Awesome

Purpose

3em was conceived as an alternate solution to SmartWeave while still accomplishing the same goal: Simple & Scalable smart contracts on the Arweave protocol.

After receiving multiple feedback from different individuals and teams, we realize there were 3 main issues that needed to be solved:

• Speed
• Security
• Multi-language support

For more information on how we solved the issues mentioned above, please refer to our technical guide.

Install

With Shell:

curl -fsSL https://3em.dev/install.sh | sh

With PowerShell:

iwr https://3em.dev/install.ps1 -useb | iex

CLI benchmarks

Measures:

• Startup time
• Filesystem cache
• Execution performance
• Interaction loading

$ hyperfine 'target/release/bench' 'target/release/bench_evm' 'target/release/bench_wasm' 'node tools/benchmarks/smartweave/index.js' 'target/release/bench_fh' -r 20 --export-json bench.json

• The JavaScript contract used in 3em JS and SmartWeave JS is t9T7DIOGxx4VWXoCEeYYarFYeERTpWIC1V3y-BPZgKE.
• The WebAssembly contract source used in 3em WASM can be found here. The block height is not fixed.
• The EVM contract source used in 3em EVM can be found here. The block height is not fixed.
• There are functional differences between evm and wasm contracts and the number of interactions (except the JavaScript contract).
• fh = Fixed height of 749180
• The gateway used is arweave.net

Multi-language support

3em supports contracts written in:

• JavaScript
• WebAssembly (Rust, AssemblyScript, etc.)
• EVM bytecode (Solidity, Yul, etc)

Please refer to the "helpers" for details on writing contracts.

Javascript Library

3EM can be integrated in both client and server side through the Javascript library.

Please click here for more information.

Smartweave Compatability

3em follows the SmartWeave contract design. This essentially means two things:

• Contracts need to be deployed to Arweave in order for 3EM to run them
• 3em is capable of running existing Smartweave contracts and exposes backward compatible APIs (like the SmartWeave global)

Determinism

3em execution is deterministic. Random operations have a constant seed and Non deterministic APIs are overriden with their deterministic version. You can read more about it in our technical guide.

CLI

Available Commands

• three_em run
  • Runs a contract deployed to Arweave given certain options.
• three_em dry-run
  • Runs a local contract which has not yet been deployed to Arweave.
  • Only JS and WASM contracts are accepted during dry-run.
• three_em serve
  • Spawns a local server with an endpoint to evaluate contracts.

run

The following flags are available for three_em run:

• --host | string
  • URL of gateway to be used during execution
  • Default: arweave.net
• --port | number
  • Port of gateway to be used during execution
  • Default: 443
• --protocol | string
  • Network protocol to be used during execution
  • Default: https
• --contract-id | string
  • ID of contract to be evaluated
• --pretty-print | boolean
  • Whether output should be printed in a prettified JSON form
  • Default: false
• --no-print | boolean
  • Whether output should be printed in the console. True will not print any output
  • Default: false
• --show-validity | boolean
  • Whether output should contain the validity table of evaluated interactions
• --save | string
  • If provided, it contains a file path where output will be saved in JSON form
• --benchmark | boolean
  • Whether to benchmark the execution time of the contract
  • Default: false
• --height | number
  • Maximum height to be used during evaluation
• --no-cache
  • Whether it should use 3em's built-in cache system
• --show-errors
  • Whether errors from failed interactions should be printed

Example

three_em run --contract-id t9T7DIOGxx4VWXoCEeYYarFYeERTpWIC1V3y-BPZgKE

dry-run

The following flags are available for three_em dry-run:

• --file
  • File path for dry run JSON input.
  • Please refer to our dry run documentation here
• --host | string
  • URL of gateway to be used during execution
  • Default: arweave.net
• --port | number
  • Port of gateway to be used during execution
  • Default: 443
• --protocol | string
  • Network protocol to be used during execution
  • Default: https
• --pretty-print | boolean
  • Whether output should be printed in a prettified JSON form
  • Default: false
• --show-validity | boolean
  • Whether output should contain the validity table of evaluated interactions

dry-run requires a JSON file containing the dry-run structure, for more information about it please refer to our dry run guide.

serve

The following flags are available for three_em serve:

• --host | string
  • Host to be used by the server
  • Default: 127.0.0.1
• --port | number
  • Port to be used by the server
  • Default: 5400

Example

three_em serve