Run-Space Emission (Runtime)
============================

Semantiva emits dedicated lifecycle records when executing pipelines as part
of a run-space launch. The flow is fully deterministic and uses the
identifiers defined in the :doc:`trace schemas <trace_stream_v1>`.

Lifecycle
---------

1. **Compute identities**
   - ``run_space_spec_id`` — canonical hash of the run-space configuration, per Run-Space Configuration Format (**RSCF v1**)
   - ``run_space_inputs_id`` *(optional)* — hash of referenced inputs when fingerprints are present, per Run-Space Materialization (**RSM v1**)
   - ``run_space_input_fingerprints`` — file fingerprint entries emitted only on ``run_space_start``
2. **Create launch/session**
   - ``run_space_launch_id`` — provided via CLI, derived from an idempotency key, or generated as a UUIDv7 fallback
   - ``run_space_attempt`` — integer retry counter (1-based)
3. **Emit ``run_space_start``** with the identifiers above, the combine mode, total runs, max runs limit, and the planned run count
4. **Execute pipelines** — each ``pipeline_start`` record is linked back to the
   enclosing run-space via a composite foreign key (``run_space_launch_id`` + ``run_space_attempt``) 
   plus run-specific metadata (``run_space_index``, ``run_space_context``)
5. **Emit ``run_space_end``** summarising the launch outcome

Pipeline linkage
----------------

``pipeline_start`` records include a **composite foreign key** (``run_space_launch_id`` + ``run_space_attempt``) 
to link to the ``run_space_start`` record, plus run-specific metadata (``run_space_index`` and ``run_space_context``).
Standalone pipelines (without a run-space) omit these fields entirely for backwards compatibility.

Launch-level constants such as ``run_space_spec_id``, ``run_space_inputs_id``, ``run_space_combine_mode``, 
and ``run_space_total_runs`` are stored once in the ``run_space_start`` event to eliminate redundancy.

Standalone runs
----------------

When pipelines are executed outside of a run-space, the runtime skips the
lifecycle records and the foreign keys, preserving existing behaviour.