Feat/add optional header support to seeds

.changes/unreleased/Features-20260105-000635.yaml

@@ -0,0 +1,6 @@
+kind: Features
+body: Add seed header option support
+time: 2026-01-05T00:06:35.693542+01:00
+custom:
+    Author: aammett
+    Issue: "11334"

core/dbt/artifacts/resources/v1/seed.py

@@ -16,6 +16,7 @@ class SeedConfig(NodeConfig):
     materialized: str = "seed"
     delimiter: str = ","
     quote_columns: Optional[bool] = None
+    header: bool = True
 
     @classmethod
     def validate(cls, data):

core/dbt/context/providers.py

@@ -1269,8 +1269,19 @@ def load_agate_table(self) -> "agate.Table":
 
         column_types = self.model.config.column_types
         delimiter = self.model.config.delimiter
+        header = self.model.config.header
+        column_names = None
+        if not self.model.config.header:
+            column_names = list(self.model.columns.keys())
+
         try:
-            table = agate_helper.from_csv(path, text_columns=column_types, delimiter=delimiter)
+            table = agate_helper.from_csv(
+                path,
+                column_names=column_names,
+                text_columns=column_types,
+                delimiter=delimiter,
+                header=header,
+            )
         except ValueError as e:
             raise LoadAgateTableValueError(e, node=self.model)
         # this is used by some adapters

tests/unit/contracts/graph/test_nodes_parsed.py

@@ -523,6 +523,7 @@ def basic_parsed_seed_dict():
             "delimiter": ",",
             "enabled": True,
             "materialized": "seed",
+            "header": True,
             "persist_docs": {},
             "post-hook": [],
             "pre-hook": [],
@@ -616,6 +617,7 @@ def complex_parsed_seed_dict():
             "delimiter": ",",
             "enabled": True,
             "materialized": "seed",
+            "header": True,
             "persist_docs": {"relation": True, "columns": True},
             "post-hook": [],
             "pre-hook": [],
@@ -677,6 +679,7 @@ def complex_parsed_seed_object():
         config=SeedConfig(
             quote_columns=True,
             delimiter=",",
+            header=True,
             persist_docs={"relation": True, "columns": True},
         ),
         docs=Docs(show=True),