🔄 opencode-gemini-business

Multi-account Gemini Business pool with intelligent rotation for OpenCode

🇷🇺 Русский | 🇬🇧 English

Auth plugin for OpenCode — pool multiple Gemini Business accounts with automatic rotation, failover, and load balancing.

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📖 Overview

opencode-gemini-business is an OpenCode plugin that enables multi-account rotation for Gemini Business API (business.gemini.google), providing automatic failover and load balancing across multiple accounts.

Important: This plugin uses the Gemini Business / Enterprise API, NOT Google AI Studio.

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✨ Features

Feature	Description
🔄 Multi-Account Rotation	Automatically rotate between multiple Gemini Business accounts
🛡️ Automatic Failover	Retry failed requests with different accounts seamlessly
🔐 JWT Authentication	Built-in XSRF token retrieval and JWT (HS256) signing
📡 Streaming Support	Full SSE streaming, JSON-lines, and fallback parsing
⚙️ Flexible Strategies	Round-robin, least-used, or random rotation
🔑 Auto Auth Setup	add-account automatically creates OpenCode auth record

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🤖 Supported Models

Model	Internal API ID	Best For
gemini-2.5-flash	gemini-2.5-flash	Everyday tasks, fast responses
gemini-2.5-pro	gemini-2.5-pro	Complex reasoning
gemini-3-flash	gemini-3-flash-preview	Next-gen fast model
gemini-3-pro	gemini-3-pro-preview	Next-gen reasoning

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🚀 Quick Start

Step 1: Configure OpenCode

Add to ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-gemini-business@latest"],
  "provider": {
    "gemini-business": {
      "name": "Gemini Business",
      "options": {
        "baseURL": "https://business.gemini.google/v1",
        "apiKey": "unused"
      },
      "models": {
        "gemini-2.5-flash": { "name": "Gemini 2.5 Flash" },
        "gemini-2.5-pro": { "name": "Gemini 2.5 Pro" },
        "gemini-3-flash": { "name": "Gemini 3 Flash" },
        "gemini-3-pro": { "name": "Gemini 3 Pro" }
      }
    }
  }
}

Step 2: Add Gemini Business account

Install the CLI tool:

npm install -g opencode-gemini-business

Then add your account:

opencode-gemini-business add-account \
  "My Account" \
  "e1f353e7-0291-44cf-9085-e0b6efd20e41" \
  "CSE.AXUaAj_MKeqeFLr_..." \
  "COS.AfQtEyCcW1aLwKb3..." \
  "1370433092"

Arguments:

#	Argument	Description
1	Account name	Display name for the account
2	team_id	UUID from URL /cid/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/
3	__Secure-C_SES	Cookie value (starts with CSE.)
4	__Host-C_OSES	Cookie value (starts with COS.)
5	csesidx	Number from URL ?csesidx=...

Or use environment variables:

export GEMINI_ACCOUNT_NAME="My Account"
export GEMINI_TEAM_ID="e1f353e7-0291-44cf-9085-e0b6efd20e41"
export GEMINI_SECURE_C_SES="CSE.AXUaAj_MKeqeFLr_..."
export GEMINI_HOST_C_OSES="COS.AfQtEyCcW1aLwKb3..."
export GEMINI_CSESIDX="1370433092"

opencode-gemini-business add-account

Note: add-account automatically creates the auth record in ~/.local/share/opencode/auth.json, so you don't need to run opencode auth login.

Step 3: Use it

# Flash model (fast)
opencode run --model=gemini-business/gemini-2.5-flash "Fix this bug"

# Pro model (best quality)
opencode run --model=gemini-business/gemini-2.5-pro "Design architecture"

# Next-gen models
opencode run --model=gemini-business/gemini-3-flash "Quick task"
opencode run --model=gemini-business/gemini-3-pro "Complex reasoning"

Set as default model in opencode.json:

{
  "model": "gemini-business/gemini-2.5-flash"
}

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🔍 Extracting Credentials

Where to find each value

Login to business.gemini.google and look at the URL:

https://business.gemini.google/home/cid/e1f353e7-0291-44cf-9085-e0b6efd20e41/r/session/123?csesidx=1370433092
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                  ^^^^^^^^^^
                                        team_id (UUID after /cid/)                            csesidx

Cookies

Method 1: Browser Extension (Recommended)

1. Install Get cookies.txt LOCALLY
2. Open business.gemini.google and export cookies
3. Find __Secure-C_SES (starts with CSE.) and __Host-C_OSES (starts with COS.)

Method 2: DevTools

1. Open DevTools (F12) → Application → Cookies → https://business.gemini.google
2. Copy __Secure-C_SES and __Host-C_OSES values

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🔧 Account Management

# List all accounts
opencode-gemini-business list-accounts

# Test account connectivity
opencode-gemini-business test-account <account_id>

# Remove account
opencode-gemini-business remove-account <account_id>

# Help
opencode-gemini-business help

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⚙️ Rotation Strategies

Strategy	Behavior
round-robin (default)	Cycles through accounts in order
least-used	Selects least recently used account
random	Random selection

Configure in ~/.config/opencode/gemini-business-accounts.json (auto-created on first add-account).

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🛠️ How It Works

1. Plugin registers as an OpenCode auth provider for gemini-business
2. When a request comes in, loader() returns a custom fetch() function
3. Custom fetch() intercepts the request from @ai-sdk/openai-compatible
4. Instead of calling baseURL/chat/completions, it:
   • Picks an account via rotation strategy
   • Gets XSRF token and creates JWT (HS256)
   • Creates a session via widgetCreateSession
   • Sends the actual request to widgetStreamAssist
   • Converts the response back to OpenAI-compatible format
5. Supports both streaming (SSE) and non-streaming responses

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❓ FAQ

Q: Where do I find team_id?

Look at the URL in your browser: https://business.gemini.google/home/cid/e1f353e7-0291-44cf-9085-e0b6efd20e41/...

The UUID after /cid/ is your team_id.

Q: Do I need to run `opencode auth login`?

No. The add-account command automatically creates the auth record in ~/.local/share/opencode/auth.json. If for some reason it wasn't created, you can run opencode auth login, select gemini-business, and enter any key (e.g. unused).

Q: Session expired errors?

The plugin automatically refreshes sessions (cached for 50 minutes). If you see persistent errors, your cookies may have expired — re-extract them from the browser.

Q: Difference from Google AI Studio?

This plugin uses Gemini Business API (business.gemini.google) — enterprise accounts with higher rate limits. NOT Google AI Studio (aistudio.google.com).

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🔒 Security

• Credentials are stored locally in ~/.config/opencode/gemini-business-accounts.json
• Never commit credentials to git
• Rotate cookies regularly
• The plugin does not send credentials to any third-party services

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📄 License

MIT © opencode-gemini-business contributors