ObzenFlow Core

Core defines the domain types and contracts shared by the framework. Application authors access these through obzenflow::schema, obzenflow::effects, and the other public facade modules.

Core is the innermost layer. It has no dependency on Runtime, Adapters, flow construction, or Infra. The companion obzenflow_core_derive crate generates implementations of Core's schema contracts at compile time.

Responsibilities

• Events, typed payloads, fact carriers, identifiers, and causal context.
• Journal append and read contracts, factories, archives, and run manifests.
• Delivery, effect, and stage-verification contracts.
• Measurement snapshots and the MetricsSnapshotExporter publication port.
• HTTP, web endpoint, and control-policy ports implemented by outer layers.

Runtime executes flows through these contracts. Storage, network clients, servers, and reporting implementations belong to outer layers.

Record contract

A logical journal record contains envelope and payload. Event authors supply envelope.provenance.event; the journal assigns envelope.provenance.journal. Application facts preserve their JSON values, including scalars, arrays, and null.

Execution accounting and causal identity belong to provenance. Optional envelope.observability attachments carry measurements and their capture stamps. Changing observation retention does not remove payloads, effect evidence, delivery receipts, or atomic membership. Missing measurements remain distinct from measured zero.

JOURNAL_SCHEMA_VERSION is the shared authority for records, framing, and manifests. The current schema is 5.0; older archives require a new recording. Infra owns the encoding described in the journal format reference.

License

Dual-licensed under MIT OR Apache-2.0. See LICENSE-MIT and LICENSE-APACHE.