# Claude Fable 5.2

Claude Fable 5.2 is an AI model released by Anthropic on Nov 9 2026. It has a 1M context window. Tracked results include 74.2% on Humanity's Last Exam (with tools), 69.9% on FrontierSWE V2 and 49.1% on FrontierCode 2.0.

## Facts

| Field | Value |
| --- | --- |
| Model | Claude Fable 5.2 |
| Developer | Anthropic |
| Release date | Monday, Nov 9 2026 |
| Licensing | Closed |
| Context window | 1M |

## API pricing

All rates in USD per 1,000,000 tokens, pay-as-you-go.

| Tier | Input | Cached input | 5 min cache write | 1 hr cache write | Output |
| --- | --- | --- | --- | --- | --- |
| All documented contexts | $8.00 | $0.20 | $10.00 | $16.00 | $40.00 |

Cache reads are priced at 0.025x base input on Claude Fable 5.2 and Mythos 5.2, the same multiplier as Fable 5.1.
Fast mode costs $16 per million input tokens and $80 per million output tokens and speeds up generation by up to 2.5 times. Availability depends on platform; see the current first-party pricing documentation.
Verified October 19, 2026 against the first-party source: https://platform.claude.com/docs/en/about-claude/pricing

## Tracked benchmark scores

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| FrontierSWE V2 | 69.9% | Lab | Engineering problems that would occupy a person for days: systems implementation, performance work, scientific computing and AI research, with up to twenty hours per task. Partial credit is awarded, because finishing one outright is still rare. Higher is better. |
| FrontierCode 2.0 | 49.1% | Lab | whether a model’s code changes to open-source repositories would be merged by their maintainers (version 2.0); separate from FrontierCode v1.1 scores |
| Terminal-Bench-Science 0.1 | 74.6% | Lab | The same command-line setup as Terminal-Bench, pointed at scientific work: the AI has to drive research tooling and computational workflows through to a result, rather than administer a machine. Version 0.1 is the first release of the task set, and scores run lower than on the general board. Higher is better. |
| RoboDojo Sim | 64.9% | Lab | control of a simulated two-arm robot from camera images, average success rate |
| WANDR (relaxed score) | 82.1% | Lab | agentic web search, relaxed scoring |
| Humanity's Last Exam (with tools) | 74.2% | Lab | Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. |
| OSWorld 2.1 (offline) | 89.3% | Lab | Can the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Version 2.1, in its offline setting. Scores are not comparable with version 2.0. Higher is better. |
| AutomationBench | 51.4% | Lab | Tests whether the AI can run real multi-step business workflows — the kind of end-to-end office processes companies want to automate — from start to finish. Higher is better. |
| AA-Briefcase v1.1 | 1785 | Lab | Artificial Analysis agentic office-work eval (Elo, v1.1 rating fit) |
| AA-Briefcase v1.1 (rubric) | 66.1% | Lab | Artificial Analysis agentic office-work eval, v1.1 rubric score; separate from the Elo rating |
| Remote Labor Index (RLI) | 41.3% | Lab | real paid remote-work projects, scored on the share completed to client standard |
| Chartography (no tools) | 73.4% | Lab | The same chart-centred test with no tools: the AI has to read each chart unaided. Scores run far lower than the with-tools version, so read the two as separate tests. Higher is better. |

## About Claude Fable 5.2

Claude Fable 5.2 was released on November 9, 2026 as the next model in Anthropic's Fable line, positioned for demanding reasoning and long-horizon agentic work. It shared its underlying model with Claude Mythos 5.2 and kept cybersecurity and biology safeguards so that it could be offered to all users. Anthropic cut the price to $8 per million input tokens and $40 per million output tokens, from $10 and $50 on Fable 5.1, and reported output up to 30% faster.

At launch it scored 49.1% on FrontierCode 2.0 at Xhigh effort, which Anthropic described as the highest result of any released model it had tested, along with 74.2% on Humanity's Last Exam with tools and 64.9% on the internally run RoboDojo Sim, more than double Fable 5.1's 27.6%. Anthropic still recommended Opus 5.5 as the starting point for most coding and knowledge work and reserved Fable for the most ambitious open-ended technical tasks. In early testing its safeguards blocked about 55% fewer requests than Fable 5.1's; blocked queries fell back to Opus 4.8 for cybersecurity and Opus 5 for biology.

## Questions and answers

### When was Claude Fable 5.2 released?

Claude Fable 5.2 was released by Anthropic on Monday, Nov 9 2026.

### Who made Claude Fable 5.2?

Claude Fable 5.2 was built by Anthropic. AI safety company building the Claude family of models. Founded in 2021 by former OpenAI researchers.

### How much does Claude Fable 5.2 cost?

Claude Fable 5.2 costs $8.00 per million input tokens and $40.00 per million output tokens through the Anthropic API. Cached input is $0.20 per million tokens. Rates are pay-as-you-go API prices verified against Anthropic's published pricing on October 19, 2026.

### What benchmark scores did Claude Fable 5.2 get?

Claude Fable 5.2 reports 12 tracked benchmark scores — FrontierSWE V2: 69.9%; FrontierCode 2.0: 49.1%; Terminal-Bench-Science 0.1: 74.6%; RoboDojo Sim: 64.9%; WANDR (relaxed score): 82.1%; Humanity's Last Exam (with tools): 74.2%; OSWorld 2.1 (offline): 89.3%; AutomationBench: 51.4%; AA-Briefcase v1.1: 1785; AA-Briefcase v1.1 (rubric): 66.1%; Remote Labor Index (RLI): 41.3%; Chartography (no tools): 73.4%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data. It holds the best score among all models tracked here on FrontierSWE V2, FrontierCode 2.0, RoboDojo Sim, WANDR (relaxed score), Humanity's Last Exam (with tools), OSWorld 2.1 (offline), AA-Briefcase v1.1 (rubric), Remote Labor Index (RLI) and Chartography (no tools).

### What is the context window of Claude Fable 5.2?

Claude Fable 5.2 has a context window of 1M. Providers may specify separate input and output token limits.

### Is Claude Fable 5.2 open source?

No. Claude Fable 5.2 is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after Claude Fable 5.2?

Anthropic's previous tracked release was Claude Haiku 5.5 on Oct 7 2026, 33 days earlier. It was followed by Claude Mythos 5.2 on Nov 9 2026.


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Canonical page: https://aireleasetracker.com/model/anthropic/claude-fable-5.2
Site index: https://aireleasetracker.com/llms.txt
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.