# Flow Settings When working inside any **Flow** in Fastn, you can adjust its behavior and appearance through the **Settings** option available in the **right-hand sidebar**.
Flow editor with the Settings option highlighted in the right-hand sidebar
The Settings panel has two main subsections: **Configuration** and **Visuals**.
Settings panel showing Configuration and Visuals subsections
## 1. Configuration The **Configuration** section controls how your flow runs and how it handles security, validation, and errors. ### **Flow Type** You must choose how the flow should execute: #### **🔹 API (Real-Time Sync API)** * Executes instantly and returns a real-time response. * Used for synchronous tasks where the result is needed immediately. #### **🔹 Workflow (Async Workflow Job)**
Workflow flow type settings with memory limit, CPU limit, priority, and timeout options
* Executes in the background without blocking the request. * Suitable for asynchronous or heavy jobs. * When you select **Workflow**, additional options appear: * **Memory Limit** – Maximum memory allocation (e.g., 2 GB). * **CPU Limit** – Maximum processing power allocated (e.g., 1 vCPU). * **Priority** – Determines how quickly the workflow is executed (Low/Medium/High). * **Timeout (min)** – Maximum duration before the workflow stops. When Workflow is selected, a new **Trigger** section appears in the **left sidebar**, where you can define how the workflow is initiated:
Trigger section in left sidebar with Manual, Event, and Schedule workflow initiation options
* **Manual** – Run the workflow manually. * **Event** – Triggered by an event. * **Schedule** – Triggered at scheduled intervals. ### **Validation & Multi-Tenancy**
Validation and Multi-Tenancy settings with Enable Validation and Enforce Multi-Tenancy toggles
* **Enable Validation** – Enforce schema validation for flow input. * **Enforce Multi-Tenancy** – Require the `x-fastn-space-tenantid` header to ensure the flow only accesses resources for the specified tenant. ### **Authentication**
Authentication settings with Enable Custom Authentication toggle for Authorization header support
* **Enable Custom Authentication** – Allow access with an `Authorization` header instead of `x-fastn-api-key`. * Uses the **fastnCustomAuth** flow for validation. * You can customize this authentication flow as needed. [Learn More](https://docs.fastn.ai/flows/tutorials/flow-customization-and-operations/how-to-customize-your-authentication-flow) ### **Error Notification**
Error Notification settings with toggle to forward errors to a notification flow like Slack
* **Enable Error Notification** – Forward errors to a notification flow (e.g., sending alerts to Slack). * You can customize this with the **fastnErrorNotification** flow. [Learn More](https://docs.fastn.ai/flows/tutorials/flow-customization-and-operations/how-to-customize-your-error-notification-flow) ## 2. Visuals The **Visuals** section customizes the flow editor interface.
Visuals settings with toggles for Side Action Panel, Flow MiniMap, and Dark Mode
* **Enable Side Action Panel** – Displays a quick-access panel for drag-and-drop actions. * **Enable Flow MiniMap** – Adds a minimap to navigate large or complex flows. * **Activate Dark Mode** – Switches the editor to dark theme.