API Stub Generator (Python)
Generate a complete mock API in minutes.
API Stub Generator turns an OpenAPI spec (YAML/JSON) or a simple endpoints file into a runnable local API server that returns realistic stub responses, consistent status codes, and predictable sample data. It is designed for frontend development, QA testing, demos, and integration work when the real backend is not ready.
What you get
A runnable stub API server (local) that mirrors your endpoints
Automatic response stubs for common HTTP methods (GET, POST, PUT, PATCH, DELETE)
Configurable status codes and latency simulation (optional)
Sample data generation based on schema types (strings, numbers, arrays, objects)
Deterministic “seed mode” for repeatable outputs
Exportable response fixtures (JSON files) for tests and CI
Works great for
Frontend teams needing an API immediately
QA engineers building test flows without backend dependencies
Product demos with stable, predictable responses
Contract-first development (OpenAPI-first workflows)
Inputs
Choose one:
OpenAPI spec: .yaml / .yml / .json
Simple endpoints file: a lightweight format you define (path, method, status, sample JSON)
Outputs
Key features
Schema-aware stubs: Produces structured JSON that matches your schema shape
Error modes: Toggle 4xx/5xx responses for resilience testing
Latency simulation: Mimic slow networks or heavy endpoints
Easy overrides: Replace any endpoint’s response with your own JSON file
CORS enabled (optional): Works smoothly with frontend dev servers
Requirements
Setup (typical)
Install dependencies
Point the tool to your OpenAPI file
Run the generated server
Start building/testing against the stub endpoints
Delivery
Downloadable ZIP (scripts + README)
or
Access product (web dashboard to upload spec and download generated project), depending on your store model
License
Personal/internal business use. Redistribution of the generator or generated package as a competing product is not allowed unless you purchase an extended license.
