Custom host

A custom host provides the persistence and runtime services that TCC Engine requires.

TCC Engine
    ↓
host_protocol_version: 1
    ↓
your host
    ├── persistence
    ├── effects
    ├── events
    ├── timers
    └── scheduling

You implement:

• Persistence — commit continuation snapshots and deltas before confirming durability. An early acknowledgement is not a durable commit.
• Effects — run the effect body and record the outcome the engine will reuse.
• Events — hold waits until your scheduler delivers a matching event.
• Timers — store wakeAt and resume at that time.
• Scheduling — activate child executions only after parent and child state is durable, with a stable child id.

Run host conformance v1 against the completed driver. tcc-host-sqlite and the Node and Python SQLite hosts provide reference implementations; a custom host does not need to subclass them.

Use the protocol notes and fixtures in tcc-engine as the implementation contract. Set host_protocol_version to 1; no additional protocol version field is defined.

If you only need managed Programs and Executions, use Trigora Cloud instead of a custom host.