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mikep0007
Known Participant
August 15, 2026
Question

Appian DevMCP Server Configuration Question

  • August 15, 2026
  • 21 replies
  • 111 views

I have been working hard to get get the AI development parts of 26.6 up and running and I am stuck on a simple thing but I have no direction.  I have the Appian MCP setup;  but it is a read only and limited query type of MCP.  I learned of the DEvMCP and that is what I am working on.  I Have also learned that Composer does not build interfaces, there is a fix coming soon for that.  The Dev Agent does not work at all, seemly network errors but I have no idea what they are or what needs to be resolved I have no detail to know what to do.  The documentation does not say we need to enable something (We are using Appian Cloud).

Now the real question.  When I set up the MCP for Claude, it is not using my user name.  It is something thing else, that the best I can tell does not exist.  The message is: INFO:lcp_mcp_server.server:Username: MikePrentice.  While that is my name… that is not my user name.  So where is it getting it.  I have searched a few places and that string value does not really exist.  NO environment variable, not in any files within the LCP directory structure.  I have even changed the username in the Claude desktop config and that value in teh log is not changing.

This issue is beyond support, but they have been trying to help me.  My Appian support team has not had the knowledge yet either.  Trying here to see if anyone has the detail knowledge on what is up with this MCP.

Thank you.

    21 replies

    Show previous replies
    mathieud0001
    mathieud0001
    Brainy
    August 16, 2026

    I don’t know. I did have an issue when I was using the browser SSO, I think I had to use USERNAME in lieu of LCP_USERNAME if I remember correctly. But for local auth, your config is fine.

    mathieud0001
    mathieud0001
    Brainy
    August 16, 2026

    Weird. I did have an issue when using browser auth (SSO) where I had to use USERNAME instead of LCP_USERNAME but for basic auth, the above config worked fine.

    M
    mikep0007Author
    Known Participant
    August 16, 2026

    Thanks, it is working for me now, so I can move forward but yeah I am lost as to why and being it is not really supported it makes it difficult.  Thanks for working through it.

    muditd727891
    muditd727891
    New Participant
    August 17, 2026

    Hi!

    I also need help on the same topic. I have done all the configuration as per documentation for DevMCP. But while testing I am getting below response from Claude Code (Desktop):

    APNX-1-4187-000 - Authentication failed. Please check your credentials and try again.

    Background: I have modified the config file multiple times, and it has correct creds for logging in.

      "mcpServers": {
        "appian": {
          "command": "C:\\Users\\India\\.local\\bin\\uv.exe",
          "args": [
            "run",
            "--directory",
            "C:\\Users\\India\\lcp-mcp-server",
            "python",
            "-m",
            "lcp_mcp_server"
          ],
          "env": {
            "LCP_URL": "https://yourSite.appiancloud.com",
            "LCP_USERNAME": "muditdixit@domain.com",
            "LCP_PASSWORD": "XXXXXX"
          }
        }
      },
      "coworkUserFilesPath": "C:\\Users\\India\\Claude",

     

    M
    mikep0007Author
    Known Participant
    August 17, 2026

    Based on what I have learned.  putting username and password in the configuration does not work, you have to use browser.  ALso make sure to look at the log file to validate what the username is, it migh tbe different

      J
      john.rogers
      Employee
      August 18, 2026

      Dev Agent: which 26.6 hotfix are you on? You’re describing a fairly broken state that’s making me wonder if your site got bad feature toggles, or toggled features on without being on the right hotfix version.

      J
      john.rogers
      Employee
      August 18, 2026

      Dev MCP: username and password auth is still possible but we changed the variable names in the last plugin release as part of a multi-part move to make browser auth the new default (without blocking basic auth). We just merged the documentation updates for that a few min ago, so you should be able to see them tomorrow.

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