Great question! In Prefect 3.x (with the prefect-sqlalchemy integration), you can set the PostgreSQL

application_name

in two ways: 1) Add it as a URL query parameter (simple/static values)

python
from prefect_sqlalchemy import SqlAlchemyConnector, ConnectionComponents, SyncDriver

connector = SqlAlchemyConnector(
    connection_info=ConnectionComponents(
        driver=SyncDriver.POSTGRESQL_PSYCOPG2,
        username="user",
        password="password",
        host="localhost",
        port=5432,
        database="mydb",
        query={"application_name": "my_prefect_flow"}  # <- here
    )
)

2) Pass it via connect_args (driver-direct, supports non-string/extra options)

python
from prefect_sqlalchemy import SqlAlchemyConnector, ConnectionComponents, SyncDriver

connector = SqlAlchemyConnector(
    connection_info=ConnectionComponents(
        driver=SyncDriver.POSTGRESQL_PSYCOPG2,
        username="user",
        password="password",
        host="localhost",
        port=5432,
        database="mydb",
    ),
    connect_args={"application_name": "my_prefect_flow"}  # <- here
)

If you prefer a raw SQLAlchemy URL string, you can also do:

python
SqlAlchemyConnector(
    connection_info="<postgresql+psycopg2://user:password@localhost:5432/mydb?application_name=my_prefect_flow>"
)

Async note (asyncpg): you can use the query parameter as above, or via

connect_args

with server settings:

python
# AsyncSqlAlchemyConnector(..., connect_args={"server_settings": {"application_name": "my_prefect_async"}})

Quick way to verify it’s set:

sql
SELECT current_setting('application_name');
-- or
SELECT application_name FROM pg_stat_activity WHERE pid = pg_backend_pid();

Docs for reference: - Integration overview: prefect-sqlalchemy docs - API reference (Database): SqlAlchemyConnector API - API reference (Credentials): ConnectionComponents API Are you using

prefect_sqlalchemy.SqlAlchemyConnector

(sync) or the async connector? I can tailor the example to your exact setup.

Yes —

application_name

is a native PostgreSQL/libpq connection parameter, not Prefect-specific. - PostgreSQL docs (connection parameters): libpq connection parameters — application_name - PostgreSQL GUC (what it does/where it appears): application_name setting - psycopg2 accepts it directly (e.g.,

psycopg2.connect(application_name="...")

): psycopg2.connect docs - asyncpg supports it via

server_settings

(e.g.,

server_settings={"application_name": "..."}

): asyncpg.connect docs In Prefect (via prefect-sqlalchemy), you just pass it through to the driver: - As a URL query param (e.g.,

...?application_name=my_app

) - Or via

connect_args={"application_name": "my_app"}

If you want, I can show the exact snippet for your driver (psycopg2 vs asyncpg).

Got it — you’re asking about the Prefect API (Prefect Server) you’re self-hosting in Docker. To set the PostgreSQL application name for the API’s own DB connections, set this environment variable on the API container: - PREFECT_SERVER_DATABASE_SQLALCHEMY_CONNECT_ARGS_APPLICATION_NAME="your_app_name" You’ll also need to provide the DB connection URL (either of these is accepted): - PREFECT_SERVER_DATABASE_CONNECTION_URL="postgresql+asyncpg://user:pass@host:5432/prefect" - or the alias PREFECT_API_DATABASE_CONNECTION_URL="postgresql+asyncpg://user:pass@host:5432/prefect" Example docker-compose snippet:

yaml
services:
  prefect-api:
    image: prefecthq/prefect:3-latest
    environment:
      PREFECT_API_DATABASE_CONNECTION_URL: <postgresql+asyncpg://user:password@postgres:5432/prefect>
      PREFECT_SERVER_DATABASE_SQLALCHEMY_CONNECT_ARGS_APPLICATION_NAME: "prefect-server"
      # optional: other connect args commonly used with Postgres/asyncpg
      # PREFECT_SERVER_DATABASE_SQLALCHEMY_CONNECT_ARGS_SEARCH_PATH: "public"
      # PREFECT_SERVER_DATABASE_SQLALCHEMY_CONNECT_ARGS_STATEMENT_CACHE_SIZE: "0"

Docs: - Settings reference (all server DB settings): Prefect 3 settings reference - Self-hosted guide: Self-hosting Prefect Server Note: - The

application_name

is a native PostgreSQL/libpq parameter. Prefect passes it through via SQLAlchemy connect args to asyncpg. - Works only when using Postgres (ignored for SQLite).