Compare frameworks
Letta vs Semantic Kernel vs Vercel AI SDK
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 | Letta | Semantic Kernel | Vercel AI SDK |
|---|---|---|---|
| Stars | 24,864Synced from sourceCurrent3h ago | 28,593 (highest of the compared values)Synced from sourceCurrent3h ago | 26,922Synced from sourceCurrent3h ago |
| downloads | — | — | 17,883,737Synced from sourceCurrent3h ago |
| Last commit | 2026-09-10Synced from sourceCurrent3h ago | 2026-09-19Synced from sourceCurrent3h ago | 2026-09-24Synced from sourceCurrent3h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | csharpSeeded, unreviewedwritten 1mo ago | typescriptSeeded, unreviewedwritten 1mo ago |
| Licence | Apache-2.0Synced from sourceCurrent3h ago | MITSynced from sourceCurrent3h ago | — |
| Archived | noSynced from sourceCurrent3h ago | noSynced from sourceCurrent3h ago | noSynced from sourceCurrent3h ago |
| Category | memorySeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago |
| Contributors | 155Synced from sourceCurrent3h ago | 416Synced from sourceCurrent3h ago | 715Synced from sourceCurrent3h ago |
| Forks | 2628Synced from sourceCurrent3h ago | 4787Synced from sourceCurrent3h ago | 5180Synced from sourceCurrent3h ago |
| Maintainer | LettaSeeded, unreviewedwritten 1mo ago | MicrosoftSeeded, unreviewedwritten 1mo ago | VercelSeeded, unreviewedwritten 1mo ago |
| npm downloads, monthly | — | — | 87791075Synced from sourceCurrent3h ago |
| npm downloads, weekly | — | — | 17883737Synced from sourceCurrent3h ago |
| npm package | — | — | aiSynced from sourceCurrent3h ago |
| npm window ends | — | — | 2026-09-21Synced from sourceCurrent3h ago |
| Open issues | 0Synced from sourceCurrent3h ago | 320Synced from sourceCurrent3h ago | 1462Synced from sourceCurrent3h ago |
| PyPI package | lettaSynced from sourceCurrent3h ago | semantic-kernelSynced from sourceCurrent3h ago | — |
| PyPI released | 2026-09-23T23:59:05.225455ZSynced from sourceCurrent3h ago | 2026-08-06T09:56:42.518861ZSynced from sourceCurrent3h ago | — |
| Requires Python | >=3.9Synced from sourceCurrent3h ago | >=3.10Synced from sourceCurrent3h ago | — |
| PyPI version | 0.33.0Synced from sourceCurrent3h ago | 1.44.1Synced from sourceCurrent3h ago | — |
| Repository | https://github.com/letta-ai/lettaSynced from sourceCurrent3h ago | https://github.com/microsoft/semantic-kernelSynced from sourceCurrent3h ago | https://github.com/vercel/aiSynced from sourceCurrent3h ago |
Sources: GitHub REST API, npm registry downloads, PyPI registry metadata, pypistats.org downloads. Most recent observation 3h 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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