langflow-mcp-server

A Model Context Protocol (MCP) server that provides AI assistants with comprehensive access to Langflow workflow automation platform.

Overview

langflow-mcp-server serves as a bridge between Langflow's workflow automation platform and AI models, enabling them to understand and work with Langflow flows effectively.

API Compatibility: This server is built on the Langflow API documentation and targets Langflow API version 1.12.6 in the 1.12.x family. The latest stable upstream release check on 2026-10-17 found v1.12.6, published 2026-10-13. The v1.12.4 to v1.12.6 source comparison found changed history limits, credential masking, and execution/attachment policies, without a required client route migration. The client preserves upstream authorization and validation errors. Workflow runs expose the optional expose_graph_state control added in 1.12.3: omitted or null uses the protocol default (conversation-only for AG-UI, graph events for Langflow); synchronous runs ignore it, and stream or background runs by a non-owner of a shared flow always run with it off. Memory Base creation exposes the optional embedding_provider added in 1.12.1. The 1.12.x API family adds headless agentic execution, provider descriptors, project upsert, governance policy endpoints, and a Kubernetes-style readiness probe. Existing A2A, v2 workflow HITL/public execution, and public build lifecycle support remains available.

Versioning: From 4.10.0 onward, the npm minor version mirrors the supported Langflow minor - langflow-mcp-server@4.<langflow_minor>.x targets Langflow 1.<langflow_minor>.x (so 4.12.x targets Langflow 1.12.x, 4.11.x targets Langflow 1.11.x). The patch component is used for fixes within the same Langflow minor.

Langflow 1.12.6 returns the newest 100 sessions or messages by default, with a maximum of 200 per request; an omitted or zero limit selects the default. Both MCP modes expose limit for normal/shared sessions and messages, plus offset and display order for message history. Session lists have no upstream offset or cursor, so they cannot enumerate older sessions beyond the cap. Message-ID lookup scans history pages within the configured Langflow timeout. Concurrent history changes can shift offset-based pages; these reads are not snapshots. MCP server configuration responses mask stored credentials as ********; these responses are not credential backups. Counted MCP discovery can return HTTP 429 when busy, and attachment/execution requests remain subject to upstream scope and policy checks.

Audit-log event filters and provider/model/store list filters retain repeated query keys. Regression tests cover these requests, history controls, masked configuration responses and upstream errors; installed-tarball smoke tests exercise both MCP modes over stdio and HTTP with local fixtures. This evidence covers source contracts and local requests, not a live end-to-end run against Langflow 1.12.6. Development builds of Langflow 1.13 are not covered by the compatibility claim above.

Consolidated Tools Mode

Consolidated Tools Mode is an architecture that groups the 236 individual tools into 29 action-based meta-tools. This significantly reduces token usage and improves AI assistant context management.

Mode	Tools	Best For
Standard	236 tools	Full granular control
Consolidated	29 tools	Reduced token usage, better context

To enable consolidated mode:

LANGFLOW_CONSOLIDATED_TOOLS=true

Consolidated tools:

• flow - All flow operations (list, get, create, update, delete, download, upload, replace, expand, batch, public, note_translations)
• flow_execution - Run flows (run, run_advanced, run_session, webhook, process, predict)
• flow_version - Flow versions and lifecycle events (list, create, get, delete, activate, get_events, create_event)
• build - Build operations (start, status, cancel, public build lifecycle, vertices)
• workflow - Run and manage v2 workflows (run with request-level globals, get_result, stop, plus HITL/public execution)
• agentic - Agentic assistant + sandbox (assist, assist_stream, assist_run, check_config, execute, get_file, reset_session)
• folder - Folder management (list, get, create, update, delete, download, upload)
• project - Project management (list, get, create, update, upsert, delete, download, upload)
• variable - Variable operations (list, create, update, delete, detect)
• knowledge_base - Knowledge base management (list, get, delete, bulk_delete, upload, create, preview/list chunks, ingest, cancel_ingest, test_connection, list_connectors, ingest_folder, ingest_connector, metadata_keys, list_runs, get_run)
• memory - Memory bases (create, list, get, list_sessions, list_messages, update, delete, flush, mismatch, regenerate) — experimental Langflow API
• file - Flow-scoped file operations (list, upload, download, delete, get_image)
• file_v2 - User-scoped v2 files (list, upload, get, rename, delete, delete_all, batch_download, batch_delete)
• monitor - Monitoring (builds, messages, sessions, transactions, job_queue)
• trace - Execution traces (list, get, delete, delete_by_flow)
• model - Models and providers (list, providers, provider descriptors, enabled, default get/set/delete, mapping, validate, options)
• governance - Langflow 1.12.x provider, catalog, and policy-bundle administration
• authz - RBAC authorization (roles, role assignments, teams, shares, audit, my permissions)
• user - User management (list, get_current, update, reset_password, create)
• auth - Authentication (login, auto_login, logout, refresh, api keys, save_store_key)
• store - Component store (list, get, tags, likes, save_api_key, create, like, update_custom)
• registration - User registration (get, register)
• validation - Code/prompt validation (code, prompt)
• mcp_server - MCP server management (list, get, create, update, delete)
• mcp_project - MCP project config/install (get/update config, get_installed, install, composer_url)
• extension - Langflow extensions (reload, events)
• response - OpenAI-compatible responses (create)
• system - System info (health, version, logs, pictures, voices, session, webhook_events, health_check, healthz)
• a2a - A2A (Agent-to-Agent) protocol (list_agents, agent_card, jsonrpc)

It provides structured access to:

• Flow Management - Create, read, update, delete, and execute Langflow flows
• Flow Execution - Run flows with inputs and trigger webhooks
• Build Operations - Compile, validate, and monitor flow builds
• Import/Export - Upload and download flows and projects
• Organization - Manage folders and projects
• Configuration - Manage global variables
• Knowledge Bases - Manage RAG document collections
• Component Discovery - List all available Langflow components

Quick Start

Prerequisites

• Node.js 20 or newer installed on your system
• A running Langflow instance
• Langflow API key

Installation

# Install from npm
npm install -g langflow-mcp-server

# OR clone the repository
git clone https://github.com/nobrainer-tech/langflow-mcp.git
cd langflow-mcp

# Install dependencies
npm install

# Build the project
npm run build

# Configure environment
cp .env.example .env
# Edit .env with your Langflow instance URL and API key

Configuration

Edit .env file:

LANGFLOW_BASE_URL=http://localhost:7860
LANGFLOW_API_KEY=your-api-key-here
MCP_MODE=stdio
LOG_LEVEL=info

Claude Desktop Setup

Add to your Claude Desktop config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json Linux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "langflow": {
      "command": "npx",
      "args": ["-y", "langflow-mcp-server"],
      "env": {
        "LANGFLOW_BASE_URL": "http://localhost:7860",
        "LANGFLOW_API_KEY": "your-api-key-here",
        "LANGFLOW_CONSOLIDATED_TOOLS": "true",
        "MCP_MODE": "stdio",
        "LOG_LEVEL": "error"
      }
    }
  }
}

Alternative (local installation):

{
  "mcpServers": {
    "langflow": {
      "command": "node",
      "args": ["/absolute/path/to/langflow-mcp/dist/mcp/index.js"],
      "env": {
        "LANGFLOW_BASE_URL": "http://localhost:7860",
        "LANGFLOW_API_KEY": "your-api-key-here",
        "MCP_MODE": "stdio",
        "LOG_LEVEL": "error"
      }
    }
  }
}

Restart Claude Desktop after updating configuration.

Claude Code, Codex, and other MCP hosts

The server supports both standard MCP transports: local stdio and remote Streamable HTTP. MCP clients use the same tool and schema surface regardless of transport. Use stdio when the host can launch a local process; use HTTP when the server runs as a separately deployed service.

Codex CLI — local stdio

codex mcp add langflow \
  --env LANGFLOW_BASE_URL=http://localhost:7860 \
  --env LANGFLOW_API_KEY=your-api-key-here \
  -- npx -y langflow-mcp-server

Claude Code — local stdio

claude mcp add langflow \
  -e LANGFLOW_BASE_URL=http://localhost:7860 \
  -e LANGFLOW_API_KEY=your-api-key-here \
  -- npx -y langflow-mcp-server

Remote Streamable HTTP

Start the server with an explicit bearer token when binding outside the local machine. HOST=127.0.0.1 is the secure default; use HOST=0.0.0.0 only with authentication and a TLS-terminating reverse proxy.

MCP_MODE=http \
HOST=0.0.0.0 \
PORT=3000 \
AUTH_TOKEN=replace-with-a-long-random-token \
LANGFLOW_BASE_URL=https://langflow.example.com \
LANGFLOW_API_KEY=your-api-key-here \
npx -y langflow-mcp-server

The MCP endpoint is https://your-host.example/mcp; the health endpoint is https://your-host.example/health. For browser-based callers, set MCP_ALLOWED_ORIGINS to a comma-separated list of exact HTTPS origins. Wildcard origins are rejected.

Codex CLI can keep the bearer token in an environment variable:

export LANGFLOW_MCP_TOKEN='set-this-in-your-shell'
codex mcp add langflow-remote \
  --url https://your-host.example/mcp \
  --bearer-token-env-var LANGFLOW_MCP_TOKEN

The environment variable must be present whenever Codex starts or reconnects to this server.

Claude Code accepts the same Streamable HTTP endpoint:

export LANGFLOW_MCP_TOKEN='set-this-in-your-shell'
claude mcp add --transport http --scope user \
  --header "Authorization: Bearer ${LANGFLOW_MCP_TOKEN}" \
  langflow-remote https://your-host.example/mcp

This stores the header in the Claude MCP configuration; keep that configuration outside source control. Hosts such as Cloud Code, Gemini clients, and other MCP-compatible tools can use the same /mcp endpoint when they support Streamable HTTP; their configuration syntax is host-specific and has not been claimed as an end-to-end test in this repository.

Docker Deployment

The MCP server can be run in a Docker container for easier deployment and isolation.

Quick Start with Docker

# Clone the repository
git clone https://github.com/nobrainer-tech/langflow-mcp.git
cd langflow-mcp

# Create .env file with your configuration
cp .env.example .env
# Edit .env with your Langflow instance URL and API key

# Build and run with docker-compose
docker-compose up -d

# View logs
docker-compose logs -f

# Stop the server
docker-compose down

Building Docker Image

# Build the image
docker build -t langflow-mcp-server:latest .

# Run in stdio mode (for Claude Desktop)
docker run -it --rm \
  -e LANGFLOW_BASE_URL=http://localhost:7860 \
  -e LANGFLOW_API_KEY=your-api-key \
  langflow-mcp-server:latest

# Run in HTTP mode (for remote access)
docker run -d \
  -p 3000:3000 \
  -e MCP_MODE=http \
  -e HOST=0.0.0.0 \
  -e PORT=3000 \
  -e AUTH_TOKEN=your-secure-token \
  -e MCP_ALLOWED_ORIGINS=https://your-client.example \
  -e LANGFLOW_BASE_URL=http://langflow:7860 \
  -e LANGFLOW_API_KEY=your-api-key \
  langflow-mcp-server:latest

Docker Compose Configuration

The included docker-compose.yml supports both stdio and HTTP modes:

# STDIO mode (default)
environment:
  - MCP_MODE=stdio
  - LANGFLOW_BASE_URL=http://localhost:7860
  - LANGFLOW_API_KEY=your-key

# HTTP mode
environment:
  - MCP_MODE=http
  - PORT=3000
  - AUTH_TOKEN=your-secure-token
  - MCP_ALLOWED_ORIGINS=https://your-client.example

Available MCP Tools

Once connected, Claude can use:

• Standard mode: 236 individual tools
• Consolidated mode: 29 action-based tools (recommended for reduced token usage)

Note: Raw Langflow transport endpoints (/api/mcp/*) and doc-rendering endpoints (/docs, /redoc, /openapi.json) are intentionally not exposed as tools — they are protocol/transport surfaces, not data operations.

Standard Mode Tools (236 tools)

Flow Management (13 tools)

• create_flow - Create a new Langflow flow
• list_flows - List all flows with pagination and filtering
• get_flow - Get details of a specific flow by ID
• update_flow - Update an existing flow
• delete_flow - Delete a single flow
• delete_flows - Delete multiple flows at once
• replace_flow - Replace a flow's full definition
• expand_flows - Expand flows with embedded component data
• upload_flow - Upload a flow from JSON data
• download_flows - Download multiple flows as JSON export
• get_basic_examples - Get pre-built example flows
• batch_create_flows - Create multiple flows in one operation
• get_public_flow - Get a public flow without authentication

Flow Execution (7 tools)

• run_flow - Execute a flow with input configuration (supports streaming)
• run_flow_advanced - Advanced flow execution with full control
• run_flow_session - Execute a flow within a session context
• trigger_webhook - Trigger a flow via webhook endpoint
• get_webhook_events - Get webhook trigger events for a flow
• process_flow - Legacy process endpoint for flows
• predict_flow - Legacy predict endpoint for flows

Flow Versions & Events (7 tools)

• list_flow_versions - List versions of a flow
• create_flow_version - Create a new flow version
• get_flow_version - Get a specific flow version
• delete_flow_version - Delete a flow version
• activate_flow_version - Activate a specific flow version
• get_flow_events - Get lifecycle events for a flow
• create_flow_event - Create a lifecycle event for a flow

Build Operations (9 tools)

• build_flow - Build/compile a flow and return job_id for async execution
• get_build_status - Poll build status and events for a specific job
• cancel_build - Cancel a running build job
• build_public_flow - Build a public flow without authentication
• get_public_build_events - Get events for a public build job
• cancel_public_build - Cancel a public build job
• get_task_status - Get status of an async task
• build_vertices - Get vertex build order for a flow
• stream_vertex_build - Stream real-time build events for a vertex

Workflows (v2) (7 tools)

• run_workflow - Run a v2 workflow
• get_workflow_result - Get the result of a workflow run
• stop_workflow - Stop a running workflow
• list_pending_workflows - List pending HITL requests for a flow
• get_workflow_events - Re-attach to a workflow job event stream
• resume_workflow - Resume a workflow with a request ID and optional decision
• run_public_workflow - Run a public stream-only workflow

Agentic (5 tools)

• agentic_assist - Get agentic assistance for a flow component
• agentic_assist_stream - Get streaming agentic assistance for a flow component
• agentic_assist_run - Run the assistant headlessly and persist flow changes
• agentic_check_config - Check whether agentic features are configured
• agentic_execute - Execute an agentic flow by name

Responses (2 tools)

• create_response - Create an OpenAI-compatible response
• get_session - Get a response/conversation session

Folder Management (7 tools)

• list_folders - List all folders with pagination
• create_folder - Create a new folder
• get_folder - Get folder details by ID
• update_folder - Update folder name, description, or parent
• delete_folder - Delete a folder
• download_folder - Download entire folder as archive
• upload_folder - Upload folder from archive

Project Management (8 tools)

• list_projects - List all projects with pagination
• create_project - Create a new project
• get_project - Get project details by ID
• update_project - Update project name or description
• upsert_project - Create or update a project at a caller-supplied ID
• delete_project - Delete a project
• upload_project - Upload a project from JSON data
• download_project - Download a project as JSON export

Variable Management (5 tools)

• list_variables - List all global variables
• create_variable - Create a new variable
• update_variable - Update variable properties
• delete_variable - Delete a variable
• detect_variables - Detect variables referenced in a value/template

Knowledge Base Management (11 tools)

• list_knowledge_bases - List all available knowledge bases
• list_knowledge_bases_detailed - List knowledge bases with detailed metadata
• get_knowledge_base - Get detailed information about a specific knowledge base
• create_knowledge_base - Create a new knowledge base
• delete_knowledge_base - Delete a specific knowledge base
• bulk_delete_knowledge_bases - Delete multiple knowledge bases at once
• upload_knowledge_base - Upload a file to create/update a knowledge base
• preview_knowledge_base_chunks - Preview how a document will be chunked
• list_knowledge_base_chunks - List stored chunks for a knowledge base
• ingest_knowledge_base - Ingest documents into a knowledge base
• cancel_knowledge_base_ingest - Cancel an in-progress ingest job

File Management (5 tools)

• upload_file - Upload a file to a specific flow
• download_file - Download a file from a flow
• list_files - List all files in a flow
• delete_file - Delete a file from a flow
• get_file_image - Get an image file from a flow

Files (v2) (8 tools)

• list_files_v2 - List all user-scoped v2 files
• upload_file_v2 - Upload a v2 file
• get_file_v2 - Get v2 file metadata or content
• rename_file_v2 - Rename a v2 file
• delete_file_v2 - Delete a v2 file
• delete_all_files_v2 - Delete all v2 files
• batch_download_files_v2 - Download multiple v2 files
• batch_delete_files_v2 - Delete multiple v2 files

Component Discovery & Custom Components (3 tools)

• list_components - List all available Langflow components
• create_custom_component - Create a new custom component
• update_custom_component - Update an existing custom component

Monitoring & Analytics (12 tools)

• get_monitor_builds - Get build execution history for a flow
• get_monitor_messages - Query a message-history window with filtering, limit, offset, and display order
• get_monitor_message - Look up a message across history pages within the configured timeout
• update_monitor_message - Update a stored message
• get_monitor_sessions - List the newest session IDs (limit: default 100, maximum 200)
• get_monitor_session_messages - Query a session's message-history window with limit, offset, and display order
• migrate_monitor_session - Migrate messages between sessions
• get_monitor_transactions - List transaction logs for a flow
• delete_monitor_builds - Delete build history for a flow
• delete_monitor_messages - Delete multiple messages by ID
• delete_monitor_session_messages - Delete all messages for a session
• delete_monitor_sessions - Delete chat sessions

Traces (4 tools)

• list_traces - List execution traces with filters
• get_trace - Get a specific execution trace
• delete_trace - Delete a specific trace
• delete_traces - Delete all traces for a flow

Shared Messages (5 tools)

• get_shared_messages - Query a shared message-history window with limit, offset, and display order
• get_shared_sessions - List the newest shared session IDs (limit: default 100, maximum 200)
• update_shared_message - Update a shared message
• migrate_shared_session - Migrate a shared session
• delete_shared_session - Delete a shared session

Models & Providers (13 tools)

• list_models - List available models
• list_model_providers - List all model providers
• list_model_provider_descriptors - List providers with stable IDs and display names
• list_enabled_providers - List enabled providers
• list_enabled_models - List enabled models
• set_enabled_models - Enable/disable models
• get_default_model - Get the default model for a type
• set_default_model - Set the default model for a type
• delete_default_model - Remove the default model for a type
• get_provider_variable_mapping - Get provider-to-variable mapping
• validate_model_provider - Validate provider credentials
• get_language_model_options - Get language model options
• get_embedding_model_options - Get embedding model options

User Management (5 tools)

• list_users - List all users (admin only)
• get_current_user - Get current authenticated user info
• update_user - Update user profile information
• reset_user_password - Reset password for a user (admin only)
• create_user - Create a new user (admin only)

API Key Management (3 tools)

• list_api_keys - List all API keys for the user
• create_api_key - Create a new API key
• delete_api_key - Delete an API key

Authentication (4 tools)

• login - Authenticate with username and password
• auto_login - Auto-login with stored credentials
• refresh_token - Refresh authentication token
• logout - Logout and invalidate session

Registration (2 tools)

• get_registration - Check whether registration is enabled
• register_user - Register a new user account

Store & Marketplace (9 tools)

• check_store - Check if component store is enabled
• check_store_api_key - Validate a store API key
• save_store_api_key - Save a store API key
• list_store_components - Browse available components in the store
• get_store_component - Get details of a store component
• create_store_component - Publish a component to the store
• like_store_component - Like a store component
• list_store_tags - List all component tags in the store
• get_user_likes - Get components liked by user

Validation (2 tools)

• validate_code - Validate Python code for custom components
• validate_prompt - Validate prompt template syntax

MCP Servers (v2) (5 tools)

• list_mcp_servers - List MCP servers registered with Langflow
• get_mcp_server - Get an MCP server by name
• create_mcp_server - Create an MCP server
• update_mcp_server - Update an MCP server
• delete_mcp_server - Delete an MCP server

MCP Project Management (5 tools)

• get_mcp_project_config - Get MCP config for a project
• update_mcp_project_config - Update MCP config for a project
• get_mcp_project_installed - Get installed MCP clients for a project
• install_mcp_project - Install MCP for a project into a client
• get_mcp_project_composer_url - Get the MCP composer URL for a project

Starter & Templates (1 tool)

• list_starter_projects - List available starter templates

Profile & Media (2 tools)

• list_profile_pictures - List available profile pictures
• get_profile_picture - Get a specific profile picture

Integration Tools (1 tool)

• list_elevenlabs_voices - List ElevenLabs text-to-speech voices

System & Health (5 tools)

• get_version - Get Langflow API version information
• health_check - Check Langflow instance health status
• get_health_check - Get a detailed health-check report
• get_healthz - Get the Kubernetes-style readiness report
• get_logs - Retrieve system logs (supports streaming)

Authorization / RBAC (23 tools, Langflow 1.10.0)

• list_authz_roles, get_authz_role, create_authz_role, update_authz_role, delete_authz_role - Manage roles
• list_authz_role_assignments, create_authz_role_assignment, delete_authz_role_assignment - Manage role assignments
• list_authz_teams, get_authz_team, create_authz_team, update_authz_team, delete_authz_team - Manage teams
• list_authz_team_members, add_authz_team_member, remove_authz_team_member - Manage team members
• list_authz_shares, get_authz_share, create_authz_share, update_authz_share, delete_authz_share - Manage resource shares
• get_authz_audit - Query the authorization audit log (superuser)
• get_my_permissions - Get the caller's effective permissions

Memory Bases (10 tools, Langflow 1.12.3 - experimental)

• create_memory_base, list_memory_bases, get_memory_base - Manage memory bases
• list_memory_base_sessions, list_memory_base_messages - Inspect tracked sessions/messages
• update_memory_base, delete_memory_base - Update/delete a memory base
• flush_memory_base, check_memory_base_mismatch, regenerate_memory_base - Lifecycle operations

Knowledge Base Overhaul (7 tools, Langflow 1.10.0)

• test_knowledge_base_connection - Test a vector backend connection
• list_knowledge_base_connectors - List available ingestion connectors
• ingest_knowledge_base_folder, ingest_knowledge_base_connector - Ingest from a server folder or connector
• get_knowledge_base_metadata_keys - List distinct metadata keys/values
• list_knowledge_base_runs, get_knowledge_base_run - Inspect ingestion runs

Extensions & Misc (6 tools, Langflow 1.10.0)

• reload_extension_bundle - Reload an extension bundle (requires server-side flag)
• get_extension_events - Poll extension events for the current user
• get_agentic_file - Read a file from the per-user agentic sandbox
• reset_agentic_session - Reset agentic session/sandbox state
• get_flow_note_translations - Get localized note-node translations for a flow
• get_job_queue_metrics - Job-queue metrics snapshot (superuser)

Langflow 1.12.x Governance (12 tools)

• get_model_provider_policy, replace_model_provider_policy - Read or replace the install-wide approved-provider policy
• get_catalog_component_policy, replace_catalog_component_policy - Read or replace blocked component keys
• get_catalog_template_policy, replace_catalog_template_policy - Read or replace blocked template keys
• get_catalog_policy_usage, get_catalog_policy_usage_flows - Inspect component usage across flows
• get_policy_bundle, replace_policy_bundle - Read or atomically replace the combined governance policy
• list_policy_bundle_history, rollback_policy_bundle - Inspect or roll back policy revisions

Policy replacement operations are superuser-only and use complete sets. Read the current policy revision before writing so optimistic concurrency conflicts are handled explicitly.

The v2 workflow runner (run_workflow / workflow action run) also accepts request-level globals, the preferred replacement for the deprecated X-LANGFLOW-GLOBAL-VAR-* headers.

A2A Protocol (3 tools, Langflow 1.12.x)

• list_a2a_agents - List available A2A (Agent-to-Agent) agents
• get_a2a_agent_card - Get a flow's A2A agent card (.well-known/agent-card.json)
• invoke_a2a_jsonrpc - Invoke a flow via the A2A JSON-RPC endpoint (passthrough envelope)

A2A endpoints require server-side enablement (LANGFLOW_A2A_ENABLED); otherwise requests surface as a thrown Failed to ... error.

v2 Workflow HITL & Public Execution (4 tools, Langflow 1.12.x)

• list_pending_workflows - List pending human-in-the-loop requests for a required flow_id
• get_workflow_events - Re-attach to a workflow job event stream by job ID
• resume_workflow - Resume a paused HITL workflow with request_id and an optional decision
• run_public_workflow - Run a public (unauthenticated-eligible) workflow

The get_workflow_events and run_public_workflow endpoints return server-sent-event streams; the initial payload is captured but streaming is not incrementally surfaced.

External / Trusted-JWT Authentication (Langflow 1.11.x)

Langflow 1.11.x adds external trusted-JWT / JIT-provisioning authentication. This is controlled entirely by the Langflow server environment and adds no MCP tools: EXTERNAL_AUTH_ENABLED, EXTERNAL_AUTH_TOKEN_HEADER/EXTERNAL_AUTH_TOKEN_COOKIE, EXTERNAL_AUTH_JWKS_URL, EXTERNAL_AUTH_ISSUER/EXTERNAL_AUTH_AUDIENCE/EXTERNAL_AUTH_ALGORITHMS, EXTERNAL_AUTH_*_CLAIM, and EXTERNAL_AUTH_ACCESS_CEILING_*. The MCP client keeps using its API key / Bearer token as before.

Example Usage

// Create a new flow
create_flow({
  name: "My Automation Flow",
  description: "A flow that processes data"
})

// List all flows
list_flows({
  page: 1,
  size: 50
})

// Get flow details
get_flow({
  flow_id: "flow-uuid-here"
})

// Update a flow
update_flow({
  flow_id: "flow-uuid-here",
  name: "Updated Flow Name"
})

// Execute a flow
run_flow({
  flow_id_or_name: "my-flow-name",
  input_request: {
    input_value: "Hello World",
    output_type: "chat",
    input_type: "chat"
  },
  stream: false
})

// Trigger via webhook
trigger_webhook({
  flow_id_or_name: "my-flow",
  input_request: {
    input_value: "Process this data"
  }
})

// Build a flow (compile/validate)
build_flow({
  flow_id: "flow-uuid-here",
  log_builds: true,
  event_delivery: "polling"
})

// Check build status
get_build_status({
  job_id: "job-uuid-from-build",
  event_delivery: "polling"
})

// List knowledge bases (RAG)
list_knowledge_bases()

// Get knowledge base details
get_knowledge_base({
  kb_name: "my-documents"
})

// Create a folder
create_folder({
  name: "My Flows",
  description: "Organized flows"
})

// Create a project
create_project({
  name: "My Project",
  description: "Project description"
})

// Manage variables
create_variable({
  name: "API_KEY",
  value: "secret-key",
  type: "string"
})

// Get basic examples
get_basic_examples()

// List all components
list_components()

Development

# Build
npm run build

# Run in development mode
npm run dev

# Run tests
npm test

# Type checking
npm run typecheck

# HTTP development server with automatic TypeScript reload
npm run dev:http

Project Structure

langflow-mcp/
├── src/
│   ├── mcp/
│   │   ├── index.ts       # MCP server entry point
│   │   ├── http.ts        # Streamable HTTP transport
│   │   ├── server.ts      # MCP server implementation
│   │   └── tools.ts       # Tool definitions
│   ├── services/
│   │   └── langflow-client.ts  # Langflow API client
│   ├── types/
│   │   └── index.ts       # TypeScript types
│   └── utils/
│       └── logger.ts      # Logging utility
├── .env.example           # Example configuration
├── package.json
├── tsconfig.json
└── README.md

Attribution

Developed with NoBrainer.Tech Flow for scoped implementation, independent reviews and release verification.

This project is inspired by and follows the structure of n8n-mcp by Romuald Czlonkowski. Special thanks to the n8n-mcp project for the excellent MCP server architecture and implementation patterns.

License

MIT License - see LICENSE for details.

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Run tests (npm test)
4. Submit a pull request

Acknowledgments

• Langflow team for the workflow automation platform
• Anthropic for the Model Context Protocol
• czlonkowski/n8n-mcp for the inspiration and architecture

Releasing

Release through .github/workflows/publish.yml on GitHub-hosted runners. The npm Trusted Publisher must use owner nobrainer-tech, repository langflow-mcp, workflow publish.yml, an empty environment and permission to run npm publish. No stored npm write token is required.

After reviewed changes are merged, push a new stable tag matching package.json and the lockfile. The workflow checks that the tag belongs to master, runs typecheck, tests, packaged MCP smoke and security audit, then publishes and verifies the exact npm commit and provenance before creating the GitHub Release. Existing tags must not be moved.

The provenance check binds the attestation's package, tarball SHA-512 digest, source repository and commit. It does not perform cryptographic verification of Sigstore signatures.

For tags created from 4.12.1 onward, recover an interrupted release by running the workflow at that exact tag (for example gh workflow run publish.yml --ref v4.12.1). This keeps the build source aligned with GitHub's provenance identity. An already-published version is accepted only when its commit and provenance match; it is never overwritten.

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Built with ❤️ for the Langflow community