Reported News
Claude Fable 5.2 and Mythos 5.2: Anthropic's top models get cheaper at $8/$40 and up to 30% faster
Claude Fable 5.2 is Anthropic's most capable generally available model, released Nov 9, 2026 as claude-fable-5-2 at $8 per million input tokens and $40 per million output tokens, down from Fable 5.1's $10/$50. Claude Mythos 5.2 is the same underlying model with lighter cyber and biology safeguards, available only through Anthropic's verification programs.
- Changes reported
- 6
- listed below, each from a source we read
- We tested
- Not tested yet
- reported from sources; we did not run it ourselves
- Gaps we flag
- 4
- things we could not verify
- Sources
- 3
- 3 primary, linked below
What changed
| # | What the source says | Status |
|---|---|---|
| 01 | Anthropic released Claude Fable 5.2 (API ID claude-fable-5-2) and Claude Mythos 5.2, which it says are the same underlying model; Fable carries stronger cyber and biology safeguards and is open to all users, while Mythos needs a Cyber or Life Sciences Verification Program approval. | Reported |
| 02 | Price drops to $8 per million input tokens and $40 per million output tokens, and Anthropic says outputs come up to 30% faster than Fable 5.1 and Mythos 5.1; an optional fast mode generates tokens up to 2.5 times faster for $16/$80. | Reported |
| 03 | The models overview lists a 1M-token context window, 128K max output tokens, always-on adaptive thinking with a default effort of high, a June 2026 knowledge cutoff and retirement not sooner than November 9, 2027. | Reported |
| 04 | In Anthropic's table Fable 5.2 scores 49.1% on FrontierCode 2.0 at Xhigh effort versus 45.5% for Opus 5.5 and 42.8% for GPT-6 Astra, and 69.9% on FrontierSWE v2 versus 62.3% for Opus 5.5; Gemini 4 Carbon leads AutomationBench at 53.9% to Fable's 51.4%. | Reported |
| 05 | Anthropic still recommends starting with Claude Opus 5.5 for most coding and knowledge work, and says Fable 5.2 can act as an Advisor that smaller Claude models consult or an Orchestrator that delegates to them. | Reported |
| 06 | It is available today on all platforms including AWS, Google Cloud and Microsoft Azure; fast mode runs in Claude Code, the Claude Platform, Google Cloud and Microsoft Foundry, and preserved thinking now applies to all accounts. | Reported |
reported by the sourcemeasured or run by usnot verified
Primary source: Anthropic: Introducing Claude Fable 5.2 and Claude Mythos 5.2. We are the fast, independent index; the vendor’s own page is the source of record for this release.
Who it matters for
Teams already paying for Fable 5.1 get a cheaper, faster drop-in upgrade by switching the model ID to claude-fable-5-2. Builders of long-running coding agents and orchestrators that hand work to Sonnet or Haiku are the main audience; Anthropic itself says most daily coding should start on Opus 5.5.
Security and life-sciences teams that need fewer refusals should look at Mythos 5.2 through the verification programs. Enterprises with zero data retention can ask about Enterprise Frontier Safeguards, which Anthropic says is in private beta; other customers get 30-day retention for safety monitoring.
In the source’s words
“Claude Fable and Claude Mythos are the same underlying model.”
“Fast mode is available for $16 per million input tokens and $80 per million output tokens.”
What we have not verified
- We did not run this release ourselves.
- All benchmark scores are Anthropic's own reporting; several (including RoboDojo Sim) were run internally, and methodology is in the system card, which we did not read in full.
- The announcement gives a date but no publish time, so the source time is left blank; our watcher first saw the model in Anthropic's Electronics Design research post and in the anthropic Python SDK v2.7.0 release, which added claude-fable-5-2 and claude-mythos-5-2.
- We did not check the launch promotion details for paid Claude plans or regional availability of fast mode.
This brief is Reported: written from the sources below, not from running the release ourselves.
Sources
- Anthropic: Introducing Claude Fable 5.2 and Claude Mythos 5.2primary source · fetched 2026-11-09
- Claude docs: Models overviewprimary source · fetched 2026-11-09
- anthropic-sdk-python v2.7.0 release notes (GitHub)primary source · fetched 2026-11-09
Related
Spotted an error? See our corrections policy or email the address on the contact page. Markdown version for agents: /news/claude-fable-5-2-mythos-5-2.md
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