty predictor.
I would be making about 3 API calls per chain every 10 minutes to suffice for my needs.
That's about 12,960 api requests in a 30 day month.
I wouldn't be willing to spend any more than $5 on those 12,960 requests... because if that's what it cost, I could just setup a digital ocean vps and run the namecoin blockchain for $5/mo.
So somewhere in the order of $5/13,000 requests or about $0.40 per 1,000 requests sounds fair to me.
Everytime I see another centralized interface to Bitcoin it depresses me. Centralized interfaces on top of Bitcoin are sort of a worst of all worlds, gaining all of the disadvantages of both centralized and decentralized approaches.