New modelReleased 9 November 2026 · 5 min read
Claude for the hardest work is now cheaper.
Anthropic released Claude Fable 5.2 on 9 November 2026, an upgrade to the model it designs for the most demanding technical work. It costs $8 per million input tokens and $40 per million output tokens, down from $10 and $50 for Fable 5.1. Anthropic still recommends most teams start with Opus 5.5 and move up to Fable when the work calls for it.
At a glance
- Released
- 9 Nov 2026
- Price per MTok
- $8 in / $40 out
- Fable 5.1 price
- $10 in / $50 out
- Context window
- 1M tokens, 128k output
- Data retention
- 30 days required
01 · What changed
What Anthropic shipped.
What changed: Fable 5.2 is now the default Fable model in Claude Code and is available on the Claude API, Claude Platform on AWS, Amazon Bedrock, Google Cloud and Microsoft Foundry. Anthropic says testers found it communicates more clearly, that it generates output up to 30% faster than Fable 5.1, and that it scores a step above Opus 5.5 in almost all the capabilities Anthropic evaluated. For engineers, switching takes more than a new model string: the prefix check, the computer use tool and the advisor tool all behave differently, and each can return a 400 error.
Input price
$8 / MTok
Down from $10 per million input tokens on Fable 5.1, with output down from $50 to $40.
Speed
Up to 30%
Anthropic says Fable 5.2 generates output up to 30% faster than Fable 5.1, and optional fast mode adds up to 2.5x at $16 input and $80 output per million tokens.
Context
1M tokens
Fable 5.2 and Mythos 5.2 take a 1M token context window, up to 128k output tokens and always-on adaptive thinking.
Which model for which work
Opus 5.5
Anthropic calls Opus 5.5 its strongest daily driver and recommends it as the starting point for most coding and knowledge tasks. Keep it as the default for an IC memo, a weekly status report or inbound email triage.
Fable 5.2
Anthropic says Fable is best for the most ambitious, open-ended technical work. Move up to it when the scope and complexity of the task call for it, at $8 input and $40 output per million tokens, with 30-day data retention required.
02 · Where it sits
Which Claude for which job.
03 · What it means
What it means for your seat.
For most firms, Fable 5.2 is a model for a small number of hard problems rather than the daily default. Anthropic itself recommends starting with Opus 5.5 and moving up to Fable when the scope and complexity of the work require it. The price cut makes that step up cheaper, and the API changes mean engineering teams have work to do before they switch.
Leadership
Keep Opus 5.5 as the default and treat Fable 5.2 as the escalation route for the most ambitious, open-ended technical work, which is how Anthropic positions it. Anthropic cut the price to $8 input and $40 output per million tokens, so ask your engineering lead what that route would cost on one real workload before approving wider use.
Your teams
Where your plan offers Fable 5.2, Medium effort is the default in the Claude apps and Claude Code, and Anthropic says it handles hard tasks with fewer tokens than Fable 5.1. For an IC memo, a weekly status report or inbound email triage, Anthropic's advice is to start with Opus 5.5 and move up only when the task needs it.
Risk and compliance
Fable 5.2 and Mythos 5.2 require 30-day data retention and are not available under zero data retention unless Anthropic expressly authorizes it. If your agreement relies on zero data retention, settle the position before anyone sends a credit agreement or a board pack to this model. Anthropic says Fable 5.2 keeps cybersecurity and biology safeguards as strong as Fable 5.1's, with fewer unnecessary blocks.
IT and engineering
Fable 5.2 enforces the prefix check on every account: editing the system prompt, tools or an earlier message and then sending back a later Fable 5.2 thinking block returns a 400 error. Computer use needs computer_toolset_20260801 (computer_20251124 fails everywhere except Amazon Bedrock), and a Fable 5.2 executor accepts only Fable 5.2 or Mythos 5.2 as its advisor. Fast mode runs on the Claude API with speed: "fast" and no beta header.
04 · This week
What to do this week.
0 of 3 done
Sources
Facts and dates are Anthropic’s own. What it means and what to do are our view, from the firms we work with. Drafted with Claude from these sources, checked against them figure by figure, and published 10 November 2026.
The short answers.
How much does Claude Fable 5.2 cost?
Claude Fable 5.2 costs $8 per million input tokens and $40 per million output tokens, down from $10 and $50 for Fable 5.1. Optional fast mode costs $16 per million input tokens and $80 per million output tokens. Claude Code's release notes list cache reads at $0.20 per million tokens.
What is the difference between Claude Fable 5.2 and Claude Mythos 5.2?
Anthropic says Fable 5.2 and Mythos 5.2 are the same underlying model. Fable 5.2 has strong cybersecurity and biology safeguards and is available to all users, while Mythos 5.2 is offered only to organizations verified through Anthropic's programs, such as the Cyber Verification Program.
Should a company use Claude Fable 5.2 or Opus 5.5?
Anthropic recommends starting with Opus 5.5 for most coding and knowledge tasks and moving up to Fable 5.2 for the most ambitious, open-ended technical work. Anthropic also reports that on FrontierCode 2.0, Fable 5.2 at High effort scored about level with Opus 5.5 at Max effort for roughly half the cost per task.
Can Claude Fable 5.2 be used with zero data retention?
Not by default. Claude Fable 5.2 and Mythos 5.2 require 30-day data retention and are not available under zero data retention unless expressly authorized by Anthropic.
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