mcp-datahub-v1.0.3

Bug Fixes

Fix: Three tools broken through Claude.ai (Anthropic Proxy schema validation)

datahub_get_entity, datahub_get_lineage, and datahub_get_data_product were returning "Anthropic Proxy: Invalid content from server" when called through Claude.ai, while succeeding via direct MCP clients. The root cause was that structured output responses did not match the declared OutputSchema on each tool.

Schema field name mismatches (output_schemas.go):

• schemaGetLineage: renamed urn → start and entities → nodes to match types.LineageResult; added missing edges (array of source/target/type) and depth fields
• schemaGetDataProduct: added missing properties field to match DataProduct.Properties map[string]string

Response wrapping — handlers were nesting results under a wrapper key but schemas declared fields at the top level:

• handleGetEntity: entity fields are now returned flat (no {"entity": ...} wrapper); query_table, query_examples, and query_availability appear at the same level
• handleGetLineage: lineage fields are now returned flat (no {"lineage": ...} wrapper); execution_context appears at the same level as start, nodes, and edges
• formatSearchResult: result fields are now returned flat (no {"result": ...} wrapper); query_context appears at the same level as entities and total

Tests: Added response-shape tests asserting no wrapper keys are present; fixed stale assertions that checked for the old "entity" and "lineage" wrapper keys.

Installation

Claude Desktop (macOS/Windows)

Download the .mcpb bundle for your platform and double-click to install:

• macOS Apple Silicon (M1/M2/M3/M4): mcp-datahub_1.0.3_darwin_arm64.mcpb
• macOS Intel: mcp-datahub_1.0.3_darwin_amd64.mcpb
• Windows: mcp-datahub_1.0.3_windows_amd64.mcpb

Homebrew (macOS)

brew install txn2/tap/mcp-datahub

Claude Code CLI

claude mcp add datahub \
  -e DATAHUB_URL=https://your-datahub.example.com/api/graphql \
  -e DATAHUB_TOKEN=your-token \
  -- mcp-datahub

Docker

docker pull ghcr.io/txn2/mcp-datahub:v1.0.3

Verification

All release artifacts are signed with Cosign. Verify with:

cosign verify-blob --bundle mcp-datahub_1.0.3_linux_amd64.tar.gz.sigstore.json \
  mcp-datahub_1.0.3_linux_amd64.tar.gz