truST Mesh¶
One runtime. The right wire for each job.
truST Mesh connects runtimes brokerless-first, keeps plant integrations native, and reserves deterministic claims for the paths that can actually prove them.
| Term | Meaning |
|---|---|
HardRT |
Same-host deterministic transport lane. |
T0 |
Lowest-latency shared-memory transport path in truST docs. |
Zenoh |
Brokerless-first runtime-to-runtime mesh transport. |
mDNS |
Local-network discovery mechanism. |
| Broker | Server that relays messages between clients. |
T0 shared memory
same-host, deterministic] Mesh[Mesh lane
Zenoh runtime-to-runtime
brokerless-first] Plant[Plant lane
MQTT · OPC UA · Modbus · EtherCAT] Operator[Operator lane
HMI · WebSocket · runtime-cloud] Runtime((truST Runtime)) HardRT --- Runtime Mesh --- Runtime Plant --- Runtime Operator --- Runtime
Figure: Unlike a one-bus architecture, truST does not force every control, plant, and operator workflow through the same protocol. The runtime chooses the communication surface that matches the job.
Pillars¶
Brokerless first¶
Runtime-to-runtime sharing can run peer-to-peer through Zenoh instead of requiring a central message broker. No mandatory server between two paired runtimes, and no extra infrastructure to operate for a simple two-site federation. See Mesh And Zenoh.
Broker-friendly when needed¶
Existing MQTT and OPC UA systems stay first-class plant boundaries, not second-class translations routed through a single internal bus. See MQTT and OPC UA.
Pairing-first trust¶
Discovery is visibility. Pairing is trust. Mapping is consent.
Discovery finds peers on the local LAN via mDNS. Pairing establishes trust through an explicit handshake. Publish/subscribe mappings declare what actually crosses the wire. Remote access is off by default. See Discovery And Pairing.
Measured, not implied¶
Communication latency is checked into the repo, not asserted in prose.
| Path | p95 | samples |
|---|---|---|
| T0 shared memory round-trip | 1.167 us |
256 |
| Mesh pub/sub (Zenoh) | 678.077 us |
256 |
| Runtime-cloud dispatch end-to-end | 210.316 us |
256 |
Source: docs/internal/testing/evidence/trust-comms-v0.3.1/2026-02-20/artifacts/bench-summary.md. Reproduce with benchmarks.
Lane map¶
| Lane | Best for | Where it lives |
|---|---|---|
| HardRT | same-host deterministic transport | Realtime T0 |
| Mesh | runtime-to-runtime data sharing | Mesh And Zenoh |
| Plant | external systems and fieldbus | External Systems, Devices And Fieldbus |
| Operator | HMI, control, federation | Runtime Cloud Federation |
Mesh is not the HardRT path. For same-host deterministic transport, stay in the HardRT lane.