Arthur
Model monitoring and firewall (Arthur Shield) for enterprise AI, focused on risk, bias and policy enforcement.
| Category | Guardrails & Safety |
| Open source | Yes |
| Self-hostable | Yes |
| Pricing model | freemium |
| Pricing notes | Open-sourced engine components; enterprise platform custom-priced |
| Framework integrations | openai-sdk, langchain |
| Funding / ownership | $42M Series B (2022) |
| GitHub stars | 429 |
| Maintenance | slow (2026-03-15) |
| License (GitHub) | MIT |
| Open issues | 1 |
| Maturity signal | 60/100 (Established) — computed from public GitHub signals, see methodology |
Pricing/feature source: https://www.arthur.ai
Maturity signal is computed from public GitHub data only. How it is calculated.
Frequently asked questions
Is Arthur open source?
Yes. Licensed under MIT.
Can I self-host Arthur?
Yes — Arthur can run in your own infrastructure.
How much does Arthur cost?
Freemium. Open-sourced engine components; enterprise platform custom-priced