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Smocker is a simple and efficient HTTP mock server and proxy


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Smocker (server mock) is a simple and efficient HTTP mock server.

The documentation is available on

Table of contents


With Docker

docker run -d \
  --restart=always \
  -p 8080:8080 \
  -p 8081:8081 \
  --name smocker \

Manual Deployment

# This will be the deployment folder for the Smocker instance
mkdir -p /opt/smocker && cd /opt/smocker
wget -P /tmp
tar xf /tmp/smocker.tar.gz
nohup ./smocker -mock-server-listen-port=8080 -config-listen-port=8081 &


curl localhost:8081/version

User Interface

Smocker exposes a configuration user interface. You can access it in your web browser on http://localhost:8081/.




Smocker exposes two ports:

  • 8080 is the mock server port. It will expose the routes you register through the configuration port
  • 8081 is the configuration port. It's the port you will use to register new mocks. This port also exposes a user interface.

Hello, World!

To register a mock, you can use the YAML and the JSON formats. A basic mock might look like this:

# helloworld.yml
# This mock register two routes: GET /hello/world and GET /foo/bar
- request:
    # Note: the method could be omitted because GET is the default
    method: GET
    path: /hello/world
    # Note: the status could be omitted because 200 is the default
    status: 200
      Content-Type: application/json
    body: >
        "hello": "Hello, World!"

- request:
    method: GET
    path: /foo/bar
    status: 204

You can then register it to the configuration server with the following command:

curl -XPOST \
  --header "Content-Type: application/x-yaml" \
  --data-binary "@helloworld.yml" \

After your mock is registered, you can query the mock server on the specified route, so that it returns the expected response to you:

$ curl -i localhost:8080/hello/world
HTTP/1.1 200 OK
Content-Type: application/json
Date: Thu, 05 Sep 2019 15:49:32 GMT
Content-Length: 31

  "hello": "Hello, World!"

To cleanup the mock server without restarting it, you can execute the following command:

curl -XPOST localhost:8081/reset

For more advanced usage, please read the project's documentation.



The backend is written in Go. You can use the following commands to manage the development lifecycle:

  • make start: start the backend in development mode, with live reload
  • make build, make VERSION=xxx build: compile the code and generate a binary
  • make lint: run static analysis on the code
  • make format: automatically format the backend code
  • make test: execute unit tests
  • make test-integration: execute integration tests


The frontend is written with TypeScript and React. You can use the following commands to manage the development lifecycle:

  • yarn install: install the dependencies
  • yarn start: start the frontend in development mode, with live reload
  • yarn build: generate the transpiled and minified files and assets
  • yarn lint: run static analysis on the code
  • yarn format: automatically format the frontend code
  • yarn test: execute unit tests
  • yarn test:watch: execute unit tests, with live reload


The application can be packaged as a standalone Docker image. You can use the following commands to manage the development lifecycle:

  • make build-docker, make VERSION=xxx build-docker: build the application as a Docker image
  • make start-docker, make VERSION=xxx start-docker: run a Smocker Docker image


If you need to test Smocker with a base path, you can use the Caddyfile provided in the repository (Caddy v2):

  • make start-release, make VERSION=xxx start-release: create a released version of Smocker and launch it with /smocker/ as base path
  • make start-caddy: start Caddy to make Smocker accessible at http://localhost:8082/smocker/


If you need to test Smocker with HTTPS enabled, the easiest way is to generate a locally signed certificate with mkcert:

# Install the local certificate authority
mkcert -install

# Create a certificate for localhost
mkcert -cert-file /tmp/cert.pem -key-file /tmp/key.pem localhost

Then, start Smocker with TLS enabled, using your generated certificate:

./smocker -mock-server-listen-port=44300 -config-listen-port=44301 -tls-enable -tls-cert-file=/tmp/cert.pem -tls-private-key-file=/tmp/key.pem