Second review of the (core) seam caught a subtle one — and that my first 'fix' was itself wrong.
The async completion of a SUSPENDED durable flow happens AFTER the synchronous process call has
returned, so an :emit captured in the run env would be stale. The correct seam is construction-
wiring: a durable runner is wired to the transport's INBOUND channel at construction and injects
its completion activity there, out-of-band; a later behavior/pump drains it → effects flow. So the
engine code was already right (pump is the async re-entry seam); only the contract comment was
wrong — corrected. New test proves the loop: process(wait) suspends (no effect), then pump drains
the out-of-band completion → the flow's digest effect flows. Also clarified: dedup is per-
invocation (global idempotency = emitter fire-once + durable inbox); retry is flow-level; the
engine-facing runner result is {:status :effects :resume :error} (:results is runner-internal).
behavior 10/10 (+ async-completion). No engine change — comment + test only.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
After review, the seam was only synchronous-complete; the durable/celery-sx runners couldn't
plug in cleanly. Additive fixes (pipeline unchanged): (1) :status branch in run-binding — 'done'
dispatches effects, 'suspended' records the flow + :resume (a durable runner holds it; completion
re-enters as a new activity via pump), 'failed' records + :error for retry/dead-letter. (2) richer
runner env — :ctx (per-activity, via engine :ctx-of) + injected :effects (external-read interfaces,
e.g. a deterministic fetch_followers). (3) dedup by content :id — a cycle is caught by identity,
not just the depth guard. (4) behavior/pump — drain transport.deliver for inbound (peer activities
+ async runner completions), sharing one trace so dedup spans the batch.
behavior 9/9 (+ suspended/failed/dedup/env/pump); full host conformance 580/580.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
