MockAPI Dog

Product Introduction

1. Definition: MockAPI Dog is a zero-configuration SaaS tool for generating instant mock REST APIs (JSON-based) and LLM (Large Language Model) streaming endpoints. It falls under the technical category of API simulation and testing platforms.
2. Core Value Proposition: It eliminates backend dependencies for frontend developers, testers, and AI builders by providing instantly deployable mock APIs without authentication, credit cards, or infrastructure setup.

Main Features

1. REST API & LLM Streaming Endpoints:
   • Generates REST APIs with customizable JSON responses (via built-in editor) and LLM streaming endpoints mimicking OpenAI/Anthropic formats.
   • Uses HTTP methods (GET/POST/PUT/PATCH/DELETE) with status code control (200, 400, 500, etc.) and CORS support.
2. Error & Delay Simulation Engine:
   • Simulates network latency (artificial delays), random failures (error rate testing), and conditional errors based on request headers.
   • Tests edge cases like 404/500 errors or slow streaming token delivery for LLMs.
3. Zero-Configuration Deployment:
   • Auto-generates unique endpoint URLs instantly. Saves endpoints without accounts via browser storage.
   • Features syntax-highlighted JSON validation and one-click "Beautify" for response structuring.

Problems Solved

1. Pain Point: Frontend development stalls due to incomplete backend APIs. MockAPI Dog provides immediate JSON/streaming endpoints to unblock UI work.
2. Target Audience:
   • Frontend developers (React/Vue.js teams), QA automation engineers, AI integrators testing ChatGPT/Claude, and educators running API workshops.
3. Use Cases:
   • Testing AI chatbot UIs without burning LLM API credits.
   • Simulating payment gateway failures (e.g., 409 Conflict) during CI/CD pipeline tests.
   • Prototyping mobile app data flows with delayed JSON responses.

Unique Advantages

1. Differentiation: Unlike Postman Mocks or paid tools (e.g., Mockoon), it requires no installation, accounts, or API keys. Competitors lack integrated LLM streaming simulation.
2. Key Innovation: Real-time LLM token streaming emulation for OpenAI/Anthropic formats—critical for testing AI streaming UIs without live providers.

Frequently Asked Questions (FAQ)

1. Is MockAPI Dog free for commercial projects?
   Yes, MockAPI Dog is 100% free for commercial and personal use, with no usage limits or hidden fees.
2. How long do mock endpoints remain active?
   Endpoints persist indefinitely if regularly accessed; inactive endpoints may be purged periodically.
3. Can I simulate OpenAI streaming responses?
   Absolutely. Configure LLM streaming endpoints with token delays to mimic ChatGPT/GPT-4 API behavior.
4. Does it support testing CORS errors?
   No—all endpoints have pre-enabled CORS headers, allowing cross-origin requests by default.
5. How secure are mock APIs for sensitive data testing?
   Use only for non-sensitive data; endpoints are public. Avoid production data due to lack of encryption.