Both are open source security options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence.
NVIDIA's programmable rails — constrain topic, dialogue path and tool use.
Policy engine and analyzer for agent traces and MCP tool calls.
| NeMo Guardrails | Invariant | |
|---|---|---|
| Licence | Open source | Open source |
| Pricing | open source | freemium |
| Self-hostable | Yes | Yes |
| Languages | Python | Python |
| Install | pip install nemoguardrails | — |
| Keys required | None | None |
| Job within the layer | policy | policy |
Both are open source security options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence. NeMo Guardrails: NVIDIA's programmable rails — constrain topic, dialogue path and tool use. Invariant: Policy engine and analyzer for agent traces and MCP tool calls.
NeMo Guardrails can run on your own infrastructure. Invariant can run on your own infrastructure.
NeMo Guardrails is open source (open source). Invariant is open source (freemium).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/nemo-guardrails-vs-invariant