Mockoon release v9.8.0

2026-07-31

Welcome to this new release of Mockoon. It brings a new CLI MCP server, a new response flag indicator in the responses list, and some bug fixes. This is also probably one of the last if not the last release of Mockoon v9, as we are now focusing on the next major version v10. Read on to learn more about this release.

 Support us!

Mockoon is proudly independent and open-source, maintained without external funding. We rely on both sponsorships and Mockoon Cloud subscriptions to keep improving the project and building new features. A big thank you to the companies below for supporting our work and helping us grow (and all the sponsors who helped this project over time!):

GitHub Localazy
SerpApi

If you'd like to support Mockoon as well, you can become a sponsor or subscribe to Mockoon Cloud. Every contribution helps keep the project alive and evolving. Thank you!

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 New CLI MCP server

Mockoon CLI now includes a new mcp command that starts a Model Context Protocol (MCP) server and exposes your local mocks to AI assistants like Claude, GitHub Copilot, or Cursor.

Running mockoon-cli mcp prints a ready-to-use MCP client configuration snippet, and the server provides tools to list local mocks, start a mock, stop a running mock, and list currently running mocks in the session.

By default, mock files are discovered from the desktop application storage directory, and you can include additional directories with the MOCKOON_DATA_DIRS environment variable (semicolon-separated paths).

Copy
{
  "servers": {
    "mockoon": {
      "command": "mockoon-cli",
      "args": ["mcp"],
      "env": {
        "MOCKOON_DATA_DIRS": "/path/to/dir1;/path/to/dir2"
      }
    }
  }
}

Learn more about the MCP server in the CLI documentation.

(Issue #2150)

 Body size limitation

This release improves request payload protection across the server stack by introducing a dedicated maxRequestBodySize setting and enforcing it consistently. You can now configure the limit from the CLI with the --max-request-body-size flag, using either raw bytes or human-readable values like "10MB".

The default body size limit is set to 100MB (not configurable in the desktop application yet), and any request exceeding this limit will receive a 413 Payload Too Large response.

(PR #2290)

 Responses list improvement

The default response flag indicator is now displayed next to the active response in the responses list. This makes it easier to identify the status of the active response without opening the menu:

Response flag indicator in the responses list

Note: this indicator is non-interactive and is only a visual indicator of the active response status. You can still change the response status by opening the response menu.

(Issue #1792)

 Fixes

  • Fixed a body parsing issue causing 404 errors when using the serverless package on AWS Lambda. (Issue #2080)

 Chores

  • We updated the libraries and application dependencies to their latest versions to fix several vulnerabilities and reduce the number of dependencies we use. (PR #2288)
  • We started migration to Angular signal forms by converting the existing custom form components to signal-based components. (PR #2289)

 Thank you

A big thank you to the following people who helped to make Mockoon better: