lib/host/behavior.sx — the substrate-independent seam every runner/transport/registry/driver
plugs into. An engine bundles four dict-of-functions adapters (trigger-registry, runner,
transport, driver); behavior/process folds an ACTIVITY through the pipeline: emit → match
triggers → run each behavior DAG → dispatch each effect-as-data → recurse on new activities
(loop closure, depth-guarded at 8). Every stage injected, so the same DAG + engine run over the
synchronous op-table runner / Erlang durable / celery-sx / fed-sx transport unchanged.
Reference tests (mock adapters) prove the contract: publish→trigger→runner→effect flows; a
non-matching activity fires nothing (log complete, execution precise); an effect that emits a new
activity re-triggers (loop closes); an unbounded loop is depth-guarded (terminates). Wired into
conformance.sh + serve.sh MODULES. behavior 4/4; full host conformance 575/575.
Next: P0 supplies the REAL adapters (publish activity ← host/blog--publish-activity, local-SX
trigger, sync op-table runner over a publish-DAG, host driver) — same engine.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>