MCP throws invalid field errors during loading of tools

Hi there,

I noticed these error logs when my MCP server boots up/reloads operations:

mcp-1 | 2026-01-09T19:33:55.538610Z ERROR load_tool: field company not found
mcp-1 | 2026-01-09T19:33:55.538640Z ERROR load_tool: field overlapEndDate not found
mcp-1 | 2026-01-09T19:33:55.538642Z ERROR load_tool: field overlapStartDate not found

However, these fields are actually valid. The Apollo MCP Server appears to be doing naive field validation when loading operations and not accounting for inline fragment type conditions.

I’d love to get this resolved to avoid the false noise!

Thanks,

Mark

Hi Mark,

Thanks for reporting this! Your diagnosis is correct — the field validation wasn’t accounting for inline fragment type conditions.

Could you let us know which version of Apollo MCP Server you’re running?

apollo-mcp-server --version

This was fixed in v1.2.1 (PR #471), so if you’re on an earlier version, upgrading should resolve it. If you’re already on 1.2.1+, we’ll want to dig deeper.

Thank you!

Camille

1 Like

Hey @Camille_Lawrence - so I had been running 1.1.1 when I reported this. I did recently upgrade to 1.3.0 and just confirmed the issues are gone. My apologies for not checking on that sooner and posting an update. Thanks for the update!