Asyncpg Python API Docs | dltHub
Build a Asyncpg-to-database pipeline in Python using dlt with AI Workbench support for Claude Code, Cursor, and Codex.
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Asyncpg is a Python library for asynchronous PostgreSQL database access. It provides an API for connecting to PostgreSQL servers and executing queries efficiently. The official documentation details its usage and features. The REST API base URL is `` and Database connection credentials (username/password) provided to asyncpg.connect().
dlt is an open-source Python library that handles authentication, pagination, and schema evolution automatically. dlthub provides AI context files that enable code assistants to generate production-ready pipelines. Install with uv pip install "dlt[workspace]" and start loading Asyncpg data in under 10 minutes.
What data can I load from Asyncpg?
Here are some of the endpoints you can load from Asyncpg:
| Resource | Endpoint | Method | Data selector | Description |
|---|---|---|---|---|
| connection | connect() | coroutine | Establish a connection to Postgres (provide dsn or connection parameters) | |
| query_fetch | Connection.fetch(query) | coroutine | Run a query and return list of Record objects | |
| query_fetchrow | Connection.fetchrow(query) | coroutine | Run a query and return first row (Record or None) | |
| query_fetchval | Connection.fetchval(query) | coroutine | Run a query and return a single value from first row | |
| prepared_statement | Connection.prepare(query) | coroutine | Prepare a statement for repeated execution | |
| cursor | Connection.cursor(query) | coroutine/iterator | Create a server‑side cursor for iterating large results | |
| pool_acquire | create_pool() / Pool.acquire() | coroutine | Create or acquire a connection from a pool |
How do I authenticate with the Asyncpg API?
asyncpg authenticates to PostgreSQL using database connection parameters (user, password, host, port, database) provided to asyncpg.connect() or via a DSN; optionally the PGPASSWORD environment variable may be used.
1. Get your credentials
Obtain a PostgreSQL username and password from your database provider or create a database role with a password; optionally store credentials in a ~/.pgpass file or provide a DSN (postgresql://user:password@host:port/dbname). Avoid using the PGPASSWORD environment variable in production.
2. Add them to .dlt/secrets.toml
[sources.asyncpg_source] dsn = "postgresql://user:password@host:5432/dbname"
dlt reads this automatically at runtime — never hardcode tokens in your pipeline script. For production environments, see setting up credentials with dlt for environment variable and vault-based options.
How do I set up and run the pipeline?
Set up a virtual environment and install dlt:
uv venv && source .venv/bin/activate uv pip install "dlt[workspace]"
1. Install the dlt AI Workbench:
dlt ai init --agent <your-agent> # <agent>: claude | cursor | codex
This installs project rules, a secrets management skill, appropriate ignore files, and configures the dlt MCP server for your agent. Learn more →
2. Install the rest-api-pipeline toolkit:
dlt ai toolkit rest-api-pipeline install
This loads the skills and context about dlt the agent uses to build the pipeline iteratively, efficiently, and safely. The agent uses MCP tools to inspect credentials — it never needs to read your secrets.toml directly. Learn more →
3. Start LLM-assisted coding:
Use /find-source to load data from the Asyncpg API into DuckDB.
The rest-api-pipeline toolkit takes over from here — it reads relevant API documentation, presents you with options for which endpoints to load, and follows a structured workflow to scaffold, debug, and validate the pipeline step by step.
4. Run the pipeline:
python asyncpg_pipeline.py
If everything is configured correctly, you'll see output like this:
Pipeline asyncpg_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset asyncpg_data The duckdb destination used duckdb:/asyncpg.duckdb location to store data Load package 1749667187.541553 is LOADED and contains no failed jobs
Inspect your pipeline and data:
dlt pipeline asyncpg_pipeline show
This opens the Pipeline Dashboard where you can verify pipeline state, load metrics, schema (tables, columns, types), and query the loaded data directly.
Python pipeline example
This example loads query_fetch and connection from the Asyncpg API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:
import dlt from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources @dlt.source def asyncpg_source(dsn=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "", "auth": { "type": "db_credentials", "password": dsn, }, }, "resources": [ {"name": "query_fetch", "endpoint": {"path": "Connection.fetch"}}, {"name": "connection", "endpoint": {"path": "connect"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="asyncpg_pipeline", destination="duckdb", dataset_name="asyncpg_data", ) load_info = pipeline.run(asyncpg_source()) print(load_info)
To add more endpoints, append entries from the resource table to the "resources" list using the same name, path, and data_selector pattern.
How do I query the loaded data?
Once the pipeline runs, dlt creates one table per resource. You can query with Python or SQL.
Python (pandas DataFrame):
import dlt data = dlt.pipeline("asyncpg_pipeline").dataset() sessions_df = data.query_fetch.df() print(sessions_df.head())
SQL (DuckDB example):
SELECT * FROM asyncpg_data.query_fetch LIMIT 10;
In a marimo or Jupyter notebook:
import dlt data = dlt.pipeline("asyncpg_pipeline").dataset() data.query_fetch.df().head()
See how to explore your data in marimo Notebooks and how to query your data in Python with dataset.
What destinations can I load Asyncpg data to?
dlt supports loading into any of these destinations — only the destination parameter changes:
| Destination | Example value |
|---|---|
| DuckDB (local, default) | "duckdb" |
| PostgreSQL | "postgres" |
| BigQuery | "bigquery" |
| Snowflake | "snowflake" |
| Redshift | "redshift" |
| Databricks | "databricks" |
| Filesystem (S3, GCS, Azure) | "filesystem" |
Change the destination in dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. See the full destinations list.
Next steps
Continue your data engineering journey with the other toolkits of the dltHub AI Workbench:
data-exploration— Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.dlthub-runtime— Deploy, schedule, and monitor your pipeline in production.
dlt ai toolkit data-exploration install dlt ai toolkit dlthub-runtime install
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