Appendix A — Current Model Reference

Estimated time: 3 minutes

Verified against platform.claude.com/docs/en/about-claude/models/overview — Verified: 2026-07-29. Reverify before next publish.

Haiku 4.5 Sonnet 5 Opus 5 Fable 5
Role Fastest, near-frontier Best speed/intelligence balance Complex agentic coding, enterprise Most capable, long-running agents
Context window 200k 1M 1M 1M
Thinking mode Extended (manual budget) Adaptive Adaptive Adaptive (always on)

This is the only place in this module where exact model names and numbers appear. If you're reading this well after 2026-07-29, treat this table with appropriate skepticism and check the source link — the framework in Section 3 above will still hold even if these specifics have moved on.