Skip to main content

Components overview

Components are the building blocks of your flows. Like classes in an application, each component is designed for a specific use case or integration.

tip

Langflow provides keyboard shortcuts for the Workspace.

In the Langflow header, click your profile icon, select Settings, and then click Shortcuts to view the available shortcuts.

Add a component to a flow

To add a component to a flow, drag the component from the Components menu to the Workspace.

The Components menu is organized by component type, and some components are hidden by default:

  • Beta components: These are Langflow's core components. They are grouped by purpose, such as Inputs or Data. Be aware that these components are in beta and not suitable for production workloads.
  • Legacy components: You can still use these components, but they are no longer supported. Legacy components are hidden by default; click Component settings to expose legacy components.
  • Bundles: These components support specific integrations, and they are grouped by provider.

Configure a component

After adding a component to a flow, configure the component's parameters and connect it to the other components in your flows.

Each component has inputs, outputs, parameters, and controls related to the component's purpose. By default, components show only required and common options. To access additional settings and controls, including meta settings, use the component's header menu.

To access a component's header menu, click the component in your Workspace.

Agent component

A few options are available directly on the header menu. For example:

  • Code: Modify component settings by directly editing the component's Python code.
  • Controls: Adjust all component parameters, including optional settings that are hidden by default.
  • Tool Mode: Enable this option when combining a component with an Agent component.

For all other options, including Delete and Duplicate controls, click Show More.

Rename a component

To modify a component's name or description, click the component in the Workspace, and then click Edit. Component descriptions accept Markdown syntax.

Run a component

To run a single component, click Run component. A Last Run value indicates that the component ran successfully.

Running a single component is different from running an entire flow. In a single component run, the build_vertex function is called, which builds and runs only the single component with direct inputs provided through the UI (the inputs_dict parameter). The VertexBuildResult data is passed to the build_and_run method that calls the component's build method and runs it. Unlike running an entire flow, running a single component doesn't automatically execute its upstream dependencies.

Inspect component output and logs

To view the output and logs for a single component, click Inspect.

Freeze a component

important

Freezing a component also freezes all components upstream of the selected component.

Use the freeze option if you expect consistent output from a component and all upstream components, and you only need to run those components once.

Freezing a component prevents that component and all upstream components from re-running, and it preserves the last output state for those components. Any future flow runs use the preserved output.

To freeze a component, click the component in the Workspace to expose the component's header menu, click Show More, and then select Freeze.

Component ports

Circular port icons () on the border of a component indicate the types of inputs and outputs that can be connected to the component at that port.

Prompt component with multiple inputs

Port colors

Component port colors indicate the data type ingested or emitted by the port. For example, a text port either accepts or emits text data.

tip

Hover over a port to see connection details for that port.

The following table lists the component port colors and their corresponding input types:

Data typePort colorPort icon example
DataRed
DataFramePink
EmbeddingsEmerald
LanguageModelFuchsia
MemoryOrange
MessageIndigo
TextIndigo
ToolCyan
UnknownGray

Component code

All components have underlying code that determines how you configure them and what actions they can perform. In the context of creating and running flows, component code does the following:

  • Determines what configuration options to show in the Langflow UI.
  • Validates inputs based on the component's defined input types.
  • Processes data using the configured parameters, methods, and functions.
  • Passes results to the next component in the flow.

All components inherit from a base Component class that defines the component's interface and behavior. For example, the Recursive character text splitter is a child of the LCTextSplitterComponent class.

Each component's code includes definitions for inputs and outputs, which are represented in the Workspace as component ports. For example, the RecursiveCharacterTextSplitter has four inputs. Each input definition specifies the input type, such as IntInput, as well as the encoded name, display name, description, and other parameters for that specific input. These values determine the component settings, such as display names and tooltips in the Langflow UI.


_26
inputs = [
_26
IntInput(
_26
name="chunk_size",
_26
display_name="Chunk Size",
_26
info="The maximum length of each chunk.",
_26
value=1000,
_26
),
_26
IntInput(
_26
name="chunk_overlap",
_26
display_name="Chunk Overlap",
_26
info="The amount of overlap between chunks.",
_26
value=200,
_26
),
_26
DataInput(
_26
name="data_input",
_26
display_name="Input",
_26
info="The texts to split.",
_26
input_types=["Document", "Data"],
_26
),
_26
MessageTextInput(
_26
name="separators",
_26
display_name="Separators",
_26
info='The characters to split on.\nIf left empty defaults to ["\\n\\n", "\\n", " ", ""].',
_26
is_list=True,
_26
),
_26
]

Additionally, components have methods or functions that handle their functionality. For example, the RecursiveCharacterTextSplitter has two methods:


_16
def get_data_input(self) -> Any:
_16
return self.data_input
_16
_16
def build_text_splitter(self) -> TextSplitter:
_16
if not self.separators:
_16
separators: list[str] | None = None
_16
else:
_16
# check if the separators list has escaped characters
_16
# if there are escaped characters, unescape them
_16
separators = [unescape_string(x) for x in self.separators]
_16
_16
return RecursiveCharacterTextSplitter(
_16
separators=separators,
_16
chunk_size=self.chunk_size,
_16
chunk_overlap=self.chunk_overlap,
_16
)

The get_data_input method retrieves the text data to be split from the component's input, which makes the data available to the class. The build_text_splitter method creates a RecursiveCharacterTextSplitter object by calling its parent class's build method. Then, the text is split with the created splitter and passed to the next component.

Component versions

Component versions and states are stored in an internal Langflow database. When you add a component to a flow, you create a detached copy of the component based on the information in the Langflow database. These copies are detached from the primary Langflow database, and they don't synchronize with any updates that can occur when you upgrade your Langflow version.

In other words, an individual instance of a component retains the version number and state from the moment you add it to a specific flow. For example, if a component is at version 1.0 when you add it to a flow, it remains at version 1.0 in that flow unless you update it.

Update component versions

When editing a flow in the Workspace, Langflow notifies you if a component's workspace version is behind the database version so you can update the component's workspace version:

  • Update ready: This notification means the component update contains no breaking changes.

  • Update available: This notification means the component update might contain breaking changes.

    Breaking changes modify component inputs and outputs, causing the components to be disconnected and break the flow. After updating the component, you might need to edit the component settings or reconnect component ports.

There are two ways to update components:

  • Click Update to update a single component. This is recommended for updates without breaking changes.

  • Click Review to view all available updates and create a snapshot before updating. This is recommended for updates with breaking changes.

    To save a snapshot of your flow before updating the components, enable Create backup flow before updating. Backup flows are stored in the same project folder as the original flow with the suffix (backup).

    To update specific components, select the components you want to update, and then click Update Components.

Components are updated to the latest available version, based on the version of Langflow you are running.

Group components

Multiple components can be grouped into a single component for reuse. This is useful for organizing large flows by combining related components together, such as a RAG Agent component and an associated vector database component.

  1. Hold Shift, and then click and drag to highlight all components you want to merge. Components must be completely within the selection area to be merged.
  2. Release the mouse and keyboard, and then click Group to merge the components into a single, group component.

Grouped components are configured and managed as a single component, including the component name, code, and settings.

To ungroup the components, click the component in the Workspace to expose the component's header menu, click Show More, and then select Ungroup.

If you want to reuse this grouping in other flows, click the component in the Workspace to expose the component's header menu, click Show More, and then select Save to save the component to the Components menu.

Search