> ## Documentation Index > Fetch the complete documentation index at: https://enterprise-docs.dify.ai/llms.txt > Use this file to discover all available pages before exploring further. # Manage Model Credentials ## Introduction You can add multiple credentials for a model provider's predefined and custom models, and easily switch between, delete, or modify these credentials. Here are some scenarios where adding multiple credentials is particularly helpful: * **Environment Isolation**: Configure separate model credentials for different environments, such as development, testing, and production. For example, use a rate-limited credential in the development environment for debugging, and a paid credential with stable performance and a sufficient quota in the production environment to ensure service quality. * **Cost Optimization**: Add and switch between multiple credentials from different accounts or model providers to maximize the use of free or low-cost quotas, thereby reducing application development and operational costs. * **Model Testing**: During model fine-tuning or iteration, you may create multiple model versions. By adding credentials for these different versions, you can quickly switch between them to test and evaluate their performance. ## Procedure After installing a model provider and configuring the first credential, click **Config** in the upper-right corner to perform the following actions: * Add a new credential * Select a credential as the default for all predefined models * Edit a credential * Delete a credential If the default credential is deleted, you must manually specify a new one. Manage credentials for predefined models ### Manage Credentials for a Single Custom Model After installing a model provider and adding a custom model, follow these steps: 1. In the model list, click the corresponding **Config**. 2. In the **Specify model credential** panel, click the default credential to open the credential list, then perform the following actions: * Add a new credential * Select a credential as the default for that custom model * Edit a credential * Delete a credential If you delete the only credential for a custom model, the model will also be deleted. Manage credentials for a single custom model When you add a new custom model with a name and type identical to an existing custom model, the system will add the new credential to that existing model rather than creating a duplicate. ### Manage Credentials for All Custom Models You can click **Manage Credentials** to view, edit, or delete the credentials for all custom models. Manage credentials for all custom models After a custom model is removed, its credentials will remain in the **Manage Credentials** list. When you click **Add Model**, the system will display all removed custom models whose credentials still exist, allowing you to quickly re-add them. Removed models displayed for quick re-add If you delete all credentials for a removed custom model from the **Manage Credentials** list, that model will no longer appear when you click **Add Model**.