Lark Parser Python API Docs | dltHub

Lark is a modern parsing toolkit for Python that parses context-free grammars and builds parse trees (an in-process Python library, not a REST service). The REST API base URL is `` and no REST auth (library usage only).

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 Lark Parser data in under 10 minutes.

---

What data can I load from Lark Parser?

Here are some of the endpoints you can load from Lark Parser:

---

How do I authenticate with the Lark Parser API?

No REST authentication—Lark is a local Python library; there is no HTTP authentication or tokens required.

1. Get your credentials

Not applicable — Lark has no REST credentials. Install via pip (pip install lark) and use by importing in Python.

2. Add them to .dlt/secrets.toml

Copy
[sources.lark_parser_source]

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:

Copy
uv venv && source .venv/bin/activate
uv pip install "dlt[workspace]"

1. Install the dlt AI Workbench:

Copy
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:

Copy
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 Lark Parser 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:

Copy
python lark_parser_pipeline.py

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

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

Inspect your pipeline and data:

Copy
dlt pipeline lark_parser_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 from the Lark Parser API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:

Copy
import dlt
from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources

@dlt.source
def lark_parser_source(=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "",
            "auth": {
                "type": "",
                "": ,
            },
        },
        "resources": [
            
        ],
    }
    yield from rest_api_resources(config)


def get_data() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="lark_parser_pipeline",
        destination="duckdb",
        dataset_name="lark_parser_data",
    )
    load_info = pipeline.run(lark_parser_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):

Copy
import dlt

data = dlt.pipeline("lark_parser_pipeline").dataset()
sessions_df = data..df()
print(sessions_df.head())

SQL (DuckDB example):

Copy
SELECT * FROM lark_parser_data. LIMIT 10;

In a marimo or Jupyter notebook:

Copy
import dlt

data = dlt.pipeline("lark_parser_pipeline").dataset()
data..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 Lark Parser data to?

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

Change the destination in dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. See the full destinations list.

---

Troubleshooting

Using Lark locally

If you see import errors, ensure Lark is installed in your environment (pip install lark).

Common runtime errors

Lark raises parsing exceptions (UnexpectedInput, UnexpectedCharacters, UnexpectedToken, UnexpectedEOF) when parsing fails—handle these in your code. See API reference for exception classes.

No REST support

If you require a remote parsing service, you must deploy your own wrapper (e.g., a small HTTP service that imports Lark and exposes parse endpoints). There is no official hosted REST API from the Lark project.

Ensure that the API key is valid to avoid 401 Unauthorized errors. Also, verify endpoint paths and parameters to avoid 404 Not Found errors.

---

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.

Copy
dlt ai toolkit data-exploration install
dlt ai toolkit dlthub-runtime install

• How to deploy a pipeline
• How to explore your data in marimo Notebooks
• How to query your data in Python with dataset
• Join the dlt community on Slack