All memos tagged #claude-model-lexicon

Claude Mythos 5 is Anthropic's Mythos-class frontier model released June 9, 2026 — the same underlying model as Claude Fable 5, with safety guardrails lifted in some domains for trusted partners....

Claude Fable 5 is Anthropic's most capable generally available model — a Mythos-class system released on June 9, 2026 with a one-million-token context window and built-in safety routing. Claude Fable...

Claude Mythos is Anthropic's Mythos-class tier within the Claude model family — its most capable system, positioned above Claude Opus 4.8 with major gains in reasoning, software engineering, agentic...

Claude Opus 5.5 is Anthropic's current Opus model, released September 22, 2026, built for long-running agentic coding and knowledge work at $4 / $20 per million input / output tokens. Claude Opus 5.5...

The Claude Model Glossary is a collection of every model in Anthropic's Claude family, from Claude 1 in March 2023 to Claude Sonnet 5.5 in September 2026, grouped by tier and listed newest first. As...

Claude Sonnet is Anthropic's mid-tier model line in the Claude family, positioned as the best balance of speed, intelligence, and cost; the current model, Claude Sonnet 5.5, was released September...

Claude Haiku is Anthropic's fastest and lowest-cost model tier in the Claude family; the current model, Claude Haiku 4.5, was released October 15, 2025 and is priced at $1 / $5 per million tokens....

Claude Opus is Anthropic's high-capability model tier within the Claude family — its most capable line from the Claude 3 launch in March 2024 until the Claude Mythos tier arrived above it in 2026....