Fixed in 1.9.0
Version 1.9.0 has been released and supports `NOTION_TOKEN`, so users should use the latest version.
The error
API token is invalid.Reported in makenotion/notion-mcp-server issue #109: “[Bug Report for notion-mcp-server] Critical Bug: MCP Server Not Passing Authorization Header to Notion API”.
What fixed it
I just released version 1.9.0, please use the latest version which supports `NOTION_TOKEN`
— a maintainer's comment on the issue. The fix ships in 1.9.0; upgrade to it or later.
Source and dates
| Repository | makenotion/notion-mcp-server |
|---|---|
| Issue | [Bug Report for notion-mcp-server] Critical Bug: MCP Server Not Passing Authorization Header to Notion API |
| Evidence | a maintainer's comment |
| Status | Fixed (per the evidence) |
| Fixed in | 1.9.0 (the version is named in the quote) |
| Issue closed | 2025-08-22 |
| Read from GitHub | 2026-11-07 |
| Approved by a person | 2026-11-07 |
This page records what the vendor's own GitHub repository says. The error text, the issue title and the quote are copied as written; the summary at the top is one sentence limited to the quote, and a person approved this fact on 2026-11-07. KanseiLink has not re-run the fix. Read the issue before applying it. Something changed? Write to contact@synapse-arrows.com.
For AI agents
lookup({ service_id: 'notion' }) on the KanseiLink MCP server (https://mcp.kansei-link.com/mcp) returns only the newest few fixes for Notion as issue_facts; this one is not among them and is published on this page. Connection guide: Notion service page.
Other Notion MCP errors
- Notion MCP: "Bug: `replace_content` and `replace_content_range` trash child pages and databases" — fixed (see the issue)
- Notion MCP: "env: node: No such file or directory" — the fix from the official GitHub issue
- Notion MCP: "{"error":"invalid_token","error_description":"Invalid token format"}" — the fix from the official GitHub issue