How to Use OpenIDEA: The Beginner's Guide (First Install, First Project, the Rust-Under-the-Hood Lesson, and the Extension Arc)

CodexFuse Team · 2026-11-07T01:35:38.289Z · 18 min read min read

How to Use OpenIDEA?

OpenIDEA is a free, open-source IDE from the l0ng-ai/openidea repository. It is not JetBrains IntelliJ IDEA, and its README says plainly that it is not affiliated with JetBrains. It rebuilds the IntelliJ way of working, its keymap, its tool windows, and its search-everything habits, inside a native app with a Rust core.

Learning how to use openidea takes seven moves: download the current release, install it, open a project folder, learn the search-everywhere habit, set up a language server, try the built-in Git and database tools, and add a plugin only when you need one. This openidea tutorial follows the official README for the current release, v0.1.38, with every fact checked as of November 2026.

If you already use a fast Rust editor, the closest sibling is Zed. The Zed beginner guide on CodexFuse covers that editor, and OpenIDEA is the full IDE next to it, with a debugger, a database client, and an HTTP client built in.

This guide opens the rust-ide lane in the dev-tools IDE cluster, and the base pillar is the VPS hosting guide on CodexFuse, which covers the Linux server where the code you edit here usually runs.

1. Download the current release from the releases page.
2. Install the build for your operating system.
3. Launch OpenIDEA and open an existing project folder.
4. Find anything with Search Everywhere.
5. Set your language server in Settings.
6. Try the Git tool window and the terminal.
7. Install a plugin only when a job needs one.

What Is OpenIDEA?

What is OpenIDEA, in one sentence? OpenIDEA is the IDE you know, rebuilt in Rust, in the project's own words. It brings the IntelliJ IDEA way of working to a native app with a Rust core, and it ships an editor, code insight, a debugger, Git, a terminal, database tools, and an HTTP client, for 60+ languages.

The project is young enough that its age is part of the story. It was created on 21 October 2026, so it is 17 days old as of this guide, and the last code push landed on the same day this guide was written. It already holds 7,442 GitHub stars and 622 forks, with 276 open issues, under the Apache 2.0 license.

CodexFuse offers no OpenIDEA tool, so this guide teaches the open-source IDE itself. The openidea ide is a download-and-run desktop app, not a web service, and everything below starts from its public repository.

The star count moved fast enough to deserve its own arithmetic. The project gained about 5,000 stars between 28 October and 4 November, which is 714.3 per day, and then 1,642 more stars between 4 November and 7 November, which is 547.3 per day. Across its whole 17-day life, that works out to 437.8 stars per day, with 11.96 stars per fork and 3.71 open issues per 100 stars.

Treat every star count here as a 7 November 2026 snapshot. The star count will have moved by the time you read this, and the releases page carries the current version.

How Do You Install OpenIDEA?

An openidea install starts at the releases page, because there is no package-manager command. The README lists no brew, apt, winget, or choco install, and the download listings confirm that gap. You download a build, install it, and launch it.

The current release is v0.1.38, published on 6 November 2026, less than a day before this guide was written. Versions move fast here: FileHorse still listed v0.1.35 as latest on 3 November, so three patch releases shipped in about three days. Check the releases page before you install, because any version number in print is stale within days.

OpenIDEA_0.1.38_x64-setup.exe
OpenIDEA_0.1.38_x64_en-US.msi
OpenIDEA_0.1.38_aarch64.dmg
OpenIDEA_0.1.38_amd64.deb
OpenIDEA-0.1.38-1.x86_64.rpm
OpenIDEA_0.1.38_amd64.AppImage

Every binary asset ships with a matching .sig signature file. The release also ships server and plugin archives, plus plugin packages for tools such as excalidraw, git-toolbox, solidity, and string-tools.

The README states no system requirements and no minimum hardware. Third-party listings suggest Windows 10 or Windows 11 on 64-bit hardware, with 8 GB of RAM and an SSD recommended, and macOS 15.0 Sequoia or later. Treat those as practical suggestions from a download site, not as official minimums.

How Do You Open Your First Project?

OpenIDEA opens an existing project folder, and that is the whole first-project flow. Launch the app, open a folder from the welcome screen, and the IDE indexes it and shows the editor with its tool windows. No New Project wizard is documented in the README, so do not go looking for one.

The releases page lives on GitHub, and the GitHub beginner guide on CodexFuse covers accounts, repositories, and releases if that site is new to you. Clone a small repository first, open that folder, and you have a safe project to learn in.

git clone https://github.com/l0ng-ai/openidea.git

Launch OpenIDEA
Open an existing project folder
Wait for indexing to finish
Open a file from the Project tool window
Open the terminal tool window

This guide quotes no testbed outputs, because none were executed. Every step above comes from the README and the project docs, not from a running install, and the same holds for every command below.

If you would rather build from source, the documented prerequisites are Rust 1.96, Node 22, and pnpm, plus the Tauri prerequisites. The build itself is two commands, and it runs the IDE in development mode.

pnpm install
pnpm tauri dev

The optional notebook tests need two distinct Python environments with ipykernel installed, and they are opt-in only. They are not part of a normal first run.

OPENIDEA_TEST_PYTHON=/first/env/bin/python \
OPENIDEA_TEST_PYTHON_SECOND=/second/env/bin/python \
cargo test -p ide-notebook --test kernel_runtime -- --ignored --test-threads=1

Why Does OpenIDEA Feel Fast?

The speed story starts with the shape of the app. OpenIDEA is a Tauri desktop app: a Rust core and a Rust back end behind a TypeScript interface, with the editor running in a WebView. Rebuilt in Rust describes the core and the shell, not every line: the interface is largely TypeScript on a Tauri WebView, with Rust behind it.

The README measures its own speed on one machine and one project, and the numbers are striking. It opens freqtrade, a Python project of about 770 files, on Windows 11 with a 32-core AMD processor and 62 GB of RAM, with warm caches, as the median of 5 runs. The table below is the README's own comparison against IntelliJ IDEA 2026.2.3.

The README carries its own warning with these numbers, and it matters more than the table. IDEA analyses Python more deeply, so ready does not mean the same work on both sides. Both sides were measured from the outside in the same way, and the project ships the comparison script so you can run it on your own machine and projects.

The ratios behind the table are easy to state. OpenIDEA uses 169 MB against 2011 MB, which is 1842 MB less, or 91.6 percent less, a ratio of 11.9 to 1. It reaches ready 12.0 times faster, saving 12.1 seconds, and it quits 19.7 times faster, while its CPU time until ready is 20.0 times lower.

One independent measurement disagrees with the headline memory figure, and it is worth hearing. A hands-on reviewer running OpenIDEA on Windows measured roughly 600 MB of memory, including the main program and its WebView2 child processes.

That is 431 MB above the README figure, or 3.55 times higher, and the gap is a reminder that USS is not total RAM. Judge the IDE by your own machine, not by either number alone.

from datetime import date, datetime, timezone
created = date(2026, 10, 21)
today = date(2026, 11, 7)
stars = 7442
forks = 622
issues = 276
v138 = datetime(2026, 11, 6, 17, 22, 4, tzinfo=timezone.utc)
now = datetime(2026, 11, 7, 1, 30, tzinfo=timezone.utc)
print("repo age days:", (today - created).days)
print("stars per day:", round(stars / 17, 1))
print("stars per fork:", round(stars / forks, 2))
print("open issues per 100 stars:", round(issues / stars * 100, 2))
print("v0.1.38 age hours:", round((now - v138).total_seconds() / 3600, 1))
print("memory ratio IDEA/OpenIDEA:", round(2011 / 169, 1))
print("ready ratio:", round(13.2 / 1.1, 1))
print("memory saved MB:", 2011 - 169)
print("memory saved pct:", round((2011 - 169) / 2011 * 100, 1))
print("ready time saved s:", round(13.2 - 1.1, 1))
print("Oct28-Nov4 growth per day:", round((5800 - 800) / 7, 1))
print("Nov4-Nov7 growth per day:", round((7442 - 5800) / 3, 1))
print("enilu measured MB vs README USS MB:", 600 - 169)
print("enilu vs README ratio:", round(600 / 169, 2))
# repo age days: 17
# stars per day: 437.8
# stars per fork: 11.96
# open issues per 100 stars: 3.71
# v0.1.38 age hours: 8.1
# memory ratio IDEA/OpenIDEA: 11.9
# ready ratio: 12.0
# memory saved MB: 1842
# memory saved pct: 91.6
# ready time saved s: 12.1
# Oct28-Nov4 growth per day: 714.3
# Nov4-Nov7 growth per day: 547.3
# enilu measured MB vs README USS MB: 431
# enilu vs README ratio: 3.55

How Does the IntelliJ-Style Workflow Work?

The workflow is the product, and it has three habits. The IntelliJ keymap is the default, the tool windows hold the project, Git, terminal, and database views, and Search Everywhere is the one-popup search across classes, files, symbols, actions, and text. Learn those three habits and the rest of the IDE falls into place.

The README documents no shortcut list, so this guide prints none. The keymap follows IntelliJ IDEA conventions, and the keymap editor lets you rebind anything that conflicts with your habits.

If you prefer a keyboard-first modal editor instead of an IDE, the Neovim beginner guide on CodexFuse covers that lane. Neovim is an editor you live inside, while OpenIDEA is an IDE that gathers the editor, the debugger, and the database client in one window.

Settings › Plugins
Settings › Languages and Frameworks › Language Servers
View ▸ Tool Windows ▸ Database

How Do Language Servers and the Debugger Work?

Code insight comes from language servers over LSP, and debugging comes from debug adapters over DAP. That pair is the whole model: a server per language for completion and errors, and an adapter per runtime for breakpoints and stepping.

The README claims 60+ languages, but it lists no per-language servers, so the depth of insight varies by language and is unverified beyond the examples below. Java is the documented case, and it has two servers to choose from.

The Java choice lives in Settings, under Languages and Frameworks, then Language Servers. Automatic prefers jdtls and falls back to kmp-lsp when jdtls is not installed, and None disables both. The kmp-lsp route offers syntax-based Java code insight without running a JVM, but it does not provide JDT compiler analysis, Lombok integration, or JDT-specific refactorings.

How Do Git, the Terminal, and the Database Tools Fit In?

Git, the terminal, and the database client are built in, not extensions, and they share the tool-window bar with the editor. The Git view covers diffs, commit history, inline blame, and a GitHub pull-request tool window, with worktrees and a shelf for stashing work aside.

The Git beginner guide on CodexFuse covers the commands behind these buttons if Git itself is new to you. The IDE runs the same Git you already have, and its history view reads the same commits.

The database tool window connects to SQLite, PostgreSQL, MySQL and MariaDB, Microsoft SQL Server, ClickHouse, and Oracle, plus the wire-compatible products listed under New, then Data Source. Connections are saved per project in .openidea/data-sources.toml, and passwords are stored outside the project, never in that file.

Oracle needs the Oracle Instant Client 19c or later installed separately, because OpenIDEA does not bundle it. On macOS, the docs give a quarantine-removal command for the client folder.

xattr -dr com.apple.quarantine /opt/oracle/instantclient_23_5

The HTTP client and the database client are the two tools that set OpenIDEA apart from a plain editor. A code editor edits files, while this IDE also queries the database the code talks to and tests the API the code calls.

How Do Plugins and Extensions Work?

Plugins add actions, completion, quick fixes, tool windows, custom editors, themes, file icons, and languages, in the README's own list. They run as sandboxed WebAssembly components, and themes, icon themes, and languages need no code at all.

Install plugins from Settings, then Plugins, or start your own with the plugin tool. The plugin API is still a preview, so expect it to move, and the official plugins are versioned 0.x. JVM-based IntelliJ plugins will not run here, because this is a new WebAssembly system, not the IntelliJ platform.

The plugin tool installs from the repository itself, and the scaffold commands below create a plugin project. The build step produces a WebAssembly file, and the link step loads the folder into the IDE.

cargo install --locked --git https://github.com/l0ng-ai/openidea ide-host --bin openidea-plugin
openidea-plugin new my-plugin
openidea-plugin new my-theme --template theme
cargo test
openidea-plugin build
openidea-plugin link

Plugins live in the plugins directory, which defaults to the app-data folder under ai.l0ng.openidea, and the plugins directory can be changed with the OPENIDEA_PLUGINS_DIR setting. A plugin shortcut never takes a keystroke the IDE or the user already uses, and the user can rebind it in the keymap editor.

How Do You Use the Agents Workspace?

The Agents workspace docks AI coding agents in a tool window, with native protocol adapters for Claude Code and Codex, plus ACP integration paths. Conversations can be docked in the Agents tool window, and the 0.1.35 changelog lists a one-click ACP install for GitHub Copilot.

Agent installation, authentication, and model costs still depend on the tools and services you connect. The IDE does not make model calls free, so budget for the agent service itself, not just the editor.

Multi-project workspaces bring several projects into one session for search, indexing, and running. A window group switches between project tabs while keeping member sessions and services alive, which is the closest thing this IDE has to a workspace switcher.

OpenIDEA vs Zed vs IntelliJ IDEA: Which One Fits You?

As an openidea rust ide, OpenIDEA sits between a fast editor and a full JVM IDE, and the right choice depends on what you miss most. Zed is the fast editor, IntelliJ IDEA is the full IDE with the deepest analysis, and OpenIDEA is the full IDE shape with a lighter machine underneath.

The honest summary is that no row above is a verdict on its own. OpenIDEA wins the benchmark table, IntelliJ IDEA wins depth of analysis, and Zed wins raw editing speed, and the deciding question is which of those three you feel every day.

This rust ide comparison stays narrow on purpose. No RustRover comparison exists in any source fetched for this guide, and no VS Code head-to-head was found, so neither is claimed here.

Seven Mistakes Beginners Make

Seven mistakes cover most of the early pain with a 17-day-old IDE, and all seven come from the sources above. Fix them once and the rest of the learning curve is the workflow itself.

The thread through all seven is the same: trust the README and the releases page, not the download listings. The listings are a week old the moment they are written, and this project ships a new patch every day or two.

Sources

The OpenIDEA README supplied the positioning, the feature list, the benchmark table with its caveat, and the plugin story, and the repository docs supplied the database tool window and the Java language servers. The GitHub API supplied the release and repository figures for l0ng-ai/openidea, all fetched on 7 November 2026.

Every number in this guide comes from one of those sources or from a Python calculation shown in the computed block above. No search volumes are quoted, because none were published for this keyword. The release figures are a 7 November 2026 snapshot.

The page-one field for the primary keyword was thin: download listings on FileHorse, AI-written overviews on HotRepo and opensourceprojects.dev, one hands-on review, and heavy homonym noise from the old OpenIDE command-line tool and a brand consultancy. Search results for openidea ide return the same listings and overviews, and no independent walkthrough exists yet. That thin field is why this guide pins every step to the current v0.1.38 release and to the README itself.

Frequently Asked Questions

Is OpenIDEA the same as IntelliJ IDEA?

No. OpenIDEA is a separate open-source project from the l0ng-ai/openidea repository, and JetBrains does not make it. It rebuilds the IntelliJ way of working, its keymap, its tool windows, and its search-everything habits, inside a native app with a Rust core.

How do I install OpenIDEA?

Download the build for your operating system from the releases page. Windows uses the setup exe or the MSI, macOS uses the dmg, and Linux uses the deb, the rpm, or the AppImage, with a portable zip on Windows as an alternative.

Can I use my IntelliJ plugins in OpenIDEA?

No. OpenIDEA loads WebAssembly plugins only, so plugins built for the IntelliJ platform do not work in it. Install plugins from Settings, then Plugins, and expect the plugin system to keep moving, because it is young.

Is OpenIDEA really faster than IntelliJ IDEA?

The README benchmark says yes on speed and memory: 0.9 seconds to a window against 3.1, 1.1 seconds to ready against 13.2, and 169 MB against 2011 MB. The same README warns that the two sides do different amounts of analysis, and one hands-on reviewer measured roughly 600 MB in real use.

Is OpenIDEA free?

Yes. OpenIDEA is free, open-source software under the Apache 2.0 license. The only costs are the ones you choose: the agent services you connect in the Agents workspace charge their own prices, so budget for the agent service as well as the editor.