pastilhasandClaude Opus 5
b953a6ba8c
Platform chat ran at 200K while the same `claude` in a terminal got Opus 5's
full 1M. Nothing to do with the model, the account or compaction tuning — the
CLI gates 1M on `provider === 'firstParty' && Fp()`, and `Fp()` is satisfied
only when ANTHROPIC_BASE_URL is unset or its host is api.anthropic.com. We
point it at 127.0.0.1:5051 so the agent's traffic goes through the OAuth
proxy, which fails that host check and silently drops the window to 200K.
_CLAUDE_CODE_ASSUME_FIRST_PARTY_BASE_URL is the CLI's own escape hatch for a
first-party passthrough, and the assertion holds: the proxy forwards verbatim
to api.anthropic.com and already preserves anthropic-beta.
Read from the CLI binary (2.1.223), not inferred: claude-opus-5 carries
context:{window:1e6, native_1m:true}, so the model half of the gate always
passed. Only the hostname was wrong.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>