Weights & Biases

license

Apache-2.0(OSI, SDK/client repo wandb/weave)

source

partial(the Apache-2.0 repo publishes the SDK and a ClickHouse-backed trace-server library, but no web UI, no deployment manifest and not the HTTP service that fronts the trace server, which its own trace_server/README.md places in W&B's closed core repository)

backend

commercial(W&B SaaS platform hosts traces/evals

eval+tracing-client

OSS

Only part of the product is published, which puts this on the source-available rung at 2 above any license test. wandb/weave is Apache-2.0 and publishes more than an SDK - weave/trace_server/ holds a working ClickHouse implementation with schema, migrations, query builders, workers, Kafka, file storage and OpenTelemetry ingest - but the repository carries no web UI, no docker-compose or Helm chart, and not the HTTP service that fronts the trace server. The repository's own weave/trace_server/README.md diagrams that service as living in core, which is W&B's closed repository; the package README's stated prerequisite is a Weights & Biases account; and W&B's deployment docs say a self-managed install needs a W&B Server license obtained before installation. You cannot stand the product up from what is published, which is what partial source means here.

• https://github.com/wandb/weave recorded 2026-06-04

  Apache-2.0 license on the Weave SDK repo; LLM logging/tracing/eval toolkit

• https://api.github.com/repos/wandb/weave/contents/ recorded 2026-08-12

  Repository root, listed to establish what ships. LICENSE (Apache-2.0 per the license endpoint), Makefile, noxfile.py, pyproject.toml, bin, dev_docs, examples, scripts, sdks, tests, trace_server_mock, weave. There is no docker-compose, no chart, no deploy or infra directory, and no web/ or ui/ - so no published way to run the application. sdks/ contains only `node`. bin/ contains only codex_setup.sh and run_setup_in_codex.sh. The server-side code that does ship is the library under weave/trace_server/, which includes clickhouse_trace_server_batched.py, clickhouse_schema.py, migrations, workers, kafka.py, file_storage.py and an opentelemetry package.

• https://raw.githubusercontent.com/wandb/weave/master/weave/trace_server/README.md recorded 2026-08-12

  The repository's own architecture diagram, which names the piece that is missing. The call-start sequence runs UserCode -> OpExecution -> GraphClientTrace -> RemoteHTTPTraceServer -> "(in core) trace_server.py TraceWebServer <FlaskApp>" -> ClickHouseTraceServer -> ClickHouseDB. The web service tier is annotated as living in core, W&B's closed repository, not in this one. The published RemoteHTTPTraceServer is the client that posts to it.

• https://raw.githubusercontent.com/wandb/weave/master/README.md recorded 2026-08-12

  The vendor's own prerequisite for using the published package, stated plainly under Prerequisites: "Python 3.10 or higher" and "A Weights & Biases account (free tier available)". The quick start is `pip install weave` then `weave.init("my-project-name")`, which registers against that account. Nothing in the README describes running Weave without W&B.

• https://docs.wandb.ai/guides/hosting/ recorded 2026-08-12

  W&B's deployment options: Multi-tenant Cloud, Dedicated Cloud and Self-Managed. On licensing it states "Some features and functionality require an Enterprise license" and routes readers to an Enterprise trial. The self-managed page adds "A W&B Server license authorizes your deployment. You must obtain a license before installation." So the on-premises route runs a licensed W&B Server distribution rather than a build of wandb/weave.