base on Lightweight Java and Android library for integration with Ethereum clients Web3j: Web3 Java Ethereum Dapp API ================================== [](https://docs.web3j.io) [](https://github.com/web3j/web3j/actions/workflows/build.yml) [](https://codecov.io/gh/web3j/web3j) [](https://discord.gg/A9UXfPF2tS) [](https://gurubase.io/g/web3j) Web3j is a lightweight, highly modular, reactive, type safe Java and Android library for working with Smart Contracts and integrating with clients (nodes) on the Ethereum network:  This allows you to work with the [Ethereum](https://www.ethereum.org/) blockchain, without the additional overhead of having to write your own integration code for the platform. The [Java and the Blockchain](https://www.youtube.com/watch?v=ea3miXs_P6Y) talk provides an overview of blockchain, Ethereum and Web3j. NEW! Get involved! -------- Since Web3J moved under Hyperledger we started to do Web3J Contributors calls every 2 weeks! Subscribe to our community page and to see check our call schedule. Your contribution matters! - [Community Link](https://lists.hyperledger.org/g/web3j) - Check our last updates! - [Calendar Invite](https://lists.hyperledger.org/g/web3j/ics/invite.ics?repeatid=57401) - Add the contributor call to your calendar! Features -------- - Complete implementation of Ethereum's [JSON-RPC](https://ethereum.org/en/developers/docs/apis/json-rpc/) client API over HTTP and IPC - Ethereum wallet support - Auto-generation of Java smart contract wrappers to create, deploy, transact with and call smart contracts from native Java code ([Solidity](http://solidity.readthedocs.io/en/latest/using-the-compiler.html#using-the-commandline-compiler) and [Truffle](https://github.com/trufflesuite/truffle-contract-schema) definition formats supported) - Reactive-functional API for working with filters - [Ethereum Name Service (ENS)](https://ens.domains/) support - Support for Parity's [Personal](https://github.com/paritytech/parity/wiki/JSONRPC-personal-module), and Geth's [Personal](https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal) client APIs - Support for [Alchemy](https://docs.alchemyapi.io/alchemy/guides/getting-started#web-3-j) and [Infura](https://infura.io/), so you don't have to run an Ethereum client yourself - Comprehensive integration tests demonstrating a number of the above scenarios - Command line tools - Android compatible - Support for JP Morgan's Quorum via [web3j-quorum](https://github.com/web3j/quorum) - Support for [EEA Privacy features as described in EEA documentation](https://entethalliance.org/technical-documents/) and implemented in [Hyperledger Besu](https://besu.hyperledger.org/private-networks/reference/api#eea-methods). It has five runtime dependencies: - [RxJava](https://github.com/ReactiveX/RxJava) for its reactive-functional API - [OKHttp](https://square.github.io/okhttp/) for HTTP connections - [Jackson Core](https://github.com/FasterXML/jackson-core) for fast JSON serialisation/deserialization - [Bouncy Castle](https://www.bouncycastle.org/) for crypto - [Jnr-unixsocket](https://github.com/jnr/jnr-unixsocket) for \*nix IPC (not available on Android) - [Java-WebSocket](https://github.com/TooTallNate/Java-WebSocket) It also uses [JavaPoet](https://github.com/square/javapoet) for generating smart contract wrappers. QuickStart --------- The simplest way to start your journey with Web3j is to create a project. We provide this functionality using the [Web3j CLI](http://docs.web3j.io/latest/command_line_tools/). This latter can be installed as follows: For Unix: ```shell script curl -L get.web3j.io | sh && source ~/.web3j/source.sh ``` For Windows, in Powershell: ```shell script Set-ExecutionPolicy Bypass -Scope Process -Force; iex ((New-Object System.Net.WebClient).DownloadString('https://raw.githubusercontent.com/hyperledger/web3j-installer/main/installer.ps1')) ``` Create a new project by running: ```shell script $ web3j new ``` Or use our [Maven](https://github.com/web3j/web3j-maven-plugin) or [Gradle](https://github.com/web3j/web3j-gradle-plugin) plugins to generate java files from Solidity contracts. #### Please head to the [Web3j Documentation](https://docs.web3j.io) for further instructions on using Web3j. Maven ----- Java: ```xml <dependency> <groupId>org.web3j</groupId> <artifactId>core</artifactId> <version>4.14.0</version> </dependency> ``` **Note:** The Web3j Java binaries are compiled using Java 21. Java 21 or a more recent version is required to use Web3j as a dependency. Android: ```xml <dependency> <groupId>org.web3j</groupId> <artifactId>core</artifactId> <version>4.12.3-android</version> </dependency> ``` Gradle ------ Java: ```groovy implementation ('org.web3j:core:5.0.1') ``` Android: ```groovy implementation ('org.web3j:core:4.12.3-android') ``` Build instructions ------------------ Web3j includes integration tests for running against a live Ethereum client. If you do not have a client running, you can exclude their execution as per the below instructions. To run a full build (excluding integration tests): ``` {.sourceCode .bash} $ ./gradlew check ``` To run the integration tests, you will need to set up these variables in order to pull the Docker images from the Docker Hub registry: - `registry.username` - `registry.password` Then run the following command: ``` {.sourceCode .bash} $ ./gradlew -Pintegration-tests=true :integration-tests:test ``` If you do not want the integration test to run: ``` {.sourceCode .bash} $ ./gradlew -Pintegration-tests=false :test ``` Check the [Docker client API](https://github.com/docker-java/docker-java/blob/master/docs/getting_started.md#instantiating-a-dockerclientconfig) for more information on configuration options. Projects using Web3j ------------------ <a href="https://alphawallet.com/"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/alphawallet-dark.svg"> <img alt="Alphawallet logo" src="static-imgs/alphawallet-light.svg" width="auto" height="50"> </picture> </a> <a href="https://linea.build"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/linea-dark.svg"> <img alt="Linea logo" src="static-imgs/linea-light.svg" width="auto" height="50"> </picture> </a> <a href="https://consensys.io/"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/consensys-dark.svg"> <img alt="ConsenSys logo" src="static-imgs/consensys-light.svg" width="auto" height="50"> </picture> </a> <a href="https://ens.domains"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/ens-dark.svg"> <img alt="ENS logo" src="static-imgs/ens-light.svg" width="auto" height="50"> </picture> </a> <a href="https://github.com/hyperledger/besu"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/hyperledger-besu-dark.svg"> <img alt="Hyperledger Besu logo" src="static-imgs/hyperledger-besu-light.svg" width="auto" height="50"> </picture> </a> <a href="https://web3auth.io"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/web3auth_dark.svg"> <img alt="Web3Auth logo" src="static-imgs/web3auth_light.svg" width="auto" height="50"> </picture> </a> <a href="https://hedera.com"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/hedera-dark.svg"> <img alt="Hedera logo" src="static-imgs/hedera-light.svg" width="auto" height="50"> </picture> </a> <a href="https://celo.org"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/celo-dark.svg"> <img alt="Celo logo" src="static-imgs/celo-light.svg" width="auto" height="50"> </picture> </a> <a href="https://explorer.walletconnect.com/"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/walletconnect-dark.svg"> <img alt="WalletConnect logo" src="static-imgs/walletconnect-light.svg" width="auto" height="50"> </picture> </a> <a href="https://argent.xyz"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/argent-dark.svg"> <img alt="Argent logo" src="static-imgs/argent-light.svg" width="auto" height="50"> </picture> </a> <a href="https://unstoppabledomains.com"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/unstoppable_domains-dark.svg"> <img alt="Unstoppable Domains logo" src="static-imgs/unstoppable_domains-light.svg" width="auto" height="50"> </picture> </a> <a href="https://www.fnality.org/home"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/fnality-dark.svg"> <img alt="Fnality logo" src="static-imgs/fnality-light.svg" width="auto" height="50"> </picture> </a> <a href="https://zksync.io/"> <picture> <source media="(prefers-color-scheme: dark)" srcset="static-imgs/zksync-dark.svg"> <img alt="zksync logo" src="static-imgs/zksync-light.svg" width="auto" height="50"> </picture> </a> Commercial support and training ------------------------------- Commercial support and training is available from [web3labs.com](https://www.web3labs.com/web3j-sdk). License ------ Apache 2.0 ", Assign "at most 3 tags" to the expected json: {"id":"8937","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"