Do these tools need a GPU?

No. Antigravity, OpenCode, and BlackboxAI call hosted models, so a normal laptop is enough.

Are they completely free?

The tools are free to install. Free model tiers have rate limits and can change, so keep more than one provider ready.

Which one should I start with?

Start with Antigravity if you want a full editor. Use OpenCode if you live in the terminal. Use BlackboxAI if you want chat and inline code inside VS Code.

Free Claude Code Alternatives 2026: Antigravity + OpenCode + BlackboxAI

Claude Code is excellent, but the subscription is hard to justify when you are still learning or freelancing on a tight budget. The good news is that the workflow is no longer unique. You can get an agent that reads your repository, edits files, runs commands, and explains its plan without paying for a Claude plan.

This post covers the three tools from the video: Antigravity 2.0, OpenCode, and BlackboxAI. All three work on Windows, macOS, and Linux, and none of them need a local GPU because the models run in the cloud.

The three tools at a glance

Antigravity 2.0 is a full editor built on the VS Code experience. It has an agent manager, a model picker, and support for VS Code extensions.
OpenCode is a terminal-first coding agent. It is model agnostic, so you can point it at OpenCode Zen, OpenRouter, or another OpenAI compatible endpoint.
BlackboxAI is a VS Code extension that adds chat, autocomplete, and code actions without replacing your editor.

You do not have to choose immediately. Install all three, use them for a week, and keep the one that matches your habits.

Step 1: Install Antigravity 2.0

Download the installer from antigravity.google/download and run it like any normal desktop app.

On first launch:

Sign in with your Google account.
Pick a theme and import your VS Code settings if you want a familiar layout.
Open the model picker and check which models are available for your account.
Open a project folder and try a small prompt in the agent panel.

Antigravity keeps the VS Code shortcuts, the command palette, and the extension marketplace. That means your existing workflow mostly survives the switch. The important difference is the agent panel, where you can describe a task and let the model plan and edit files.

If you already use VS Code, the migration is low risk. Keep VS Code installed for a few days, duplicate your settings, and compare the two editors on a real task instead of a toy example.

Step 2: Install OpenCode

OpenCode is the terminal option. Install Node.js 18 or newer first, then install the CLI globally:

npm install -g opencode-ai

Verify the install:

opencode --version

Inside any project folder, start the agent:

opencode

The first run asks you to connect a provider. You can choose OpenCode Zen, OpenRouter, or another compatible API. If you are not sure which model to pick, start with a free model and switch later. The agent is only as good as the model behind it, so test the same prompt on two models before you settle.

Running OpenCode inside Antigravity

You do not need a separate terminal window. Open the integrated terminal in Antigravity with Ctrl+`` and run opencode` there. The agent sees the same project folder as the editor, so edits appear in the file explorer immediately.

This combination is useful: Antigravity gives you the visual editor and extension ecosystem, while OpenCode gives you a terminal agent that is easy to script and automate.

Step 3: Install BlackboxAI

Open the Extensions view in VS Code or Antigravity, search for BlackboxAI, and install the official extension. After installation:

Sign in with your account.
Open the chat panel.
Ask it to explain a file or generate a function.
Try the inline code action on a selected block.

BlackboxAI is the least disruptive option because it lives inside the editor you already use. It is a good fit if you want assistance while keeping your current VS Code setup, themes, and keybindings.

Which one should you use?

Choose Antigravity if you want an all-in-one editor and you are comfortable moving your daily work into a new app.
Choose OpenCode if you prefer the terminal, want to script your workflow, or need to switch providers often.
Choose BlackboxAI if you want to stay in VS Code and only add an assistant panel.

Many developers end up using two: an editor agent for large refactors and a terminal agent for quick commands. That is fine. The tools are free to install, and you can remove the ones you do not use.

Common mistakes

Skipping Node.js. OpenCode needs a recent Node runtime. If opencode is not recognized, check node --version first.
Expecting unlimited free usage. Free models have rate limits. Keep a second provider configured so you can switch when one is busy.
Ignoring the model choice. A weak model makes any agent look bad. Test one real task before judging the tool.
Installing random extensions. Use the official marketplace listing and check the publisher name.
Forgetting to review edits. Treat every agent as a fast junior developer. Read the diff before you commit.

Final thoughts

The free tier of AI coding is good enough for learning, side projects, and most everyday edits. Antigravity gives you the editor, OpenCode gives you the terminal agent, and BlackboxAI gives you an in-editor assistant. Install one today, finish a real task with it, and then decide whether you need the paid tier at all.