Antigravity vs opencodex
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A plugin that lets the Opencode coding tool sign in to Google's Antigravity IDE via OAuth to use its models.
Open source · MIT
A local proxy that lets Codex and Claude Code use models from other providers.
The short answer
Choose Antigravity if you need…
- Developers who already use Opencode and have a Google account with Antigravity access
- People who want to switch between several Google accounts and check their quota status
- Users comfortable editing a JSON config file and running commands in a terminal
Choose opencodex if you need…
- Developers who already use Codex or Claude Code and want to try other model providers
- People who want one local dashboard to manage multiple provider keys and models
- Users who want to route different sessions to different accounts or models
- Anyone running local models through Ollama who wants them inside a coding tool
Side-by-side
| Antigravity | opencodex | |
|---|---|---|
| Type | Dev tool | Dev tool |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 11k | 18.2k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | TypeScript | TypeScript |
| Last code update | 10 days ago | 4 days ago |
What each one is
Antigravity
This is an unofficial plugin for Opencode, a terminal coding tool. It lets you sign in with your Google account through OAuth so Opencode can call models that Antigravity (Google's IDE) provides, such as Gemini and Claude models, using Antigravity's rate limits. Accounts are stored locally, and the README notes that Google may restrict accounts that use third-party clients.
opencodex
opencodex runs on your computer as a local gateway between AI coding tools and model providers. It accepts requests in the Responses, Chat Completions and Anthropic Messages formats and translates them into what each provider expects. The README says this lets tools like Codex and Claude Code work with models such as Claude, Gemini, Grok, DeepSeek and Ollama.
Best for
Antigravity
- Developers who already use Opencode and have a Google account with Antigravity access
- People who want to switch between several Google accounts and check their quota status
- Users comfortable editing a JSON config file and running commands in a terminal
opencodex
- Developers who already use Codex or Claude Code and want to try other model providers
- People who want one local dashboard to manage multiple provider keys and models
- Users who want to route different sessions to different accounts or models
- Anyone running local models through Ollama who wants them inside a coding tool
Strengths
Antigravity
- Uses the setup flow already built into opencode auth login
- Lets you manage several accounts and see quota status in one place
- Written in TypeScript under the MIT license with a documented test suite
opencodex
- Works with many clients and providers through one local address, http://localhost:10100
- Has a web dashboard for adding providers, picking models and managing accounts
- MIT licensed and open source on GitHub
Not ideal for
Antigravity
- Anyone who needs guaranteed account safety, since the README warns Google may restrict accounts using third-party clients
- People not using Opencode, because the plugin only works inside it
- Users on older Opencode or Node.js versions, since it requires OpenCode 2.1.2+ and Node.js 20+
opencodex
- People who only use one provider and do not need routing, since the proxy adds a layer to set up and maintain
- Users who need guaranteed feature parity; the README says streaming, tool calls, reasoning and images work only where the client, model and provider support them
- Non-technical users who are uncomfortable installing Node packages or editing tool configs
Trade-offs
Antigravity
- Unofficial, and Google may restrict accounts using third-party clients
- Model availability depends on your Google plan and the README does not spell out limits
- Accounts file contains credentials and must be backed up and protected carefully
opencodex
- The README describes support as conditional on client, model and provider, so behavior varies by combination
- Several setup paths (CLI, desktop app, managed integrations) mean more to learn; the README is long and partly truncated
- Desktop app is labeled beta in the README
Getting started
Antigravity
Add the plugin to your Opencode config (in ~/.config/opencode/opencode.json, not a shell command)
"plugins": ["opencode-antigravity-auth@2.1.2"]Log in to Google through Opencode
opencode auth login googleopencodex
Install the CLI globally
npm install -g @bitkyc08/opencodexStart the proxy and dashboard
ocx startFrequently asked questions
What is the difference between Antigravity and opencodex?
Antigravity: A plugin that lets the Opencode coding tool sign in to Google's Antigravity IDE via OAuth to use its models. opencodex: A local proxy that lets Codex and Claude Code use models from other providers. Antigravity suits developers who already use opencode and have a google account with antigravity access, while opencodex suits developers who already use codex or claude code and want to try other model providers.
Are Antigravity and opencodex free?
Antigravity: Free and open source. opencodex: Free and open source.
Is Antigravity or opencodex more popular?
opencodex has more GitHub stars (18.2k) than Antigravity (11k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Antigravity and opencodex?
Other options people compare them with include wshobson/agents, oh-my-claudecode, Claude Code Router, ECC, 9Router.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.