Compare frameworks
Haystack vs DeepEval 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 | Haystack | DeepEval | Letta |
|---|---|---|---|
| Stars | 26,584 (highest of the compared values)Synced from sourceCurrent2h ago | 18,419Synced from sourceCurrent2h ago | 24,864Synced from sourceCurrent2h ago |
| Last commit | 2026-09-23Synced from sourceCurrent2h ago | 2026-09-23Synced from sourceCurrent2h ago | 2026-09-10Synced from sourceCurrent2h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago |
| Licence | Apache-2.0Synced from sourceCurrent2h ago | Apache-2.0Synced from sourceCurrent2h ago | Apache-2.0Synced from sourceCurrent2h ago |
| Archived | noSynced from sourceCurrent2h ago | noSynced from sourceCurrent2h ago | noSynced from sourceCurrent2h ago |
| Category | ragSeeded, unreviewedwritten 1mo ago | evaluationSeeded, unreviewedwritten 1mo ago | memorySeeded, unreviewedwritten 1mo ago |
| Contributors | 475Synced from sourceCurrent2h ago | 337Synced from sourceCurrent2h ago | 155Synced from sourceCurrent2h ago |
| Forks | 3176Synced from sourceCurrent2h ago | 1973Synced from sourceCurrent2h ago | 2628Synced from sourceCurrent2h ago |
| Maintainer | deepsetSeeded, unreviewedwritten 1mo ago | Confident AISeeded, unreviewedwritten 1mo ago | LettaSeeded, unreviewedwritten 1mo ago |
| Open issues | 168Synced from sourceCurrent2h ago | 654Synced from sourceCurrent2h ago | 0Synced from sourceCurrent2h ago |
| PyPI package | haystack-aiSynced from sourceCurrent2h ago | deepevalSynced from sourceCurrent2h ago | lettaSynced from sourceCurrent2h ago |
| PyPI released | 2026-09-03T09:27:43.312258ZSynced from sourceCurrent2h ago | 2026-09-22T19:26:34.903554ZSynced from sourceCurrent2h ago | 2026-09-23T23:59:05.225455ZSynced from sourceCurrent2h ago |
| Requires Python | >=3.10Synced from sourceCurrent2h ago | <4.0,>=3.9Synced from sourceCurrent2h ago | >=3.9Synced from sourceCurrent2h ago |
| PyPI version | 3.1.1Synced from sourceCurrent2h ago | 4.2.5Synced from sourceCurrent2h ago | 0.33.0Synced from sourceCurrent2h ago |
| Repository | https://github.com/deepset-ai/haystackSynced from sourceCurrent2h ago | https://github.com/confident-ai/deepevalSynced from sourceCurrent2h ago | https://github.com/letta-ai/lettaSynced from sourceCurrent2h ago |
Sources: GitHub REST API, npm registry downloads, PyPI registry metadata, pypistats.org downloads. Most recent observation 2h 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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