nsfwbot for Matrix

nsfwbot is a Maubot plugin for Matrix that helps maintain appropriate content in chat rooms by detecting NSFW (Not Safe For Work) images. It uses nsfwdetection, a lightweight model that can run efficiently without requiring a GPU.

Features

• Image Analysis: Detects and analyses images posted in Matrix chats.
• Text Message Parsing: Analyses images embedded in text messages.
• Configurable Concurrency: Controls concurrent image processing tasks.
• Configurable Threshold: Adjust the NSFW detection threshold to avoid false positives.
• Custom Actions: Configurable actions for detected content, including reporting and redacting messages.
• Error Reporting: Option to report processing errors to a moderation room.

Requirements

• Maubot
• Python Dependencies:
  • beautifulsoup4: For HTML message parsing
  • nsfwdetection: For image content analysis

Important: As well as requiring the above plugins, the default Alpine-based Maubot Docker image is not compatible with nsfwdetection. You can use my custom Debian-based image instead: ghcr.io/tcpipuk/maubot:debian

Quick Start

1. Use our Debian-based Maubot image:

   docker pull ghcr.io/tcpipuk/maubot:debian

2. Install the plugin (choose one method):

   • Download from releases

   • Build from source:

     git clone https://github.com/tcpipuk/matrix-nsfwbot
     cd matrix-nsfwbot
     zip -r nsfwbot.mbp nsfwbot/ maubot.yaml base-config.yaml

3. Upload and Configure:

   • Upload through the Maubot admin interface
   • Configure settings (see Configuration section)
   • Enable the plugin

Configuration Guide

Edit settings in the Maubot admin interface or base-config.yaml:

# Control concurrent processing
max_concurrent_jobs: 2

# NSFW detection threshold (0.0 to 1.0)
nsfw_threshold: 0.65

# Central reporting room
report_to_room: "#moderation:example.org"

# Servers for matrix.to URLs
via_servers:
  - "matrix.org"
  - "example.org"

# Response configuration
actions:
  # Skip reporting safe content
  ignore_sfw: true

  # Remove inappropriate messages
  redact_nsfw: false

  # Reply in the source room
  direct_reply: true

  # Report processing errors to moderation room
  post_errors: false

Tip: Using room IDs (like !room:server) is more efficient than aliases (like #room:server) for the report_to_room setting.

Usage Examples

Single Image Upload

User: [uploads image]
Bot: mxc://matrix.org/abc123 in https://matrix.to/#/!room:example.org/$event
     appears NSFW with score 87.93%

Multiple Embedded Images

User: [message with embedded images]
Bot: - mxc://matrix.org/abc123 appears SFW with score 2.45%
     - mxc://matrix.org/xyz789 appears NSFW with score 94.82%

Deployment Example

Using matrix-docker-ansible-deploy:

maubot:
  plugins:
    nsfwbot:
      image: "ghcr.io/tcpipuk/maubot:debian"
      version: "v0.3.0"
      config:
        max_concurrent_jobs: 4
        nsfw_threshold: 0.65
        actions:
          redact_nsfw: true
          post_errors: true

Contributing

Contributions are welcome! Open an issue or submit a pull request on GitHub.

Licence

This project is licensed under the AGPLv3 Licence. See the LICENCE file for details.