Langflow

https://docs.langflow.org
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### Install dependencies and start local site

Source: https://docs.langflow.org/contributing-how-to-contribute

Installs dependencies and starts a local Docusaurus static site with hot reload. The documentation is served at http://localhost:3000.

```bash
npm install
npm run start
```

--------------------------------

### Install extension with pip and run Langflow

Source: https://docs.langflow.org/extensions-quickstart

Installs the published extension into a Langflow environment and starts the server. Discovery happens at startup.

```bash
pip install lfx-my-extension
langflow run
```

--------------------------------

### LFX server startup output

Source: https://docs.langflow.org/lfx-serve

Example output from starting the LFX server, showing the flow ID, server URL, and API key usage.

```text
 LFX Server
 Flow loaded: simple-agent-flow.json (c1dab29d-3364-58ef-8fef-99311d32ee42)
 Server:      http://127.0.0.1:8000
 Run flows at: POST /flows/{flow_id}/run
 API key:     x-api-key header or ?x-api-key= query parameter
```

--------------------------------

### Multiple category folders example

Source: https://docs.langflow.org/components-custom-components

Illustrates organizing components into multiple category folders, each containing an __init__.py and component files.

```text
/app/custom_components/
    ├── data/
    │   ├── __init__.py
    │   ├── custom_component.py
    │   └── dataframe_processor.py
    └── tools/
        ├── __init__.py
        └── custom_tool.py
```

--------------------------------

### README note example for template flow

Source: https://docs.langflow.org/contributing-templates

Example of a Note in Markdown syntax to include in the template flow. It should contain brief README, quickstart, or other essential details. The example shows a financial assistant agent with prerequisites and quickstart steps.

```markdown
# Financial Assistant Agents

The Financial Assistant Agent retrieves web content and writes reports about finance.

## Prerequisites

* [OpenAI API key](https://platform.openai.com/api-keys)
* [Tavily AI Search key](https://docs.tavily.com/welcome)
* [Sambanova API key](https://sambanova.ai/)

## Quickstart

1. In both **Agent** components, add your OpenAI API key.
2. In the **Model Provider** field, select **Sambanova**, and select a model.
3. In the **Sambanova** component, add your **Sambanova API key**.
4. In the **Tavily Search** component, add your **Tavily API key**.
5. Click the **Playground** and ask `Why did Nvidia stock drop in January?`
```

--------------------------------

### Install all no-Torch opt-in providers

Source: https://docs.langflow.org/bundles-confluent

Install all optional provider bundles at once using the bundles extra.

```bash
uv pip install "langflow[bundles]"
```

--------------------------------

### Install Docker on Ubuntu using snap

Source: https://docs.langflow.org/deployment-caddyfile

Installs Docker on an Ubuntu server using snap packages. This is specific to Ubuntu; other operating systems should follow the official Docker installation guide.

```bash
snap install docker
```

--------------------------------

### GET /v1/starter-projects/

Source: https://docs.langflow.org/api-reference-api-examples

Return a list of templates.

```APIDOC
## GET /v1/starter-projects/

### Description
Return a list of templates.

### Method
GET

### Endpoint
/v1/starter-projects/

### Response
#### Success Response (200)
Returns a list of starter project templates.
```

--------------------------------

### Get current user result

Source: https://docs.langflow.org/api-users

Example JSON response from the GET /api/v1/users/whoami endpoint, showing user details such as id, username, and timestamps.

```json
{
  "id": "07e5b864-e367-4f52-b647-a48035ae7e5e",
  "username": "langflow",
  "profile_image": null,
  "store_api_key": null,
  "is_active": true,
  "is_superuser": true,
  "create_at": "2025-05-08T17:59:07.855965",
  "updated_at": "2025-05-29T15:06:56.157860",
  "last_login_at": "2025-05-29T15:06:56.157016",
}
```

--------------------------------

### Approved provider IDs example

Source: https://docs.langflow.org/api-governance-policy

Example of approving providers using lowercase IDs, such as openai. GET /api/v1/model-provider-policy lists every provider the process is aware of.

```json
"approved_provider_ids": ["openai", "anthropic"]
```

--------------------------------

### Start Valkey server with search support

Source: https://docs.langflow.org/bundles-valkey

Runs the valkey/valkey-bundle Docker image to start a Valkey server with the valkey-search module enabled by default. Required for the Valkey Vector Store component.

```bash
docker run -d --name valkey -p 6379:6379 valkey/valkey-bundle:8.1
```

--------------------------------

### GET /v1/mcp/project/{project_id}/installed

Source: https://docs.langflow.org/api-reference-api-examples

Checks which clients have MCP config installed.

```APIDOC
## GET /v1/mcp/project/{project_id}/installed

### Description
Checks which clients have MCP config installed.

### Method
GET

### Endpoint
/v1/mcp/project/{project_id}/installed

### Parameters
#### Path Parameters
- **project_id** (string) - Required - The ID of the project.

```

--------------------------------

### Python: Start background workflow and get status

Source: https://docs.langflow.org/workflow-api

Sends a POST request to start a background workflow and prints the response. Requires environment variables LANGFLOW_URL or LANGFLOW_SERVER_URL, FLOW_ID, and LANGFLOW_API_KEY.

```python
import os

import requests

base = os.environ.get("LANGFLOW_URL") or os.environ.get("LANGFLOW_SERVER_URL", "")
flow_id = os.environ.get("FLOW_ID", "")
api_key = os.environ.get("LANGFLOW_API_KEY", "")

headers = {"Content-Type": "application/json", "x-api-key": api_key}

start = requests.post(
    f"{base}/api/v2/workflows",
    headers=headers,
    json={
        "flow_id": flow_id,
        "input_value": "Process this in the background",
        "mode": "background",
    },
    timeout=60,
)
start.raise_for_status()
print(start.text)
```

--------------------------------

### Example output from running the JavaScript flow

Source: https://docs.langflow.org/agent-tutorial

This is an example response from the tutorial's flow. The actual output may differ due to LLM variability and input differences. It shows the startup messages, connection details, session ID, and three URLs extracted from the chat message.

```text
Starting Langflow Agent...

Connecting to Langflow server at: http://localhost:7860
Flow ID: local-db-search
Email: isabella.rodriguez@example.com

Sending request to agent...

=== Response from Langflow ===
Session ID: isabella.rodriguez@example.com

URLs found:
https://www.facebook.com/marketplace/258164108225783/electronics/
https://www.facebook.com/marketplace/458332108944152/furniture/
https://www.facebook.com/marketplace/613732137493719/kitchen-cabinets/
```

--------------------------------

### Example component-not-found error

Source: https://docs.langflow.org/lfx-run

Example error message from LFX when a flow component is missing. It includes a hint naming the bundle to install, which can be used to find the pip package in the Bundle list.

```text
component-not-found-with-hint: DuckDuckGoSearchComponent not found.
Hint: try ext:duckduckgo:DuckDuckGoSearchComponent@official
```

--------------------------------

### Install lfx-bundles with youtube extra

Source: https://docs.langflow.org/extensions-bundle-list

Install the lfx-bundles package with the youtube extra using uv.

```bash
uv pip install "lfx-bundles[youtube]"
```

--------------------------------

### Policy bundle response example

Source: https://docs.langflow.org/api-governance-policy

Example JSON response from the GET /api/v1/policy-bundle endpoint. Shows the revision, initialized flag, and lists of blocked items. If managed_externally is true, writes return 409.

```json
{
  "revision": 1,
  "initialized": true,
  "source": "default",
  "approved_provider_ids": [],
  "blocked_component_keys": [],
  "blocked_template_keys": [],
  "blocked_model_keys": [],
  "content_hash": "ef74cccb21593ac02fc514e669c911768e740b1135d7a91d3fb15f72837ab762",
  "created_at": null,
  "created_by": null,
  "reason": null,
  "rollback_of_revision": null,
  "managed_externally": false
}
```

--------------------------------

### Populated .env file example

Source: https://docs.langflow.org/api-keys-and-authentication

Example .env file with populated values. Use strong credentials in production; the secret key is recommended for encrypting sensitive data.

```text
LANGFLOW_AUTO_LOGIN=False
LANGFLOW_SUPERUSER=administrator
LANGFLOW_SUPERUSER_PASSWORD=securepassword
LANGFLOW_SECRET_KEY=dBuu...2kM2_fb
LANGFLOW_NEW_USER_IS_ACTIVE=False
LANGFLOW_ENABLE_SIGNUP=False
LANGFLOW_ENABLE_SUPERUSER_CLI=False
```

--------------------------------

### Start and enable Nginx

Source: https://docs.langflow.org/deployment-nginx-ssl

Starts the Nginx service and enables it to start automatically on boot.

```bash
sudo systemctl start nginx
sudo systemctl enable nginx
```

--------------------------------

### Get version result

Source: https://docs.langflow.org/api-reference-api-examples

Example text response from the /api/v1/version endpoint showing the version, main_version, and package.

```text
{
    "version": "1.6.0",
    "main_version": "1.6.0",
    "package": "Langflow"
}

```

--------------------------------

### Get Vertex builds with Python

Source: https://docs.langflow.org/api-monitor

Python example using the requests library to call the /api/v1/monitor/builds endpoint. It reads LANGFLOW_URL, FLOW_ID, and LANGFLOW_API_KEY from environment variables, sends a GET request, and prints the response text.

```python
import os

import requests

url = f"{os.getenv('LANGFLOW_URL', '')}/api/v1/monitor/builds?flow_id={os.getenv('FLOW_ID', '')}"

headers = {
    "accept": "application/json",
    "x-api-key": f"{os.getenv('LANGFLOW_API_KEY', '')}",
}

response = requests.request("GET", url, headers=headers)
response.raise_for_status()

print(response.text)
```

--------------------------------

### GET /api/v1/starter-projects/

Source: https://docs.langflow.org/api

Get a list of starter projects. Optionally include blocked projects by setting the include_blocked query parameter to true.

```APIDOC
## [GET] /api/v1/starter-projects/

### Description
Get a list of starter projects.

### Method
GET

### Endpoint
/api/v1/starter-projects/

### Parameters
#### Query Parameters
- **include_blocked** (boolean) - Optional - Default: false - Include Blocked

### Authorizations
- OAuth2PasswordBearerCookie
- API key query
- API key header

### Response
#### Success Response (200)
Returns a list of starter projects.

#### Response Example
[
  {
    "data": {
      "edges": [
        {}
      ],
      "nodes": [
        {}
      ],
      "viewport": {
        "x": 0,
        "y": 0,
        "zoom": 0
      }
    },
    "description": "string",
    "endpoint_name": "string",
    "is_component": true,
    "name": "string",
    "name_key": "string"
  }
]

#### Error Response (422)
Validation Error

```

--------------------------------

### JavaScript: Fetch build events with stream=false

Source: https://docs.langflow.org/api-build

JavaScript example using fetch to GET /api/v1/build/{flow_id}/events?stream=false, disabling streaming to get all events at once. Uses environment variables for the base URL and API key.

```javascript
const url = `${process.env.LANGFLOW_URL ?? ""}/api/v1/build/123e4567-e89b-12d3-a456-426614174000/events?stream=false`;

const options = {
  method: 'GET',
  headers: {
    "accept": `application/json`,
    "x-api-key": `${process.env.LANGFLOW_API_KEY ?? ""}`,
  },
};

fetch(url, options)
  .then(async (response) => {
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}`);
    }
    const text = await response.text();
    console.log(text);
  })
  .catch((error) => console.error(error));
```

--------------------------------

### Install lfx-bundles with qdrant extra

Source: https://docs.langflow.org/extensions-bundle-list

Install the lfx-bundles package with the qdrant extra using uv.

```bash
uv pip install "lfx-bundles[qdrant]"
```

--------------------------------

### Start the reference Loki + Alloy + Grafana stack

Source: https://docs.langflow.org/observability-grafana-loki

Run these commands from the repository's deploy/observability/grafana-loki directory to start the reference stack. Set LANGFLOW_LOG_DIR to the directory that Alloy watches.

```bash
cd deploy/observability/grafana-loki
export LANGFLOW_LOG_DIR=/var/log/langflow
docker compose up -d
```

--------------------------------

### GET /api/v1/flows/basic_examples/

Source: https://docs.langflow.org/api-flows

Retrieves a list of sample flows. This endpoint returns a list of basic example flows available in Langflow.

```APIDOC
## GET /api/v1/flows/basic_examples/

### Description
Retrieves a list of sample flows.

### Method
GET

### Endpoint
/api/v1/flows/basic_examples/

### Parameters
#### Headers
- **accept** (string) - Required - Must be `application/json`.
- **x-api-key** (string) - Required - API key for authentication.

### Request Example
No request body required.

### Response
#### Success Response (200)
Returns a list of sample flows.

#### Response Example
No explicit response example provided in the source.

```

--------------------------------

### Install lfx-bundles with searchapi extra

Source: https://docs.langflow.org/extensions-bundle-list

Install the lfx-bundles package with the searchapi extra using uv.

```bash
uv pip install "lfx-bundles[searchapi]"
```

--------------------------------

### DELETE /api/v1/monitor/messages

Source: https://docs.langflow.org/api-monitor

Deletes specific messages by their IDs. The example deletes the first two messages retrieved from the GET /messages endpoint.

```APIDOC
## DELETE /api/v1/monitor/messages

### Description
Delete specific messages by their IDs.

### Method
DELETE

### Endpoint
/api/v1/monitor/messages

### Parameters
#### Query Parameters
- **message_ids** (array of UUID) - Required - The IDs of the messages to delete.

### Request Example
```json
["MESSAGE_ID_1", "MESSAGE_ID_2"]
```

### Response
#### Success Response (204)
No Content

#### Response Example
```text
204 No Content
```

```

--------------------------------

### Install lfx-azure

Source: https://docs.langflow.org/extensions-bundle-list

Install command for the Azure standalone package.

```bash
uv pip install lfx-azure
```

--------------------------------

### OpenSearch cluster response

Source: https://docs.langflow.org/knowledge

Example JSON response from a successful curl request to the OpenSearch cluster, indicating the container has started and can receive requests.

```json
{
  "name" : "your-node-name",
  "cluster_name" : "docker-cluster",
  "version" : {
    "distribution" : "opensearch",
    "number" : "3.6.0"
  },
  "tagline" : "The OpenSearch Project: https://opensearch.org/"
}
```

--------------------------------

### Install lfx-bundles with notion extra

Source: https://docs.langflow.org/extensions-bundle-list

Install the lfx-bundles package with the notion extra using uv.

```bash
uv pip install "lfx-bundles[notion]"
```

--------------------------------

### Get configuration result

Source: https://docs.langflow.org/api-reference-api-examples

Example JSON response from the /api/v1/config endpoint showing configuration details such as feature flags, serialization limits, and timeouts.

```json
{
  "feature_flags": {
    "mvp_components": false
  },
  "serialization_max_items_length": 1000,
  "serialization_max_text_length": 6000,
  "frontend_timeout": 0,
  "auto_saving": true,
  "auto_saving_interval": 1000,
  "health_check_max_retries": 5,
  "max_file_size_upload": 1024,
  "webhook_polling_interval": 5000,
  "public_flow_cleanup_interval": 3600,
  "public_flow_expiration": 86400,
  "event_delivery": "streaming",
  "webhook_auth_enable": true,
  "voice_mode_available": false,
  "default_folder_name": "Starter Project",
  "hide_getting_started_progress": false
}

```

--------------------------------

### List all users result

Source: https://docs.langflow.org/api-users

Example JSON response from the GET /api/v1/users/ endpoint, showing a paginated list of users with total_count and user objects.

```json
{
  "total_count": 3,
  "users": [
    {
      "id": "07e5b864-e367-4f52-b647-a48035ae7e5e",
      "username": "langflow",
      "profile_image": null,
      "store_api_key": null,
      "is_active": true,
      "is_superuser": true,
      "create_at": "2025-05-08T17:59:07.855965",
      "updated_at": "2025-05-29T15:06:56.157860",
      "last_login_at": "2025-05-29T15:06:56.157016",
      "optins": {
        "github_starred": false,
        "dialog_dismissed": true,
        "discord_clicked": false,
        "mcp_dialog_dismissed": true
      }
    },
    {
      "id": "c48a1f68-cc7e-491a-a507-a1a627708470",
      "username": "newuser",
      "profile_image": null,
      "store_api_key": null,
      "is_active": false,
      "is_superuser": false,
      "create_at": "2025-05-29T16:00:33.483386",
      "updated_at": "2025-05-29T16:00:33.483392",
      "last_login_at": null,
      "optins": {
        "github_starred": false,
        "dialog_dismissed": false,
        "discord_clicked": false
      }
    },
    {
      "id": "10c1c6a2-ab8a-4748-8700-0e4832fd5ce8",
      "username": "newuser2",
      "profile_image": null,
      "store_api_key": null,
      "is_active": false,
      "is_superuser": false,
      "create_at": "2025-05-29T16:02:20.132436",
      "updated_at": "2025-05-29T16:02:20.132442",
      "last_login_at": null,
      "optins": {
        "github_starred": false,
        "dialog_dismissed": false,
        "discord_clicked": false
      }
    }
  ]
}
```

--------------------------------

### POST /v1/mcp/project/{project_id}/install

Source: https://docs.langflow.org/api-reference-api-examples

Installs MCP client config for Cursor/Windsurf/Claude (local only).

```APIDOC
## POST /v1/mcp/project/{project_id}/install

### Description
Installs MCP client config for Cursor/Windsurf/Claude (local only).

### Method
POST

### Endpoint
/v1/mcp/project/{project_id}/install

### Parameters
#### Path Parameters
- **project_id** (string) - Required - The ID of the project.

```
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