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Deweb Linking

The Problem​

In web2, you can link site A to another site B by displaying the URL of site B in site A.
In web3, displaying a link to a decentralized website is not so straightforward. A deweb website is identified by one (or several) MNS (Massa Name System) domain but you can't just display it inside a <a> tag because most browsers don't handle MNS.
To access a deweb site, you have to incorporate its MNS as a subdomain of the URL of a deweb provider. But which provider should you choose when you want to create a link to a deweb site ?
The usual way is to hardcode the provider into a URL like this: <mns>.<provider domain name> The drawback of this approach is that you force the user to use a specific provider. This causes the following issues:

  • Add centralization
  • If the provider is down, the link is dead
  • If the user is running his own provider (see here and here) they can't use it to access the linked site.

Solution​

resolveDeweb function​

Massa-web3 provides a function that abstracts provider selection logic:

async function resolveDeweb(uri: string, chainId = CHAIN_ID.Mainnet): Promise<string>
  • uri: The mns domain of the deweb site. Must be suffixed by ".massa" e.g., "dws.massa", "mip.massa"...
  • chainId: Optional parameter to specify the network (mainnet, buildnet) on which the website is stored. Default: mainnet.
  • Returns: A promise that resolves to an operational URL containing a provider and the mns URI as subdomain. If no providers have been found, return a fallback URL that redirects to a page allowing the user to choose a public provider.
info

This function only works in a browser

For example, if you want to put a link to Syntra (onchain token scheduling Dapp powered by autonomous smart contracts) decentralized website in your website, you can do something like that:

<a href={resolveDeweb("syntra.massa")}>syntra.massa</a>

Under the hood, resolveDeweb function does the following:

  • Checks if the current browser natively supports Massa name system. If so, it just returns the URI as passed in parameter:
    "http://<mns domain>.massa/<path and query params>".
    For now, the only browser that supports MNS is Decentr, on Windows OS only.
  • If no native support, checks if the deweb provider plugin of Massa Station is running. If so, it will return
    "http://<mns domain>.localhost:<deweb plugin port>/<path and query params>".
    e.g. "massexplo.massa/blocks" -> "http://massexplo.localhost:4242/blocks" (the port is random)
  • If no station deweb plugin is available, check if the user is running a local deweb server. If so, return
    "http://<mns domain>.localhost:8080/<path and query params".
    e.g. "adm.massa/options/nodes" -> "http://adm.localhost:8080/options/nodes"
  • If no local deweb server is running, check if the current website, the one displaying the link, is served to the user by a deweb provider. If the website the user is currently visiting is a decentralized one, it means that it is served to him via a deweb provider. So we can use the same provider the user is currently using to serve the deweb website in the link. The function will thus return
    "http://<mns domain>.<current provider domain>/<path and query params>".
    e.g. "compound.massa/lend" -> "http://compound.massa.network/lend"
  • If none of the previous providers are available, return a fallback URL : 
https://deweb.massa.network/deweb_redirect?chain_id=<chain id>&deweb_url=<mns domain>

This fallback URL has two query parameters:

  • chain_id: the chain id used in the resolveDeweb function
  • deweb_url: the URI passed as parameter to resolveDeweb

redirection page​

The redirection page targeted by the fallback URL is hosted on deweb.massa decentralized website. The page helps the user to get a provider in two means:

  • It allows the user to choose a public deweb provider among a community-maintained list. When the user clicks on the button, the deweb website required by the user is automatically opened in a new tab with the URL of the selected provider.
  • The page also suggests the user to access the deweb site by using their own deweb provider. The user is invited to download one of the following tools :
    • massa station deweb plugin
    • decentr browser if the current OS is Windows
    • run the provider server binary localy on the computer.

redirection page

caution

Public providers proposed on the page are not checked. Ensure you trust the provider's admin.

useResolveDeweb​

useResolveDeweb is a react hook available in Massalabs react ui kit react tool kit. It's a wrapper around resolveDeweb function.

function useResolveDeweb(Url: string, chainId?: bigint): {resolvedUrl: string, isLoading: boolean, error: string | null}

Parameters:

  • Url: the URL of the deweb site. The URL can be a mns domain with a deweb provider domain. The ".massa" suffix after the mns domain is not required, but the protocol prefix ("http://") does.
  • chainId: Same as for resolveDeweb

Result:

  • resolvedUrl: the result returned by resolveDeweb
  • isLoading: Whether the URL creation process is pending or not
  • error: eventual error of the process.