Mythos-Class Reasoning
Handles complex knowledge work with minimal oversight, producing novel first-principles outputs for enterprise workflows.
claude-fable-5 / web-search
Claude Fable 5 is the premier mythos-class model for elite coding and multi-day projects. This new claude generation offers state-of-the-art vision and agentic capabilities for your most ambitious enterprise software development workflows.
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API
Submit Task
curl --request POST "https://gptproto.com/v1/messages" \
--header "Authorization: Bearer $GPTPROTO_API_KEY" \
--header "Content-Type: application/json" \
--data '{
"model": "claude-fable-5",
"max_tokens": 1024,
"messages": [
{
"role": "user",
"content": "What'\''s the weather in NYC?"
}
],
"tools": [
{
"type": "web_search_20250305",
"name": "web_search",
"max_uses": 5
}
]
}'Key Claude Fable 5 Features
Harness the power of a mythos-class model for your most ambitious enterprise coding workflows and research.
Advanced Multimodal Vision
Claude fable 5 interprets detailed figures and tables in documents, verifying its own coding work via visual feedback.
Secure Enterprise Fallback
Requests flagged by safeguards route to Opus 4.8, ensuring safe usage of fable 5 without compromising on project momentum.
Agentic Coding Autonomy
Claude 5 performs multi-day autonomous coding tasks, planning stages and delegating to sub-agents with fable 5 intelligence.
Build with claude fable 5 in Minutes
Follow these simple steps to set up your account, get credits, and start sending API requests to claude fable 5 via GPT Proto.
Sign up
Create your free GPT Proto account to begin. You can set up an organization for your team at any time.
Top up
Your balance can be used across all models on the platform, including claude fable 5, giving you the flexibility to experiment and scale as needed.
Generate your API key
In your dashboard, create an API key — you'll need it to authenticate when making requests to claude fable 5.
Make your first API call
Use your API key with our sample code to send a request to claude fable 5 via GPT Proto and see instant AI-powered results.
Claude Fable 5 Frequently Asked Questions
What is the pricing for Claude Fable 5?
Claude Fable 5 is priced at $10 per million input tokens and $50 per million output tokens. For organizations building on the Claude platform, this pricing supports the fable 5 mythos-level intelligence required for elite coding. Additionally, prompt caching offers a 90% discount on input tokens, making long-horizon projects more cost-effective for developers handling ambitious, multi-day asynchronous tasks.
How does the Claude Fable 5 fallback work?
To ensure safety, Claude Fable 5 uses classifiers to detect requests involving cybersecurity or biology. If a query is flagged, it automatically routes to the Opus 4.8 model. Users only pay for the intelligence they receive, and they won't be charged fable 5 rates for rerouted requests. This mechanism preserves the reliability of the mythos 5 infrastructure while maintaining robust ethical safeguards for general use.
Can Claude Fable 5 handle autonomous coding?
Yes, Claude is built for agentic coding. In a harness like Claude Code, fable 5 can work for days, planning across multiple stages and delegating tasks to sub-agents. It proactively writes its own tests to check implementations, making it the most capable Claude model for large-scale software migrations and complex engineering projects that require high-fidelity results and minimal supervision throughout the lifecycle.
What is the data retention policy for Claude 5?
Using the fable 5 or mythos 5 models requires a 30-day data retention period for safety monitoring. This data is not used to train new Claude models but helps defend against novel jailbreak attempts. Anthropic has instituted strict privacy protections, including logging all human access to ensure your enterprise coding data remains secure and is deleted after the 30-day window in almost all cases.
How does Fable 5 compare to Claude Mythos 5?
Claude Fable 5 is the generally available version of the underlying mythos-class model. While Fable 5 includes active classifiers for cybersecurity and biology research, Claude Mythos 5 has these specific safeguards lifted for vetted partners. Both models share the same elite coding capabilities and 5th-generation intelligence, but Mythos 5 is currently restricted to specialized research programs like Project Glasswing.
Is Claude Fable 5 available for vision tasks?
Claude 5 is state-of-the-art for vision. It extracts precise data from diagrams, charts, and tables nested in PDFs. For coding projects, Claude uses its vision capabilities to check UI outputs against original design goals. This allows fable 5 to rebuild web applications from screenshots alone, demonstrating a level of multimodal reasoning that far exceeds previous model generations and competitor benchmarks.