ADL Open Source LRS vs Ralph

ADL Open Source LRS stores learning data collected through the Experience API, or xAPI. The repository says this version conforms to IEEE 9274.1.1, also known as xAPI 2.0, and describes it as stable but intended for proof-of-concept use with a small number of users. It is free and distributed under the Apache License, Version 2.0.

Docker and Docker Compose are the recommended installation route. The deployment includes a Django web service using uWSGI, an nginx HTTP/HTTPS proxy, PostgreSQL, RabbitMQ, and Redis. OAuth is off by default; the project describes enabling it with the OAUTH_ENABLED setting and registering clients with the LRS. Optional webhooks can filter incoming statements and send matches to a client endpoint, and they are disabled by default. A webhook can include a secret used to send an HMAC hex digest in the X-LRS-Signature header. Celery handles activity metadata retrieval, statement voiding, and LRS hooks asynchronously. Database settings can be changed in settings.ini. The Docker guide describes an included Certbot container for obtaining a certificate for a public domain and restarting nginx to use it.

Ralph is an open-source learning analytics toolbox delivered as an LRS HTTP API server, command-line interface, and library. It runs through an API, on Linux, or as a self-hosted deployment. Ralph follows xAPI specification 1.0.3, but xAPI 2.0 is not supported. Its LRS stores data in Elasticsearch, MongoDB, or ClickHouse. The library documents connections to OVH Log Data Platform, OpenStack Swift, Amazon S3, filesystems, other LRS systems, and WebSockets. The API server supports HTTP Basic authentication and OpenID Connect over OAuth 2.0, either separately or together. Statement access can be restricted by authority, and user scopes can limit endpoints or functions; both controls are off by default. Received xAPI statements can be forwarded to other LRS servers with configurable retries and timeouts. Sentry monitors the LRS server and CLI. The CLI converts selected OpenEdX events to xAPI statements. Ralph is distributed as a Python package and Docker image under the MIT License.