# API Mock Server Generate a runnable Redis-backed mock API server with 1-hour TTL, hot updates, and dynamic templated responses > Canonical page: https://elysiatools.com/en/tools/api-mock-server - **Category:** Development - **Keywords:** api, mock, mock server, http, frontend, testing, redis, hot reload ## Overview Create a temporary mock server for frontend and API testing. - Input endpoint description as JSON - Generate a unique mock server ID - Store mock definition in Redis for 1 hour - Test immediately through /mock/{id} - Re-run with the same ID to hot-update responses without restarting ## Inputs - **Mock Definition JSON** (textarea): { "name": "User Service Mock", "basePath": "/api", "endpoints": \[ { "method": "GET", "path": "/users/:id", "status": 200, "responseType": "json", "dynamicResponse": true, "responseBody": { "id": "{{params.id}}", "name": "Mock User", "requestedAt": "{{now}}" } }, { "method": "POST", "path": "/login", "status": 200, "responseType": "json", "responseBody": { "token": "mock-token", "username": "{{body.username}}" } } \] } - **Existing Mock ID (Optional)** (text): Reuse an existing ID to hot-update the mock server ## When to use - When backend development is delayed and you need to unblock frontend integration. - When you need to test how your application handles specific API responses or dynamic data. - When you want to quickly prototype an API contract without setting up a full local server environment. ## How it works - Input your API endpoint definitions, including methods, paths, and response bodies, using the Mock Definition JSON format. - Generate a unique mock server ID that hosts your endpoints at a temporary URL. - Access your mock API immediately via the provided base URL. - Re-run the tool with the same mock ID to apply hot updates to your endpoints without downtime. ## Use cases - Simulating user authentication flows by mocking login POST requests. - Testing frontend data binding with dynamic GET requests that include URL parameters. - Rapidly iterating on API response structures during the design phase of a new feature. ## Frequently asked questions ### How long does the mock server stay active? Each mock server instance is stored in Redis and remains active for 1 hour after creation or last update. ### Can I update my mock responses after creating the server? Yes, simply re-run the tool using the same mockId to hot-update your endpoint definitions instantly. ### Does the server support dynamic responses? Yes, you can use template tags like {{params.id}}, {{body.username}}, or {{now}} within your response body to generate dynamic data. ### Is there a limit to the number of endpoints I can define? You can define multiple endpoints within a single JSON configuration to simulate a complete API service. ### What happens after the 1-hour TTL expires? The mock server and its data are automatically removed from Redis once the 1-hour TTL is reached. ## Related tools - [API Request Code Snippet Generator](https://elysiatools.com/en/tools/api-request-code-snippet-generator): Generate cURL and common language code snippets from a request URL, method, headers, query parameters, and body - [OpenAPI to Postman Collection](https://elysiatools.com/en/tools/openapi-to-postman-collection): Turn an OpenAPI 3.x or Swagger 2.0 spec (JSON/YAML) into an importable Postman Collection v2.1.0 with folders, variables, auth and example responses. - [Test Data Faker Builder](https://elysiatools.com/en/tools/test-data-faker-builder): Generate structured test data from field configuration with support for faker fields, regex rules, credit cards, IDs, and batch export - [OpenAPI to TypeScript Generator](https://elysiatools.com/en/tools/openapi-to-typescript-generator): Convert OpenAPI or Swagger JSON/YAML specs into TypeScript API types, request payloads, and response models with configurable output and naming styles - [CSV to Database Migration Planner](https://elysiatools.com/en/tools/csv-to-database-migration-planner): Infer a relational schema from CSV data and generate create-table plus ALTER migration plans for PostgreSQL, MySQL, SQLite, or SQL Server - [Fitness Workout PDF Generator](https://elysiatools.com/en/tools/fitness-workout-pdf-generator): Generate a printable workout-plan PDF from JSON or CSV data with exercise tables, progress boxes, and optional QR video links - [JSON Schema Generator](https://elysiatools.com/en/tools/json-schema-generator): Infer JSON Schema from sample JSON, optionally merge manual schema edits, and validate data against the active schema - [PDF Financial Report](https://elysiatools.com/en/tools/pdf-financial-report): Generate a financial report PDF with balance sheet, income statement, and merged table cells ## Samples - [Postman Collections - API Testing](https://elysiatools.com/en/samples/postman-collections): Comprehensive Postman collection examples including API testing, automation scripts, environment variables, mock servers, and advanced testing patterns for REST APIs - [WebRTC Real-Time Communication Samples](https://elysiatools.com/en/samples/webrtc-samples): Comprehensive WebRTC samples for peer-to-peer audio/video communication, data channels, screen sharing, and signaling server implementation - [macOS Networking Objective-C Samples](https://elysiatools.com/en/samples/macos-networking-objectivec): macOS Objective-C networking examples including URLSession, HTTP requests, WebSocket, and network reachability - [Windows Networking - C++ Samples](https://elysiatools.com/en/samples/windows-networking-cpp): Comprehensive C++ networking examples for Windows platform including HTTP requests, TCP sockets, and HTTP server implementation ## Related content - [API Mock Fixture Generation and Review](https://elysiatools.com/en/hubs/api-mock-fixture-generation-and-review): Build repeatable mock payloads, generate format-valid edge values, catch confusing field names, and review a temporary mock service before sharing it with a development team. - [API Request Format, Replay Preparation, and Debugging Tools](https://elysiatools.com/en/hubs/api-request-replay-and-debugging): Check request structure, prepare a local replay, compare responses, and debug API clues. These tools analyze or generate locally and do not replace real authentication or server tests. - [API Contract Definition, Schema Validation, and Change Testing](https://elysiatools.com/en/hubs/api-contract-testing): Define an API contract, validate schemas and captured payloads, detect compatibility risks, and record test acceptance.