rusty-bacnet-mcp

Dedicated MCP (Model Context Protocol) server for agentic interaction with BACnet building automation networks. Lets LLM agents discover devices, read sensor values, write setpoints, and manage local objects on the rusty-bacnet protocol stack — over MCP, via stdio (Claude Desktop / Claude Code) or streamable-HTTP (remote / multi-client).

What you get

• MCP server with both stdio and streamable-HTTP transports — pick one or run both.
• BACnet tools — discover_devices, read_property, write_property, local-object CRUD, plus more landing in 0.3 (ReadPropertyMultiple, priority array, trends, alarms, schedules).
• Built-in BACnet reference resources — an LLM connected via MCP can troubleshoot devices, diagnose alarms, and read sensors with zero prior BACnet knowledge. Reference content is compiled into the binary.
• Bearer-token auth on the HTTP transport with constant-time comparison.
• Read-only by default — operators must explicitly opt in to writes via config or --writes-enabled.
• JSON configuration with full validation at boot.
• Single static binary (bacnet-mcp) — no runtime deps beyond the JSON config.

Status

Version 0.2.0 dropped the legacy HTTP REST API and MS/TP transport to focus the project on MCP-only agentic access over IP-based BACnet (BIP + SC).

Coming next:

• Phase 2 — feature expansion (RPM, priority array, trends, alarms, schedules, layered safety)
• Phase 3 — bacnet-mcp-tui operator console (ratatui)
• Phase 4 — BACnet/SC Hub + Node transport wiring

Install

The crate is not published to crates.io yet. Build from source:

git clone https://github.com/jscott3201/rusty-bacnet-mcp
cd rusty-bacnet-mcp
cargo build --release --features bin
# Binary at target/release/bacnet-mcp

Or via cargo install --git:

cargo install --git https://github.com/jscott3201/rusty-bacnet-mcp bacnet-mcp --features bin

Quick Start

Copy the starter config:

cp examples/bacnet-mcp.json ./bacnet-mcp.json
# Edit transports.bip.broadcast to match your subnet

Stdio (for Claude Desktop / Claude Code)

bacnet-mcp --config bacnet-mcp.json

Stdio is the default. Logs go to $TMPDIR/bacnet-mcp-<pid>.log (override with --log-file); stdout is reserved for JSON-RPC.

In Claude Desktop / Claude Code MCP config, add:

{
  "mcpServers": {
    "bacnet": {
      "command": "/absolute/path/to/bacnet-mcp",
      "args": ["--config", "/absolute/path/to/bacnet-mcp.json"]
    }
  }
}

Streamable-HTTP (remote / multi-client)

bacnet-mcp --config bacnet-mcp.json --transport http --bind 127.0.0.1:3000

Endpoint: http://127.0.0.1:3000/mcp. Set mcp.api_key in the config (or --api-key / BACNET_MCP_API_KEY) to require bearer-token auth.

Both transports concurrently

bacnet-mcp --config bacnet-mcp.json --transport both --bind 127.0.0.1:3000

MCP Surface

Tools (10 today; expanding in 0.3):

discover_devices, list_known_devices, get_device_info, register_device,
read_property, write_property,
list_local_objects, read_local_property, write_local_property,
create_local_object, delete_local_object

Resources:

• bacnet://reference/{object-types,properties,units,errors,reliability,priority-array,networking,services,troubleshooting} — compiled-in reference text.
• bacnet://reference/object-types/{type} — per-type drill-down.
• bacnet://state/{devices,local-objects,config} — live state snapshots.

Configuration (JSON)

{
  "mcp": {
    "read_only": true,
    "api_key": "your-secret-key",
    "http": { "bind": "127.0.0.1:3000" }
  },
  "device": {
    "instance": 389001,
    "name": "BACnet MCP Gateway",
    "vendor_id": 999
  },
  "transports": {
    "bip": {
      "interface": "0.0.0.0",
      "port": 47808,
      "broadcast": "192.168.1.255",
      "network_number": 1
    }
  }
}

Full schema: see src/config.rs. Starter file: examples/bacnet-mcp.json.

CLI

bacnet-mcp [OPTIONS]
  -c, --config <PATH>          JSON config file (default: bacnet-mcp.json)
  -t, --transport <MODE>       stdio | http | both (default: stdio)
      --bind <ADDR>            HTTP transport bind override
  -k, --api-key <KEY>          Bearer token (or BACNET_MCP_API_KEY env)
  -r, --read-only              Force read-only
      --writes-enabled         Force writes on (overrides config)
  -v, --verbose                -v info, -vv debug, -vvv trace
  -q, --quiet                  Errors only
      --log-file <PATH>        Log file (auto $TMPDIR/bacnet-mcp-<pid>.log for stdio)
      --print-config           Print resolved config and exit

Safety

mcp.read_only defaults to true — out of the box, every write tool returns Gateway is in read-only mode. To enable writes, set "read_only": false in JSON config or pass --writes-enabled. Phase 2 will add a layered safety control plane: per-tool dry-run, write allow/deny lists, priority-range caps, and an append-only audit log exposed as bacnet://audit/recent.

Built On

Consumes the rusty-bacnet library crates (^0.8):

• bacnet-types, bacnet-encoding, bacnet-services
• bacnet-transport, bacnet-network
• bacnet-client, bacnet-objects, bacnet-server

cargo-deny runs against the advisory database in CI on every push.

Documentation

• CLAUDE.md — architectural notes for contributors.
• CHANGELOG.md — release notes.

License

MIT — see LICENSE.