v0.4.0

mcp-clickhouse v0.4.0

This release adds OAuth/OIDC authentication, official GHCR container images, and fixes concurrency and MCP protocol issues. It includes a few behavior changes (see Behavior changes section before upgrading).

Behavior changes

• Auth modes are now mutually exclusive. Static token, FastMCP OAuth, and disabled mode can no longer be combined — configure exactly one. If you currently set more than one, pick a single mode.
• /health is now unauthenticated in all modes (previously gated under static-token mode). Response bodies are trimmed to OK / a generic error string and no longer expose ClickHouse version or exception details. Update any monitoring that parsed the old body.
• Tool responses are now JSON-encoded strings rather than raw dicts. This fixes MCP protocol validation errors, but the wire format clients receive has changed.

Added

• OAuth/OIDC auth providers on HTTP/SSE transports via FASTMCP_SERVER_AUTH (Azure Entra, Google, GitHub, WorkOS, etc.). (#173, fixes #171)
• Official multi-arch Docker images on GHCR, published automatically on every release: ghcr.io/clickhouse/mcp-clickhouse:0.4.0, :0.4, and :latest (linux/amd64 + linux/arm64). Swap your image reference from mcp/clickhouse to ghcr.io/clickhouse/mcp-clickhouse:latest — same env-var config, same entrypoint. (#174, #187)

Fixed

• Long-running queries no longer block other tool calls. run_query and run_chdb_select_query now await their thread-pool futures asynchronously, so concurrent calls are served while a slow query is in flight. (#136, fixes #128)
• Tool responses return valid JSON strings, avoiding MCP protocol validation errors on successful queries. (#154)

Docker image

docker pull ghcr.io/clickhouse/mcp-clickhouse:0.4.0

Full changelog: v0.3.0...v0.4.0