Compare frameworks
Pydantic AI vs Vercel AI SDK vs Mastra
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 | Pydantic AI | Vercel AI SDK | Mastra |
|---|---|---|---|
| Stars | 20,220Synced from sourceCurrent4h ago | 27,001Synced from sourceCurrent4h ago | 28,378 (highest of the compared values)Synced from sourceCurrent4h ago |
| downloads | 3,076,771Synced from sourceStale1mo ago· past SLA | 29,813,554 (highest of the compared values)Synced from sourceCurrent4h ago | 1,980,114Synced from sourceCurrent4h ago |
| Last commit | 2026-09-28Synced from sourceCurrent4h ago | 2026-09-28Synced from sourceCurrent4h ago | 2026-09-28Synced from sourceCurrent4h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | typescriptSeeded, unreviewedwritten 1mo ago | typescriptSeeded, unreviewedwritten 1mo ago |
| Licence | MITSynced from sourceCurrent4h ago | — | — |
| Archived | noSynced from sourceCurrent4h ago | noSynced from sourceCurrent4h ago | noSynced from sourceCurrent4h ago |
| Category | structured-outputSeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago |
| Contributors | 609Synced from sourceCurrent4h ago | 719Synced from sourceCurrent4h ago | 682Synced from sourceCurrent4h ago |
| Forks | 2796Synced from sourceCurrent4h ago | 5207Synced from sourceCurrent4h ago | 2871Synced from sourceCurrent4h ago |
| Maintainer | PydanticSeeded, unreviewedwritten 1mo ago | VercelSeeded, unreviewedwritten 1mo ago | MastraSeeded, unreviewedwritten 1mo ago |
| npm downloads, monthly | — | 92989638Synced from sourceCurrent4h ago | 5868462Synced from sourceCurrent4h ago |
| npm downloads, weekly | — | 29813554Synced from sourceCurrent4h ago | 1980114Synced from sourceCurrent4h ago |
| npm package | — | aiSynced from sourceCurrent4h ago | @mastra/coreSynced from sourceCurrent4h ago |
| npm window ends | — | 2026-09-26Synced from sourceCurrent4h ago | 2026-09-26Synced from sourceCurrent4h ago |
| Open issues | 1013Synced from sourceCurrent4h ago | 1450Synced from sourceCurrent4h ago | 477Synced from sourceCurrent4h ago |
| PyPI downloads, monthly | 13478631Synced from sourceStale1mo ago· past SLA | — | — |
| PyPI downloads, weekly | 3076771Synced from sourceStale1mo ago· past SLA | — | — |
| PyPI package | pydantic-aiSynced from sourceCurrent4h ago | — | — |
| PyPI released | 2026-09-25T23:32:17.554286ZSynced from sourceCurrent4h ago | — | — |
| Requires Python | >=3.10Synced from sourceCurrent4h ago | — | — |
| PyPI version | 2.51.0Synced from sourceCurrent4h ago | — | — |
| Repository | https://github.com/pydantic/pydantic-aiSynced from sourceCurrent4h ago | https://github.com/vercel/aiSynced from sourceCurrent4h ago | https://github.com/mastra-ai/mastraSynced 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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