Claude Code Flags Unrecognized Model IDs in Print Mode

Claude Code writes [claude-code:unrecognized_model] to stderr when a pinned model ID doesn't match anything it recognizes, per the changelog. The diagnostic landed in print mode, the -p flag most headless and scheduled runs use. Anyone running a pinned or proxied model name in a script has a place to look when output seems off.

Before this, an unrecognized model name failed silently or fell back to a different model without saying so. That's the failure mode that lets a scheduled job run for weeks on the wrong model. Nothing in the output looks wrong, so nobody checks.

The fix ships with an escape hatch. Map the unrecognized ID with modelOverrides and the warning goes away, per the changelog. Silencing it on purpose beats not knowing which model actually ran.

I pin model IDs in my own cron jobs and don't check stderr once a job has run clean for a month. That's a habit worth breaking.