marshmallow
Lightweight library for converting complex datatypes to and from native Python datatypes.
Used in agent projects
20
0.2% of 12,697 public repos built with AI coding agents
Rank in forms, validation and schemas
#22 of 22
by use in those projects
Downloads
20.1M
PyPI, last 7 days, marshmallow
GitHub stars
7,242
last push Oct 6, 2026
How marshmallow is used
marshmallow is a dependency in 20 of the 12,697 public GitHub projects set up for AI coding agents that we scanned (0.2%), #22 of 22 in forms, validation and schemas. The most used alternative there is Zod. Projects that use it most often also use Requests (100.0%), NumPy (95.0%), Pydantic (95.0%).
Often used with marshmallow
| Requests | 100.0% of marshmallow projects · 18.8× more than average |
|---|---|
| NumPy | 95.0% of marshmallow projects · 24.8× more than average |
| Pydantic | 95.0% of marshmallow projects · 18.6× more than average |
| PyYAML | 95.0% of marshmallow projects · 31.3× more than average |
| python-dotenv | 90.0% of marshmallow projects · 13.8× more than average |
| urllib3 | 85.0% of marshmallow projects · 55.9× more than average |
| attrs | 80.0% of marshmallow projects · 79.4× more than average |
| charset-normalizer | 80.0% of marshmallow projects · 64.3× more than average |
By coding agent
| GitHub Copilot | 0.2% of projects set up for it |
|---|---|
| Claude Code | 0.2% of projects set up for it |
Share of public repos configured for each agent that list marshmallow as a dependency.
Install
| Package | pip install marshmallow |
|---|---|
| Main stacks | Python (18), Next.js (2) |
| Example projects | owid/etl, mikegianfelice/Hunter, NA-DEGEN-GIRL/multi-perp-dex, ManojINaik/manimAnimationAgent |
Alternatives to marshmallow
| Tool | Used in agent projects | Downloads / wk | GitHub stars | License |
|---|---|---|---|---|
| Zod npm TypeScript-first schema validation library with static type inference. |
2,153 (17.0%) | 326M | 44.1K | MIT |
| React Hook Form npm Performant form state library using React Hooks with minimal rerenders. |
1,021 (8.0%) | 54.7M | 44.9K | MIT |
| React Hook Form Resolvers npm Validation resolvers for React Hook Form supporting Zod, Yup, and others. |
885 (7.0%) | 45.1M | 2,264 | MIT |
| Pydantic pypi Data validation and parsing library using Python type hints. |
649 (5.1%) | 222M | 29K | — |
| Ajv npm Fast JSON Schema validator for runtime schema validation and serialization. |
131 (1.0%) | 391M | 14.9K | MIT |
| jsonschema pypi Python implementation of JSON Schema validation for structured data. |
129 (1.0%) | 125M | 4,989 | — |
| Protocol Buffers pypi Serialization format and code generator for structured data. |
75 (0.6%) | 154M | — | 3-Clause BSD License |
| drizzle-zod npm Generate Zod validation schemas automatically from Drizzle ORM database schemas. |
68 (0.5%) | 3.2M | 36K | Apache-2.0 |