AnthropicVerified Active: September 18, 2026
Claude Fable 5.1API Pricing & Specifications
Anthropic's Mythos-tier frontier model featuring advanced safety architectures and nuanced reasoning.
📊 Core Specifications & Pricing Rates
Standard Input
$10.00 / 1M tokens
Standard Output
$50.00 / 1M tokens
Cached Input
$0.2500 / 1M tokens
Cache Write
$12.50 / 1M tokens
Context Window
1M (1,000,000 tokens)
Max Output Tokens
128,000 tokens
Supported Capabilities:✓ Vision✓ Function Calling / Tools✓ JSON Mode✓ Deep Reasoning
📦 Asynchronous Batch API Supported: Official provider documentation offers a 50% discount on non-streaming 24h batch requests.
Live Workload Cost Estimator: Claude Fable 5.1
Adjust token volumes to simulate your exact monthly API bill.
Estimated 60% repeated context
Estimated Total Monthly Cost
Compare All Models in Calculator→$655.63/ month
$0.02622 per API request(Saves $219.38/mo with caching)
💡 Estimated Monthly Workload Scenarios
High-Stakes Legal & Regulatory Synthesis
$1400.00/mo10,000 regulatory compliance analyses (8,000 input, 1,200 output)
10,000 requests • 8000 in / 1200 out
⚖️ Head-to-Head Competitor Comparisons
Claude Fable 5.1 vs. GPT-6 Astra
Competes directly in the $10/$50 tier; Fable specializes in high-compliance safety hardening and long-horizon writing.
Identical rate ($10 in / $50 out)View GPT-6 Astra →
📜 Historical Price Changes & Updates
2026-09-01
Claude Fable 5.1 launched as Anthropic's highest-assurance Mythos tier model at $10 in / $50 out per 1M tokens.
🔗 Verified Primary Sources
All pricing, token limits, and capabilities are cross-checked against official provider documentation and live API endpoints.