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 | 24,923Synced from sourceCurrent4h ago | 28,608 (highest of the compared values)Synced from sourceCurrent4h ago | 27,001Synced from sourceCurrent4h ago |
| downloads | — | — | 29,813,554Synced from sourceCurrent4h ago |
| Last commit | 2026-09-10Synced from sourceCurrent4h ago | 2026-09-19Synced from sourceCurrent4h ago | 2026-09-28Synced from sourceCurrent4h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | csharpSeeded, unreviewedwritten 1mo ago | typescriptSeeded, unreviewedwritten 1mo ago |
| Licence | Apache-2.0Synced from sourceCurrent4h ago | MITSynced from sourceCurrent4h ago | — |
| Archived | noSynced from sourceCurrent4h ago | noSynced from sourceCurrent4h ago | noSynced from sourceCurrent4h ago |
| Category | memorySeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago |
| Contributors | 155Synced from sourceCurrent4h ago | 416Synced from sourceCurrent4h ago | 719Synced from sourceCurrent4h ago |
| Forks | 2631Synced from sourceCurrent4h ago | 4793Synced from sourceCurrent4h ago | 5207Synced from sourceCurrent4h ago |
| Maintainer | LettaSeeded, unreviewedwritten 1mo ago | MicrosoftSeeded, unreviewedwritten 1mo ago | VercelSeeded, unreviewedwritten 1mo ago |
| npm downloads, monthly | — | — | 92989638Synced from sourceCurrent4h ago |
| npm downloads, weekly | — | — | 29813554Synced from sourceCurrent4h ago |
| npm package | — | — | aiSynced from sourceCurrent4h ago |
| npm window ends | — | — | 2026-09-26Synced from sourceCurrent4h ago |
| Open issues | 0Synced from sourceCurrent4h ago | 338Synced from sourceCurrent4h ago | 1450Synced from sourceCurrent4h ago |
| PyPI package | lettaSynced from sourceCurrent4h ago | semantic-kernelSynced from sourceCurrent4h ago | — |
| PyPI released | 2026-09-28T04:32:31.896015ZSynced from sourceCurrent4h ago | 2026-08-06T09:56:42.518861ZSynced from sourceCurrent4h ago | — |
| Requires Python | >=3.9Synced from sourceCurrent4h ago | >=3.10Synced from sourceCurrent4h ago | — |
| PyPI version | 0.33.5Synced from sourceCurrent4h ago | 1.44.1Synced from sourceCurrent4h ago | — |
| Repository | https://github.com/letta-ai/lettaSynced from sourceCurrent4h ago | https://github.com/microsoft/semantic-kernelSynced from sourceCurrent4h ago | https://github.com/vercel/aiSynced from sourceCurrent4h ago |
Sources: GitHub REST API, npm registry downloads, PyPI registry metadata, pypistats.org downloads. Most recent observation 4h 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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