Head to head · Agent harnesses · October 2026 research run

Antigravity CLI vs T3 Code

Antigravity CLI scores 54.7 (C) on agent readiness against T3 Code's 51.9 (D), and leads in 4 of 7 scored categories. T3 Code leads on payments & pricing and maintenance & community. Both do agent harnesses.

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Which one, for what

Antigravity CLI C

Best for Developers on Google AI plans or Gemini Enterprise who want a terminal agent with a sandbox on by default and access to several model families, depending on plan.

Ahead on

  • Schema & documentation, 78 against 55
  • Agent ergonomics, 78 against 60
  • Security & auth, 53 against 35

Watch for

Closed source. The repository holds the README, changelog and examples, with no source and no licence file

T3 Code D

Best for Developers who want one app, including on their phone, to drive several coding agents they already pay for.

Ahead on

  • Payments & pricing, 60 against 30
  • Maintenance & community, 75 against 68

Also in its favour

  • No key needed to call it
  • Open source
  • No incidents deducted, where Antigravity CLI loses 3 points for them

Watch for

Usage data on by default, with hashed OpenAI and Claude account identifiers, and relay traces to Axiom

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Payments & pricing T3 Code +30

Antigravity CLI 30

Harness reading of the published rubric. No payment protocol in the docs, the pricing page or the plans page (0). Plan prices are public without a login, with a $0 individual plan and Gemini Enterprise Standard or Plus from $30 a seat a month, and Google AI Pro at $20 and Ultra at $100 or $200 a month per Google's 19 May 2026 post. Overages draw on AI credits at Gemini Enterprise consumption rates, which were not read, so this is plan-level pricing (10). The pricing page lists the $0 plan as needing no subscription, and none of the pages read asks for a payment method, but the account flow was not tested (20). Sign-in is a browser flow with a Google account, or a Gemini API key set by hand, and the CLI won't start unauthenticated (0). 0+10+20+0 = 30.

T3 Code 60

Free self-hosted software with nothing to buy, so 0 for a protocol and 20 each for public pricing, a free tier and onboarding with no sign-up, 60.

Schema & documentation Antigravity CLI +23

Antigravity CLI 78

Framework reading. No published JSON Schema for settings.json, mcp_config.json or hooks.json was found, although the docs type each key (10). llms.txt at antigravity.google/llms.txt, and every docs page has a Markdown copy (10). Pages say when to use each permission preset and execution mode, what each allows and when the sandbox applies (15). Presets, modes, output formats, status values and effort levels are enumerated (13). The headless page documents the output envelope, the status values and exit codes, with a jq example (15). A dated changelog on the docs site and versioned release notes and tags in the repository (15). 10+10+15+13+15+15 = 78.

T3 Code 55

Harness reading. User docs in the repository (managed policy, handoffs, providers, telemetry), AGENTS.md for contributors, a server other clients connect to (55).

Agent ergonomics Antigravity CLI +18

Antigravity CLI 78

Framework reading, adapted to a harness driven by a pipeline. MCP tools can be allowed or refused by server and tool, and a 20,000-token budget for user rules stops large rule sets from crowding out skills and MCP tools (16). No turn or spend cap appears in the flag reference, and --print-timeout sets a wall-clock limit only, with no limit by default (10). The JSON envelope carries a status field and token usage, and since 1.4.11 a finished_reason field says why a turn ended early (16). Exit codes are documented, but a tool soft-denied in headless mode still exits 0 (14). --continue and --conversation resume earlier runs (14). A Python SDK on PyPI, which is a separate package, and no second SDK language for the CLI (8). 16+10+16+14+14+8 = 78.

T3 Code 60

Harness reading. Remote control from phone or browser, portable handoffs between providers and managed policies for teams (60).

Security & auth Antigravity CLI +18

Antigravity CLI 53

Framework reading (credentials and telemetry defaults, approvals and sandboxing, guardrails, audit, security programme), five lines. Credentials are a Google account sign-in kept in the operating system keyring, or a Gemini API key in settings.json. The README says using the CLI allows Google to collect Interactions until the user opts out (10). Since 1.3.5 on macOS and Linux and 1.4.4 on Windows 11 24H2 the default for personal accounts is Auto mode, which runs commands in the terminal sandbox, hides ~/.ssh, .env and, since 1.4.6, ~/.docker and ~/.kube, blocks network access outside approved domains, and has a separate agent review commands that leave the sandbox. Auto approves file edits and safe commands without asking, Turbo turns the sandbox off, and business accounts start in Default (18). Hooks run before and after tool calls and can block one, and since 1.4.11 a PreInvocation hook can stop a turn. No documented defence against prompt injection in fetched content was found (7). The CLI log records model resolution, and approvals show in the conversation, but no exportable audit log was found (10). google.com has a valid security.txt with reports to g.co/vulnz (per the 10 October check), antigravity.google serves none, no CLI advisory appears in the changelog, and NVD returns no CVE for Antigravity on 4 November. The repository's advisory page couldn't be read (8). 10+18+7+10+8 = 53.

T3 Code 35

Harness reading. Product usage events go by default to ingest.t3.codes and PostHog, with hashed identifiers for your T3 Connect, OpenAI and Claude accounts, and relay traces to Axiom, which can include machine names and error text. Off with T3CODE_TELEMETRY_ENABLED=false or a managed policy. Disclosed in docs/user/telemetry.md, not the README (10 of 30). Permission modes and managed policies (12 of 20). No prompt-injection guidance (5). No audit log (5). No security policy file found (3). 10 + 12 + 5 + 5 + 3 = 35.

Maintenance & community T3 Code +7

Antigravity CLI 68

1.4.12 on 30 October 2026, marked Latest in the docs changelog, 5 days before this check (30). 56 tagged releases from 1.1.11 (6 August) to 1.4.12, each with a changelog entry; 1.5.0 is tagged and in the repository changelog on 4 November but not yet in the docs changelog, so it isn't counted (20). Responsiveness rests on a public changelog, a community forum linked from the terms and the GitHub repository, but no replies could be read (8). The google-antigravity Python SDK is a separate package and no SDK for the CLI itself was found; PyPI couldn't be read on 4 November, so the line rests on the 10 October reading (10). No public CI or dependency list for the CLI, since the source is not published (0). 30+20+8+10+0 = 68.

T3 Code 75

Commits and nightly tags on 6 November 2026 (30). More than three releases in 90 days (20). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Current official apps and install script (15). CI on push (10). 30 + 20 + 0 + 15 + 10 = 75.

Score by category

CategoryWeight this runAntigravity CLIT3 CodeEdge
Reliability16%204343even
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27855Antigravity CLI +23
Agent ergonomics13%16.27860Antigravity CLI +18
Security & auth14%17.55335Antigravity CLI +18
Payments & pricing10%12.53060T3 Code +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86875T3 Code +7
Transparency & trust7%8.85551Antigravity CLI +4
Negative events≤15-30
TotalC 54.7/100D 51.9/100

Facts side by side

FactAntigravity CLIT3 Code
KindAgent harnessAgent harness
VendorGoogleT3 Tools Inc.
Hosted endpointno (local only)no (local only)
Transports
AuthOAuth or keyNone
PricingFreemiumFree
x402nono
LicenceProprietary. The repository holds the README, changelog and examples, with no source and no licence file. Use is under the Google Antigravity Additional Terms of Service, the Google Terms of Service and the Privacy PolicyMIT
Read-only variant documentednono
llms.txtyesno
Last release2026-10-302026-11-06
Terms last updatedno date givenno document linked
Privacy policy last updated2026-10-01no document linked
Customer content may train modelsyes, with an opt-outnot read yet
Terms restrict automated accessnot found in the textnot read yet
Terms restrict benchmarkingnot found in the textnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waivernot found in the textnot read yet

How the scores have moved

Verdicts

Antigravity CLI

Google's terminal agent, a closed-source binary whose default Auto mode runs commands in a terminal sandbox on macOS, Linux and Windows 11, with documented headless JSON output. Interactions are collected for Google product improvement unless users opt out, a headless run exits 0 when a tool is denied, and 1.4.7 fixed a cross-user token flaw without an advisory.

T3 Code

A fast-moving open-source way to run and steer several coding agents from desktop, browser or phone, using the subscriptions you already have. It's pre-1.0, and it sends usage data by default, including hashed identifiers for your OpenAI and Claude accounts, with the opt-out documented outside the README.

Before you call either

Antigravity CLI

  1. Read the status and finished_reason fields from --output-format json and read stderr too. A tool refused for lack of approval still exits 0
  2. Pre-approve each shell command and tool a headless run needs with action(target) rules under permissions.allow in ~/.gemini/antigravity-cli/settings.json, because headless runs cannot ask
  3. Export GEMINI_API_KEY after setting modelProvider to gemini. The CLI won't start when the key is missing, and setting the variable alone has no effect
  4. Turn off Enable Telemetry in /config before running on private repositories if Interactions should not be used for product improvement
  5. Grant sandbox access to ~/.docker or ~/.kube explicitly since 1.4.6 if a task needs Docker or Kubernetes credentials

T3 Code

  1. Set T3CODE_TELEMETRY_ENABLED=false before starting the server if you don't want usage events sent
  2. Install and log in to at least one provider CLI first, such as codex login or claude auth login
  3. Use a managed policy to fix settings across a team

Questions

Which is better for AI agents, Antigravity CLI or T3 Code?

Antigravity CLI scores 54.7 (C) on agent readiness against T3 Code's 51.9 (D), and leads in 4 of 7 scored categories. T3 Code leads on payments & pricing and maintenance & community.

Are Antigravity CLI and T3 Code open source?

No open-source release is listed for Antigravity CLI. T3 Code is open source (MIT).

Other comparisons with Antigravity CLI or T3 Code

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