Realtime T0

What T0 is

In the runtime code, T0 is the deterministic same-host HardRT route. It is not the generic network mesh path.

Relevant contracts in the implementation:

• route class: RealtimeRoute::T0HardRt
• QoS tier: QosTier::T0HardRt
• transport object: T0Transport

The code explicitly rejects using generic mesh/IP routes for T0-only traffic.

Use this when

• publisher and subscriber are on the same host
• you need bounded shared-memory style behavior
• payload layout and schema binding are fixed ahead of time

Core constraints

T0 assumes:

• fixed-layout payloads
• explicit schema hash binding
• bounded stale-data policy
• bounded spin retries and spin time
• pre-bound channel handles instead of ad hoc generic network requests

Not for

• plant-wide peer discovery
• normal network mesh sharing
• browser/fleet orchestration
• external-system protocols like MQTT or Modbus TCP

Benchmark surface

Use the built-in benchmark if you need to evaluate T0 behavior directly:

trust-runtime bench t0-shm --samples 2000 --output json

Related

• Transport Matrix
• Communication Planes
• Benchmarks