Unable to execute tools on Atlassian Rovo MCP Server from Postman despite successful authentication

[Richa Goyal]

Issue Summary

Unable to execute tools on Atlassian Rovo MCP Server from Postman despite successful authentication and tool discovery.

Description

I am attempting to connect Postman to the Atlassian Rovo MCP Server.

I have created OAuth credentials using both:

1. Atlassian Service Account

2. Atlassian Developer Console

Using the Client Credentials grant type, I am successfully able to:

• Obtain an access token using https://auth.atlassian.com/oauth/token

• Connect to the Rovo MCP endpoint https://mcp.atlassian.com/v1/mcp/authv2

• Retrieve and list the available MCP tools.

However, when invoking any of the discovered tools, the request fails and returns the following error:

{
  "message": "We are having trouble completing this action. Please try again shortly."
}

Observations

• Authentication appears to be successful since access tokens are generated correctly.

• MCP tool discovery works as expected.

• The issue occurs only during tool execution.

• The behavior is consistent across credentials created from both the Service Account and Developer Console.

[Dr Valeri Colon _Connect Centric_]

Hi @Richa Goyal. Tool discovery working does not always mean tool execution is authorized. The error often appears when MCP connects but the requested action is blocked by permissions, scopes, auth method, or the site’s Rovo MCP settings. Also, MCP uses JSON-RPC rather than normal REST calls, so Postman must send the exact MCP message format. I’d verify Jira/Confluence Read/Search/Write permissions in Admin → Rovo → Rovo MCP server → Permissions, then test with a supported MCP client to isolate Postman formatting from Atlassian-side execution.

[Richa Goyal]

Hi  @Dr Valeri Colon _Connect Centric_ 

I did more changes and found that Rovo does not work on grant_type as 'client credentials' but it worked on 'Auth with PKCE'.
I found out that Rovo is in beta version, and it will start supporting grant_type as 'client credentials' by end of June.

If you have any such updates, please help in confirming.

Thank you for your response :)

Thanks,

Richa

[Dr Valeri Colon _Connect Centric_]

Thanks for sharing your findings, @Richa Goyal its helpful to know. One additional thing worth noting is that several MCP-related discussions over the past few weeks have involved authentication, OAuth metadata, dynamic client registration, and grant-type behavior. In a number of cases, tool discovery succeeded while execution failed, making troubleshooting more difficult because the connection initially appeared healthy.

If client credentials support is being rolled out, that should help clarify whether future execution issues are truly permission-related versus grant-type limitations. It will be interesting to see whether the rollout also changes the guidance around service accounts and machine-to-machine integrations, which has been a common question in the community. Thanks for sharing the update.

[Philipp Sendek _catworkx_]

Hi @Richa Goyal and welcome to the community,

what is/are the exact requests that you're sending to the Atlassian Rovo MCP Server using Postman?
That way I can try to help you find what the issue might be.

Without this knowledge, I'd like to point out that compared to normal REST APIs, the communication with an MCP server is using JSON RPC (remote procedure calls). I personally haven't used Postman for this purpose, so I don't know if it's capable of it. 

Maybe this helps, otherwise I'm happy to help you when you share more about the requests you're running.

Greetings
Philipp

[Richa Goyal]

Hi @Philipp Sendek _catworkx_ 

I did more changes and found that Rovo does not work on grant_type as 'client credentials' but it worked on 'Auth with PKCE'.
I found out that Rovo is in beta version, and it will start supporting grant_type as 'client credentials' by end of June.

If you have any such updates, please help in confirming.

Thank you for your response :)

Thanks,

Richa