Agents cosmos-dbt-core
Use when turning a dbt Core project into an Airflow DAG/TaskGroup using Astronomer Cosmos. Does not cover dbt Fusion. Before implementing, verify dbt engine, warehouse, Airflow version, execution environment, DAG vs TaskGroup, and manifest availability.
git clone https://github.com/astronomer/agents
T=$(mktemp -d) && git clone --depth=1 https://github.com/astronomer/agents "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/cosmos-dbt-core" ~/.claude/skills/astronomer-agents-cosmos-dbt-core && rm -rf "$T"
skills/cosmos-dbt-core/SKILL.mdCosmos + dbt Core: Implementation Checklist
Execute steps in order. Prefer the simplest configuration that meets the user's constraints.
Version note: This skill targets Cosmos 1.11+ and Airflow 3.x. If the user is on Airflow 2.x, adjust imports accordingly (see Appendix A).
Reference: Latest stable: https://pypi.org/project/astronomer-cosmos/
Before starting, confirm: (1) dbt engine = Core (not Fusion → use cosmos-dbt-fusion), (2) warehouse type, (3) Airflow version, (4) execution environment (Airflow env / venv / container), (5) DbtDag vs DbtTaskGroup vs individual operators, (6) manifest availability.
1. Configure Project (ProjectConfig)
| Approach | When to use | Required param |
|---|---|---|
| Project path | Files available locally | |
| Manifest only | load | + |
from cosmos import ProjectConfig _project_config = ProjectConfig( dbt_project_path="/path/to/dbt/project", # manifest_path="/path/to/manifest.json", # for dbt_manifest load mode # project_name="my_project", # if using manifest_path without dbt_project_path # install_dbt_deps=False, # if deps precomputed in CI )
2. Choose Parsing Strategy (RenderConfig)
Pick ONE load mode based on constraints:
| Load mode | When to use | Required inputs | Constraints |
|---|---|---|---|
| Large projects; containerized execution; fastest | | Remote manifest needs |
| Complex selectors; need dbt-native selection | dbt installed OR | Can also be used with containerized execution |
| dbt_ls selection without running dbt_ls every parse | | / won't work |
(default) | Simple setups; let Cosmos pick | (none) | Falls back: manifest → dbt_ls → custom |
CRITICAL: Containerized execution (
/DOCKER/etc.)KUBERNETES
from cosmos import RenderConfig, LoadMode _render_config = RenderConfig( load_method=LoadMode.DBT_MANIFEST, # or DBT_LS, DBT_LS_FILE, AUTOMATIC )
3. Choose Execution Mode (ExecutionConfig)
Reference: See reference/cosmos-config.md for detailed configuration examples per mode.
Pick ONE execution mode:
| Execution mode | When to use | Speed | Required setup |
|---|---|---|---|
| Fastest; single visibility | Fastest | dbt adapter in env OR or dbt Fusion |
| Fastest isolated method; single visibility | Fast | dbt installed in container |
+ | dbt + adapter in the same Python installation as Airflow | Fast | dbt 1.5+ in |
+ | dbt + adapter available in the Airflow deployment, in an isolated Python installation | Medium | |
| BigQuery + long-running transforms | Fast | Airflow ≥2.8; provider deps |
| Isolation between Airflow and dbt | Medium | Airflow ≥2.8; provider deps |
| Can't modify image; runtime venv | Slower | in operator_args |
| Other containerized approaches | Support Airflow and dbt isolation | Medium | container config |
from cosmos import ExecutionConfig, ExecutionMode _execution_config = ExecutionConfig( execution_mode=ExecutionMode.WATCHER, # or LOCAL, VIRTUALENV, AIRFLOW_ASYNC, KUBERNETES, etc. )
4. Configure Warehouse Connection (ProfileConfig)
Reference: See reference/cosmos-config.md for detailed ProfileConfig options and all ProfileMapping classes.
Option A: Airflow Connection + ProfileMapping (Recommended)
from cosmos import ProfileConfig from cosmos.profiles import SnowflakeUserPasswordProfileMapping _profile_config = ProfileConfig( profile_name="default", target_name="dev", profile_mapping=SnowflakeUserPasswordProfileMapping( conn_id="snowflake_default", profile_args={"schema": "my_schema"}, ), )
Option B: Existing profiles.yml
CRITICAL: Do not hardcode secrets; use environment variables.
from cosmos import ProfileConfig _profile_config = ProfileConfig( profile_name="my_profile", target_name="dev", profiles_yml_filepath="/path/to/profiles.yml", )
5. Configure Testing Behavior (RenderConfig)
Reference: See reference/cosmos-config.md for detailed testing options.
| TestBehavior | Behavior |
|---|---|
(default) | Tests run immediately after each model (default) |
| Combine run + test into single |
| All tests after all models complete |
| Skip tests |
from cosmos import RenderConfig, TestBehavior _render_config = RenderConfig( test_behavior=TestBehavior.AFTER_EACH, )
6. Configure operator_args
Reference: See reference/cosmos-config.md for detailed operator_args options.
_operator_args = { # BaseOperator params "retries": 3, # Cosmos-specific params "install_deps": False, "full_refresh": False, "quiet": True, # Runtime dbt vars (XCom / params) "vars": '{"my_var": "{{ ti.xcom_pull(task_ids=\'pre_dbt\') }}"}', }
7. Assemble DAG / TaskGroup
Option A: DbtDag (Standalone)
from cosmos import DbtDag, ProjectConfig, ProfileConfig, ExecutionConfig, RenderConfig from cosmos.profiles import SnowflakeUserPasswordProfileMapping from pendulum import datetime _project_config = ProjectConfig( dbt_project_path="/usr/local/airflow/dbt/my_project", ) _profile_config = ProfileConfig( profile_name="default", target_name="dev", profile_mapping=SnowflakeUserPasswordProfileMapping( conn_id="snowflake_default", ), ) _execution_config = ExecutionConfig() _render_config = RenderConfig() my_cosmos_dag = DbtDag( dag_id="my_cosmos_dag", project_config=_project_config, profile_config=_profile_config, execution_config=_execution_config, render_config=_render_config, operator_args={}, start_date=datetime(2025, 1, 1), schedule="@daily", )
Option B: DbtTaskGroup (Inside Existing DAG)
from airflow.sdk import dag, task # Airflow 3.x # from airflow.decorators import dag, task # Airflow 2.x from airflow.models.baseoperator import chain from cosmos import DbtTaskGroup, ProjectConfig, ProfileConfig, ExecutionConfig, RenderConfig from pendulum import datetime _project_config = ProjectConfig(dbt_project_path="/usr/local/airflow/dbt/my_project") _profile_config = ProfileConfig(profile_name="default", target_name="dev") _execution_config = ExecutionConfig() _render_config = RenderConfig() @dag(start_date=datetime(2025, 1, 1), schedule="@daily") def my_dag(): @task def pre_dbt(): return "some_value" dbt = DbtTaskGroup( group_id="dbt_project", project_config=_project_config, profile_config=_profile_config, execution_config=_execution_config, render_config=_render_config, ) @task def post_dbt(): pass chain(pre_dbt(), dbt, post_dbt()) my_dag()
Option C: Use Cosmos operators directly
import os from datetime import datetime from pathlib import Path from typing import Any from airflow import DAG try: from airflow.providers.standard.operators.python import PythonOperator except ImportError: from airflow.operators.python import PythonOperator from cosmos import DbtCloneLocalOperator, DbtRunLocalOperator, DbtSeedLocalOperator, ProfileConfig from cosmos.io import upload_to_aws_s3 DEFAULT_DBT_ROOT_PATH = Path(__file__).parent / "dbt" DBT_ROOT_PATH = Path(os.getenv("DBT_ROOT_PATH", DEFAULT_DBT_ROOT_PATH)) DBT_PROJ_DIR = DBT_ROOT_PATH / "jaffle_shop" DBT_PROFILE_PATH = DBT_PROJ_DIR / "profiles.yml" DBT_ARTIFACT = DBT_PROJ_DIR / "target" profile_config = ProfileConfig( profile_name="default", target_name="dev", profiles_yml_filepath=DBT_PROFILE_PATH, ) def check_s3_file(bucket_name: str, file_key: str, aws_conn_id: str = "aws_default", **context: Any) -> bool: """Check if a file exists in the given S3 bucket.""" from airflow.providers.amazon.aws.hooks.s3 import S3Hook s3_key = f"{context['dag'].dag_id}/{context['run_id']}/seed/0/{file_key}" print(f"Checking if file {s3_key} exists in S3 bucket...") hook = S3Hook(aws_conn_id=aws_conn_id) return hook.check_for_key(key=s3_key, bucket_name=bucket_name) with DAG("example_operators", start_date=datetime(2024, 1, 1), catchup=False) as dag: seed_operator = DbtSeedLocalOperator( profile_config=profile_config, project_dir=DBT_PROJ_DIR, task_id="seed", dbt_cmd_flags=["--select", "raw_customers"], install_deps=True, append_env=True, ) check_file_uploaded_task = PythonOperator( task_id="check_file_uploaded_task", python_callable=check_s3_file, op_kwargs={ "aws_conn_id": "aws_s3_conn", "bucket_name": "cosmos-artifacts-upload", "file_key": "target/run_results.json", }, ) run_operator = DbtRunLocalOperator( profile_config=profile_config, project_dir=DBT_PROJ_DIR, task_id="run", dbt_cmd_flags=["--models", "stg_customers"], install_deps=True, append_env=True, ) clone_operator = DbtCloneLocalOperator( profile_config=profile_config, project_dir=DBT_PROJ_DIR, task_id="clone", dbt_cmd_flags=["--models", "stg_customers", "--state", DBT_ARTIFACT], install_deps=True, append_env=True, ) seed_operator >> run_operator >> clone_operator seed_operator >> check_file_uploaded_task
Setting Dependencies on Individual Cosmos Tasks
from cosmos import DbtDag, DbtResourceType from airflow.sdk import task, chain with DbtDag(...) as dag: @task def upstream_task(): pass _upstream = upstream_task() for unique_id, dbt_node in dag.dbt_graph.filtered_nodes.items(): if dbt_node.resource_type == DbtResourceType.SEED: my_dbt_task = dag.tasks_map[unique_id] chain(_upstream, my_dbt_task)
8. Safety Checks
Before finalizing, verify:
- Execution mode matches constraints (AIRFLOW_ASYNC → BigQuery only)
- Warehouse adapter installed for chosen execution mode
- Secrets via Airflow connections or env vars, NOT plaintext
- Load mode matches execution (complex selectors → dbt_ls)
- Airflow 3 asset URIs if downstream DAGs scheduled on Cosmos assets (see Appendix A)
Appendix A: Airflow 3 Compatibility
Import Differences
| Airflow 3.x | Airflow 2.x |
|---|---|
| |
| |
Asset/Dataset URI Format Change
Cosmos ≤1.9 (Airflow 2 Datasets):
postgres://0.0.0.0:5434/postgres.public.orders
Cosmos ≥1.10 (Airflow 3 Assets):
postgres://0.0.0.0:5434/postgres/public/orders
CRITICAL: Update asset URIs when upgrading to Airflow 3.
Appendix B: Operational Extras
Caching
Cosmos caches artifacts to speed up parsing. Enabled by default.
Reference: https://astronomer.github.io/astronomer-cosmos/configuration/caching.html
Memory-Optimized Imports
AIRFLOW__COSMOS__ENABLE_MEMORY_OPTIMISED_IMPORTS=True
When enabled:
from cosmos.airflow.dag import DbtDag # instead of: from cosmos import DbtDag
Artifact Upload to Object Storage
AIRFLOW__COSMOS__REMOTE_TARGET_PATH=s3://bucket/target_dir/ AIRFLOW__COSMOS__REMOTE_TARGET_PATH_CONN_ID=aws_default
from cosmos.io import upload_to_cloud_storage my_dag = DbtDag( # ... operator_args={"callback": upload_to_cloud_storage}, )
dbt Docs Hosting (Airflow 3.1+ / Cosmos 1.11+)
AIRFLOW__COSMOS__DBT_DOCS_PROJECTS='{ "my_project": { "dir": "s3://bucket/docs/", "index": "index.html", "conn_id": "aws_default", "name": "My Project" } }'
Reference: https://astronomer.github.io/astronomer-cosmos/configuration/hosting-docs.html
Related Skills
- cosmos-dbt-fusion: For dbt Fusion projects (not dbt Core)
- authoring-dags: General DAG authoring patterns
- testing-dags: Testing DAGs after creation