Cat API Python API Docs | dltHub

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

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The Cat API is a service providing access to cat images, breed data, and categories, along with support for voting and favoriting actions. The REST API base URL is https://api.thecatapi.com/v1 and all requests requiring user-level access use an x-api-key header.

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 Cat API data in under 10 minutes.


What data can I load from Cat API?

Here are some of the endpoints you can load from Cat API:

ResourceEndpointMethodData selectorDescription
images/images/searchGETSearch and retrieve cat images
images/images/GETList your uploaded images
breeds/breedsGETList all cat breeds
categories/categoriesGETList image categories
votes/votesGETList votes
favourites/favouritesGETList favourites

How do I authenticate with the Cat API API?

Authentication is performed by passing an API key in the 'x-api-key' HTTP header. Ensure the 'Content-Type' header is set to 'application/json' for requests that require it.

1. Get your credentials

  1. Navigate to https://thecatapi.com and sign up for a free account. 2. Once registered, check your email for your API key. 3. You can manage, create, or delete your API keys by logging into the account dashboard at https://account.thecatapi.com.

2. Add them to .dlt/secrets.toml

[sources.cat_api_source] 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 Cat API 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 cat_api_pipeline.py

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

Pipeline cat_api_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset cat_api_data The duckdb destination used duckdb:/cat_api.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 /images/search and /images from the Cat API 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 cat_api_source(api_key=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://api.thecatapi.com/v1", "auth": {"type": "api_key", "api_key": api_key, "name": "x-api-key", "location": "header"}, }, "resources": [ {"name": "images", "endpoint": {"path": "v1/images/search"}}, {"name": "categories", "endpoint": {"path": "v1/categories"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="cat_api_pipeline", destination="duckdb", dataset_name="cat_api_data", ) load_info = pipeline.run(cat_api_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("cat_api_pipeline").dataset() sessions_df = data.images.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM cat_api_data.images LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("cat_api_pipeline").dataset() data.images.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 Cat API 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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