Actions

An action defines what LiveMock answers when an expectation matches. Three kinds of action exist:

Action	Badge in the list	What it does
Custom response	RESPONSE	Returns a status code, headers and a body you write yourself.
Proxy	PROXY	Forwards the request to another host and returns its response. Also proxies WebSocket connections.
Static	STATIC	Serves files from a folder on the machine running LiveMock.

Creating an action

In the Expectation detail view click Add action on the Action card (or the pencil, when the expectation already has one). The dialog has three tabs - Custom response, Proxy and Static - and applies the change when you click Save action. An expectation has exactly one action: switching the tab converts the existing action instead of adding a second one. An expectation without any action is skipped during matching, so remember to add one - an empty expectation matches nothing.

Custom response

Field	Meaning
HTTP status	The status code of the response, for example 200 or 404.
Response type	JSON or TEXT. It decides the Content-Type of the response.
Content handler	NONE returns the content as written; MOCKJS renders it with Mock.js templates.
Response headers	Extra headers appended to the response.
Content	The response body.

Mock.js templates

With the content handler set to MOCKJS, the content is a Mock.js template and the data is generated on every request:

{
  "id": "@id",
  "name": "@name",
  "email": "@email",
  "createdAt": "@datetime"
}

Proxy

Field	Meaning
Host	The target host, for example api.stripe.com. The protocol selector in front of the field chooses http:// or https://; pasting a full URL moves its scheme into that selector automatically. The host must not contain a path. The port always stays the default for the protocol (80 for http, 443 for https), and there is no separate field for a target port.
Prefix remove	A path prefix removed from the request before it is forwarded, for example /api: a request to /api/users is forwarded as /users.
Request headers	Headers appended to the outgoing request.
Response headers	Headers appended to the response before it is sent back.
Handle cross	Adds permissive CORS headers to the response.
Allow credentials	With Handle cross, sends Access-Control-Allow-Credentials: true so browser clients can send cookies.
Support websocket	Forwards Upgrade: websocket connections too. The messages exchanged are recorded in the request log.

Static

Field	Meaning
Folder path	Absolute path of the folder on the machine running LiveMock, for example /home/user/mock-assets. Relative paths are resolved against the working directory of the server, which in Docker is /app.
URL prefix	Requests under this prefix are served from the folder; the rest of the path is used as the file path. Leave it empty to serve request paths as-is.

For example, with folder /srv/assets and prefix /static, a request to /static/logo.svg returns /srv/assets/logo.svg. A request outside the prefix, or a file that does not exist, gets a 404.

Delay

The delay is not part of the action: it is set on the expectation itself (Timing & state) and applies to every kind of action. An expectation with a delay of 5000 waits five seconds before answering, which is handy to reproduce timeouts in the client.

note

The proxy host does not have a port field: connections are made to the default port of the chosen protocol, which is why a backend that listens on a custom port (for example localhost:3000) cannot be targeted directly. Put a reverse proxy in front of such a backend, or point the host at a hostname that already resolves to the right service.