Stacks Python API Docs | dltHub

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

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The Stacks Blockchain API provides indexed data and proxying capabilities for the Stacks network, enabling dApps and explorers to interact with the blockchain without running a full node. The REST API base URL is https://api.hiro.so and API keys are passed via 'x-api-key' for Hiro services, or an 'authorization' header for node RPC..

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 add "dlt[hub]" and start loading Stacks data in under 10 minutes.


What data can I load from Stacks?

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

ResourceEndpointMethodData selectorDescription
blocks/extended/v1/blockGETresultsGet a list of recent blocks
transactions/extended/v1/txGETresultsGet a list of transactions
address_transactions/extended/v1/address/{principal}/transactionsGETresultsGet transactions for a specific address
microblocks/extended/v1/microblockGETresultsGet a list of microblocks
assets_events/extended/v1/address/{principal}/assetsGETresultsGet asset events for an address

How do I authenticate with the Stacks API?

The Stacks Blockchain API uses an 'x-api-key' header for Hiro hosted services, while direct node RPC interactions use an 'authorization' header with a plain-text secret token configured in the node settings.

1. Get your credentials

To obtain an API key for the Hiro Stacks Blockchain API, visit the Hiro platform website (hiro.so), sign up for an account, and navigate to the dashboard to generate your secret API key.

2. Add them to .dlt/secrets.toml

[sources.stacks_source] stacks_api_key = "your_api_key_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 init uv add "dlt[hub]"

1. Install the dlt AI harness:

uv run dlthub 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:

uv run dlthub ai toolkit install rest-api-pipeline

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 Stacks 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:

uv run python stacks_pipeline.py

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

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

Inspect your pipeline and data:

uv run dlthub 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 /extended/v1/address/{principal}/balances and /v3/block_proposal from the Stacks 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 stacks_source(api_key=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://api.hiro.so", "auth": {"type": "api_key", "api_key": api_key, "name": "authorization", "location": "header"}, }, "resources": [ {"name": "transactions", "endpoint": {"path": "extended/v1/tx", "data_selector": "results"}}, {"name": "blocks", "endpoint": {"path": "extended/v1/block", "data_selector": "results"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="stacks_pipeline", destination="duckdb", dataset_name="stacks_data", ) load_info = pipeline.run(stacks_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("stacks_pipeline").dataset() sessions_df = data.transactions.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM stacks_data.transactions LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("stacks_pipeline").dataset() data.transactions.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 Stacks 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 harness:

  • data-exploration — Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.
  • dlthub-platform — Deploy, schedule, and monitor your pipeline in production.
uv run dlthub ai toolkit install data-exploration uv run dlthub ai toolkit install dlthub-platform

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