Implementing Subscriptions in your App

Reference material for building subscription products on Superfluid

Write Operations

Unless you have a very specific reason to use a smart contract or a deeper integration for these write operations, we recommend that you use our Superfluid Checkout Widget toolkit. If you prefer to use the . You can find several examples of our SDK in action with front end examples , and a node module example .

Getting Stream Data

There are two ways to get stream data: via our SDK and our Subgraph. If you only want to check whether a single address is streaming to you, then is the simplest way to get this data is to load the token you'd like to use like this.

Note that tokens may be loaded by symbol or by address

// Some code
const daix = await sf.loadSuperToken("DAIx"); 
let flowInfo = await daix.getFlow({ 
    sender: string, 
    receiver: string, 
    providerOrSigner: ethers.providers.Provider | ethers.Signer 
});

But if you want to get a list of all addresses streaming to you, then is going to be best for this. This is also our recommended method for querying data on a subset of those addresses based on specific criteria (i.e. all addresses with an existing flow rate about x amount).

You can workshop different subgraph queries at and use Apollo Client or a similar framework to actually run these queries inside of your application.

Here’s an example which will give you all streams that are currently open to your address:

//graphql query
query MyQuery { 
    streams(where: {receiver: "YOUR_ADDRESS_HERE", currentFlowRate_gt: "0"}) { 
        currentFlowRate 
        token { 
            symbol 
        } 
        sender { 
            id 
        } 
        receiver { 
            id     
        } 
    }     
}

Events

If you want to get these events from the subgraph, then you can do so with a query like this:

// graph query
query MyQuery {
  flowUpdatedEvents(
    where: {receiver: "MY_ADDRESS"}
  ) {
    sender
    token
    flowRate
    timestamp
  }
}

Simple Flow Authentication Example

If you’re interesting in seeing this all together, here is an example of an Express app that checks whether or not a stream exists to a specific address before returning 200 (if the stream does not exist, a 401 error is returned).

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Last updated 1 year ago

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// Some code const daix = await sf.loadSuperToken("DAIx"); let flowInfo = await daix.getFlow({ sender: string, receiver: string, providerOrSigner: ethers.providers.Provider | ethers.Signer });

//graphql query query MyQuery { streams(where: {receiver: "YOUR_ADDRESS_HERE", currentFlowRate_gt: "0"}) { currentFlowRate token { symbol } sender { id } receiver { id } } }

Simple Flow Authentication Example