I Built an Open-Source, Self-Hosted Alternative to PostHog on ClickHouse

Per-event pricing models used by managed analytics services can result in escalating costs as product usage grows. To provide a more cost-effective alternative, I developed SensorFlow, an open-source, self-hosted event analytics stack that manages data from collection to SQL and BI, keeping all data on the user's servers. You can access the project at https://sensorflow.site/ or view the source code on GitHub at https://github.com/data-analyze-bi/sensorflow (licensed under Apache-2.0). There is also a live demo available at https://superset.sensorflow.site.

The traditional managed analytics approach charges based on the volume of events, meaning that as a product's success increases, so does the associated bill—growing revenue is taxed by the pricing structure. In contrast, self-hosting an analytics solution flips this model, allowing organizations to pay for servers rather than product success.

The architecture of SensorFlow is deliberately straightforward: the SDK collects data, the Go collector processes the data, ClickHouse stores the data for analytical queries, and SQL or Apache Superset provides the means to analyze the data. The SDK is compatible with existing Sensors Data SDKs, making it easy for teams to integrate and utilize existing instrumentation with minor adjustments for SDK version, encryption, identity, property types, and timestamps.

SensorFlow's components include a local installation script (run ./install.sh for the demo) and an activation script (run ./activate.sh for real SDK ingestion) with no Kubernetes requirements needed. Comparatively, SensorFlow offers a narrower focus on providing a SQL-first experience using ClickHouse, while PostHog provides a broader suite of features, including UI-driven analytics and usage-based pricing.

PostHog's pricing starts at an annual license of $699, while SensorFlow offers a discounted introductory rate of $349 per year, with the first month free. SensorFlow does not provide additional features like replay or feature flags, which PostHog includes in its suite. SensorFlow is an independent open-source project, not affiliated with Sensors Data.