Confluence Cloud attachment download 401 through the Atlassian MCP server

Confluence Cloud attachment download 401 through the Atlassian MCP server

TL;DR: Set CONFLUENCEATTACHMENTDOWNLOADUSEV1=true in the server env. The v2 download path rejects the MCP auth on some tenants; the v1 path accepts it. Restart the client and retry the attachment download.

The error

401 Unauthorized downloading a Confluence Cloud attachment via /wiki/download/attachments/... through the MCP server

Fix it

1. Confirm other Confluence MCP calls (pages, search) work.

Expected: Only attachment downloads 401.

1. Set CONFLUENCEATTACHMENTDOWNLOADUSEV1=true in the server env.

Expected: The flag is saved.

1. Restart the MCP client.

Expected: Attachment downloads succeed.

When this applies

Confluence attachment downloads 401 through mcp-atlassian while the rest of Confluence works fine.

When this does NOT apply

If all Confluence calls 401, the token or base URL is wrong; fix auth first.

Tool compatibility

sooperset/mcp-atlassian, Confluence Cloud

Also seen as

• Confluence MCP attachment unauthorized
• wiki download attachments 401 MCP
• CONFLUENCEATTACHMENTDOWNLOADUSEV1

Why it happens

Attachment binaries are served on a different path with different auth handling than the REST API. On some Cloud tenants the v2 path rejects the MCP credential while v1 accepts it; the flag switches the download path.

Edge cases

• Very large attachments may still time out; retry or fetch in ranges.
• The flag only affects downloads, not page content.
• Server/DC instances do not need this flag.