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Mastra vs PydanticAI
Trust Score comparison · March 2026
Signal Comparison
40k / wknpm downloads180k / wk
260 commitsCommits (90d)290 commits
5k ★GitHub stars9k ★
20 q'sStack Overflow80 q's
GrowingCommunityGrowing
MastraPydanticAI
Key Differences
| Factor | Mastra | PydanticAI |
|---|---|---|
| License | Apache 2.0 | MIT |
| Language | TypeScript | Python |
| Hosted | Self-hosted | Self-hosted |
| Free tier | — | — |
| Open Source | ✓ Yes | ✓ Yes |
| TypeScript | ✓ | — |
Pick Mastra if…
- Building AI agents in TypeScript without switching to Python
- You need built-in workflow orchestration alongside agent logic
- Next.js projects that want a unified TS agent + RAG solution
Pick PydanticAI if…
- You want full type safety and IDE autocompletion for agent code
- Structured output validation is critical for your pipeline
- Teams already using Pydantic and FastAPI who want familiar patterns
Side-by-side Quick Start
Mastra
import { Mastra } from '@mastra/core';
import { openai } from '@ai-sdk/openai';
const mastra = new Mastra();
const agent = mastra.createAgent({
name: 'assistant',
model: openai('gpt-4o'),
instructions: 'You are a helpful assistant.',
});
const result = await agent.generate('Hello!');
console.log(result.text);PydanticAI
from pydantic_ai import Agent
from pydantic import BaseModel
class Response(BaseModel):
answer: str
confidence: float
agent = Agent('openai:gpt-4o', result_type=Response)
result = agent.run_sync('What is 2+2?')
print(result.data.answer)Community Verdict
Based on upvoted notes🏆
PydanticAI wins this comparison
Trust Score 82 vs 79 · 3-point difference
PydanticAI leads on Trust Score with stronger signal data across downloads and community health. That said, the other tool is worth considering if your use case matches its specific strengths above.