mirror of https://github.com/NoeFabris/opencode-antigravity-auth.git synced 2026-05-13 23:53:18 +00:00

Files

tctinh 16f4bb07a1 feat: add E2E testing scripts and simplify Gemini Flash model config

- Add test-models.ts for validating all supported model endpoints
- Add test-regression.ts for multi-turn regression testing (Issue #50)
- Consolidate Gemini 3 Flash variants (low/medium/high) into single model
- Fix schema structure by flattening nested signature_cache properties
- Extract streaming transformer utilities to dedicated module

2025-12-28 00:04:57 +07:00

35 KiB

Raw Blame History

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-high and claude-opus-4-5-thinking with your Google credentials.

What you get

Google OAuth sign-in (multi-account via opencode auth login) with automatic token refresh
Multi-account load balancing Automatically cycle through multiple Google accounts to maximize throughput
Two quota sources for Gemini Choose between Antigravity quota (antigravity- prefix) or Gemini CLI quota (no prefix) per request
Real-time SSE streaming including thinking blocks and incremental output
Advanced Claude support Interleaved thinking, stable multi-turn signatures, and validated tool calling
Automatic endpoint fallback between Antigravity API endpoints (daily → autopush → prod)
Antigravity API compatibility for OpenAI-style requests
Debug logging for requests and responses
Drop-in setup Opencode auto-installs the plugin from config

Installation

For Humans

Option A: Let an LLM do it for you

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

Install the opencode-antigravity-auth plugin and add the Antigravity model definitions (see "Available models") to ~/.config/opencode/opencode.json by following: https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/README.md

If the agent only installs the plugin, ask it to also add models under provider.google.models.

Option B: Do it yourself

Add the plugin to your config:

mkdir -p ~/.config/opencode

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

{
  "plugin": ["opencode-antigravity-auth@1.2.7"]
}

Authenticate:
```
opencode auth login
```
Select Google → OAuth with Google (Antigravity) → Press Enter to skip Project ID → Sign in via browser.

Add models to your config:

Add the models you want to use to the same config file:

{
  "plugin": ["opencode-antigravity-auth@1.2.7"],
  "provider": {
    "google": {
      "models": {
        "antigravity-gemini-3-pro-high": {
          "name": "Gemini 3 Pro High (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5": {
          "name": "Claude Sonnet 4.5 (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        }
      }
    }
  }
}

See Available models for the full list.

Use it:

opencode run "Hello" --model=google/antigravity-gemini-3-pro-high

For LLMs

🤖 Detailed Installation Guide for LLM Agents (click to expand)

If you're an LLM agent helping a user set up this plugin, follow these steps:

Step 1: Verify OpenCode is installed

command -v opencode && opencode --version || echo "OpenCode not installed - see https://opencode.ai/docs"

Step 2: Create or update the config

mkdir -p ~/.config/opencode

if [ -f ~/.config/opencode/opencode.json ]; then
    if command -v jq &> /dev/null; then
        jq '.plugin = ((.plugin // []) + ["opencode-antigravity-auth@1.2.7"] | unique)' \
            ~/.config/opencode/opencode.json > /tmp/oc.json && \
            mv /tmp/oc.json ~/.config/opencode/opencode.json
    else
        echo "Add \"opencode-antigravity-auth@1.2.7\" to the plugin array manually"
    fi
else
    echo '{"plugin":["opencode-antigravity-auth@1.2.7"]}' > ~/.config/opencode/opencode.json
fi

Step 3: Ask user about multi-account setup

Before running opencode auth login, ask the user:

Do you want to add multiple Google accounts for load balancing?

Adding 2-10 accounts maximizes rate limits and provides automatic failover

You can always add more accounts later

Based on their answer:

Yes, multiple accounts → After first login, prompt: "Sign in complete. Add another account? (up to 10 supported)"
No, just one → Single account is fine, they can add more later with opencode auth login

Step 4: Run authentication

Tell the user to run:

opencode auth login

Guide them through the prompts:

Select Google as the provider
Select OAuth with Google (Antigravity)
Project ID prompt → Tell user: "Press Enter to skip (most users don't need this)"
Browser opens for Google sign-in
If multi-account: repeat for additional accounts, or press Enter to finish

Step 5: Add models to config

Merge model definitions into the user's config file (~/.config/opencode/opencode.json):

# If jq is available, merge models programmatically
if command -v jq &> /dev/null; then
    jq '.provider.google.models = {
      "antigravity-gemini-3-pro-low": {"name": "Gemini 3 Pro Low (Antigravity)", "limit": {"context": 1048576, "output": 65535}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-gemini-3-pro-medium": {"name": "Gemini 3 Pro Medium (Antigravity)", "limit": {"context": 1048576, "output": 65535}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-gemini-3-pro-high": {"name": "Gemini 3 Pro High (Antigravity)", "limit": {"context": 1048576, "output": 65535}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-gemini-3-flash": {"name": "Gemini 3 Flash (Antigravity)", "limit": {"context": 1048576, "output": 65536}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "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-low": {"name": "Claude Sonnet 4.5 Thinking Low (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-claude-sonnet-4-5-thinking-medium": {"name": "Claude Sonnet 4.5 Thinking Medium (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-claude-sonnet-4-5-thinking-high": {"name": "Claude Sonnet 4.5 Thinking High (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-claude-opus-4-5-thinking-low": {"name": "Claude Opus 4.5 Thinking Low (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-claude-opus-4-5-thinking-medium": {"name": "Claude Opus 4.5 Thinking Medium (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-claude-opus-4-5-thinking-high": {"name": "Claude Opus 4.5 Thinking High (Antigravity)", "limit": {"context": 200000, "output": 64000}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}},
      "antigravity-gpt-oss-120b-medium": {"name": "GPT-OSS 120B Medium (Antigravity)", "limit": {"context": 131072, "output": 32768}, "modalities": {"input": ["text", "image", "pdf"], "output": ["text"]}}
    } + (.provider.google.models // {})' ~/.config/opencode/opencode.json > /tmp/oc.json && mv /tmp/oc.json ~/.config/opencode/opencode.json
fi

Or edit the file manually and add the models from the Available models section.

Step 6: Verify setup

opencode run "Hello" --model=google/antigravity-gemini-3-pro-high

If successful, tell the user: "Setup complete! You can now use Antigravity models in OpenCode."

Migration Guide

Upgrading to v1.2.7

Version 1.2.7 standardizes model naming with the antigravity- prefix for all models using Antigravity quota.

What Changed

All Antigravity-routed models now use the antigravity- prefix consistently. This ensures clear distinction between:

Antigravity models (antigravity-gemini-3-pro-high) → Routed through this plugin, uses Antigravity quota
Gemini CLI models (gemini-2.5-flash) → Handled by OpenCode's built-in Gemini support, uses Gemini CLI quota

Upgrade Steps

Update the plugin version in ~/.config/opencode/opencode.json:
```
{
  "plugin": ["opencode-antigravity-auth@1.2.7"]
}
```

Add antigravity- prefix to your model IDs:

Old Model ID	New Model ID
`gemini-3-pro-high`	`antigravity-gemini-3-pro-high`
`gemini-3-flash`	`antigravity-gemini-3-flash`
`claude-sonnet-4-5`	`antigravity-claude-sonnet-4-5`
`claude-opus-4-5-thinking-high`	`antigravity-claude-opus-4-5-thinking-high`

Replace your model configuration in ~/.config/opencode/opencode.json:

Copy the full configuration from the Full model configuration section, or use this complete config:

{
  "plugin": ["opencode-antigravity-auth@1.2.7"],
  "provider": {
    "google": {
      "models": {
        "antigravity-gemini-3-pro-low": {
          "name": "Gemini 3 Pro Low (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-gemini-3-pro-high": {
          "name": "Gemini 3 Pro High (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
         "antigravity-gemini-3-flash": {
           "name": "Gemini 3 Flash (Antigravity)",
           "limit": { "context": 1048576, "output": 65536 },
           "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
         },
        "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-low": {
          "name": "Claude Sonnet 4.5 Thinking Low (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking-medium": {
          "name": "Claude Sonnet 4.5 Thinking Medium (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking-high": {
          "name": "Claude Sonnet 4.5 Thinking High (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-low": {
          "name": "Claude Opus 4.5 Thinking Low (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-medium": {
          "name": "Claude Opus 4.5 Thinking Medium (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-high": {
          "name": "Claude Opus 4.5 Thinking High (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-gpt-oss-120b-medium": {
          "name": "GPT-OSS 120B Medium (Antigravity)",
          "limit": { "context": 131072, "output": 32768 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        }
      }
    }
  }
}

Restart OpenCode to load the new version.

Available models

Add these models to your ~/.config/opencode/opencode.json under provider.google.models:

Two Gemini sources: This plugin provides Antigravity-routed Gemini models (antigravity- prefix). OpenCode also has built-in Gemini CLI support (no prefix, e.g., gemini-2.5-flash). See How Quota Routing Works for details.

Gemini Models (Antigravity)

Model ID	Description	Thinking	Quota
`antigravity-gemini-3-pro-low`	Gemini 3 Pro (low thinking)	thinkingLevel: "low"	Antigravity
`antigravity-gemini-3-pro-high`	Gemini 3 Pro (high thinking)	thinkingLevel: "high"	Antigravity
`antigravity-gemini-3-flash`	Gemini 3 Flash	Default	Antigravity

Claude Models

Model ID	Description	Thinking Budget
`antigravity-claude-sonnet-4-5`	Claude Sonnet 4.5 (no thinking)	None
`antigravity-claude-sonnet-4-5-thinking-low`	Claude Sonnet 4.5 Thinking	8,192 tokens
`antigravity-claude-sonnet-4-5-thinking-medium`	Claude Sonnet 4.5 Thinking	16,384 tokens
`antigravity-claude-sonnet-4-5-thinking-high`	Claude Sonnet 4.5 Thinking	32,768 tokens
`antigravity-claude-opus-4-5-thinking-low`	Claude Opus 4.5 Thinking	8,192 tokens
`antigravity-claude-opus-4-5-thinking-medium`	Claude Opus 4.5 Thinking	16,384 tokens
`antigravity-claude-opus-4-5-thinking-high`	Claude Opus 4.5 Thinking	32,768 tokens

Note: Claude and GPT models are only available through Antigravity API. The antigravity- prefix is required for these models.

Other Models

Model ID	Description
`antigravity-gpt-oss-120b-medium`	GPT-OSS 120B Medium

Tier suffixes: Use -low, -medium, or -high to control thinking budget. Higher tiers = more reasoning tokens.

Full model configuration (click to expand)

{
  "provider": {
    "google": {
      "models": {
        "antigravity-gemini-3-pro-low": {
          "name": "Gemini 3 Pro Low (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-gemini-3-pro-high": {
          "name": "Gemini 3 Pro High (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-gemini-3-flash": {
          "name": "Gemini 3 Flash (Antigravity)",
          "limit": { "context": 1048576, "output": 65536 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "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-low": {
          "name": "Claude Sonnet 4.5 Thinking Low (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking-medium": {
          "name": "Claude Sonnet 4.5 Thinking Medium (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-sonnet-4-5-thinking-high": {
          "name": "Claude Sonnet 4.5 Thinking High (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-low": {
          "name": "Claude Opus 4.5 Thinking Low (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-medium": {
          "name": "Claude Opus 4.5 Thinking Medium (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-claude-opus-4-5-thinking-high": {
          "name": "Claude Opus 4.5 Thinking High (Antigravity)",
          "limit": { "context": 200000, "output": 64000 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        },
        "antigravity-gpt-oss-120b-medium": {
          "name": "GPT-OSS 120B Medium (Antigravity)",
          "limit": { "context": 131072, "output": 32768 },
          "modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
        }
      }
    }
  }
}

How Quota Routing Works

This plugin gives you access to two separate quota pools for Gemini models, allowing you to maximize your usage by switching between them.

Two Gemini Model Sources

Source	Model ID Example	Handled By	Quota Pool
Antigravity	`google/antigravity-gemini-3-pro-high`	This plugin	Antigravity quota
Gemini CLI	`google/gemini-2.5-flash`	OpenCode built-in	Gemini CLI quota

Request Flow

┌─────────────────────────────────────────────────────────────────────┐
│                         Request Routing                             │
├─────────────────────────────────────────────────────────────────────┤
│                                                                     │
│  google/antigravity-gemini-3-pro-high                               │
│     └─→ This plugin intercepts (has "antigravity-" prefix)          │
│         └─→ Routes to Antigravity API                               │
│             └─→ Uses YOUR Antigravity quota                         │
│                                                                     │
│  google/gemini-2.5-flash (no prefix)                                │
│     └─→ This plugin ignores (no "antigravity-" prefix)              │
│         └─→ Falls through to OpenCode's built-in Gemini handler     │
│             └─→ Uses YOUR Gemini CLI quota                          │
│                                                                     │
│  google/antigravity-claude-sonnet-4-5                               │
│     └─→ This plugin intercepts (Claude only via Antigravity)        │
│         └─→ Routes to Antigravity API                               │
│             └─→ Uses YOUR Antigravity quota                         │
│                                                                     │
└─────────────────────────────────────────────────────────────────────┘

Routing Examples

Model ID	Routed Via	Quota Used
`google/antigravity-gemini-3-pro-high`	This plugin	Antigravity
`google/antigravity-gemini-3-flash`	This plugin	Antigravity
`google/gemini-2.5-flash`	OpenCode built-in	Gemini CLI
`google/gemini-2.5-pro`	OpenCode built-in	Gemini CLI
`google/antigravity-claude-sonnet-4-5`	This plugin	Antigravity
`google/antigravity-claude-opus-4-5-thinking-high`	This plugin	Antigravity

Why This Matters

Double your Gemini quota: Use both Antigravity and Gemini CLI pools by switching model prefixes
Automatic failover strategy: When Antigravity quota is exhausted, switch to non-prefixed Gemini models
Claude/GPT require Antigravity: These models are only available through Antigravity API, so they always need the antigravity- prefix

Tip: Configure both prefixed (antigravity-gemini-3-pro-high) and non-prefixed (gemini-2.5-flash) Gemini models in your config to maximize quota availability.

Multi-account load balancing

The plugin supports multiple Google accounts to maximize rate limits and provide automatic failover.

How it works

Sticky account selection: The plugin sticks to the same account for all requests until it hits a rate limit. This preserves Anthropic's prompt cache, which is organization-scoped.
Per-model-family rate limits: Rate limits are tracked separately for Claude and Gemini models. If an account is rate-limited for Claude, it can still be used for Gemini requests.
Dual quota pools for Gemini: Gemini models have access to two separate quota pools (Antigravity and Gemini CLI). When one pool is exhausted, the plugin automatically switches to the other before trying a different account.
Smart retry threshold: Short rate limits (≤5s) are retried on the same account to avoid unnecessary switching.
Exponential backoff: Consecutive rate limits trigger exponential backoff with increasing delays.
Quota-aware messages: Rate limit toasts show quota reset times when available from the API.
Automatic failover: On HTTP 429 (rate limit), the plugin automatically switches to the next available account for that model family.
Smart cooldown: Rate-limited accounts are temporarily cooled down and automatically become available again after the cooldown expires.
Single-account retry: If you only have one account, the plugin waits for the rate limit to reset and retries automatically.
Debounced notifications: Toast notifications are debounced to avoid spam during streaming responses.

Dual quota pools (Gemini only)

Gemini models can access two independent quota pools. See How Quota Routing Works for details.

Quota Pool	Model ID Example	Endpoint
Antigravity	`antigravity-gemini-3-pro-high`	`daily-cloudcode-pa.sandbox.googleapis.com`
Gemini CLI	`gemini-2.5-flash` (no prefix)	`cloudcode-pa.googleapis.com`

Tip: When Antigravity quota is exhausted for one account, the plugin tries the next account. You can also switch to non-prefixed Gemini models to use Gemini CLI quota instead.

Quiet mode

To suppress account-related toast notifications (useful for streaming/recording):

export OPENCODE_ANTIGRAVITY_QUIET=1

Adding accounts

CLI flow (opencode auth login):

When you run opencode auth login and already have accounts saved, you'll be prompted:

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

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

Press a to add more accounts to your existing pool
Press f to clear all existing accounts and start fresh

TUI flow (/connect):

The /connect command in the TUI adds accounts non-destructively — it will never clear your existing accounts. To start fresh via TUI, run opencode auth logout first, then /connect.

Account storage

Account pool is stored in ~/.config/opencode/antigravity-accounts.json (or %APPDATA%\opencode\antigravity-accounts.json on Windows)
This file contains OAuth refresh tokens; treat it like a password and don't share or commit it
The plugin automatically syncs with OpenCode's auth state — if you log out via OpenCode, stale account storage is cleared automatically

Automatic account recovery

If Google revokes a refresh token (invalid_grant), that account is automatically removed from the pool
Rerun opencode auth login to re-add the account

Configuration

Config file

Create ~/.config/opencode/antigravity.json (or .opencode/antigravity.json for project-specific settings):

{
  "$schema": "https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/assets/antigravity.schema.json",
  "quiet_mode": false,
  "debug": false,
  "log_dir": null,
  "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,
  "auto_update": true,
  "signature_cache": {
    "enabled": true,
    "memory_ttl_seconds": 3600,
    "disk_ttl_seconds": 172800,
    "write_interval_seconds": 60
  }
}

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

Thinking Blocks (Claude)

Option	Default	Description
`keep_thinking`	`false`	Preserve thinking blocks (may cause signature errors)
`signature_cache.enabled`	`true`	Cache signatures to disk
`signature_cache.memory_ttl_seconds`	`3600`	In-memory cache TTL
`signature_cache.disk_ttl_seconds`	`172800`	Disk cache TTL (48h)

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
`proactive_refresh_check_interval_seconds`	`300`	Check interval (5min)

Environment variables

Environment variables override config file values.

Variable	Values	Description
`OPENCODE_ANTIGRAVITY_QUIET`	`1`	Suppress toast notifications
`OPENCODE_ANTIGRAVITY_DEBUG`	`1`, `2`	Debug logging level (2 = verbose)
`OPENCODE_ANTIGRAVITY_LOG_DIR`	path	Custom log directory
`OPENCODE_ANTIGRAVITY_KEEP_THINKING`	`1`	Preserve thinking blocks
`OPENCODE_ANTIGRAVITY_SESSION_RECOVERY`	`0`/`1`	Enable/disable session recovery
`OPENCODE_ANTIGRAVITY_AUTO_RESUME`	`0`/`1`	Enable/disable auto-resume
`OPENCODE_ANTIGRAVITY_RESUME_TEXT`	string	Custom resume text
`OPENCODE_ANTIGRAVITY_AUTO_UPDATE`	`0`/`1`	Enable/disable auto-updates

Known plugin interactions

opencode-gemini-auth (Gemini CLI OAuth)

Compatibility: This plugin (opencode-antigravity-auth) fully covers the Gemini CLI OAuth functionality provided by opencode-gemini-auth.

If you install this plugin, you do not need to install opencode-gemini-auth separately. Our plugin provides:

All Gemini CLI OAuth features (authentication, token refresh)
Additional Antigravity API access (Claude, GPT models)
Dual quota pool support (both Antigravity and Gemini CLI quotas)

Plugin	Gemini CLI OAuth	Antigravity API	Claude/GPT
`opencode-gemini-auth`	Yes	No	No
`opencode-antigravity-auth` (this plugin)	Yes	Yes	Yes

Note: If you have both plugins installed, remove opencode-gemini-auth to avoid conflicts.

@tarquinen/opencode-dcp (Dynamic Context Pruning)

Issue: DCP creates synthetic assistant messages to summarize pruned tool outputs. These synthetic messages lack the thinking block that Claude's API requires for thinking-enabled models.

Error you'll see:

Expected 'thinking' or 'redacted_thinking', but found 'text'

Solution: Ensure this plugin loads before DCP. We inject redacted_thinking blocks into assistant messages, and DCP's processing runs after our fixes are applied.

Order	Result
antigravity → DCP	Works - DCP processes messages after our fixes
DCP → antigravity	Broken - DCP creates messages before our fix runs

Correct:

{
  "plugin": [
    "opencode-antigravity-auth@1.2.7",
    "@tarquinen/opencode-dcp@latest"
  ]
}

Incorrect:

{
  "plugin": [
    "@tarquinen/opencode-dcp@latest",
    "opencode-antigravity-auth@1.2.7"
  ]
}

oh-my-opencode (Subagent Orchestration)

Issue: When oh-my-opencode spawns multiple subagents in parallel, each subagent runs as a separate OpenCode process. Without coordination, multiple processes may select the same Antigravity account simultaneously, causing rate limit errors.

Error you'll see:

429 Too Many Requests

Current workaround:

Increase your account pool (add more OAuth accounts via opencode auth login)
Reduce parallel subagent count in your configuration

Status: A file-based reservation system to coordinate account selection across processes is planned but not yet implemented.

Architecture & Flow

For contributors and advanced users, see the detailed documentation:

Architecture Guide - Full request/response flow, module structure, and troubleshooting
Antigravity API Spec - API reference and schema support matrix

Streaming & thinking

This plugin supports real-time SSE streaming, meaning you see thinking blocks and text output incrementally as they are generated.

Claude Thinking & Tools

For models like claude-opus-4-5-thinking:

Interleaved Thinking: The plugin automatically enables anthropic-beta: interleaved-thinking-2025-05-14. This allows Claude to think between tool calls and after tool results, improving complex reasoning.
Smart System Hints: A system instruction is silently added to encourage the model to "think" before and during tool use.
Multi-turn Stability: Thinking signatures are cached and restored using a stable sessionId, preventing "invalid signature" errors in long conversations.
Thinking Budget Safety: If a thinking budget is enabled, the plugin ensures output token limits are high enough to avoid budget-related errors.
Tool Use: Tool calls and responses are assigned proper IDs, and tool calling is set to validated mode for better Claude compatibility.

Troubleshooting: If you see signature errors in multi-turn tool loops, restart opencode to reset the plugin session/signature cache.

Debugging

Enable debug logging via environment variable:

export OPENCODE_ANTIGRAVITY_DEBUG=1

Level 1 (1 or true): Basic logging of URLs, headers, status codes, and request/response previews.
Level 2 (2 or verbose): Verbose logging including full request and response bodies (up to 50KB).
TUI Reasoning View: Debug logs are injected into the model's "thinking/reasoning" blocks in the Opencode TUI (requires thinking-capable models).
Log Files: Logs are written to ~/.config/opencode/antigravity-logs/antigravity-debug-<timestamp>.log. Override with OPENCODE_ANTIGRAVITY_LOG_DIR.
Auto-Stripping: Injected debug blocks are automatically stripped from outgoing requests to prevent leaking into conversation history.

Development

npm install

Safety, usage, and risk notices

Intended use

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

Not suitable for

Production application traffic
High-volume automated extraction
Any use that violates Acceptable Use Policies

⚠️ Warning (assumption of risk)

By using this plugin, you acknowledge and accept the following:

Terms of Service risk: This approach may violate the Terms of Service of AI model providers (Anthropic, OpenAI, etc.). You are solely responsible for ensuring compliance with all applicable terms and policies.
Account risk: Providers may detect this usage pattern and take punitive action, including suspension, permanent ban, or loss of access to paid subscriptions.
No guarantees: Providers may change APIs, authentication, or policies at any time, which can break this method without notice.
Assumption of risk: You assume all legal, financial, and technical risks. The authors and contributors of this project bear no responsibility for any consequences arising from your use.

Use at your own risk. Proceed only if you understand and accept these risks.

Legal

Not affiliated with Google. This is an independent open-source project and is not endorsed by, sponsored by, or affiliated with Google LLC.
"Antigravity", "Gemini", "Google Cloud", and "Google" are trademarks of Google LLC.
Software is provided "as is", without warranty. You are responsible for complying with Google's Terms of Service and Acceptable Use Policy.

Credits

Built with help and inspiration from:

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

Support

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

35 KiB Raw Blame History

Antigravity + Gemini CLI OAuth Plugin for Opencode

What you get

Installation

For Humans

For LLMs

Step 1: Verify OpenCode is installed

Step 2: Create or update the config

Step 3: Ask user about multi-account setup

Step 4: Run authentication

Step 5: Add models to config

Step 6: Verify setup

Migration Guide

Upgrading to v1.2.7

What Changed

Upgrade Steps

Available models

Gemini Models (Antigravity)

Claude Models

Other Models

How Quota Routing Works

Two Gemini Model Sources

Request Flow

Routing Examples

Why This Matters

Multi-account load balancing

How it works

Dual quota pools (Gemini only)

Quiet mode

Adding accounts

Account storage

Automatic account recovery

Configuration

Config file

General Settings

Session Recovery

Thinking Blocks (Claude)

Error Recovery

Token Management

Environment variables

Known plugin interactions

opencode-gemini-auth (Gemini CLI OAuth)

@tarquinen/opencode-dcp (Dynamic Context Pruning)

oh-my-opencode (Subagent Orchestration)

Architecture & Flow

Streaming & thinking

Claude Thinking & Tools

Debugging

Development

Safety, usage, and risk notices

Intended use

Not suitable for

⚠️ Warning (assumption of risk)

Legal

Credits

Support

35 KiB

Raw Blame History