Open-source data collection and tag management

Collect and route your behavioral data with full control and ownership. Privacy-first, vendor-free, and built for developers.

Get started View on GitHub

Self-host on your infrastructureConfig-as-codeVersion control in GitMIT-licensed

Sources

Collector

Destinations

Sources

Client-side

Browser

dataLayer

and more…

Server-side

Express

Fetch

AWS Lambda

GCP Functions

and more…

Collector

Destinations

Client-side

GA4

Google Ads

Meta Pixel

Plausible

Piwik PRO

API

and more…

Server-side

AWS

BigQuery

Meta CAPI

and more…

Getting started with walkerOS

Choose your preferred operating mode

Build a standalone script from JSON config with npx walkeros

Install walkerOS CLI

Tracking-as-code

Ship tracking as code, not in configuration UIs

Composable tagging

Tag your entire application with simple HTML attributes. No custom JavaScript required. Bake analytics into component libraries once & scale.

Learn more about tagging →

Universal event transformation

Transform events once at the source, then again for each destination. The same mapping syntax works everywhere: rename, reshape, filter.

Learn more about mapping →

Easy consent handling

Respect user privacy from the ground up. Queue events before consent, process when granted, and handle race conditions automatically.

Learn more about consent handling →

Pre-built integrations for client-side and server-side data collection

Data ownership from the root

Tracking infrastructure you can trust

Your analytics infrastructure gets the same treatment as your application code: version controlled, code reviewed, tested, and deployed through your existing CI/CD pipeline.

Version controlled: Your tracking code lives in your repository alongside your application code. Changes go through the same PR review, testing, and deployment process.
AI readiness: Fully typed TypeScript with SKILL files for AI agents. Let them understand, extend, and maintain your tracking setup.
Infrastructure parity: If your frontend, backend, and infrastructure are code-first, why isn't your tracking? Treat it like real engineering work.
You control what runs: No "agency access" that bypasses engineering review. No arbitrary third-party scripts executing without your knowledge.
Data sovereignty: Self-hosted means your data stays on your infrastructure. Full control over what runs on your domain.
Testable privacy logic: Consent management in code, not configuration UIs. Test privacy compliance locally before production.
Security by design: Code review gates prevent unauthorized changes. Eliminates the "security leak box" problem of UI-based tag managers.
CI/CD integration: Deploy tracking changes through your existing pipeline. Same tools, same process, same reliability guarantees.

Enabling the next generation of MarTech developers

A project by elbwalker

We are a team of passionate analytics developers based in Hamburg

About us Request demo