Crate tatara_export_worker 

Pure decision logic for tatara-export-worker — the binary that ships one declared ExportSpec from an ephemeral Process to its Vector-native channel.

The compounding move: every function in this module is pure (no HTTP, no NATS, no kube client, no clock), takes its inputs by reference, and returns a typed value the I/O layer in main.rs then consumes. That means the whole worker is unit-testable without standing up infrastructure — and any new artifact source or channel can be added by extending this module first, then the I/O glue mechanically follows.

Three substrate primitives live here:

1. prepare_event_payload — given an ArtifactVariant + raw artifact bytes + run id + signal_type, produces the JSON event the channel will ship. Encoded once, shared by all channels.

2. resolve_run_id / resolve_subject — string-template substitution for {{run_id}} in NATS subjects + event labels. Single source of truth so the worker, the reconciler, and any downstream cohort-correlation logic agree on what the run id means.

3. compose_export_receipt — builds a typed ReceiptEnvelope of the export action itself, with the three BLAKE3 pillars derived from the ExportSpec (intent), the shipped payload bytes (artifact), and the outcome (control). The receipt chains into the Process’s attestation tree, so the act of exporting is itself attested.

The I/O glue in main.rs is thin — argv → ExportSpec → call these functions → ship to channel → write receipt.

Structs

ExportEvent

JSON event shape shipped through every VectorChannel. Stable schema — shinryu’s analytical SQL plane reads from it directly.

Enums

ExportOutcome

Final state of the export action — feeds the control_hash pillar of the typed receipt.

Functions

compose_export_receipt

Build a typed ReceiptEnvelope of the export action via the existing ReceiptEnvelope::build() constructor (single source of truth for the three-pillar composition + BLAKE3 root).

prepare_event_payload

Build the JSON event the channel ships.

resolve_run_id

Resolve the run id used in event labels + subject templates.

resolve_subject

Substitute {{run_id}} placeholders in a NATS subject template.

run_marker_event

Convenience for the worker — calls the right run marker preparation when no artifact bytes exist (e.g. start/end markers the worker synthesizes itself).