Claude Fable 5

The cheap Claude-Fable-5 API offers Mythos-level intelligence for your hardest projects. It excels at autonomous coding, multi-day reasoning, and complex vision tasks, all while maintaining high safety standards and token efficiency.

Modalities

Context

API Usage Examples

curl --request POST "https://gptproto.com/v1/chat/completions" \
  --header "Authorization: Bearer $GPTPROTO_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "model": "claude-fable-5",
    "messages": [
      {
        "role": "user",
        "content": "Hello"
      }
    ]
  }'

Claude Fable 5 pricing

Estimate a request with real work scenarios. GPTProto token pricing is 10% below official rates.

UsageQuantityRateCost

Input tokens($9/1M)

tokens

$9/1M$0.0135

Output tokens($45/1M)

tokens

$45/1M$0.036

Cache write tokens($11.25/1M)

tokens

$11.25/1M$0.0337

Cache read tokens($0.9/1M)

tokens

$0.9/1M$0.0225

Cost per request$0.1057

Requests

Top-up amount

Top-up $100 and you get:

Top-up credits with permanent validity. You will receive a total of $100.00.

Additional 10% model discount, saving $11.0374 versus direct official Claude API calls.

Related Models

All Models

Claude Fable 5

Current

byClaude1M context$9/M input$45/M output

Hy4 Preview

byHunyuan$0.7923/M input$2.376/M output

GPT 6 Astra

byOpenAI1.05M context$8/M input$40/M output

Gemini 3.8 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Claude Fable 5.1

byClaude1M context$9/M input$45/M output

Qwen3.8 Max 0902

byQwen1M context$1.8/M input$5.4/M output

GLM 5.3 Flash

byZ-AI1.31M context$0.15/M input$0.5/M output

DeepSeek v4 Flash Vision Exp

byDeepSeek1.05M context$0.44/M input$1.32/M output

GLM 5.3

byZ-AI1.31M context$1.26/M input$3.96/M output

Gemini 3.7 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Grok 4.6

byGrok500K context$1.2/M input$3.6/M output

Qwen3.8 Max

byQwen1M context$1.8/M input$5.4/M output

Claude Opus 5

byClaude1M context$4.5/M input$22.5/M output

Gemini 3.6 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Kimi K3

byMoonshotAI1.05M context$2.7/M input$13.5/M output

GPT 5.6 Luna

byOpenAI1.05M context$0.16/M input$0.96/M output

GPT 5.6 Terra

byOpenAI1.05M context$1.6/M input$9.6/M output

Grok 4.5

byGrok500K context$1.2/M input$3.6/M output

Claude Sonnet 5

byClaude1M context$1.8/M input$9/M output

MiniMax M3

byMiniMax1.05M context$0.48/M input$0.96/M output

GLM 5.2

byZ-AI1.05M context$1.26/M input$3.96/M output

Qwen3.7 Max

byQwen1M context$0.36/M input$1.44/M output

Claude Opus 4.8 Thinking

byClaude1M context$4.5/M input$22.5/M output

Claude Opus 4.8

byClaude1M context$4.5/M input$22.5/M output

DeepSeek v4 Flash

byDeepSeek1.05M context$0.374/M input$1.122/M output

DeepSeek v4 Pro

byDeepSeek1.05M context$1.122/M input$3.366/M output

Grok 4.3

byGrok1M context$0.75/M input$1.5/M output

Kimi K2.6

byMoonshotAI262K context$0.855/M input$3.6/M output

Claude Opus 4.7 Thinking

byClaude1M context$4.5/M input$22.5/M output

MiniMax M2.5

byMiniMax205K context$0.24/M input$0.96/M output

Kimi K2.5

byMoonshotAI262K context$0.54/M input$2.7/M output

Doubao Seed 1.6 Thinking (Build 250715)

byBytedance262K context$0.0971/M input$0.9714/M output

Doubao Seed 1.6 Thinking (Build 250615)

byBytedance262K context$0.0971/M input$0.9714/M output

Doubao Seed 1.6 Flash (Build 250615)

byBytedance262K context$0.0182/M input$0.1821/M output

Model					Input → Output
Claude Fable 5Current $		1M	$9.00 / $45.00 per 1M	$11.25 / $0.90 per 1M	Input: TextInput: Document Output: Text
Hy4 Preview $		—	$0.79 / $2.38 per 1M	— / $0.04 per 1M	Input: Text Output: Text
GPT 6 Astra $		1.05M	$8.00 / $40.00 per 1M	$10.00 / $0.80 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.8 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 per 1M	Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text
Claude Fable 5.1 $		1M	$9.00 / $45.00 per 1M	$11.25 / $0.23 per 1M	Input: TextInput: ImageInput: Document Output: Text
Qwen3.8 Max 0902 $		1M	$1.80 / $5.40 per 1M	$2.25 / $0.23 per 1M	Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text
GLM 5.3 Flash $	—	1.31M	$0.15 / $0.50 per 1M	— / $0.03 per 1M	Input: TextInput: ImageInput: VideoInput: Document Output: Text
DeepSeek v4 Flash Vision Exp $	—	1.05M	$0.44 / $1.32 per 1M	— / $0.01 per 1M	Input: TextInput: Image Output: Text
GLM 5.3 $		1.31M	$1.26 / $3.96 per 1M	— / $0.23 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.7 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 per 1M	Input: TextInput: ImageInput: Document Output: Text
Grok 4.6 $		500K	$1.20 / $3.60 per 1M	— / $0.30 per 1M	Input: TextInput: Image Output: Text
Qwen3.8 Max $		1M	$1.80 / $5.40 per 1M	$2.25 / $0.23 per 1M	Input: TextInput: ImageInput: VideoInput: Document Output: Text
Claude Opus 5 $		1M	$4.50 / $22.50 per 1M	$5.63 / $0.45 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.6 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 per 1M	Input: TextInput: ImageInput: Document Output: Text
Kimi K3 $		1.05M	$2.70 / $13.50 per 1M	$0.27 / $0.27 per 1M	Input: TextInput: ImageInput: Document Output: Text
GPT 5.6 Luna $		1.05M	$0.16 / $0.96 per 1M	$0.20 / $0.02 per 1M	Input: TextInput: ImageInput: Document Output: Text
GPT 5.6 Terra $		1.05M	$1.60 / $9.60 per 1M	$2.00 / $0.16 per 1M	Input: TextInput: ImageInput: Document Output: Text
Grok 4.5 $		500K	$1.20 / $3.60 per 1M	$0.30 / $0.30 per 1M	Input: TextInput: Image Output: Text
Claude Sonnet 5 $		1M	$1.80 / $9.00 per 1M	$2.25 / $0.18 per 1M	Input: TextInput: Document Output: Text
MiniMax M3 $		1.05M	$0.48 / $0.96 per 1M	$0.10 / $0.10 per 1M	Input: TextInput: ImageInput: Document Output: Text
GLM 5.2 $		1.05M	$1.26 / $3.96 per 1M	$0.23 / $0.23 per 1M	Input: TextInput: ImageInput: Document Output: Text
Qwen3.7 Max $		1M	$0.36 / $1.44 per 1M	$0.07 / $0.07 per 1M	Input: TextInput: Document Output: Text
Claude Opus 4.8 Thinking $		1M	$4.50 / $22.50 per 1M	$5.63 / $0.45 per 1M	Input: TextInput: Document Output: Text
Claude Opus 4.8 $		1M	$4.50 / $22.50 per 1M	$5.63 / $0.45 per 1M	Input: TextInput: Document Output: Text
DeepSeek v4 Flash $		1.05M	$0.37 / $1.12 per 1M	— / $0.01 per 1M	Input: Text Output: Text
DeepSeek v4 Pro $		1.05M	$1.12 / $3.37 per 1M	— / $0.04 per 1M	Input: Text Output: Text
Grok 4.3 $		1M	$0.75 / $1.50 per 1M	$0.12 / $0.12 per 1M	Input: TextInput: Image Output: Text
Kimi K2.6 $		262K	$0.85 / $3.60 per 1M	$0.14 / $0.14 per 1M	Input: TextInput: Document Output: Text
Claude Opus 4.7 Thinking $		1M	$4.50 / $22.50 per 1M	$5.63 / $0.45 per 1M	Input: TextInput: Document Output: Text
MiniMax M2.5 $		205K	$0.24 / $0.96 per 1M	$0.30 / $0.02 per 1M	Input: TextInput: Document Output: Text
Kimi K2.5 $		262K	$0.54 / $2.70 per 1M	$0.09 / $0.09 per 1M	Input: TextInput: Document Output: Text
Doubao Seed 1.6 Thinking (Build 250715) $		262K	$0.10 / $0.97 per 1M	—	Input: TextInput: Image Output: Text
Doubao Seed 1.6 Thinking (Build 250615) $		262K	$0.10 / $0.97 per 1M	—	Input: TextInput: Image Output: Text
Doubao Seed 1.6 Flash (Build 250615) $		262K	$0.02 / $0.18 per 1M	—	Input: TextInput: Image Output: Text

Fable 5: Mythos Power for Everyone

Why a cheap Claude-Fable-5 API is the ultimate tool for frontier intelligence.

Long-Horizon Autonomy

Tackle projects that take days with a proactive model that plans across stages and delegates to sub-agents.

Senior-Grade Reasoning

Achieve senior research scientist grade outputs, picking directions and producing novel first-principles results.

Token Efficiency

Handle 50-million-line codebases with fewer turns and higher reliability than any previous Claude iteration.

Vision-First Audit

Extract precise numbers from scientific figures or rebuild source code from screenshots with zero scaffolding.

What is Claude Fable 5?

Claude Fable 5 is the first model in Anthropic's Claude 5 family and its first Mythos-class model released to the public, a capability tier above Claude Opus. It's state-of-the-art on most published benchmarks for software engineering, knowledge work, vision, and scientific reasoning, and its lead grows the longer and more multi-step the task. Launched June 9, 2026.

Spec	Value
Model string	claude-fable-5
Context window	1,000,000 tokens
Max output	128,000 tokens / request
Input	Text + image + file
Output	Text
Reasoning	Summarized thinking (raw chain-of-thought not returned)
Provider	Anthropic
GPTProto endpoint	https://gptproto.com/v1/messages

Claude Fable 5 vs Opus 4.8 vs GPT-5.5

	Claude Fable 5	Claude Opus 4.8	GPT-5.5
SWE-Bench Pro	80.3%	69.2%	58.6%
Context window	1M	1M	1M
Input	Text + image + file	Text + image	Text + image
Best for	Long-horizon agentic work, migrations, vision audits	General reasoning; cheapest of the three	Codex-style coding workflows
GPTProto price (in / out per 1M)	$8 / $40	$4 / $20	$4 / $24

Benchmarks as reported by Anthropic / OpenAI; validate on your own workload before committing. The honest read: Fable 5 tops the benchmarks but runs ~2× the price of the others. Opus 4.8 is the cheapest of the three and the better default for most general reasoning. GPT-5.5 sits in the middle on price and is the pick if you're standardized on OpenAI / Codex tooling. All three run from one GPTProto key and balance, so you can route each task to the right model without switching providers.

Claude-Fable-5 FAQ: Cheap API & Safeguards

Answers about the cheap Claude-Fable-5 API, including pricing models, safeguard fallbacks, and autonomous agent capabilities for your enterprise.

How much does the cheap Claude-Fable-5 API cost?

Claude Fable 5 is priced at $10 per million input tokens and $50 per million output tokens. This is less than half the price of the previous Mythos Preview. Additionally, users can leverage a 90% discount on input tokens through prompt caching, making it a very cheap Claude-Fable-5 API option for high-volume, repetitive tasks that require persistent context or large document sets stored in memory.

When should I use Fable 5 instead of Opus 4.8?

Use Fable 5 for your most ambitious, long-running projects that require autonomy. While Opus 4.8 is excellent for general reasoning, Fable 5 is built for tasks that span days, such as large-scale code migrations or deep research. If your query is flagged by cybersecurity or biology safeguards, the system will automatically route to Opus 4.8 to ensure safety without interrupting your workflow or charging you Fable prices.

Does Fable 5 support autonomous coding?

Yes, it is Anthropic's most capable model for agentic coding. It can perform codebase-wide migrations, write its own tests, and use vision to compare outputs against design goals. Stripe reported that Fable 5 compressed months of manual engineering work into just a few days. It functions effectively in agent harnesses like Claude Code, planning across multiple stages and delegating to sub-agents without supervision.

How do the vision capabilities compare?

Fable 5 is the state-of-the-art for vision tasks. It extracts precise data from complex charts, diagrams, and tables within PDFs. Unlike earlier models that required complex harnesses to interpret game states, Fable 5 has demonstrated the ability to beat games like Pokémon FireRed using only raw screenshots. This makes it ideal for rebuilding web apps from UI captures or auditing document-heavy files in legal sectors.

What are the data retention policies?

To maintain high safety standards for Mythos-class models, Fable 5 requires a 30-day data retention period for safety monitoring. This applies to both first-party and third-party surfaces. This data is not used for training new models; instead, it helps identify and reduce false positives in the safeguard classifiers. All human access to this logged data is strictly monitored and recorded to protect user privacy.

Is US-only inference available?

For organizations with strict data residency requirements, US-only inference is available. This ensures that the model processing stays within US borders. This specialized routing is priced at 1.1x the standard rate for both input and output tokens. This means you can still access a relatively cheap Claude-Fable-5 API while satisfying the compliance needs of legal, financial, or government-contracted projects.

Guides, comparisons, and updates related to this model.

All Articles

Claude Fable 5: The Complete Guide and Honest Review (2026)

Claude Fable 5 is Anthropic's first public Mythos-class model. See what it does, what it costs, and when to pick it over Opus 4.8.

Fable 5: Mythos Power for Everyone

Long-Horizon Autonomy

Senior-Grade Reasoning

Token Efficiency

Vision-First Audit

What is Claude Fable 5?

Claude Fable 5 vs Opus 4.8 vs GPT-5.5

How much does the cheap Claude-Fable-5 API cost?

When should I use Fable 5 instead of Opus 4.8?

Does Fable 5 support autonomous coding?

How do the vision capabilities compare?

What are the data retention policies?

Is US-only inference available?

Related Articles

Claude Fable 5: The Complete Guide and Honest Review (2026)