Anthropic Claude Fable 5.2 vs OpenAI GPT-6 Astra — API Pricing, 150K Cache & Latency Benchmark
Side-by-side unit economics audit comparing Anthropic Claude Fable 5.2 (anthropic/claude-fable-5-2: Input $8/1M, Output $40/1M, Warm Cache Read $0.2/1M) against OpenAI GPT-6 Astra (openai/gpt-6-astra: Input $10/1M, Output $50/1M, Warm Cache Read $1/1M).
Activate 4-breakpoint prefix caching on Anthropic Claude Fable 5.2 to cut input token costs from $8/1M down to $0.2/1M, or route async workloads via Batch API for 50% off.
Lock static system prompt prefixes on OpenAI GPT-6 Astra to pay $1/1M warm cache rates instead of $10/1M uncached input, plus eligible startup cloud credits.
In Etuki FinOps telemetry comparing Anthropic Claude Fable 5.2 (API ID: anthropic/claude-fable-5-2) vs OpenAI GPT-6 Astra (API ID: openai/gpt-6-astra), Anthropic Claude Fable 5.2 offers lower standard uncached input pricing at $8/1M tokens, while Anthropic Claude Fable 5.2 leads in 10-turn 150K cache-pinned coding economics at $2.2700 per 10 turns (saving $1.5800 over OpenAI GPT-6 Astra). For latency-sensitive interactive agents, Anthropic Claude Fable 5.2 delivers 30ms faster P90 time-to-first-token (460ms vs 490ms).
| Specification / FinOps Dimension | Anthropic Claude Fable 5.2 (anthropic/claude-fable-5-2) | OpenAI GPT-6 Astra (openai/gpt-6-astra) | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | anthropic/claude-fable-5-2 | openai/gpt-6-astra | UMCE 563-Registry Locked |
| 563-Registry & Routing Eligibility | is_known: true | routable: true | is_known: true | routable: true | Both Merkle Verified |
| Standard Uncached Input (/1M tokens) | $8 / 1M | $10 / 1M | Anthropic Claude Fable 5.2 |
| Warm Prefix Cache Read (/1M tokens) | $0.2 / 1M | $1 / 1M | Anthropic Claude Fable 5.2 |
| Standard Output (/1M tokens) | $40 / 1M | $50 / 1M | Anthropic Claude Fable 5.2 |
| Context Window Capacity | 1000K Tokens | 200K Tokens | Anthropic Claude Fable 5.2 |
| 150K Prompt × 10 Turns (Unpinned Cold + 2K Out) | $12.8000 | $16.0000 | Anthropic Claude Fable 5.2 |
| 150K × 10 Turns Case A (100% Static Pinned) | $2.2700 (saves $10.5300) | $3.8500 (saves $12.1500) | Anthropic Claude Fable 5.2 (-$1.5800) |
| 150K × 10 Turns Case B (90% Static + 10% Tail) | $3.3230 (saves $9.4770) | $5.0650 (saves $10.9350) | Anthropic Claude Fable 5.2 |
| P50 / P90 First-Token Latency | 286ms / 460ms (92 tok/s) | 333ms / 490ms (76 tok/s) | Anthropic Claude Fable 5.2 (-30ms) |
1. Full-Turn Rate-Card Substitution for Anthropic Claude Fable 5.2: At an uncached input rate of $8/1M, output rate of $40/1M, and warm cache read rate of $0.2/1M, running 10 consecutive 150,000-token coding agent turns (with 2,000 output tokens/turn) without prefix pinning costs $12.8000. Locking 100% static prefixes (Case A: 1 cold turn + 9 warm cached turns + 20K total output) reduces 10-turn spend to $2.2700 (saving $10.5300); under a 90% static prefix + 10% dynamic tail workload (Case B), 10-turn spend is $3.3230.
2. Full-Turn Rate-Card Substitution for OpenAI GPT-6 Astra & Winner Verdict: On OpenAI GPT-6 Astra ($10/1M input, $50/1M output, $1/1M warm cache), 10 unpinned 150K turns cost $16.0000, dropping to $3.8500 in Case A and $5.0650 in Case B. Across every 10-turn 150K coding loop (including output tokens), Anthropic Claude Fable 5.2 delivers an additional $1.5800 Case-A cost advantage.
Production Workload TCO: 25,000 MAU • 50M Tokens/Mo (50% Cache Hit) • 2,000 GB Egress
💡 Optimal FinOps Verdict: Deploying Anthropic Claude Fable 5.2 saves $156.00/month ($1872/year) at 25,000 MAU & 50M monthly tokens (80% input / 20% output split with 50% prefix cache hit rate).