Fixed in v1.9.2
Updating to v1.9.2 resolved the issue in Claude Desktop / Cowork environments.
The error
The default validator supports JSON Schema 2020-12 only; pass a pre-configured Ajv instance to AjvJsReported in kintone/mcp-server issue #544: “[Bug] Tool outputSchema uses JSON Schema draft-07, causing "unsupported dialect" error in MCP clients requiring 2020-12 (SEP-1613)”.
What fixed it
v1.9.2 に更新したところ、Claude Desktop / Cowork 環境でも事象が解消したことを確認しました。
— the reporter's confirmation on the issue (Japanese, quoted as written). The fix ships in v1.9.2; upgrade to it or later.
Source and dates
| Repository | kintone/mcp-server |
|---|---|
| Issue | [Bug] Tool outputSchema uses JSON Schema draft-07, causing "unsupported dialect" error in MCP clients requiring 2020-12 (SEP-1613) |
| Evidence | the reporter's confirmation |
| Status | Fixed (per the evidence) |
| Fixed in | v1.9.2 (the version is named in the quote) |
| Issue closed | 2026-08-19 |
| 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
The same fact is returned as issue_facts by lookup({ service_id: 'kintone' }) on the KanseiLink MCP server (https://mcp.kansei-link.com/mcp), next to the other checked facts for kintone. Connection guide: kintone service page.