Create and Manage MotherDuck Flights

Source Of Truth

• Non-negotiable ordering: when MotherDuck MCP is available, call get_flight_guide before create_flight, update_flight, or edit_flight_source. The guide defines the current authoring contract, runtime limits, and tool semantics.
• get_flight_guide also surfaces conventions from the reserved flights Guide topic. Apply those conventions when they fit the requested workload.
• Prefer current MotherDuck Flights docs over memory. Verify lifecycle status, runtime limits, and tool semantics instead of preserving them as durable prompt claims.
• Without MCP, the same operations exist as SQL functions (MD_CREATE_FLIGHT, MD_RUN_FLIGHT, MD_LIST_FLIGHTS(), ...) that execute server-side on a MotherDuck connection. Parameter names differ slightly between the two surfaces; see the naming table in references/FLIGHTS_GUIDE.md.

Default Posture

• One Flight = one single-file Python script with def main(): ... and if __name__ == "__main__": main(). No CLI args — every knob comes from env vars via config (non-secret) or TYPE flights secrets (sensitive).
• Connect with duckdb.connect("md:"); the runtime injects MOTHERDUCK_TOKEN automatically. Never hardcode a token in source, config, or requirements.
• Always pin dependencies in requirements_txt. Resolve the highest MotherDuck-supported DuckDB version from https://motherduck.com/docs/duckdb-versions.json before authoring a new Flight; use the tested pin in the included templates only when reproducing those examples. An unpinned or unsupported duckdb can fail at connect.
• Each secret param is injected under a stable namespaced <secret_name>_<PARAM> key and, when safe, a bare <PARAM> convenience alias. Prefer namespaced keys in deployed Flight code; bare aliases can collide, be overridden by config, and are withheld for reserved runtime keys.
• Bulk-load, never row-by-row: stage to /tmp/ and read_csv_auto/read_json_auto/read_parquet, or one CTAS / INSERT ... SELECT. No executemany() against MotherDuck.
• Make every run idempotent: CREATE OR REPLACE TABLE full refresh, partition DELETE + INSERT, or dlt write_disposition="merge" with a primary key. Bootstrap with CREATE DATABASE IF NOT EXISTS / CREATE SCHEMA IF NOT EXISTS so the first run succeeds on a fresh account.
• Validate any config-supplied identifier (database, schema, table names) against [A-Za-z_][A-Za-z0-9_]* before interpolating it into DDL; bind all data values as ? parameters.
• Create the flight without a schedule first, trigger one on-demand run, read the logs, and only then attach schedule_cron (5-field cron, UTC).
• Set and validate max_runtime_sec when the workload needs an explicit cap; read the current plan limit from get_flight_guide instead of hardcoding it.
• For production, use a service-account token via access_token_name and keep its database permissions as narrow as the workload allows.
• Treat a Flight as orchestration and light processing, not a place to crunch large tables in Python memory. Push heavy compute into SQL and verify runtime capacity with get_flight_guide before sizing disk- or memory-intensive work.

Workflow

1. Classify the job: ingestion, transformation/refresh, export or alerting, or admin automation. If the job is interactive analysis or a one-off query, use motherduck-query instead — no Flight needed.
2. Call get_flight_guide (MCP) and confirm which database the flight writes to with motherduck-explore.
3. Reuse a matching template in references/FLIGHT_EXAMPLES.md when it fits; otherwise write a focused script that preserves the runtime, secrets, and idempotency contracts.
4. Create any required TYPE flights secret first, then create_flight with name, source_code, pinned requirements_txt, config, and secret names — no schedule_cron yet.
5. run_flight, poll get_flight_run when available (or list_flight_runs as a fallback) until terminal, and read get_flight_logs. Iterate with edit_flight_source (surgical) or update_flight (full field replacement); each content change creates a new version.
6. If scheduling was requested, set it only after a successful run with update_flight(schedule_cron = ...) and state that cron is UTC. Clear it with schedule_cron = "" only when requested; preserve an existing schedule during unrelated edits.

For answer, review, or planning requests, do not create or schedule a Flight. For create or update requests, complete the requested in-scope deployment and on-demand validation; attaching a recurring schedule is authorized only when the request includes scheduling.

References

Read only the reference sections needed for the current task.

• Read references/FLIGHTS_GUIDE.md for the full concept and operations reference: anatomy, runtime environment, config vs secrets, scheduling, versioning, run lifecycle, the complete MCP tool reference, MCP-vs-SQL naming, loading strategies by data volume, and troubleshooting.
• Read references/FLIGHT_EXAMPLES.md for three complete, best-practice flight templates (dlt ingestion, Postgres ingestion, scheduled S3 partition refresh) with their requirements.txt, secret setup, and deploy calls.

Related Skills

Load related skills only for missing capabilities; reuse established context.

• motherduck-load-data for choosing the ingestion SQL the flight will run (CTAS, INSERT ... SELECT, cloud-storage secrets)
• motherduck-query for validating the DuckDB SQL inside the flight before deploying it
• motherduck-explore for confirming target databases, schemas, and tables exist
• motherduck-build-data-pipeline when the work is a full raw/staging/analytics pipeline design and the flight is just its scheduler
• motherduck-cli when the agent has a shell and should keep Flight source in local files
• motherduck-manage-guides for reusable personal or organization Flight conventions