AI & Agents

How to Add File Storage to Flowise Chatflows

Flowise makes it easy to build AI agents, but managing the files they create or use can be tricky. Most default setups store files on the local disk or inside ephemeral containers, meaning you lose everything if the system restarts. This guide shows you how to connect external storage so your agent documents and outputs stay safe and accessible.

Fastio Editorial Team 6 min read
Connect Flowise agents to persistent cloud storage for secure file handling.

Why Flowise Needs External File Storage

Flowise is an open-source platform for building LLM apps without code. It lets you build chatflows that handle documents, manage knowledge bases, and save agent outputs. However, the default setup uses a local database and the local filesystem for uploads. This causes three main issues for real-world apps:

Data Loss in Containers: If you run Flowise on Docker, Railway, or Render, the local disk is temporary. When the container restarts, your uploads and files vanish. 2.

Scaling Issues: Storing big PDFs or datasets on the same server as your app makes the instance heavy and hard to scale. 3.

Handoff Friction: If an agent generates a report, there is no easy way for a user to find it later. You usually end up with broken download links and no history for the user. Using external storage fixes this by keeping your data separate from the code running your agents.

Helpful references: Fastio Workspaces, Fastio Collaboration, and Fastio AI.

Logs showing file persistence issues in containerized environments

Native Storage Options: Local vs. S3

Flowise has basic support for external storage through environment variables. You can change where files are saved by updating your config.

Local Storage (Default)

By default, STORAGE_TYPE is set to local. Files go to .flowise/storage on the machine running the app. This is fine for testing on your laptop but risky for anything else.

AWS S3 Integration

You can tell

Flowise to use AWS S3 by setting STORAGE_TYPE=s3 and adding your AWS keys (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION, AWS_BUCKET_NAME).

The Good:

  • Files stay safe even if the container dies. * Uses a standard industry tool.

The Bad:

  • Setting up IAM permissions is a chore. * There is no interface for users to see their files. * You have to write extra code to create shareable links for users.

A More Reliable Option: Fastio for Agent Storage

If your agents need to give files to people (or if people need to send files to agents), Fastio is a better way to handle it. It goes beyond simple storage by providing a branded portal for your users, global speed, and a dedicated MCP server for your agents.

Why use Fastio with Flowise? * Built-in Delivery Portals: When an agent saves a file, it shows up in a secure, branded portal. You don't have to build a frontend for file downloads. * Simple MCP Connection: The Fastio MCP server connects your Flowise agent to storage with one command, giving it 251 tools to manage files. * Free for Developers: The free plan gives you 50GB of storage and 5,000 API credits a month, which is plenty for building and testing. Industry trends suggest enterprise AI workflows increasingly require persistent file handoffs between agents and humans.

Fastio AI agent delivery portal interface
Fastio features

Give Your AI Agents Persistent Storage

Stop losing agent data when your system restarts. Get 50GB of free, persistent storage with a built-in delivery portal for your AI workflows.

Step-by-Step: Connecting Fastio to Flowise

You can connect Flowise to Fastio in two ways: with the HTTP Request Tool (simple) or the MCP Tool (for advanced agents).

Method 1: Using the HTTP Request Node

Use this for simple file uploads.

Get your API Key: Sign up for a free account at Fastio and grab an API key. 2.

Add HTTP Request Node: Drag a "Custom Tool" or "HTTP Request" node into your Flowise chatflow. 3.

Configure the Endpoint: * URL: https://api.fast.io/v1/files/upload * Method: POST * Headers: Authorization: Bearer <YOUR_KEY>

  • Body: Send the file content from the previous node in your chain.

Fastio MCP Server Method

If your agent needs to search, read, and organize files, use the Model Context Protocol.

Start the MCP Server: Run the Fastio MCP server using Docker or Node.js. 2.

Connect Flowise: In Flowise, use the "MCP Tool" node and point it to your server. 3.

Choose Your Tools: Enable tools like files_list, files_read, or files_write. Now the agent can decide when to save its work, check for existing files, or look up information from a previous chat.

Example: Document Processing Pipeline

A popular use for Flowise is building an automated document pipeline. Here is how you can set one up with reliable storage:

Upload: A user drops a PDF into a Fastio "Input" folder using a shared link. 2.

Trigger: A webhook tells your Flowise workflow that a new file is ready. 3.

Process: * The agent uses the files_read tool to pull the PDF. * The LLM (like GPT-4o or Claude) pulls out the data you need, like invoice dates or totals. 4.

Save: * The agent saves the results as a JSON file in an "Output" folder. * The agent moves the original PDF to an archive folder. This way, nothing gets lost in the chat window. Everything is stored, logged, and easy to find later.

AI agent document processing pipeline with audit logs

Security for Agent Files

When agents handle files, security is the top priority. Standard local storage doesn't give you much control over who sees what.

How Fastio secures agent data:

  • Full Audit Logs: You can see every time an agent reads or writes a file.
  • File Locking: This prevents two agents from trying to edit the same file at the same time, which stops data from getting corrupted.
  • Isolation: Your files live in the cloud, separate from your Flowise server. This keeps your data safe even if your agent environment has a security issue. For teams in serious industries, keeping your compute (Flowise) and your storage (Fastio) separate is a key security practice.

Frequently Asked Questions

How do I add file storage to Flowise?

You can add storage by changing the `STORAGE_TYPE` environment variable to `s3`, or by using external APIs like Fastio with the HTTP Request node or MCP tools. We don't recommend using the default `local` storage for production apps.

Can Flowise chatbots save files?

Yes, they can. But they need a place to put them. By default, they save to the local server, which isn't reliable. For a better experience, connect a cloud storage provider so users can access their files later.

What storage options work with Flowise?

Flowise supports Local disks and AWS S3 out of the box. You can also connect to Fastio, Google Drive, or Dropbox by using the Custom Tool or HTTP Request nodes in your workflow.

How do I use Flowise for document processing?

Upload your files to a storage system like Fastio, trigger your workflow with a webhook, and have an agent read the file, extract the data, and save the result back to a folder.

Related Resources

Fastio features

Give Your AI Agents Persistent Storage

Stop losing agent data when your system restarts. Get 50GB of free, persistent storage with a built-in delivery portal for your AI workflows.