Z.ai: GLM 4.5 Air vs Anthropic Claude Fable 5.1: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Z.ai: GLM 4.5 Air (z-ai/glm-4.5-air) vs Anthropic Claude Fable 5.1 (claude-fable-5-1). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Z.ai: GLM 4.5 Air (z-ai/glm-4.5-air) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Z.ai: GLM 4.5 Air: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.065/1M) or route via asynchronous Batch API for 50% off standard token rates.
Anthropic Claude Fable 5.1 (claude-fable-5-1) — $25,000 Startup Credits & 97.5% Cache Promo
Anthropic's Q4 2026 developer promotion combines $25,000 in Claude API credits for early-stage builders with a permanent 20% base price reduction on Opus 5.5 ($4/$20), 0.05x ($0.20/1M) prompt cache reads, and 50% off Batch API processing ($2/$10 with 300K max output).
In Etuki October 2026 FinOps telemetry comparing Z.ai: GLM 4.5 Air (API ID: z-ai/glm-4.5-air) vs Anthropic Claude Fable 5.1 (API ID: claude-fable-5-1), Z.ai: GLM 4.5 Air offers lower standard input pricing at $0.13/1M tokens ($0.85/1M output), while Z.ai: GLM 4.5 Air leads in cached prefix economics at $0.065/1M tokens (50% discount). Z.ai: GLM 4.5 Air achieves a 210ms faster P90 time-to-first-token latency (280ms vs 490ms).
Auto-discovered via live global telemetry registry.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | Z.ai: GLM 4.5 Air | Anthropic Claude Fable 5.1 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | z-ai/glm-4.5-air | claude-fable-5-1 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.13 / $0.85 | $10 / $50 | Z.ai: GLM 4.5 Air |
| Cache Read Price (per 1M) | $0.065/1M (50% Off) | $0.25/1M (97.5% Off) | Z.ai: GLM 4.5 Air |
| Context Window / Max Output | 128K In / 96K Out | 1000K In / 128K Out | Anthropic Claude Fable 5.1 |
| P90 First-Token / Edge Latency | 280ms | 490ms | Z.ai: GLM 4.5 Air (-210ms) |
GLM-4.5-Air is the lightweight variant of our latest flagship model family, also purpose-built for agent-centric applications. Like GLM-4.5, it adopts the Mixture-of-Experts (MoE)
Anthropic specialized frontier model for demanding scientific reasoning, OfficeQA leadership, and long-horizon agentic work.
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
📜Switch from Z.ai: GLM 4.5 Air to Anthropic Claude Fable 5.1
Anthropic specialized frontier model for demanding scientific reasoning, OfficeQA leadership, and long-horizon agentic work. Verified P90 latency of 490ms.