Overview
Claude Fable 5.2 is Anthropic’s generally available model for demanding, open-ended technical work, including software engineering, scientific research and finance. It shares an underlying model with Claude Mythos 5.2, but has stronger cybersecurity and biology safeguards. (anthropic.com)
Capabilities and uses
- Supports text and image input and text output, with a 1 million-token context window and a maximum output of 128,000 tokens. Adaptive thinking is always enabled; its depth can be adjusted through the effort parameter. (platform.claude.com)
- Intended uses include multi-repository coding, coordinating agents, scientific and mathematical research, data analysis, financial analysis, and hardware or 3D design. Anthropic reports improvements in coding, reasoning and vision over the preceding generation. (anthropic.com)
Limitations and availability
- Cybersecurity and biology safeguards can block requests or route eligible requests to another model; API customers must configure fallback behavior. Mythos access for relevant research requires verification. (anthropic.com)
- The API does not support forced tool choice for this model. The documented reliable-knowledge and training-data cutoffs are June 2026. Anthropic requires 30-day data retention unless it expressly authorizes zero-data-retention use. (platform.claude.com)
- Available through the Claude API and supported cloud platforms. Availability and pricing may differ by platform and account. (platform.claude.com)
Pricing
Anthropic’s Claude API prices are in USD per million tokens, checked November 14, 2026:
- Standard: $8 input; $40 output.
- Prompt caching under standard pricing: $10 for 5-minute cache writes, $16 for 1-hour cache writes, and $0.20 for cache reads, per million tokens.
- Batch API: 50% off standard input and output rates, or $4 input and $20 output per million tokens.
- Optional fast mode: $16 input and $80 output per million tokens. It is not available with the Batch API; caching and data-residency modifiers can apply. Other platforms may set their own prices.
- US-only inference carries a 1.1× input and output pricing multiplier. (platform.claude.com)
Release and official sources
Anthropic dates the release and announcement November 9, 2026; the supplied date of November 10, 2026 does not match the official sources. (anthropic.com)