# Meddle

> Meddle is a visual data integration platform for industrial automation and IoT. It provides 22 connector types to read data from sources, write data to destinations, and process/transform data in transit—all without writing code.

Meddle connects to industrial systems (OPC UA, Modbus, Siemens S7, Allen-Bradley/Rockwell Logix, CoAP), IoT protocols and databases (MQTT, HTTP, InfluxDB, MongoDB, SQL, Redis, Firebase), and provides processing connectors for data transformation (Filter, Merge, Reshape, Trigger, Cron, Auth, Anomaly Detection, Alert, Chart).

Key concepts:
- **Connectors**: Building blocks that read, write, or process data
- **Worksheets**: Visual workflows connecting connectors together
- **Variables**: For industrial connectors, define what data to read/write
- **Data Payload**: Standard key-value JSON format for all data exchange

## Documentation

- [Getting Started](/en/getting-started/): Quick start guide for Meddle
- [Connectors Overview](/en/connectors/overview/): Overview of all 22 connector types

## Industrial Connectors

- [OPC UA](/en/connectors/industrial/opcua/): Industry-standard protocol for industrial automation with multiple auth methods
- [Modbus](/en/connectors/industrial/modbus/): Serial and TCP communication with PLCs, supports all register types
- [Siemens S7](/en/connectors/industrial/s7/): Direct communication with Siemens S7-300/400/1200/1500 PLCs
- [Logix](/en/connectors/industrial/logix/): Allen-Bradley/Rockwell PLC communication via EtherNet/IP (CIP)
- [CoAP](/en/connectors/industrial/coap/): Constrained Application Protocol for resource-limited IoT devices

## IoT & Database Connectors

- [MQTT](/en/connectors/iot-database/mqtt/): Publish/subscribe messaging for IoT devices
- [HTTP](/en/connectors/iot-database/http/): REST API integration with customizable headers and methods
- [InfluxDB](/en/connectors/iot-database/influxdb/): Time-series database for industrial and IoT data
- [MongoDB](/en/connectors/iot-database/mongodb/): NoSQL document database storage
- [SQL](/en/connectors/iot-database/sql/): MySQL, PostgreSQL, and SQL Server support
- [Redis](/en/connectors/iot-database/redis/): In-memory data store for caching and queuing
- [Firebase](/en/connectors/iot-database/firebase/): Google Cloud Firestore for NoSQL document storage

## Processing Connectors

- [Filter](/en/connectors/processing/filter/): Whitelist or blacklist specific data keys
- [Conveyor](/en/connectors/processing/conveyor/): Pass data unchanged for many-to-many routing
- [Merge](/en/connectors/processing/merge/): Combine data from multiple sources
- [Reshape](/en/connectors/processing/reshape/): Rename fields or enrich data with static values
- [Trigger](/en/connectors/processing/trigger/): Conditional logic using MXL expressions
- [Cron](/en/connectors/processing/cron/): Schedule data release at specific times
- [Auth](/en/connectors/processing/auth/): JWT authentication and validation
- [Anomaly Detection](/en/connectors/processing/anomaly-detection/): ML-based anomaly detection using Isolation Forest
- [Alert](/en/connectors/processing/alert/): Send notifications based on conditions
- [Chart](/en/connectors/processing/chart/): Real-time data visualization

## Reference

- [MXL Expression Language](/en/reference/mxl/): Conditional expressions for Trigger and Alert connectors