The Forge MCP Server - How to Use it when building Forge apps

[#1]

Building Forge apps is now easier now that the Forge MCP Server  is available.

Here is an article I've just written, showing how I've been using it over the past couple of weeks:

https://www.atlassian.com/blog/developer/understand-enhance-and-troubleshoot-your-apps-with-the-forge-mcp-server

I would love to know if you try it and what kind of apps you are building with it.

Caterina

[Darryl Lee]

Hey @Caterina Curti - Last week I used the Forge MCP Server with Rovo Dev CLI, which wasn't as convenient as using an IDE like VS Code.

Still, I was able to use Rovo Dev CLI + Forge MCP Server to a write an app that provides an "Comments Unthreaded" activity if you or your users don't like threaded comments.

Here's my initial prompt:

Ok, here's what I really want to implement: Ideally the reverse sort direction will let me switch the order of sorting. (Does that mean they have to be Events objects? I don't know

After we got the base functionality working, Rovo Dev Cli suggested adding these features:

• Search within comments
• Filter by date range or author
• Better text formatting
• Comment statistics (count by author, time range, etc.)

Which it did!

Asked the CLI to make some formatting tweaks, and after soliciting some feedback, added pagination, and refactored from multiple useState hooks to a single useReducer hook (whatever that means. :-)

So yay, that's two Forge apps I've written with AI. :-O

[Miten Patel]

Hi Darryl, I used the Forge MCP last week, using Claude's code to make it work. However, I think Claude got confused and installed the Rovo MCP instead of the Forge MCP. Then I figured it out, but I found that Rovo CLI and Forge MCP can't work together because they use the Forge command to initiate the task, and that is the leading cause of the issue here. Also you can't use both at same time. 

I would say we need to have proper guidelines for commands and separate those commands for better performance.  Additionally, I discovered that the Forge MCP lacks sufficient tools and requires improvement in this area, as well as in the documentation to facilitate understanding.

[Darryl Lee]

Ah, you know I think I may have denied the CLI from executing things like "forge deploy" because I was already running a tunnel, and really just relied on the CLI + Forge MCP to look at and edit my code.

I think if you're going to try to develop a Forge app, even if you don't have a coding background, really need to understand how the forge command line tool works. Like do the Hello World and other tutorials just so you understand different environments, and the different uses of forge deploy, install, tunnel, register, etc.

This is a good start:

Prepare to build your first Forge app 

[Miten Patel]

I mean, not exactly like that, but I've already built 2-3 apps, and I'm testing with Forge MCP. However, I think the article regarding Forge MCP isn't that great, that's my opinion. 

[Darryl Lee]

@Miten Patel I respectfully disagree.

I think the article is a great introduction to how Forge MCP can help you understand and build Forge apps.

However do I think Forge MCP isn't perfect (just like AI isn't perfect, nor deterministic, which is one of my big gripes about it). In my testing, it found an issue with my code using an oudated version of Node, but then recommended upgrading to soon-to-be deprecated Node 20 instead of 22.

[Caterina Curti]

@Miten Patel I would love to better understand what's happening here:

Then I figured it out, but I found that Rovo CLI and Forge MCP can't work together because they use the Forge command to initiate the task, and that is the leading cause of the issue here. Also you can't use both at same time. 

I just did some tests and I didn't run into any issues.

As an example, I've tried to validate the manifest in the folder of an app using one of the tools included in the Forge MCP Server. I used the `forge-app-manifest-guide` tool (more on this later).

And the validation continued:

Maybe you could share some screenshots or some more details about the question you've been asking to the Rovo Dev CLI.

The reason I chose the option above is also to test the feedback from @Darryl Lee regarding the node version.

If I use it today, the Final Verdict is pretty clear about suggesting upgrading to nodejs22.x.

I then continued asking to update the node version and it did the change to the code. Note that this is calling the "find_and_replace_code" which is provided by the "filesystem-tools" MCP server and not the Forge MCP one.

Notes about MCP servers and tools available in the Rovo Dev CLI

It might be good for me to share here how to check the MCP servers available and their tools in the Rovo Dev CLI.

Enter /mcp to check the available MCP Servers

Select the MCP Server and continue to view the related tools

Entering the tool name in the prompt is not required, but it might be beneficial if the LLM is not recognising a request as specific to an MCP Server. I used it in this example to make sure that the Forge MCP Server was being used instead of the generic knowledge.

@Miten Patel I take your feedback on the blog as well. If you have any suggestions on content you would like to see to help you when using the Forge MCP Server, I would love to know them.

- Caterina