FieldExclude: Open-Source Middleware + Commercial Support Package
A lightweight, language-agnostic middleware library (Express, FastAPI, Django, etc.) that intercepts API responses and applies field-exclusion rules via simple configuration files or decorators, eliminating the need to manually whitelist fields. Developers define a blacklist of sensitive fields once per model, and the middleware automatically strips them from all endpoints—breaking changes to the data model don't break the API contract.
15 weeks • 70% confidence
Value Proposition
Reduces boilerplate by 60-80% compared to manual field listing; eliminates the cognitive load of maintaining inclusion lists; automatically adapts when new fields are added to models; provides audit trails of what data was exposed per endpoint. Beats existing solutions because it inverts the problem—exclude what you don't want, not include what you do.
Target Audience
Mid-market SaaS companies and startups (10-200 engineers) building REST/GraphQL APIs with complex data models; teams already using Node, Python, or Go backends
Key Features
- Declarative field-exclusion rules in YAML or JSON (no code changes needed)
- Automatic schema introspection for popular ORMs (SQLAlchemy, Prisma, TypeORM)
- Role-based exclusion rules (e.g., hide salary from non-admin roles)
- And more, with full implementation detail...
Tech Stack
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Sign up freeOriginal Problem
Developers waste time manually specifying which fields to include in API responses instead of excluding unwanted onesBackend developers building APIs must tediously list every single field they want to return when working with large data models, even when they only need to exclude 1-2 fields. This creates repetitive, error-prone code that becomes harder to maintain as data structures grow. Current API response libraries force developers to use the 'whitelist' approach (only/include) rather than the more intuitive 'blacklist' approach (exclude/except) when dealing with large datasets.
Score: 17.5%