Transactions
Transactions are the fundamental building blocks of the Arweave network.
This section covers the different types of transactions, and introduces the ways they can be posted to the network.
Posting Transactions
Like most blockchains, Arweave requires transactions to be created, signed, and then posted to the network.
Arweave has multiple ways to post a transaction - but generally speaking, they fall into the category of direct transactions to a gateway, using a bundler, or dispatching a transaction.
Transaction types
Transactions posted directly to Arweave come in two varieties wallet-to-wallet transactions and data transactions. The first transfers AR tokens between wallet addresses. The second posts data to Arweave and pays the associated storage costs.
Interestingly, data transactions may also transfer AR tokens to a wallet address while paying storage costs at the same time.
All transactions allow the user to specify up to 2KB worth of metadata in the form of custom tags.
Direct to Gateway
Gateways sit between clients and Arweave's network of peers. One of the primary functions of the gateway is to index transactions and optimistically cache the data posted to the network while waiting for it to be included in a block. This makes the transaction queryable in a "Pending" state almost instantly which allows applications built on top of a gateway to be more responsive. There is still a risk of transactions dropping out of the optimistic cache if they are not mined in a block by the peers.
An example of how to post a direct transaction using arweave-js can be found in this guide.
Guaranteed Transactions
When posting a large quantity of transactions or when fast settlement time is desireable consider using a bundling service.
Bundlers settle large volumes of transactions immediately and make the transaction data available within milliseconds. The bundling service holds onto posted transactions until they are confirmed onchain.
If the transactions are not included in the most recent block, the bundling service re-posts them with each new block until they are recorded on chain with a sufficient number of confirmations.
Bundled Transactions
Services built on top of Arweave that provide additional utility for Permaweb builders are sometimes called Permaweb Services. A bundler is one such service.
Bundlers take multiple individual transactions and bundle them together into a single transaction that is posted directly to Arweave.
In this way a single transaction at the protocol level can contain tens of thousands of bundled transactions. There is one restriction, however, only data transactions can be included in a bundle. Wallet-to-wallet transactions (that transfer AR tokens between wallet addresses) must be done as individual transactions posted directly to Arweave.
Dispatched Transactions
Another way to post bundled transactions is from the browser. While browsers enforce some constraints around the size of data that can be uploaded, browser based wallets are able to post transactions to bundlers.
Arweave browser wallets implement a dispatch() API method. If you are posting small transactions (100KB or less) you can use the wallets dispatch() method to take advantage of bundled transactions.
An example of how to post a 100KB or less bundled transaction with an Arweave wallets dispatch() method can be found in this guide.
Resources
- arweave-js example
- dispatch example
- Turbo SDK example