FieldWorks protocol adapters
Rust MCP adapters with one tool surface. MQTT and OPC UA are implemented; Modbus, DNP3, and EtherNet/IP are stubs.
Who it's for
An engineer attaching an MCP client to MQTT / Sparkplug, OPC UA. Treat the write policy as the safety boundary: a gated write is still a write once you arm it.
Caveat / limitations
Apache-2.0 workspace. mqtt-mcp and opcua-mcp are marked complete. modbus-mcp, dnp3-mcp, ethernetip-mcp, and aveva-mcp are marked stubs, so they are not listed as protocols here. The MQTT adapter is MQTT 3.1.1/5, not Sparkplug B. The shared surface includes setpoint writes. Check topology.yaml before connecting anything real.
Protocols
- MQTT / SparkplugMQTT is the broker transport. Sparkplug B is a specific payload and state model on top of it, common in unified-namespace designs. A server that only speaks MQTT does not automatically decode Sparkplug.
- OPC UAThe cross-vendor information model most modern PLCs, SCADA hosts, and historians can expose. Security policy, certificates, and user identity matter as much as the node id.
Sources
- Repositoryhttps://github.com/fieldworks-build/fieldworks-adapters
This page: https://otaihub.com/tools/fieldworks-adapters
Same protocol
Compare all OPC UA MCP servers
- Proxus Industrial MCP ServerRead-only Modbus TCP and OPC UA server with named register maps and a connection diagnostic.
- IndustriConnect OPC UA MCPPython and Node OPC UA MCP servers with the same tools: browse, read, history, alarms, and gated writes.
- plctapOne MCP server for Modbus, FINS, MELSEC, S7, IEC 104, EtherNet/IP, and OPC UA, with protocol detection.
- kukapay/opcua-mcpSmall Python OPC UA MCP server with read, write, browse, and batch tools turned on together.
Same category
- CODESYS Development System MCP ServerOfficial CODESYS add-on that lets an MCP client read and write the open project, compile, and fix Structured Text.
- IndustriConnect Modbus MCPOpen-source Modbus TCP, UDP, and RTU client for MCP hosts, with a mock device and writes off by default.
- IndustriConnect OPC UA MCPPython and Node OPC UA MCP servers with the same tools: browse, read, history, alarms, and gated writes.
- IndustriConnect MQTT / Sparkplug MCPMQTT client that publishes, subscribes, and decodes Sparkplug B instead of handing the model raw bytes.