Fathom analytics Python API Docs | dltHub
Build a Fathom analytics-to-database pipeline in Python using dlt with AI Workbench support for Claude Code, Cursor, and Codex.
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Fathom is a privacy-first web analytics platform providing site and event metrics via a REST API. The REST API base URL is https://api.usefathom.com/v1 and All requests require Bearer token authentication..
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 Fathom analytics data in under 10 minutes.
What data can I load from Fathom analytics?
Here are some of the endpoints you can load from Fathom analytics:
| Resource | Endpoint | Method | Data selector | Description |
|---|---|---|---|---|
| sites | /v1/sites | GET | data | List sites owned by the API key |
| site | /v1/sites/{site_id} | GET | Retrieve a single site object | |
| events | /v1/sites/{site_id}/events | GET | data | List events for a site |
| event | /v1/sites/{site_id}/events/{event_id} | GET | Retrieve a single event object | |
| milestones | /v1/sites/{site_id}/milestones | GET | data | List milestones for a site |
| aggregations | /v1/aggregations | GET | Run an aggregation (returns a top‑level array) | |
| account | /v1/account | GET | Get account information |
How do I authenticate with the Fathom analytics API?
For v1, supply an API token in the Authorization header: 'Authorization: Bearer <API_TOKEN>'. For v2, obtain an access token via POST to https://api.fathom.global/v2/auth/token and then use 'Authorization: Bearer <ACCESS_TOKEN>'.
1. Get your credentials
- Log into your Fathom dashboard → Settings → API (or API Keys) → create or copy your API token.
- For the v2 OAuth flow, go to the developer/organization settings, obtain a client_id and client_secret, then POST them to https://api.fathom.global/v2/auth/token to receive an access_token.
2. Add them to .dlt/secrets.toml
[sources.fathom_analytics_source] api_token = "your_api_token_here" # For v2 OAuth-style (if used): client_id = "your_client_id" client_secret = "your_client_secret"
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 Fathom analytics 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 fathom_analytics_pipeline.py
If everything is configured correctly, you'll see output like this:
Pipeline fathom_analytics_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset fathom_analytics_data The duckdb destination used duckdb:/fathom_analytics.duckdb location to store data Load package 1749667187.541553 is LOADED and contains no failed jobs
Inspect your pipeline and data:
dlt pipeline fathom_analytics_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 sites and aggregations from the Fathom analytics 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 fathom_analytics_source(api_token=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://api.usefathom.com/v1", "auth": { "type": "bearer", "token": api_token, }, }, "resources": [ {"name": "sites", "endpoint": {"path": "v1/sites", "data_selector": "data"}}, {"name": "aggregations", "endpoint": {"path": "v1/aggregations"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="fathom_analytics_pipeline", destination="duckdb", dataset_name="fathom_analytics_data", ) load_info = pipeline.run(fathom_analytics_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("fathom_analytics_pipeline").dataset() sessions_df = data.sites.df() print(sessions_df.head())
SQL (DuckDB example):
SELECT * FROM fathom_analytics_data.sites LIMIT 10;
In a marimo or Jupyter notebook:
import dlt data = dlt.pipeline("fathom_analytics_pipeline").dataset() data.sites.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 Fathom analytics 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.
Troubleshooting
Authentication failures
If you receive HTTP 401 or a JSON payload like {"error":"This token doesn't have permission to access this endpoint"}, verify that the Authorization header is exactly Authorization: Bearer <API_TOKEN> for v1 or Authorization: Bearer <ACCESS_TOKEN> for v2.
Pagination and large result sets
List endpoints return an object with keys object, url, has_more and data. Use the limit (1‑100), starting_after, and ending_before query parameters to paginate through results.
Rate limiting
The API enforces 2000 requests per hour on Sites & Events endpoints and 10 requests per minute on aggregations and currents. Exceeding these limits returns HTTP 429; implement exponential back‑off and retry.
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.
dlt ai toolkit data-exploration install dlt ai toolkit dlthub-runtime install
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