Berd
Berd is worth a look mainly because a public company with real engineering resources open-sourced it rather than selling it, so there is no subscription risk and the source is inspectable. It is aimed at people comfortable managing their own model provider API keys and costs, not at someone wanting an all-inclusive subscription product.
Pros
- Free and open-source under Apache 2.0, with no subscription fee from Berd itself
- Built and maintained by Block, a company with an existing agent-tooling track record
- Runs locally on macOS, Windows, and Linux rather than only in a browser
- Canvas approach lets several providers and automations be wired together visually
Cons
- Model provider costs are still paid directly, so total cost isn't zero for real use
- Being new and open-source, documentation and stability are less mature than an established commercial product