Atlassian MCP plugin OAuth token exchange fails — [object Response] JSON parse error

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The Atlassian MCP plugin OAuth flow completes the authorization step successfully (browser redirect with authorization code works), but the token exchange fails because Cursor’s internal OAuth client passes a raw Response object to JSON.parse() instead of first reading the response body.

Error from logs:

Failed to complete OAuth exchange Invalid OAuth error response: SyntaxError: Unexpected token 'o', "[object Response]" is not valid JSON. Raw body: [object Response]

Full log sequence:

Successfully connected to streamableHttp server
Storing streamableHttp client
[MCP Allowlist] Creating adapter with serverName="atlassian", identifier="plugin-atlassian-atlassian"
Successfully reloaded client
Received OAuth callback with code
Using attempt-scoped OAuth client information for callback flow
Using redirect URL
Failed to complete OAuth exchange Invalid OAuth error response: SyntaxError: Unexpected token 'o', "[object Response]" is not valid JSON. Raw body: [object Response]

Note: This bug seems to be a code defect where the Response object itself is being stringified ([object Response]) rather than its body being read first (e.g., await response.json() or await response.text()).

Steps to Reproduce

  1. Install the official Atlassian plugin from the Cursor marketplace
  2. Cursor prompts to authenticate — click to proceed
  3. Browser opens Atlassian OAuth consent screen — log in and authorize
  4. Browser redirects back to Cursor with authorization code (succeeds)
  5. Token exchange fails with the [object Response] error above

Expected Behavior

Token exchange succeeds and Atlassian MCP tools become available.

Operating System

MacOS

Version Information

Version: 2.7.0-pre.158.patch.0
VSCode Version: 1.105.1
Commit: 11e7a0514e3c19ee0ed19b37725c111fe5fb44f0
Date: 2026-03-28T10:42:16.149Z
Layout: editor
Build Type: Stable
Release Track: Nightly
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

6

Hi @Iago_Rodrigues Thanks for the report and I apologize for the inconvenience. This is a known issue with how Cursor handles the OAuth token exchange for MCP plugins like Atlassian.

The team is aware of the issue, and we’ll keep you apprised of any updates.

1 Like
9

Thank you @kevinn. Appreciate the effort.

Do you have a timeline for this to be fixed?

10

@Iago_Rodrigues I don’t have a timeline to share at the moment but we have automations connecting this post to the issue so we should be able to alert you to any important updates.

11

@Iago_Rodrigues Can you try updating Cursor and letting me know if you still face this issue?

If you’re comfortable, you can run this Cmd + Shift + P > Cursor: Clear All MCP Tokens And then re-authenticate.