Skip to main content
Apicentric is a Rust-based CLI tool and API simulator platform that helps developers mock APIs, test contracts, generate code, and simulate IoT devices—all from the terminal.

​
What is Apicentric?

Apicentric transforms how you work with APIs during development and testing. Whether you’re a frontend developer needing a backend API, a QA engineer validating service contracts, or an IoT developer simulating device fleets, Apicentric has you covered.

Quick start

Get up and running with your first mock API in minutes

Installation

Install via npm, Homebrew, or build from source

CLI reference

Explore all commands and options

Examples

Learn from real-world use cases

​
Key features

Apicentric provides everything you need for modern API development and testing:

​
API simulator

Mock REST and GraphQL APIs with simple YAML configuration. Define endpoints, responses, and data fixtures in minutes.
  • Path parameters and regex matching
  • Dynamic templates with Handlebars
  • Request validation and conditional responses
  • Scenarios for different API states (latency, errors, maintenance)
  • Recording proxy to capture real API traffic

​
Contract testing

Validate that your mocks match real APIs automatically.
  • Compare mock vs. real responses
  • HTML reports with visual diffs
  • CI/CD integration
  • Compatibility policies (strict, lenient, recommended)

​
Code generation

Generate client code from your service definitions.
  • TypeScript type definitions
  • React Query hooks
  • React components
  • Export to OpenAPI and Postman

​
MCP integration

Power AI assistants like Claude with API mocking tools via Model Context Protocol.
  • Natural language API creation
  • Automated testing setup
  • Service management from chat

​
IoT digital twins

Simulate industrial devices with realistic physics and protocols.
  • Actor-based device simulation
  • MQTT and Modbus TCP support
  • Physics strategies (sine waves, noise, custom scripts)
  • Multi-device fleet simulation

​
Terminal UI

Manage services with an interactive terminal dashboard.
  • Real-time service status
  • Live request logs with filtering
  • Keyboard-driven workflow
  • Multi-pane layout

​
Who is it for?

Mock backend APIs instantly without waiting for backend teams. Define your ideal API contract and start building immediately.
Test edge cases and error scenarios easily. Validate API contracts between services automatically.
Prototype APIs before implementation. Generate OpenAPI specs from your mocks.
Simulate device fleets without physical hardware. Test MQTT and Modbus integrations.
Containerize services with Docker. Integrate into CI/CD pipelines.

​
How it works

Apicentric follows a simple workflow:
1

Define your API

Create a YAML file describing your endpoints, responses, and data fixtures.
2

Start the simulator

Run apicentric simulator start to launch your mock API.
3

Test and iterate

Send requests to your API and refine your service definition.
4

Generate code (optional)

Generate TypeScript types, React Query hooks, or export to OpenAPI.
5

Deploy (optional)

Dockerize your service for easy sharing and deployment.

​
Why Apicentric?

Apicentric is built for developers who love the terminal and want powerful tools that stay out of their way.
Simple YAML configuration — No complex UIs or heavy frameworks. Just clean, version-controllable YAML. Powerful templating — Handlebars templates with Faker integration for realistic data. Multiple protocols — REST, GraphQL, WebSocket, SSE, MQTT, Modbus TCP. Production-ready — Docker support, CI/CD integration, contract testing. Extensible — Plugin system (experimental), Rhai scripting, custom templates. Fast — Built in Rust for performance and reliability.

​
Next steps

Install Apicentric

Choose your preferred installation method

Quick start guide

Create your first mock API in 5 minutes

Core concepts

Learn about service definitions, fixtures, and scenarios

Browse examples

Explore real-world use cases

Build docs developers (and LLMs) love

Get started for freeTalk to us