Compare frameworks
Guardrails vs CrewAI vs Letta
Every figure below carries the source that reported it and the moment it was observed. Values that failed validation are withheld rather than shown, and a dash means no source we track carries that field for that framework.
| Field | Guardrails | CrewAI | Letta |
|---|---|---|---|
| Stars | 7,443Synced from sourceCurrent5h ago | 58,958 (highest of the compared values)Synced from sourceCurrent5h ago | 24,864Synced from sourceCurrent5h ago |
| Last commit | 2026-09-22Synced from sourceCurrent5h ago | 2026-09-23Synced from sourceCurrent5h ago | 2026-09-10Synced from sourceCurrent5h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago |
| Licence | Apache-2.0Synced from sourceCurrent5h ago | MITSynced from sourceCurrent5h ago | Apache-2.0Synced from sourceCurrent5h ago |
| Archived | noSynced from sourceCurrent5h ago | noSynced from sourceCurrent5h ago | noSynced from sourceCurrent5h ago |
| Category | validationSeeded, unreviewedwritten 1mo ago | multi-agentSeeded, unreviewedwritten 1mo ago | memorySeeded, unreviewedwritten 1mo ago |
| Contributors | 79Synced from sourceCurrent5h ago | 340Synced from sourceCurrent5h ago | 155Synced from sourceCurrent5h ago |
| Forks | 708Synced from sourceCurrent5h ago | 8560Synced from sourceCurrent5h ago | 2628Synced from sourceCurrent5h ago |
| Maintainer | Guardrails AISeeded, unreviewedwritten 1mo ago | CrewAISeeded, unreviewedwritten 1mo ago | LettaSeeded, unreviewedwritten 1mo ago |
| Open issues | 80Synced from sourceCurrent5h ago | 463Synced from sourceCurrent5h ago | 0Synced from sourceCurrent5h ago |
| PyPI package | guardrails-aiSynced from sourceCurrent5h ago | crewaiSynced from sourceCurrent5h ago | lettaSynced from sourceCurrent5h ago |
| PyPI released | 2026-08-14T14:22:27.750056ZSynced from sourceCurrent5h ago | 2026-09-16T22:10:41.471882ZSynced from sourceCurrent5h ago | 2026-09-23T23:59:05.225455ZSynced from sourceCurrent5h ago |
| Requires Python | <3.14,>=3.10Synced from sourceCurrent5h ago | <3.14,>=3.10Synced from sourceCurrent5h ago | >=3.9Synced from sourceCurrent5h ago |
| PyPI version | 0.11.0Synced from sourceCurrent5h ago | 1.15.22Synced from sourceCurrent5h ago | 0.33.0Synced from sourceCurrent5h ago |
| Repository | https://github.com/guardrails-ai/guardrailsSynced from sourceCurrent5h ago | https://github.com/crewAIInc/crewAISynced from sourceCurrent5h ago | https://github.com/letta-ai/lettaSynced from sourceCurrent5h ago |
Sources: GitHub REST API, npm registry downloads, PyPI registry metadata, pypistats.org downloads. Most recent observation 5h ago. Where a row is marked, ▲ is the highest of the values shown and ▼ the lowest — arithmetic on the figures above, not a ranking or a recommendation. Rows where neither extreme is meaningful are left unmarked rather than given a direction they do not have.
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