fastjsonschema
Fast JSON schema validation for Python with optimized performance.
Forms, validation and schemas PyPI BSD
How fastjsonschema is used
fastjsonschema is a dependency in 8 of the 6,208 public GitHub projects set up for AI coding agents that we scanned, too few to describe it from them alone. Our scan also samples projects by dependency (Solana 2,661, Ethereum and EVM 1,496, 3D and games 2,818, agent frameworks and SDKs 10,983); counting those, it appears in 206 projects, and what it is used with below comes from all of them. The most used alternative in our scan is Pydantic (536 projects). Projects that use it most often also use attrs (98.1%), Jinja2 (97.1%), NumPy (97.1%).
fastjsonschema popularity over time
Gid Score 57: downloads 95, use in agent projects 61, GitHub stars 0, downloads trend 56 (each 0-100). How it is calculated.
Often used with fastjsonschema
| attrs | 98.1% of fastjsonschema projects · 141.6× more than average |
|---|---|
| Jinja2 | 97.1% of fastjsonschema projects · 44.6× more than average |
| NumPy | 97.1% of fastjsonschema projects · 16.6× more than average |
| charset-normalizer | 96.6% of fastjsonschema projects · 89.5× more than average |
| MarkupSafe | 96.6% of fastjsonschema projects · 130.4× more than average |
| jsonschema | 96.1% of fastjsonschema projects · 59.1× more than average |
| packaging | 96.1% of fastjsonschema projects · 65.6× more than average |
From all 206 projects in our scan that use fastjsonschema, including the dependency samples.
By coding agent
| Claude Code | 0.2% of projects set up for it |
|---|---|
| GitHub Copilot | 0.2% of projects set up for it |
Share of public repos configured for each agent that list fastjsonschema as a dependency.
How fastjsonschema is funded
Install
| Package | pip install fastjsonschema |
|---|---|
| Main stacks | Python (203), Next.js (3) |
| Example projects | Paper2Poster/Paper2Poster, YuhangChen1/Paper2All, Luffy03/Large-Scale-Medical, bingreeky/MaAS, aihes/LangChain-Tutorials-and-Examples |
Alternatives to fastjsonschema
Tools that do the same job, so a project picks one or the other. Add-ons and libraries used alongside fastjsonschema are not listed here; they are in "Often used with".
| Tool | Gid Score | Used in agent projects | Downloads / wk | GitHub stars | License |
|---|---|---|---|---|---|
| Pydantic pypi Data validation and parsing library using Python type hints. |
86 | 536 (33.0%) | 243M | 29.1K | MIT |
| jsonschema pypi Python implementation of JSON Schema validation for structured data. |
75 | 101 (6.2%) | 135M | 4,990 | MIT |
| schema pypi Lightweight Python library for validating data structures against defined schemas. |
53 | 3 (0.2%) | 4.7M | 2,943 | MIT |
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