Dagger Python API Docs | dltHub

Build a Dagger-to-database pipeline in Python using dlt with AI Workbench support for Claude Code, Cursor, and Codex.

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Dagger API documentation provides reference for configuring and managing Dagger, including CLI, troubleshooting, and deployment options. The PHP namespace for Dagger includes standardized addresses for loading containers and objects. The GraphQL API reference details HTTP URL formats for content retrieval. The REST API base URL is http://127.0.0.1:$DAGGER_SESSION_PORT/query and All requests require HTTP Basic authentication using the session token..

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 Dagger data in under 10 minutes.


What data can I load from Dagger?

Here are some of the endpoints you can load from Dagger:

ResourceEndpointMethodData selectorDescription
containerqueryPOSTdata.containerGraphQL query field container — operations to create/load containers and run commands
httpqueryPOSTdata.httpGraphQL query field http — fetches remote HTTP URL content (returns file object with size/contents)
filequeryPOSTdata.fileGraphQL file‑related fields (depends on query selection)
secretqueryPOSTdata.secretSecret‑related query fields (SecretID objects handled via GraphQL)
servicequeryPOSTdata.serviceService‑related fields (start services and retrieve endpoints)

How do I authenticate with the Dagger API?

Dagger exposes a per‑session local GraphQL HTTP endpoint. The endpoint requires HTTP Basic auth where the username is the session token (DAGGER_SESSION_TOKEN) and the password is empty. Requests are typically POSTed to /query with a GraphQL payload and Content‑Type: application/json.

1. Get your credentials

  1. Start or obtain a Dagger session (e.g., via dagger run or an SDK). 2) Read DAGGER_SESSION_TOKEN from the environment where the session is running. 3) Use that value as the HTTP Basic username when calling the local API endpoint. Treat the token as a secret.

2. Add them to .dlt/secrets.toml

[sources.dagger_source] session_token = "your_dagger_session_token_here"

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 Dagger 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 dagger_pipeline.py

If everything is configured correctly, you'll see output like this:

Pipeline dagger_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset dagger_data The duckdb destination used duckdb:/dagger.duckdb location to store data Load package 1749667187.541553 is LOADED and contains no failed jobs

Inspect your pipeline and data:

dlt pipeline dagger_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 container and http from the Dagger 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 dagger_source(session_token=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "http://127.0.0.1:$DAGGER_SESSION_PORT/query", "auth": { "type": "http_basic", "session_token": session_token, }, }, "resources": [ {"name": "container", "endpoint": {"path": "query", "data_selector": "data.container"}}, {"name": "http", "endpoint": {"path": "query", "data_selector": "data.http"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="dagger_pipeline", destination="duckdb", dataset_name="dagger_data", ) load_info = pipeline.run(dagger_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("dagger_pipeline").dataset() sessions_df = data.http.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM dagger_data.http LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("dagger_pipeline").dataset() data.http.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 Dagger data to?

dlt supports loading into any of these destinations — only the destination parameter changes:

DestinationExample 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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