Articles

Which Model Is Claude Code Actually Using? settings.json vs ANTHROPIC_MODEL vs --model, Tested

Multi-agent setups, CI, and batch scripts all rest on one assumption: the session actually runs on the model you configured. But the model can be set in four places — settings.json, the ANTHROPIC_MODEL environment variable, the --model flag, and /model in-session — and the docs never give you one table saying which wins. Meanwhile a GitHub issue reports settings.json silently ignored on Windows, with a full day of work run on the wrong model and discarded. Using modelUsage as hard evidence, we tested the chain layer by layer: --model > ANTHROPIC_MODEL > project settings.json > built-in default, with the [1m] suffix form working too — plus a verification method more trustworthy than any UI hint.