Package Exports

opencode-antigravity-auth
opencode-antigravity-auth/dist/index.js
opencode-antigravity-auth/dist/src/constants
opencode-antigravity-auth/dist/src/constants.js
opencode-antigravity-auth/dist/src/plugin/request.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (opencode-antigravity-auth) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Antigravity + Gemini CLI OAuth Plugin for Opencode

Enable Opencode to authenticate against Antigravity (Google's IDE) via OAuth so you can use Antigravity rate limits and access models like gemini-3-pro and claude-opus-4-5-thinking with your Google credentials.

What you get

Google OAuth sign-in with automatic token refresh via opencode auth login
Dual Quota System - Access both Antigravity quota (Claude, Gemini 3) and Gemini CLI quota from a single plugin
Multi-Account Rotation - Add multiple Google accounts; automatically rotates when one is rate-limited
Real-time SSE streaming including thinking blocks and incremental output
Model Variants - Configure thinking budget dynamically via OpenCode's variant system
Extended Thinking - Native support for Claude thinking budgets and Gemini 3 thinking levels
Auto Recovery - Automatic session recovery from Claude tool_result_missing errors
Plugin Compatible - Works alongside other OpenCode plugins (opencodesync, etc.)

Installation

For Humans

Option A: Let an LLM do it

Paste this into any LLM agent (Claude Code, OpenCode, Cursor, etc.):

Install the opencode-antigravity-auth plugin and add the Antigravity model definitions to ~/.config/opencode/opencode.json by following: https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/dev/README.md

Option B: Manual setup

Add the plugin to your config (~/.config/opencode/opencode.json):
```
{
  "plugin": ["opencode-antigravity-auth@beta"]
}
```
Authenticate:
```
opencode auth login
```

Add models (see Available Models for full list):

{
  "plugin": ["opencode-antigravity-auth@beta"],
  "provider": {
    "google": {
      "models": {
         "antigravity-claude-sonnet-4-5-thinking": {
           "name": "Claude Sonnet 4.5 Thinking",
           "limit": { "context": 200000, "output": 64000 },
           "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
           "variants": {
             "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
             "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
           }
         }
      }
    }
  }
}

Use it:

opencode run "Hello" --model=google/antigravity-claude-sonnet-4-5-thinking --variant=max

Installation Guide for LLM Agents

Step-by-Step Instructions

Edit the OpenCode configuration file:
- Linux/Mac: ~/.config/opencode/opencode.json
- Windows: %APPDATA%\opencode\opencode.json
Add the plugin to the plugins array
Set provider to "google" and choose a model

Complete Configuration Example

Create ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-antigravity-auth@beta"],
  "provider": {
    "google": {
      "models": {
        "antigravity-gemini-3-pro": {
          "name": "Gemini 3 Pro (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingLevel": "low" },
            "high": { "thinkingLevel": "high" }
          }
        },
        "antigravity-gemini-3-flash": {
          "name": "Gemini 3 Flash (Antigravity)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "minimal": { "thinkingLevel": "minimal" },
            "low": { "thinkingLevel": "low" },
            "medium": { "thinkingLevel": "medium" },
            "high": { "thinkingLevel": "high" }
          }
        },
        "antigravity-claude-sonnet-4-5": {
          "name": "Claude Sonnet 4.5 (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking": {
          "name": "Claude Sonnet 4.5 Thinking (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
            "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
          }
        },
        "antigravity-claude-opus-4-5-thinking": {
          "name": "Claude Opus 4.5 Thinking (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
            "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
          }
        },
        "gemini-2.5-flash": {
          "name": "Gemini 2.5 Flash (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-2.5-pro": {
          "name": "Gemini 2.5 Pro (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-3-flash-preview": {
          "name": "Gemini 3 Flash Preview (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-3-pro-preview": {
          "name": "Gemini 3 Pro Preview (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        }
      }
    }
  }
}

Verification

opencode run "Hello" --model=google/antigravity-claude-sonnet-4-5-thinking --variant=max

Available Models

Antigravity Quota (with Variants)

Models with antigravity- prefix use Antigravity quota. Thinking models support variants for dynamic thinking budget configuration:

Model	Variants	Description
`google/antigravity-gemini-3-pro`	low, high	Gemini 3 Pro with configurable thinking
`google/antigravity-gemini-3-flash`	minimal, low, medium, high	Gemini 3 Flash with configurable thinking
`google/antigravity-claude-sonnet-4-5`	-	Claude Sonnet 4.5 (no thinking)
`google/antigravity-claude-sonnet-4-5-thinking`	low, max	Claude Sonnet with configurable thinking
`google/antigravity-claude-opus-4-5-thinking`	low, max	Claude Opus with configurable thinking

Variant configuration:

Gemini 3: Uses thinkingLevel string ("low", "medium", "high")
Claude: Uses thinkingBudget number (8192, 32768 tokens)

Usage:

opencode run "Hello" --model=google/antigravity-claude-sonnet-4-5-thinking --variant=max

Gemini CLI Quota

Models with -preview suffix use Gemini CLI quota:

Model	Description
`google/gemini-2.5-flash`	Gemini 2.5 Flash
`google/gemini-2.5-pro`	Gemini 2.5 Pro
`google/gemini-3-flash-preview`	Gemini 3 Flash (preview)
`google/gemini-3-pro-preview`	Gemini 3 Pro (preview)

Full models configuration (copy-paste ready)

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-antigravity-auth@beta"],
  "provider": {
    "google": {
      "models": {
        "antigravity-gemini-3-pro": {
          "name": "Gemini 3 Pro (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingLevel": "low" },
            "high": { "thinkingLevel": "high" }
          }
        },
        "antigravity-gemini-3-flash": {
          "name": "Gemini 3 Flash (Antigravity)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "minimal": { "thinkingLevel": "minimal" },
            "low": { "thinkingLevel": "low" },
            "medium": { "thinkingLevel": "medium" },
            "high": { "thinkingLevel": "high" }
          }
        },
        "antigravity-claude-sonnet-4-5": {
          "name": "Claude Sonnet 4.5 (no thinking) (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking": {
          "name": "Claude Sonnet 4.5 Thinking (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
            "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
          }
        },
        "antigravity-claude-opus-4-5-thinking": {
          "name": "Claude Opus 4.5 Thinking (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
          "variants": {
            "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
            "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
          }
        },
        "gemini-2.5-flash": {
          "name": "Gemini 2.5 Flash (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-2.5-pro": {
          "name": "Gemini 2.5 Pro (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-3-flash-preview": {
          "name": "Gemini 3 Flash Preview (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "gemini-3-pro-preview": {
          "name": "Gemini 3 Pro Preview (Gemini CLI)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        }
      }
    }
  }
}

Model Variants

OpenCode's variant system allows you to configure thinking budget dynamically instead of defining separate models for each thinking level.

How Variants Work

When you define a model with variants, OpenCode will show variant options in the model picker. Selecting a variant passes the providerOptions to the plugin, which extracts the thinking configuration.

Variant Configuration

{
  "antigravity-claude-sonnet-4-5-thinking": {
    "name": "Claude Sonnet 4.5 Thinking",
    "limit": { "context": 200000, "output": 64000 },
    "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
    "variants": {
      "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
      "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
    }
  }
}

Supported Variant Formats

The plugin accepts different variant formats depending on the model family:

Model Family	Variant Format
Gemini 3	`{ "thinkingLevel": "low" \| "medium" \| "high" }`
Claude	`{ "thinkingConfig": { "thinkingBudget": N } }`
Gemini 2.5	`{ "thinkingConfig": { "thinkingBudget": N } }`

Gemini 3 Thinking Levels

Gemini 3 models use string-based thinking levels. Available levels differ by model:

Level	Flash	Pro	Description
`minimal`	Yes	No	Minimal thinking, lowest latency
`low`	Yes	Yes	Light thinking
`medium`	Yes	No	Balanced thinking
`high`	Yes	Yes	Maximum thinking (default for both Pro and Flash)

Note: The API will reject invalid levels (e.g., "minimal" on Pro). Configure variants accordingly.

Legacy Budget Format (Deprecated)

For Gemini 3 models, the old thinkingBudget format is still supported but deprecated:

Budget Range	Maps to Level
≤ 8192	low
≤ 16384	medium
> 16384	high

Backward Compatibility

Legacy tier-suffixed models still work:

antigravity-claude-sonnet-4-5-thinking-low
antigravity-claude-sonnet-4-5-thinking-medium
antigravity-claude-sonnet-4-5-thinking-high
antigravity-gemini-3-pro-low
antigravity-gemini-3-pro-high

However, we recommend using variants for a cleaner model picker and more flexibility.

Multi-Account Setup

Add multiple Google accounts for higher combined quotas. The plugin automatically rotates between accounts when one is rate-limited.

opencode auth login

How multi-account works

Load Balancing Behavior

Sticky account selection - Sticks to the same account until rate-limited (preserves Anthropic's prompt cache)
Per-model-family limits - Rate limits tracked separately for Claude and Gemini models
Dual quota pools for Gemini - Automatic fallback between Antigravity quota and Gemini CLI quota before switching accounts
Smart retry threshold - Short rate limits (≤5s) are retried on same account
Exponential backoff - Increasing delays for consecutive rate limits

Dual Quota Pools (Gemini only)

For Gemini models, the plugin accesses two independent quota pools per account:

Quota Pool	When Used
Antigravity	Primary (tried first)
Gemini CLI	Fallback when Antigravity is rate-limited

This effectively doubles your Gemini quota per account.

Adding Accounts

When running opencode auth login with existing accounts:

2 account(s) saved:
  1. user1@gmail.com
  2. user2@gmail.com

(a)dd new account(s) or (f)resh start? [a/f]:

Account Storage

Stored in ~/.config/opencode/antigravity-accounts.json
Contains OAuth refresh tokens - treat like a password
If Google revokes a token (invalid_grant), that account is automatically removed

Configuration

Create ~/.config/opencode/antigravity.json (or .opencode/antigravity.json in project root):

General Settings

Option	Default	Description
`quiet_mode`	`false`	Suppress toast notifications (except recovery)
`debug`	`false`	Enable debug logging to file
`log_dir`	OS default	Custom directory for debug logs
`auto_update`	`true`	Enable automatic plugin updates

Session Recovery

Option	Default	Description
`session_recovery`	`true`	Auto-recover from tool_result_missing errors
`auto_resume`	`true`	Auto-send resume prompt after recovery
`resume_text`	`"continue"`	Text to send when auto-resuming

Error Recovery

Option	Default	Description
`empty_response_max_attempts`	`4`	Retries for empty API responses
`empty_response_retry_delay_ms`	`2000`	Delay between retries
`tool_id_recovery`	`true`	Fix mismatched tool IDs from context compaction
`claude_tool_hardening`	`true`	Prevent tool parameter hallucination

Token Management

Option	Default	Description
`proactive_token_refresh`	`true`	Refresh tokens before expiry
`proactive_refresh_buffer_seconds`	`1800`	Refresh 30min before expiry
`max_rate_limit_wait_seconds`	`300`	Max wait time when rate limited (0=unlimited)
`quota_fallback`	`false`	Try alternate quota when rate limited

Account Selection

Option	Default	Description
`account_selection_strategy`	`"sticky"`	Strategy for distributing requests across accounts
`pid_offset_enabled`	`false`	Use PID-based offset for multi-session distribution

Available strategies:

Strategy	Behavior	Best For
`sticky`	Same account until rate-limited	Prompt cache preservation
`round-robin`	Rotate to next account on every request	Maximum throughput
`hybrid`	Touch all fresh accounts first, then sticky	Sync reset timers + cache

Error handling:

Error Type	Behavior
`MODEL_CAPACITY_EXHAUSTED`	Wait (escalating 5s→60s) and retry same account
`QUOTA_EXCEEDED`	Switch to next available account immediately

This prevents unnecessary account switching when server-side capacity issues affect all accounts equally.

Environment Overrides

OPENCODE_ANTIGRAVITY_QUIET=1                              # quiet_mode
OPENCODE_ANTIGRAVITY_DEBUG=1                              # debug
OPENCODE_ANTIGRAVITY_LOG_DIR=/path                        # log_dir
OPENCODE_ANTIGRAVITY_KEEP_THINKING=1                      # keep_thinking
OPENCODE_ANTIGRAVITY_ACCOUNT_SELECTION_STRATEGY=round-robin  # account_selection_strategy
OPENCODE_ANTIGRAVITY_PID_OFFSET_ENABLED=1                 # pid_offset_enabled

Full configuration example

{
  "$schema": "https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/assets/antigravity.schema.json",
  "quiet_mode": false,
  "debug": false,
  "log_dir": "/custom/log/path",
  "auto_update": true,
  "keep_thinking": false,
  "session_recovery": true,
  "auto_resume": true,
  "resume_text": "continue",
  "empty_response_max_attempts": 4,
  "empty_response_retry_delay_ms": 2000,
  "tool_id_recovery": true,
  "claude_tool_hardening": true,
  "proactive_token_refresh": true,
  "proactive_refresh_buffer_seconds": 1800,
  "proactive_refresh_check_interval_seconds": 300,
  "max_rate_limit_wait_seconds": 300,
  "quota_fallback": false,
  "account_selection_strategy": "sticky",
  "pid_offset_enabled": false,
  "signature_cache": {
    "enabled": true,
    "memory_ttl_seconds": 3600,
    "disk_ttl_seconds": 172800,
    "write_interval_seconds": 60
  }
}

Troubleshoot

Multi account auth issues

If you encounter auth issue please try remove antigravity-account.json and auth again

Gemini model not found

Try add this line to in google field under provider "npm": "@ai-sdk/google"

Error during the session

If you encounter error during the session, try chat continue the recover session mechanism should be trigger and you can continue the session, if the error blocked the session please workaround by use command /undo to revert to the state before the error and try again it should work

Known Plugin Interactions

@tarquinen/opencode-dcp

DCP creates synthetic assistant messages that lack thinking blocks. Our plugin must be listed BEFORE DCP:

{
  "plugin": [
    "opencode-antigravity-auth@beta",
    "@tarquinen/opencode-dcp@latest",
  ]
}

oh-my-opencode

When using opencode-antigravity-auth, disable the built-in auth and override agent models in oh-my-opencode.json:

{
  "google_auth": false,
  "agents": {
    "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
    "document-writer": { "model": "google/gemini-3-flash" },
    "multimodal-looker": { "model": "google/gemini-3-flash" }
  }
}

When spawning parallel subagents, multiple processes may select the same account causing rate limit errors. Workaround: Enable pid_offset_enabled: true to distribute sessions across accounts, or add more accounts via opencode auth login.

Plugins You Don't Need

gemini-auth plugins - Not needed. This plugin handles all Google OAuth authentication.

Migration Guide (v1.2.8+ - Variants)

What Changed

v1.2.8+ introduces model variants for dynamic thinking configuration. Instead of separate models for each thinking level, you now define one model with variants.

Before (v1.2.7)

{
  "antigravity-claude-sonnet-4-5-thinking-low": { ... },
  "antigravity-claude-sonnet-4-5-thinking-medium": { ... },
  "antigravity-claude-sonnet-4-5-thinking-high": { ... }
}

After (v1.2.8+)

{
  "antigravity-claude-sonnet-4-5-thinking": {
    "name": "Claude Sonnet 4.5 Thinking",
    "limit": { "context": 200000, "output": 64000 },
    "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] },
    "variants": {
      "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
      "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
    }
  }
}

Benefits

Cleaner model picker - 4 models instead of 12+
Flexible budgets - Define any budget, not just low/max
Future-proof - Works with OpenCode's native variant system

Backward Compatibility

Old tier-suffixed models (antigravity-claude-sonnet-4-5-thinking-low, etc.) still work. No action required if you prefer the old style.

Migration Guide (v1.2.7 - Prefix)

If upgrading from v1.2.6 or earlier:

What Changed

v1.2.7+ uses explicit prefixes to distinguish quota sources:

Model Type	New Name (Recommended)	Old Name (Still Works)
Gemini 3 (Antigravity)	`antigravity-gemini-3-pro`	`gemini-3-pro-low`
Gemini 3 (CLI)	`gemini-3-pro-preview`	N/A
Claude	`antigravity-claude-sonnet-4-5`	`claude-sonnet-4-5`

Action Required

Update your config to use antigravity- prefix:

- "gemini-3-pro-low": { ... }
+ "antigravity-gemini-3-pro": { ... }

Why update? Old names work now as a fallback, but this depends on Gemini CLI using -preview suffix. If Google removes -preview in the future, old names may route to the wrong quota. The antigravity- prefix is explicit and stable.

Step 1: Clear Old Tokens (Optional - do this if you have issues calling models)

rm -rf ~/.config/opencode/antigravity-account.json
opencode auth login

Step 2: Update opencode.json

Models now use antigravity- prefix for Antigravity quota. See Available Models.

Step 3: Create antigravity.json (Optional)

{
  "$schema": "https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/assets/antigravity.schema.json",
  "quiet_mode": false,
  "debug": false
}

E2E Testing

The plugin includes regression tests for stability verification. Tests consume API quota.

# Sanity tests (7 tests, ~5 min)
npx tsx script/test-regression.ts --sanity

# Heavy tests (4 tests, ~30 min)
npx tsx script/test-regression.ts --heavy

# Concurrent tests (3 tests)
npx tsx script/test-regression.ts --category concurrency

# Run specific test
npx tsx script/test-regression.ts --test thinking-tool-use

# List tests without running
npx tsx script/test-regression.ts --dry-run

Debugging

OPENCODE_ANTIGRAVITY_DEBUG=1 opencode   # Basic logging
OPENCODE_ANTIGRAVITY_DEBUG=2 opencode   # Verbose (full request/response bodies)

Logs are written to ~/.config/opencode/antigravity-logs/.

Documentation

Architecture - Plugin internals and request flow
API Spec - Antigravity API reference

Safety, Usage & Legal

Intended Use

Personal / internal development only
Respect internal quotas and data handling policies
Not for production services or bypassing intended limits

Warning (Assumption of Risk)

By using this plugin, you acknowledge:

Terms of Service risk - This approach may violate ToS of AI model providers
Account risk - Providers may suspend or ban accounts
No guarantees - APIs may change without notice
Assumption of risk - You assume all legal, financial, and technical risks

Legal

Not affiliated with Google. This is an independent open-source project.
"Antigravity", "Gemini", "Google Cloud", and "Google" are trademarks of Google LLC.
Software is provided "as is", without warranty.

Credits

Built with help from:

opencode-gemini-auth - Gemini OAuth groundwork by @jenslys
CLIProxyAPI - Antigravity API reference

Support

If this plugin helps you, consider supporting its continued maintenance:

License

MIT