May 2026 gave us two new multi-agent coding platforms in the same week. Google shipped Antigravity 2.0 at I/O on May 19. xAI launched Grok Build on May 14. Both use parallel subagents. Both aim to replace your existing coding workflow. But they take fundamentally different approaches to getting there.

Antigravity 2.0 is a full platform: desktop app, CLI, and SDK bundled together. Grok Build is a CLI-only tool with model flexibility and a plugin ecosystem. Here’s how they compare when you’re actually writing code.

Quick Comparison

Feature	Grok Build	Antigravity 2.0
Launch	May 14, 2026	May 19, 2026
Status	Early beta	Stable release
Architecture	Multi-agent (parallel)	Multi-agent (parallel)
Components	CLI only	Desktop App + CLI + SDK
Default model	Grok	Gemini 3.5 Flash
Model flexibility	Any model via OpenRouter	Gemini models only
Context window	256K tokens	1M+ tokens
Sandbox	None	Cloud-based Linux sandbox
Extensions	Skills Marketplace + MCP	SDK for custom agents
Project instructions	CLAUDE.md	GEMINI.md / CLAUDE.md
Headless/CI	Yes (-p flag)	Yes
Multimodal	Text + images	Text + images + video
Pricing	$99/mo or ~$1/1M tokens	$20-200/mo (compute-based)
Code execution	Local only	Cloud sandbox + local

Architecture: Same Concept, Different Execution

Both tools use multi-agent architectures with parallel subagents. The concept is identical: break complex tasks into subtasks, run them simultaneously, merge results. But the implementation differs significantly.

Grok Build’s approach:

• Coordinator agent runs locally on your machine
• Subagents are lightweight and share the same context
• All execution happens locally (your filesystem, your terminal)
• You see which subagents are active in the CLI output

Antigravity 2.0’s approach:

• Manager agent orchestrates from Google’s cloud
• Specialized agents (code writer, terminal runner, browser agent) work in parallel
• Execution happens in a secure cloud sandbox
• Agents can verify each other’s work through the sandbox environment

The key difference: Antigravity’s agents run in an isolated cloud environment where they can safely execute code, run tests, and even browse the web without touching your local machine. Grok Build runs everything locally, which is faster for simple tasks but riskier for destructive operations.

Antigravity’s sandbox means it can run npm test in isolation without affecting your local environment. Grok Build runs commands directly on your machine, so a bad rm -rf is a bad rm -rf.

Model and Speed

Antigravity 2.0 uses Gemini 3.5 Flash, a model specifically optimized for the platform. xAI claims 289 tokens per second output speed. It’s locked to Gemini models with no option to use other providers.

Grok Build defaults to Grok models but lets you route to any model through OpenRouter:

/model claude-sonnet-4
/model gpt-5
/model gemini-3.5-flash

This flexibility is Grok Build’s strongest differentiator. You can literally use Gemini through Grok Build if you want Google’s model quality with xAI’s tooling. Antigravity gives you no such choice.

In terms of raw speed, Antigravity’s optimized Gemini 3.5 Flash is faster for token generation. But Grok Build’s local execution means less network latency for file operations. The net result depends on your task: Antigravity is faster for compute-heavy tasks (running tests, building projects), Grok Build is faster for quick edits.

Context Window

Antigravity 2.0 wins here decisively: 1M+ tokens vs Grok Build’s 256K. For large codebases, this matters. Antigravity can hold more of your project in context simultaneously, which means fewer compaction cycles and better understanding of cross-file relationships.

Both tools offer context compaction when you hit limits, but starting with 4x more space means Antigravity needs it less often.

Platform Scope

This is where the philosophies diverge most.

Antigravity 2.0 is a full platform:

• Desktop App: VS Code fork with deep agent integration
• CLI: Terminal tool for developers who prefer their own editor
• SDK: Build custom agents on top of the platform
• Managed API: Use the Antigravity agent as a single API call

Grok Build is a CLI tool with extensibility:

• CLI: The entire product
• Skills Marketplace: Community plugins
• ACP: Protocol for third-party integration
• Hooks: Lifecycle event system

If you want an all-in-one solution that replaces your editor, Antigravity offers that. If you want a focused terminal tool that fits into your existing workflow, Grok Build is the better fit.

I prefer the CLI-only approach. I don’t want my coding agent to also be my editor. But teams that want a unified experience will find Antigravity more complete.

Extensions and Ecosystem

Antigravity 2.0 extends through its SDK. You write custom agents in Python or TypeScript that use the same primitives as the built-in agents (code execution, file management, web browsing). It’s powerful but requires writing code to extend.

Grok Build extends through Skills (installable plugins) and MCP servers:

grok skills search "kubernetes"
grok skills install @xai/k8s-deploy

Plus lifecycle hooks for custom automation:

{
  "post-edit": "npm run lint --fix",
  "pre-command": "echo 'Running: ${command}'"
}

Grok Build’s approach is more accessible. Installing a Skill is one command. Writing a custom Antigravity agent requires understanding the SDK. But Antigravity’s SDK is more powerful for complex custom workflows.

The Skills Marketplace is nearly empty right now (the tool is one week old). Antigravity’s SDK has more examples and documentation given Google’s resources.

Pricing

Tier	Grok Build	Antigravity 2.0
Entry	~$1/1M tokens (API)	$20/mo (Google AI Pro)
Standard	$99/mo (SuperGrok)	$100/mo (Google AI Ultra)
Heavy use	$99/mo (unlimited)	$200/mo (Google AI Ultra+)

The pricing models are fundamentally different:

Grok Build: Flat $99/month for unlimited use (SuperGrok), or pay-per-token via API. Simple.

Antigravity 2.0: Compute-based with 5-hour refresh cycles. You get a budget that refills every 5 hours. Higher tiers get larger budgets. You can buy top-up credits if you exhaust your budget before the refresh.

For light to moderate use, Antigravity’s $20/month entry tier is much cheaper. For heavy all-day use, Grok Build’s flat $99/month is more predictable than Antigravity’s compute-based model where you might hit limits.

If you’re already paying for SuperGrok ($99/month) for other xAI products, Grok Build is effectively free. Similarly, if you’re on Google AI Pro ($20/month) for other Google AI features, Antigravity access is included.

Sandbox and Security

Antigravity 2.0 runs code in a secure cloud-based Linux sandbox. This means:

• Commands can’t damage your local machine
• Network access is controlled
• File system is isolated
• You can run untrusted code safely

Grok Build has no sandbox. Commands run directly on your machine with your user permissions. This means:

• Faster execution (no network round-trip to cloud)
• Full access to your local tools and environment
• Risk of destructive commands if the agent makes a mistake

For production codebases, Antigravity’s sandbox is a significant safety advantage. For personal projects where speed matters more than isolation, Grok Build’s local execution is fine.

Use Plan Mode in Grok Build to review commands before they execute. It’s not a sandbox, but it prevents the worst mistakes.

Maturity and Stability

Antigravity 2.0: Stable release from Google with significant resources behind it. The original Antigravity has been in production for months, and 2.0 builds on that foundation. Documentation is comprehensive. The community is growing quickly.

Grok Build: Early beta, one week old. Core functionality works but expect bugs, missing features, and breaking changes. Documentation is minimal. Community is just forming.

This gap will close over time, but right now Antigravity is the more reliable choice for production work.

Migration Path

Coming from Claude Code?

• To Grok Build: Your CLAUDE.md works immediately. No changes needed. Install and go.
• To Antigravity 2.0: You’ll need to adapt to GEMINI.md format (or Antigravity reads CLAUDE.md with some compatibility). The desktop app has a different workflow than pure CLI.

Coming from Codex CLI?

• To Grok Build: Similar CLI experience. Modes map roughly (suggest → plan, auto-edit → code). No sandbox equivalent.
• To Antigravity 2.0: Bigger shift. The platform approach is different from a pure CLI tool.

Use Cases: When to Pick Each

Choose Grok Build if:

• You want a focused CLI tool, not a platform
• Model flexibility matters (use any model through one interface)
• You want a plugin ecosystem with easy installation
• You prefer local execution and speed over cloud sandboxing
• You’re already on SuperGrok
• You value CLAUDE.md compatibility for easy migration

Choose Antigravity 2.0 if:

• You want a complete platform (desktop + CLI + SDK)
• Security and sandboxing are priorities
• You need the largest context window (1M+ tokens)
• You want Google’s infrastructure and stability
• You prefer compute-based pricing with a low entry point ($20/month)
• You need video input or web browsing capabilities
• You want to build custom agents with the SDK

The Verdict

These tools serve different developer profiles.

Antigravity 2.0 is the better choice for teams and developers who want a complete, stable platform with strong security guarantees. The sandbox, the SDK, and the desktop app make it a full development environment. The $20/month entry point makes it accessible.

Grok Build is the better choice for terminal-native developers who want flexibility and simplicity. Model routing, the Skills marketplace, and CLAUDE.md compatibility make it the most adaptable CLI agent available. The flat $99/month pricing is predictable for heavy users.

If I had to pick one today, I’d pick Antigravity 2.0 for the stability and sandbox alone. But I’m keeping Grok Build installed because model routing is genuinely useful, and the Skills ecosystem has potential. In 3 months, once the beta stabilizes, this could be a much closer race.

FAQ

Can I use both Grok Build and Antigravity 2.0 on the same project?

Yes. They don’t conflict. Grok Build reads CLAUDE.md, Antigravity reads GEMINI.md (and has CLAUDE.md compatibility). You can use whichever tool fits the task.

Which is faster for everyday coding tasks?

For quick edits and local operations, Grok Build is faster (no cloud round-trip). For tasks that require running tests or building projects, Antigravity’s cloud sandbox can be faster because it runs on Google’s infrastructure rather than your local machine.

Do both support MCP servers?

Grok Build supports MCP servers natively. Antigravity 2.0 uses its own SDK-based extension system rather than MCP. If you have existing MCP servers, they work with Grok Build but not directly with Antigravity.

Which has better multi-agent performance?

Antigravity 2.0’s multi-agent system is more mature and better coordinated. It has specialized agent types (code writer, terminal runner, browser agent) that are purpose-built for their roles. Grok Build’s subagents are more general-purpose and occasionally produce coordination conflicts.

Is Antigravity 2.0 really free at $20/month?

The $20/month Google AI Pro tier includes Antigravity access with standard compute limits. It’s not unlimited, but it’s enough for moderate daily use. Heavy users will need the $100 or $200 tier, or pay for top-up credits.

Can Grok Build match Antigravity’s context window?

No. Grok Build is limited to 256K tokens. Antigravity offers 1M+. For very large codebases, this is a meaningful advantage for Antigravity. For typical projects, 256K is sufficient.

Which tool will be better in 6 months?

Impossible to say definitively, but Google has more resources and a head start with the original Antigravity. xAI is moving fast and the model routing flexibility gives Grok Build a unique advantage. Both will improve significantly. The real question is whether xAI can match Google’s execution speed on stability and ecosystem development.