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Co-authored-by: April I. Murphy <36110273+aimurphy@users.noreply.github.com>
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Co-authored-by: April I. Murphy <36110273+aimurphy@users.noreply.github.com>
(cherry picked from commit 7fd8469917)
157 lines
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157 lines
8.0 KiB
Plaintext
---
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title: Build flows
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slug: /concepts-flows
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---
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import Icon from "@site/src/components/icon";
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A _flow_ is a functional representation of an application workflow.
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Flows receive input, process it, and produce output.
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Flows consist of _components_ that represent individual steps in your application's workflow.
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Langflow flows are fully serializable and can be saved and loaded from the file system where Langflow is installed.
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:::tip
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To try building and running a flow in a few minutes, see the [Langflow quickstart](/get-started-quickstart).
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:::
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## Create a flow
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From the [**Projects** page](#projects), there are four ways to create a flow:
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* **Create a blank flow**: Select a project, click **New Flow**, and then click **Blank Flow**.
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* **Create a flow from a template**: Select a project, click **New Flow**, and then click the template that you want to use.
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<details>
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<summary>What are templates?</summary>
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Templates are pre-built flows that you can use as a starting point for your own flow.
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They range from basic flows with a few components to complex flows with many components and sub-flows.
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For example, the **Basic Prompting** template demonstrates a small flow that passes both chat input and pre-defined instructions (as a prompt) to an LLM.
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In contrast, the **Vector Store RAG** template consists of two sub-flows that demonstrate how to create a Retrieval Augmented Generation (RAG) chatbot. One sub-flow populates the vector store with contextually relevant data and embeddings, and the other sub-flow queries the vector store for similar data to answer user questions.
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You can also [contribute templates](/contributing-templates) to the Langflow codebase.
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</details>
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* **Duplicate an existing flow**: Locate the flow you want to copy, click <Icon name="Ellipsis" aria-hidden="true" /> **More**, and then select **Duplicate**.
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* **Import a flow**: See [Import and export flows](/concepts-flows-import).
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You can also create a flow with the [Langflow API](/api-flows), but the Langflow team recommends using the [visual editor](/concepts-overview) until you are familiar with flow creation.
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### Add components
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Flows consist of [components](/concepts-components), which are nodes that you configure and connect in the [workspace](/concepts-overview#workspace).
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Each component performs a specific task, like serving an AI model or connecting a data source.
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Drag and drop components from the <Icon name="Component" aria-hidden="true" /> **Core components** and <Icon name="Blocks" aria-hidden="true" /> **Bundles** menus to add them to your flow.
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Then, configure the component settings and connect the components together.
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Each component has configuration settings and options. Some of these are common to all components, and some are unique to specific components.
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To form a cohesive flow, you connect components by _edges_ or _ports_, which have a specific data type they receive or send.
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For example, message ports send text strings between components.
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For more information about component configuration, including port types and underlying component code, see [Components overview](/concepts-components).
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### Run a flow
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After you build a prototype flow, you can test it in the [**Playground**](/concepts-playground).
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When you're ready to use Langflow for application development, learn how to [trigger flows with the Langflow API](/concepts-publish), explore more advanced configuration options like [custom dependencies](/install-custom-dependencies), and, eventually, [containerize your Langflow application](/develop-application).
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When you're ready to go to production or deploy a Langflow MCP server for access over the public internet, see [Langflow deployment overview](/deployment-overview).
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#### Flow graphs
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When a flow runs, Langflow builds a Directed Acyclic Graph (DAG) object from the nodes (components) and edges (connections), and the nodes are sorted to determine the order of execution.
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The graph build calls each component's `def_build` function to validate and prepare the nodes.
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This graph is then processed in dependency order.
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Each node is built and executed sequentially, with results from each built node being passed to nodes that are dependent on that node's results.
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## Manage flows in projects {#projects}
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The **Projects** page is where you arrive when you launch Langflow.
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From here, you can manage flows and your projects' [MCP servers](/mcp-server).
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Langflow projects are like folders that you can use to organize related flows.
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The default project is **Starter Project**, and your flows are stored here unless you create another project.
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To create a project, click <Icon name="Plus" aria-hidden="true"/> **Create new project**.
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:::tip
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To get back to the **Projects** page after editing a flow, click the project name or Langflow icon in the Langflow header.
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:::
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### Edit flow details
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1. On the **Projects** page, locate the flow you want to edit.
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2. Click <Icon name="Ellipsis" aria-hidden="true" /> **More**, and then select **Edit details**.
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3. Edit the **Name** and **Description**, and then click **Save**.
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### Save and restore flow versions
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You can save versions of a flow from the <Icon name="History" aria-hidden="true" /> **Version History** menu in the flow editor.
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1. Open the flow that you want to version.
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2. In the flow editor sidebar, click <Icon name="History" aria-hidden="true" /> **Version History**.
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3. In **Current**, click **Save** to capture the current state of the flow as a saved version.
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4. Select a previously saved version to preview the flow in read-only mode.
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5. To replace the current draft with the selected version, click **Restore**.
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From a saved version's <Icon name="EllipsesVertical" aria-hidden="true" /> menu, you can also **Export** or **Delete** that version.
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Saved flow versions are stored in the database configured for your Langflow deployment.
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When restoring a saved version, if **Save current draft before restoring** is enabled, then Langflow creates a backup of your current work before the selected version replaces it.
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[Flow auto-save](/environment-variables#visual-editor-and-playground-behavior) and flow versions serve different purposes.
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Auto-save keeps your current flow draft up to date in the background, but it doesn't create version entries.
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A saved _version_ is an explicit snapshot that you create when you want a restore point.
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When previewing a saved version, Langflow temporarily pauses auto-save so the preview doesn't overwrite your current draft.
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### Lock a flow
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To prevent changes to a flow, you can lock it:
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1. On the **Projects** page, locate the flow you want to lock.
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2. Click <Icon name="Ellipsis" aria-hidden="true" /> **More**, and then select **Edit details**.
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3. Enable **Lock Flow**, and then click **Save**.
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Repeat these steps to unlock the flow by disabling **Lock Flow**.
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When editing a flow, the **Lock Status** indicates whether the flow is <Icon name="Lock" aria-hidden="true" /> **Locked** or <Icon name="LockOpen" aria-hidden="true" /> **Unlocked**.
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You cannot change the lock status while editing the flow.
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### Move a flow
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To move a flow from one project to another, do the following:
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1. On the **Projects** page, locate the flow you want to move.
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2. Click and drag the flow from the list of flows to the target project name in the list of projects.
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### Delete a flow
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1. On the **Projects** page, locate the flow you want to delete.
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2. Click <Icon name="Ellipsis" aria-hidden="true" /> **More**, and then select **Delete**.
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## Flow storage and logs
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By default, flows and flow execution data are stored in the Langflow database, and flow logs are stored with other Langflow logs in the Langflow config directory.
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For more information, see [Memory management options](/memory) and [Logging](/logging).
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## See also
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* [Share and embed flows](/concepts-publish)
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* [Import and export flows](/concepts-flows-import)
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* [Langflow environment variables](/environment-variables) |