A run keeps the inputs its flow declared at submit

Run.declared (migration 2e7ca7d10044) snapshots the declarations on submit
and import. The run detail's Inputs panel reads them, and a run from before
falls back to the flow's current declarations.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx

backend/fluksio/alembic/versions/2e7ca7d10044_run_declared.py

@@ -0,0 +1,30 @@
+"""run.declared
+
+The inputs the flow declared when a run was submitted, so its record reads
+against that version of the flow and not against whatever the flow declares
+now.
+
+Revision ID: 2e7ca7d10044
+Revises: 930ffa094aad
+Create Date: 2026-10-15
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "2e7ca7d10044"
+down_revision = "930ffa094aad"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Nullable: a run submitted before this kept no snapshot, and its readers
+    # fall back to the flow's current declarations.
+    op.add_column("run", sa.Column("declared", sa.JSON(), nullable=True))
+
+
+def downgrade():
+    op.drop_column("run", "declared")

backend/fluksio/api/routes/runs.py

@@ -210,6 +210,10 @@ class RunRow(BaseModel):
 class RunDetail(RunRow):
     result: dict[str, Any] = Field(default_factory=dict)
     flow_version: int = 1
+    #: The inputs the flow declared when this was submitted, with their
+    #: declared values. Null for a run from before this was kept, which reads
+    #: against the flow's current declarations instead.
+    declared: dict[str, Any] | None = None
     nodes: list[RunNodeRow] = Field(default_factory=list)
     artifacts: list[ArtifactRow] = Field(default_factory=list)
 

backend/fluksio/flow/runs.py

@@ -454,6 +454,14 @@ def seed_values(
     return values
 
 
+def declared_inputs(flow: FlowDef) -> dict[str, Any]:
+    """What a flow declares it can be given, by name, with the declared values.
+
+    Kept on each run, since the flow can change after it.
+    """
+    return {one.spec.name: one.initial for one in flow.inputs}
+
+
 def collect_result(flow: FlowDef, state: StateBackend) -> dict[str, Any]:
     """What the run produced, keyed by message name without the flow prefix."""
     prefix = f"{flow.name}."
@@ -925,6 +933,7 @@ class RunService:
             code_digest=run_digest(flow),
             params=params,
             passed=named if passed is None else passed,
+            declared=declared_inputs(flow),
             params_digest=digest_of(params, seed),
             seed=seed,
             group_id=group_id,
@@ -1047,6 +1056,7 @@ class RunService:
                 flow_version=flow.version,
                 params=params,
                 passed=passed,
+                declared=declared_inputs(flow),
                 params_digest=digest_of(params, seed),
                 seed=seed,
                 group_id=entry["group_id"],

backend/fluksio/models.py

@@ -362,6 +362,9 @@ class Run(SQLModel, table=True):
     #: The names in `params` the caller chose; the rest are the flow's declared
     #: values. Null for a run recorded before this was kept.
     passed: list[str] | None = Field(sa_column=Column(JSON), default=None)
+    #: The inputs the flow declared when this was submitted, by name, with
+    #: their declared values. Null for a run recorded before this was kept.
+    declared: dict[str, Any] | None = Field(sa_column=Column(JSON), default=None)
     #: sha256 over params and seed. Two runs of the same thing share it, which
     #: is what makes "have I already run this?" a lookup.
     params_digest: str = Field(default="", index=True, max_length=64)

backend/tests/api/routes/test_runs.py

@@ -456,6 +456,9 @@ def test_a_run_records_the_inputs_it_actually_starts_from():
         assert spelled.params_digest == defaulted.params_digest
         # Only what the caller chose says which value was the flow's own.
         assert (defaulted.passed, spelled.passed) == (["epochs"], ["epochs", "lr"])
+        # And what the flow declared then, so an input it adds later is not
+        # drawn on this run as a default it never received.
+        assert defaulted.declared == {"lr": 0.01, "epochs": None}
     finally:
         with Session(db_engine) as session:
             for run in session.exec(select(Run).where(col(Run.id).in_(made))).all():