AI Models
Claude Fable 5.2, Online in Zentor
Claude Fable 5.2 is Anthropic's most capable model. On Zentor it runs behind the Ultra tier: pick Ultra and send a task. No API key, no setup.
Zentor is a workspace where you can run frontier models with no setup or self-hosting.
All integrationsSee Claude Fable 5.2 in action
Community demos built with Claude Fable 5.2, not Zentor output.
A playable 3D kart racer, built in three prompts
A browser-based kart racer with six racers, drifting, ramps, items, and single- and multiplayer modes, built with Claude Fable 5.2 in three prompts and deployed free to play. A community demo of the model's front-end and game-building range, not Zentor output.
One iceberg prompt at four effort levels
The same iceberg scene rendered by Claude Fable 5.2 across escalating effort settings, per @0xRhinoX's test: $24.31 and 1h 05m at High up to $642.42 and 10h 21m at the tester's top setting, a real community cost curve for the effort dial.
Fable 5.2 vs Opus 5.5 on a rocket-launch scene
A same-prompt comparison: Claude Fable 5.2 produced the rocket launch scene in 32 minutes for $23.45 against Opus 5.5's 24 minutes and $10.35, with the tester calling Fable's detail and realism the stronger result.
What Claude Fable 5.2 Is Built For
The kind of work Claude Fable 5.2 is made for.
The hardest coding and agent work
Fable 5.2 sits above the Opus tier for open-ended technical work: multi-stage plans, delegated subtasks, self-checking over long horizons. Zentor runs that end to end on a live file system, browser, and tools.
Try itLong-horizon, open-ended runs
Adaptive thinking is always on and Fable 5.2 can act as an orchestrator, so it holds a goal over long runs instead of answering one prompt at a time.
Try itFrontier analysis and knowledge work
A 1M-token context window and up to 128K output tokens mean whole repositories, long reports, and multi-document analysis fit in a single run.
Try itWhen the job justifies the top tier
Anthropic's own guidance: start most work on Opus 5.5 and move up to Fable for the most ambitious tasks. On Zentor you move up to Ultra in one click when a task earns it.
Try itHow it works
3 steps to wire up Claude Fable 5.2, no engineering required.
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Pick Ultra in the model picker
Zentor's chat model picker lists tiers, not model names. Ultra is the highest-capability tier and runs Anthropic's Fable line, now Claude Fable 5.2. No waitlist, no setup, no separate key.
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Send the task
Describe the job the way you would brief a colleague. Fable 5.2 plans it, runs it as your agent on a live file system, browser, and tools, and checks its own work before handing it back.
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Switch mid-conversation
Switch to Ultra in the middle of a thread and the rest keeps working, and your files, history, and prompt caching carry over, with no re-setup.
Why Run Claude Fable 5.2 Inside Zentor
What is Claude Fable 5.2?
Claude Fable 5.2 is Anthropic's most capable model, released on November 9, 2026 alongside Claude Mythos 5.2. The two are the same underlying model; Fable carries the cyber and bio safeguards and is open to all users, while Mythos is restricted to Anthropic's Life Sciences and Cyber Verification Programs. Fable 5.2 ships with a 1-million-token context window, up to 128K output tokens in the sync API, adaptive thinking that is always on, a default effort level of high, and a knowledge cutoff of June 2026. It is up to 30% faster at output generation than Fable 5.1.
On Anthropic's benchmark table, Fable 5.2 scores 69.9 on FrontierSWE v2 (Fable 5.1: 56.3, Opus 5.5: 62.3), 51.4 on AutomationBench (31.4 / 42.5), and 49.1% on FrontierCode 2.0 at xhigh effort (32.4% / 45.5%). Anthropic's own positioning is deliberate: start most coding and knowledge work on Opus 5.5, and move up to Fable for the most ambitious, open-ended technical work, where it can act as an orchestrator or advisor.
Running Claude Fable 5.2 on Zentor
Claude Fable 5.2 is available on Zentor now. Open any chat, pick Ultra in the model picker, and the Fable tier runs your task as your agent: Ultra is Zentor's highest-capability tier, backed by Anthropic's Fable line and currently serving Fable 5.2. The picker lists tiers (Fast, Standard, Ultra) rather than model names, so you will not see the word Fable there. There is no API key, no allowlist, and no separate billing account, and you can switch to Ultra mid-conversation while your files, history, and prompt caching carry over.
Claude Fable 5.2 pricing and access
On Anthropic's API, Claude Fable 5.2 costs $8 per million input tokens and $40 per million output tokens, a 20% cut from Fable 5.1's $10 / $50. Cache writes cost $10 (5-minute) or $16 (1-hour) per million tokens, cache reads $0.20, the Batch API takes 50% off, and an optional fast mode runs up to 2.5x faster at $16 / $80. On Zentor, Fable 5.2 runs on your plan credits with prompt caching, so you use the top tier without metering an API account yourself.
Claude Fable 5.2 vs Opus 5.5 and Fable 5.1
Versus Fable 5.1, the 5.2 release is cheaper ($8 / $40 vs $10 / $50), up to 30% faster on output, and stronger on every benchmark Anthropic published. Versus Opus 5.5 ($4 / $20, default effort medium), Fable 5.2 is the higher-ceiling, higher-cost tier: Opus 5.5 remains Anthropic's recommended daily driver, Fable 5.2 the one for the hardest open-ended runs. On Zentor the same logic applies inside the picker: start on Standard for everyday work and reach for Ultra when a task earns it.
Claude Fable 5.2 vs Opus 5.5 and Fable 5.1
Pick the one that fits how you use AI.
| What you get | Anthropic API price | |
|---|---|---|
| Claude Fable 5.2 | The top tier: the most ambitious open-ended agent work, orchestration, frontier benchmarks. Default effort high. | $8 / $40 per M tokens ($16 / $80 fast mode). Cache read $0.20, batch 50% off. |
| Claude Fable 5.1 | The previous Fable generation, superseded by 5.2 on price, speed, and benchmarks. | $10 / $50 per M tokens. |
| Claude Opus 5.5 | Anthropic's recommended daily driver for most coding and knowledge work. Default effort medium. | $4 / $20 per M tokens. |
| Zentor Ultra | The tier in Zentor's model picker that runs Fable 5.2 as your agent, with files, browser, and tools. | Runs on your plan credits. No API account to meter. |
Pairs with
Integrations people commonly connect alongside Claude Fable 5.2.
Comparing tools?
How Zentor stacks up against the tools people weigh it against for Claude Fable 5.2 work.
FAQ
Quick answers about pricing, privacy, and limits.
- Is Claude Fable 5.2 available on Zentor?
- Yes. Claude Fable 5.2 runs inside your Zentor workspace now. Pick Ultra in the chat model picker. The picker shows tiers rather than model names, and Ultra is the one that runs Fable 5.2, with no API key, no allowlist, and no separate setup.
- What is Claude Fable 5.2?
- Claude Fable 5.2 is Anthropic's most capable model, released November 9, 2026. It has a 1M-token context window, up to 128K output tokens, always-on adaptive thinking, a default effort of high, and up to 30% faster output than Fable 5.1.
- How much does Claude Fable 5.2 cost?
- On Anthropic's API, Claude Fable 5.2 is $8 per million input tokens and $40 per million output tokens, 20% below Fable 5.1. Cache reads are $0.20, batch is 50% off, and fast mode is $16 / $80. On Zentor it runs on your plan credits with no markup.
- What is the difference between Claude Fable 5.2 and Opus 5.5?
- Opus 5.5 is Anthropic's recommended daily driver at $4 / $20 per M tokens; Fable 5.2 is the tier above it at $8 / $40, with the higher ceiling on frontier benchmarks. Anthropic's guidance: start most work on Opus 5.5, move up to Fable for the most ambitious open-ended tasks.
- What is the difference between Claude Fable 5.2 and Fable 5.1?
- Fable 5.2 is cheaper ($8 / $40 vs $10 / $50 per M tokens), up to 30% faster on output, and scores higher on Anthropic's published benchmarks: 69.9 vs 56.3 on FrontierSWE v2, 51.4 vs 31.4 on AutomationBench, 49.1% vs 32.4% on FrontierCode 2.0.
- Can I use Claude Fable 5.2 without an API key?
- Yes. On Zentor, Claude Fable 5.2 runs through the Ultra tier in the model picker on your plan credits, so there is no Anthropic account or key to manage.
- Is Claude Fable 5.2 the same as Claude Mythos 5.2?
- They are the same underlying model. Fable 5.2 carries the cyber and bio safeguards and is open to all users; Mythos 5.2 is restricted to Anthropic's Life Sciences and Cyber Verification Programs.
- What effort level does Claude Fable 5.2 use?
- Fable 5.2 defaults to high effort with adaptive thinking always on. On Zentor you do not tune effort by hand; pick Ultra and the Fable tier handles depth for you.
Related reading
Guides that go deeper on Claude Fable 5.2 and AI automation.
How to Access Claude Fable 5.2 (Every Way)
How to access Claude Fable 5.2 on Claude apps, Claude Code, the API, Bedrock, Vertex, Foundry, and Zentor, plus the plan and version gotchas that hide it.
Claude Fable 5.2 vs Opus 5.5: Tested
Claude Fable 5.2 vs Opus 5.5: official benchmarks, real same-prompt community tests, pricing, effort defaults, and which model to pick for which work.
Claude Fable 5.2 Usage Limit: Why It Hits Fast
Hit the Claude Fable 5.2 usage limit in minutes? Why high effort, usage credits, and launch-week demand burn Pro allowances fast, and how to stretch them.
Claude Fable 5.2 Pricing, Broken Down
Claude Fable 5.2 pricing explained: $8/$40 API rates, fast mode, caching, batch discounts, plan access, and what real tasks cost vs Opus 5.5.