Fact check · 17 October 2026
Google Antigravity wrote a report on its own first year. Claude Code checked every claim in it. Antigravity then reviewed those corrections and accepted every one it looked at. This is the full record, including the two places where its review got things wrong.
Research and fact check by Silent Key Technologies. Published by Club Cedro in The i.
Google Antigravity was asked to write a report on how it has changed over the past year and how it compares with Cursor, Claude Code, Devin, Windsurf and GitHub Copilot. The draft read well. It also had no dates in it, described three competitors as they were a year earlier, and named nine features and commands for Antigravity itself that we could not find in Google's own documentation.
We ran the draft through Claude Code with one instruction: check every factual claim, and leave the opinions alone. Claude Code opened Google's docs, the Antigravity changelog, the Gemini release notes, DeepMind's repositories and the coverage of each competitor. Every claim was marked corrected, confirmed or removed, and each one carries the source it was checked against.
We then gave the corrections back to Antigravity. It returned a written review titled "Fact-Check Corrections and Accuracy Verification", went through the corrections item by item, and gave an overall verdict of "100% Verified and Accurate".
We checked that review too, because a verdict is only worth something if it holds up.
Antigravity grouped our eleven corrections into seven areas. It marked all seven accurate. Five of them match our findings exactly. Two of them add detail that our sources do not support.
1. Launch date and origin
Antigravity confirmed the 18 November 2025 launch alongside Gemini 3, and that it was built largely by the Windsurf team Google brought in through a licensing deal of about $2.4 billion. Its review describes this as Windsurf "architectural provenance". Our sources support the team coming from Windsurf. None of them describe the architecture.
2. From one IDE to four surfaces
Antigravity confirmed the 19 May 2026 I/O launch of the 2.0 desktop app, the agy CLI as a Go binary replacing Gemini CLI, the Python SDK, and the extensions for VS Code, Visual Studio, JetBrains, Zed and Xcode. It added two things we did not say. It calls the desktop app an Electron app, and it dates the five editor extensions to the I/O launch. Google's I/O feature deep dive mentions neither, and we found no other source for either.
3. Gemini model versions
Antigravity confirmed Gemini 3 at launch, 3.5 Flash as the 2.0 default, 3.8 Flash in September 2026, and Gemini 4 Argon generally available on 13 October 2026.
4. Windsurf is now Devin Desktop
Antigravity confirmed the rename on 2 June 2026 and the end of Cascade on 1 July 2026 in favour of Devin Local, and called comparing against Windsurf "factually obsolete".
5. Claude Code is not terminal only
Antigravity accepted that its draft had pinned Claude Code to the terminal, and that Claude Code now runs on desktop with a built-in browser pane and page publishing, on the web and in IDEs.
6. Copilot Workspace no longer exists
Antigravity confirmed the preview ended on 30 May 2025 and that the GitHub Copilot coding agent replaced it.
7. Science Skills
Antigravity confirmed the 19 May 2026 launch and the 30 plus databases. But its restatement lists Foldseek and PubChem as supported, and our check had removed both. We checked again. Google's announcement names UniProt, AlphaFold Database, AlphaGenome API and InterPro. DeepMind's science-skills repository names AlphaGenome, AFDB, UniProt, OpenAlex and ClinVar. Neither page names Foldseek or PubChem.
The nine removals. Our check removed nine claims from Antigravity's draft because no source could be found for them, most of them claims about Antigravity's own features. The review did not defend any of them. They are listed in section 06.
Two corrections. The review did not cover our corrections on subagent function names or on worktree modes. Its seven areas cover the other nine of our eleven corrections.
The eight confirmations. These were things the draft got right, so there was nothing to dispute.
There was no timeline at all.
"A year back... early precursors to Antigravity", with no dates.
Antigravity launched on 18 November 2025, the same day as Gemini 3. Antigravity 2.0, the agy CLI and the SDK came out at Google I/O on 19 May 2026.
The Windsurf connection was not mentioned.
Windsurf listed only as a rival.
Antigravity was built largely by the Windsurf founders and R&D staff Google brought in through a non-exclusive licensing deal of about $2.4 billion in July 2025. Cognition bought the rest of Windsurf.
Gemini model versions were off.
"Gemini 3.8 / Pro / Flash Engine" and "Gemini 1.5, 2.0, and 3.8".
Gemini 3.8 Flash went generally available on 2 September 2026 and 3.8 Live followed on 24 September. The newest model is Gemini 4 Argon, generally available since 13 October 2026. Gemini 3.5 Flash was the default when Antigravity 2.0 launched. One source says Gemini 3.5 Pro had not shipped as of early October, so "Pro" was dropped.
The IDE is not only a VS Code fork anymore.
"Antigravity IDE (VS Code)" as the single editor surface.
There is still a standalone Antigravity IDE, and Antigravity now also ships extensions for VS Code, Visual Studio, JetBrains, Zed and Xcode.
What agy actually is.
"A lightweight, terminal-native daemon".
It is a single Go binary and the successor to Gemini CLI, running the same agent harness as the desktop app. Gemini CLI stopped serving free and Pro requests on 18 June 2026.
How subagents work in the SDK.
Agents "declare (define_subagent) or invoke (invoke_subagent)" workers.
The SDK has dynamic subagents, turned on with enable_subagents=True, and static ones defined with SubagentConfig. Each gets its own context window, and restrictions on the parent carry down. The function names in the draft do not appear in the docs.
Worktree modes.
Git worktrees with "branch and share modes".
Projects start in "Local mode" or "New worktree mode", and a subagent can use its own worktree in branch mode. No source describes a "share" mode.
Science integrations.
"AlphaFold, AlphaGenome, Foldseek, PubChem" plus a Mol* 3D viewer.
DeepMind released Science Skills on 19 May 2026, open source and built into Antigravity, connecting to more than 30 sources including the AlphaFold Database, the AlphaGenome API, UniProt and InterPro. Foldseek, PubChem and Mol* appear in neither Google's announcement nor the repository.
Windsurf is now Devin Desktop.
"Windsurf (Codeium)" and its Cascade timeline, described as current.
Cognition renamed Windsurf to Devin Desktop on 2 June 2026. Cascade reached end of life on 1 July 2026 and was replaced by Devin Local.
GitHub Copilot Workspace no longer exists.
A full comparison row for "GitHub Copilot Workspace".
The technical preview ended on 30 May 2025. Its ideas carried into the Copilot coding agent.
Claude Code is not terminal only, and the model name was old.
Claude Code "fundamentally cannot render images, charts, or interactive components", and "Claude 3.7 Sonnet".
Claude Code runs in a desktop app, on the web and in IDEs. The desktop app has a built-in browser pane and publishes rich pages, which this check confirmed first hand because it was run there. Claude 3.7 Sonnet is several generations old.
Checked directly in the Claude desktop app, 17 October 2026
The 2.0 desktop app runs several agents in parallel and schedules work in the background, on macOS, Linux and Windows. I/O deep dive
The SDK installs with pip install google-antigravity. SDK overview
/schedule runs an instruction once after a delay or on a cron schedule. Antigravity docs
Sidecar links show as pills and open in the auxiliary pane. Changelog
There is a terminal sandbox and a permissions system. Antigravity docs
The built-in browser has an allowlist and a denylist. Antigravity docs
MCP servers, skills, rules and lifecycle hooks are all supported. Antigravity docs
At launch it had an Editor view and a Manager view, and agents could drive the editor, terminal and a built-in browser. The New Stack
Each of these was searched in the official docs, the changelog and general coverage, and none turned up. Antigravity's review did not dispute any of them.
A Mol* 3D molecular viewer and sidecar:// links.
PubChem as an integration.
define_subagent and invoke_subagent commands.
A "share" worktree mode.
Lazy and eager MCP tool loading.
An .agents/ project folder.
"Supercomplete", tab to jump, tab to import and Ctrl+I. These are Windsurf feature names. The Antigravity docs list "Tab completion".
KaTeX math, mermaid diagrams and UI carousels in artifacts.
Supermaven as a separate rival, and an unsourced "sub 50ms" figure for autocomplete.
An agent writing about itself is the hardest case for accuracy. It knows the product's direction but not always its current state, and it fills gaps with things that sound right. Most of what Antigravity got wrong was about its own features. Its review then accepted every correction it looked at, which is the right outcome and a good sign for how these tools can check each other.
The review also shows why the second check matters. In confirming our science correction, it put back two databases we had removed, and it added two product details with no source behind them. A verdict of 100 percent should be checked like any other claim, and in this case it was 100 percent on direction and slightly off on detail.
The method is simple and it carries over to any report. Check every factual claim against a page you actually opened. Mark each one corrected, confirmed or removed. Leave opinion as opinion. Then check the response the same way.