# mockserver

One process that stands in for any HTTP, gRPC or WebSocket dependency. Useful when the backend isn't ready or keeps failing.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed · ★ 4996
- Author: mock-server
- License: Apache-2.0 · policy=link-only · description only; the file stays with the author
- Source: https://github.com/mock-server/mockserver-monorepo
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/mcp/mockserver

## What it does

MockServer listens on port 1080 and takes instructions over a REST control plane on that same port. You describe what a request looks like — method, path, headers, body — and what should come back: a fixed response, a templated one, or the result of a callback.

It also works as a proxy. Point your app at it, record real traffic, then replay it later. TLS-encrypted exchanges stay readable. On top of that you can inject latency, dropped connections and error codes to see how the app handles a dependency going bad. Chat-completion APIs from OpenAI, Anthropic, Gemini, Bedrock, Azure OpenAI and Ollama are mockable too, streaming included.

Start it with `docker run -d --rm -p 1080:1080 mockserver/mockserver`, or install through Homebrew and run `mockserver run --port 1080`. Helm charts exist for Kubernetes. Client libraries cover Java, Node, Python, Ruby, Go, .NET, Rust and PHP. Nothing works over MCP until that process is actually up — the server drives a running MockServer, it doesn't replace it.

## Requirements
- Needs: Docker
- A remote (HTTP) option exists: the address is in the README

## Install

### Claude Code (native platform)

**Install**
- The MCP registry has no launch command for it: see the repository README

## When to use it
- stand up a mock REST endpoint before the backend exists
- record live traffic and replay it in tests
- check how the app behaves when a dependency drops the connection
- generate mocks from an OpenAPI spec instead of writing them by hand
- swap out chat-completion responses while debugging an agent

## Example prompts
- Start MockServer on port 1080 and mock GET /hello with a 200 response
- Record traffic through the proxy and show me which requests hit the backend
- Add a 3 second delay to every request to /pets and run the tests

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