Key Switcher

A lightweight Windows GUI application for quickly switching Claude Code API keys, providers, base URLs, and models.

Key Switcher uses an Excel file to store API keys and a providers.json file to manage provider-specific configuration. When you click APPLY, the selected configuration is written directly to the Claude Code settings.json file.

---

Features

• 🔑 Store and manage multiple API keys
• 🏷️ Give each API key a custom nickname
• 🔌 Support multiple providers
• 🤖 Provider-specific model lists
• 🌐 Provider-specific base URLs
• ⚡ Quickly switch between API keys and models
• 📝 Automatically update Claude Code settings.json
• 📊 Store API keys in an Excel file
• ⚙️ Edit providers and models from the application
• 🗑️ Delete saved API keys
• 🚫 No backup files are created
• 🎯 Simple main interface with only the required controls

---

How It Works

Key Switcher uses three main configuration sources:

                 ┌──────────────────┐
                 │    keys.xlsx     │
                 │                  │
                 │ Provider         │
                 │ Nickname         │
                 │ API Key          │
                 └────────┬─────────┘
                          │
                          ▼
                   Selected Nickname
                          │
                          ▼
                    Find Provider
                          │
                          ▼
                 ┌──────────────────┐
                 │  providers.json  │
                 │                  │
                 │ Base URL         │
                 │ Models           │
                 └────────┬─────────┘
                          │
                          ▼
                  Selected Model
                          │
                          ▼
                 ┌──────────────────┐
                 │  settings.json   │
                 │                  │
                 │ Auth Token        │
                 │ Base URL         │
                 │ Model Settings   │
                 └──────────────────┘

The provider is not selected from the main interface.

Instead:

1. You select a Nickname.
2. Key Switcher finds the provider associated with that nickname in keys.xlsx.
3. It loads that provider's models from providers.json.
4. You select a model.
5. Clicking APPLY updates Claude Code's settings.json.

---

Project Structure

A typical project structure is:

Key Switcher/
│
├── Switcher_v2.py
├── providers.json
└── README.md

The Excel key file is stored separately:

C:\My Space\Data\keys.xlsx

Claude Code's settings file is:

C:\Users\Nishant\.claude\settings.json

---

Requirements

Python

Python 3.10+ is recommended.

Check your Python installation:

python --version

---

Required Python Packages

Install the required packages with:

pip install PySide6 openpyxl

The application uses:

• PySide6 — GUI
• openpyxl — Excel file management
• json — provider/settings configuration
• pathlib — file path management

json and pathlib are included with Python.

---

Installation

Clone or download the project.

Then open a terminal in the project directory:

cd "C:\path\to\Key Switcher"

Install dependencies:

pip install PySide6 openpyxl

Run the application:

python Switcher_v2.py

---

Configuration Files

1. keys.xlsx

API keys are stored in:

C:\My Space\Data\keys.xlsx

The Excel file contains only three columns:

Provider	Nickname	API Key
Ollama	Ollama Main	your-api-key
Hugging Face	HF Key	your-api-key

Important

The application does not store the model or base URL in Excel.

Those values come from providers.json.

The provider is stored with each key so that Key Switcher knows which provider configuration to use.

---

2. providers.json

providers.json is located in the same directory as the Python application.

Example:

{
  "providers": {
    "Ollama": {
      "base_url": "https://ollama.com",
      "models": [
        "gemma4:31b",
        "gpt-oss:120b",
        "gpt-oss:20b",
        "nemotron-3-nano:30b",
        "nemotron-3-super",
        "nemotron-3-ultra"
      ]
    },
    "Hugging Face": {
      "base_url": "https://router.huggingface.co/v1",
      "models": [
        "Qwen/Qwen3.8-27B"
      ]
    }
  }
}

Each provider contains:

Provider
 ├── base_url
 └── models

Base URL

The base_url is provider-wide.

For example:

"Ollama": {
  "base_url": "https://ollama.com"
}

All keys belonging to Ollama use that base URL.

Similarly:

"Hugging Face": {
  "base_url": "https://router.huggingface.co/v1"
}

All Hugging Face keys use that base URL.

---

Adding a Provider

Open the application and click the:

⋮

menu.

Select:

Provider Settings

From there you can edit the provider configuration.

You can:

• Change the Base URL
• Add models
• Delete models

The changes are saved directly to:

providers.json

---

Adding an API Key

Click:

⋮

Then select:

Add Key

The application asks for:

1. Provider
2. Nickname
3. API Key

Example:

Provider: Ollama
Nickname: My Ollama
API Key: ********

The resulting Excel row is:

Ollama | My Ollama | ********

---

Switching API Keys

The main interface contains:

Nickname: [ My Ollama ▼ ]

Model:    [ gemma4:31b ▼ ]

                         ⋮  APPLY

When you select a nickname, the application automatically determines the provider.

For example:

Nickname
    │
    ▼
My Ollama
    │
    ▼
Provider = Ollama
    │
    ▼
providers.json
    │
    ├── Base URL
    │
    └── Models

The model dropdown is then populated with the models configured for that provider.

---

Applying Settings

After selecting:

Nickname

and:

Model

click:

APPLY

The application updates:

C:\Users\Nishant\.claude\settings.json

The following environment variables are updated:

ANTHROPIC_AUTH_TOKEN
ANTHROPIC_BASE_URL
ANTHROPIC_MODEL
ANTHROPIC_SMALL_FAST_MODEL
ANTHROPIC_DEFAULT_SONNET_MODEL
ANTHROPIC_DEFAULT_OPUS_MODEL
ANTHROPIC_DEFAULT_HAIKU_MODEL

---

Example

Suppose keys.xlsx contains:

Provider       Nickname       API Key
Ollama         Work           abc123
Hugging Face   Testing        xyz789

And providers.json contains:

{
  "providers": {
    "Ollama": {
      "base_url": "https://ollama.com",
      "models": [
        "gemma4:31b",
        "gpt-oss:120b"
      ]
    },
    "Hugging Face": {
      "base_url": "https://router.huggingface.co/v1",
      "models": [
        "Qwen/Qwen3.8-27B"
      ]
    }
  }
}

If you select:

Nickname: Work
Model: gpt-oss:120b

Key Switcher determines:

Provider = Ollama
Base URL = https://ollama.com
API Key = abc123
Model = gpt-oss:120b

Then it writes those values to Claude Code.

---

settings.json

The application modifies the existing:

C:\Users\Nishant\.claude\settings.json

It preserves the other existing settings and updates the env section.

For example:

{
  "env": {
    "ANTHROPIC_AUTH_TOKEN": "your-api-key",
    "ANTHROPIC_BASE_URL": "https://ollama.com",
    "ANTHROPIC_MODEL": "gpt-oss:120b",
    "ANTHROPIC_SMALL_FAST_MODEL": "gpt-oss:120b",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "gpt-oss:120b",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "gpt-oss:120b",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "gpt-oss:120b"
  }
}

Other settings already present in settings.json are preserved.

---

Key Management

The Key Manager provides:

Add Key

Adds a new provider, nickname, and API key to keys.xlsx.

Delete Selected Key

Deletes the currently selected nickname from keys.xlsx.

Provider Settings

Opens the provider configuration editor.

---

Security

API keys are stored locally in:

C:\My Space\Data\keys.xlsx

They are not intentionally uploaded by Key Switcher to a remote server.

However, anyone who can access the Excel file may be able to read the API keys.

Recommended

Protect the Excel file and your Windows account appropriately.

Do not commit keys.xlsx containing real API keys to Git.

Add it to .gitignore:

keys.xlsx
*.xlsx

You should also avoid committing real API keys anywhere in the repository.

---

No Backups

Key Switcher intentionally does not create backup copies of:

settings.json

or:

keys.xlsx

When changes are applied, the existing file is updated directly.

Make sure your important configuration is recoverable before making changes.

---

Error Handling

The application handles several common errors.

Settings file not found

If this file does not exist:

C:\Users\Nishant\.claude\settings.json

the application will show an error.

---

Excel file locked

If keys.xlsx is open in Microsoft Excel while trying to add or delete a key, close the Excel file and try again.

---

Invalid JSON

If settings.json or providers.json contains invalid JSON, the application reports the problem instead of applying the configuration.

---

Provider Not Found

If a provider stored in keys.xlsx does not exist in providers.json, the model list cannot be loaded and the application reports the missing provider.

---

Missing Base URL

If the selected provider has no base_url, the application will not apply the configuration.

---

Data Flow

The complete configuration flow is:

                    ┌──────────────┐
                    │   keys.xlsx  │
                    └──────┬───────┘
                           │
                     Nickname
                           │
                           ▼
                  ┌─────────────────┐
                  │ Find Provider   │
                  └────────┬────────┘
                           │
                           ▼
                  ┌─────────────────┐
                  │ providers.json  │
                  └───────┬─────────┘
                          │
                 ┌────────┴────────┐
                 │                 │
              Base URL           Models
                 │                 │
                 │                 ▼
                 │          Model Dropdown
                 │                 │
                 └────────┬────────┘
                          │
                       APPLY
                          │
                          ▼
                ┌───────────────────┐
                │   settings.json   │
                └───────────────────┘

---

Main Interface

The main interface intentionally contains only:

Nickname
Model

⋮   APPLY

The provider is hidden from the main interface because it is automatically determined from the selected nickname.

---

Project Design

The application separates key storage from provider configuration.

Excel

Responsible for:

Provider
Nickname
API Key

providers.json

Responsible for:

Provider
Base URL
Models

settings.json

Responsible for:

Claude Code environment configuration

This makes it possible to use multiple keys for the same provider without duplicating the provider's model and base URL configuration.

---

Example Multi-Key Setup

You can have multiple keys for the same provider:

Provider    Nickname       API Key
Ollama      Personal       key-1
Ollama      Work           key-2
Ollama      Testing        key-3

All three automatically use:

"Ollama": {
  "base_url": "https://ollama.com",
  "models": [...]
}

You can also have keys for different providers:

Provider       Nickname       API Key
Ollama         Personal       key-1
Ollama         Work           key-2
Hugging Face   HF Testing     key-3

Selecting HF Testing automatically switches the available model list to the models configured under Hugging Face.

---

Troubleshooting

Model dropdown is empty

Check that:

1. The nickname exists in keys.xlsx.
2. The provider is correctly written in the Provider column.
3. The provider exists in providers.json.
4. The provider has at least one model.

---

APPLY does not work

Check:

1. settings.json exists.
2. settings.json contains valid JSON.
3. The selected nickname has an API key.
4. The nickname has a provider.
5. The provider exists in providers.json.
6. The provider has a valid base_url.
7. The selected model exists.

---

Excel changes are not detected

Close keys.xlsx in Excel and restart Key Switcher if necessary.

---

Running the Application

From the project directory:

python Switcher_v2.py

If the Python command is not available, try:

py Switcher_v2.py

---

Future Improvements

Possible future improvements include:

• System tray support
• Global keyboard shortcuts
• Searchable model list
• Import/export provider configurations
• Encrypted API-key storage
• Windows executable build
• Automatic Claude Code restart/reload
• Connection testing
• Provider status indicators
• Dark/light theme support

---

License

Add your preferred license here.

For example:

MIT License

if you decide to release the project under the MIT License.

---

Summary

Key Switcher provides a simple way to manage multiple Claude Code API configurations.

The architecture is:

keys.xlsx
    │
    ├── Provider
    ├── Nickname
    └── API Key
         │
         ▼
providers.json
    │
    ├── Base URL
    └── Models
         │
         ▼
settings.json
    │
    ├── API Key
    ├── Base URL
    └── Model Configuration

Select a nickname, select a model, and press APPLY to switch the Claude Code configuration.