Claude Fable 5.1
Claude Fable 5.1 by Anthropic: $10 input and $50 output per 1M tokens, 1M context. Call it through the odnoga LLM gateway.
Claude Fable 5.1 is served by Anthropic and called through odnoga with the same OpenAI-compatible request shape as every other model in the catalog. It accepts images alongside text. It supports tool and function calling. Its 1M-token context window sets how much input you can send in one request. Cached input is billed at $0.25 per 1M tokens, so repeated prefixes cost less.
Specification and price
| Vendor | Anthropic |
|---|---|
| Model ID | claude-fable-5-1 |
| Context window | 1M tokens |
| Max output | 128K tokens |
| Input / 1M tokens | $10 |
| Output / 1M tokens | $50 |
| Cached input / 1M tokens | $0.25 |
| Capabilities | Vision, Tools, Streaming |
Prices are the vendor list price per million tokens as recorded in the odnoga catalog. Your odnoga cost is this price plus your plan margin — see pricing. Pricing
Call it through odnoga
const res = await fetch("https://api.odnoga.com/functions/v1/airouter-openai-compat/v1/chat/completions", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.ODNOGA_API_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
model: "claude-fable-5-1",
messages: [{ role: "user", content: "Hello" }],
}),
});
Same request shape for every vendor in the catalog — swap the model id and odnoga handles keys, routing, limits and cost accounting.
How to use Claude Fable 5.1
Reviewed 2026-09-14
Best for
- Long-horizon agentic coding: multi-step refactors, migrations and tool-using coding agents that run for hours
- Multistep research workflows that gather, cross-check and synthesize many sources
- Demanding reasoning and knowledge work where Claude Opus 5 at higher effort still falls short
- Document, spreadsheet and slide work — creating and editing complex office artefacts
- Workloads with heavy prompt caching: cache reads are $0.25/MTok, 75% cheaper than Fable 5
Not the right pick when
- Simple chat, classification or extraction — Claude Sonnet 5 or Haiku 4.5 are far cheaper for that
- Most everyday workloads — Anthropic itself recommends starting with Claude Opus 5 first
- Latency-sensitive interactive features: this is a frontier reasoning model, not a speed pick
- Cost-sensitive high-volume traffic without caching or batch — at $10/$50 per MTok the bill grows fast
Practical tips through odnoga
- 01Pin claude-fable-5-1 in a managed prompt version so a future Fable upgrade never silently changes behaviour
- 02Turn on Anthropic prompt caching for repeated system prompts and tools — cache reads cost $0.25/MTok here
- 03Use the Batch API tier for offline evaluations: it supports batch and cuts cost on large test suites
- 04Run it in the evaluation lab against Opus 5 and Sonnet 5 on your own prompts before committing
- 05Set a per-tenant budget and a cheaper fallback model in odnoga before routing production traffic
- 06Use the effort parameter (low/medium/high/max/xhigh) to trade latency against reasoning depth per call
What a month costs
1,000 calls a month, 10,000 input tokens and 2,000 output tokens each, at this model’s catalog price:
| Input (10M tokens) | $100 |
|---|---|
| Output (2M tokens) | $100 |
| Vendor cost per month | $200 |
Vendor list price only — your odnoga price adds your plan margin, and cached input or answer reuse lowers it. odnoga records both numbers per request.
Claude Fable 5.1 compared
| Model | Context | Input / 1M | Output / 1M | Capabilities |
|---|---|---|---|---|
| Claude Fable 5.1 | 1M | $10 | $50 | Vision, Tools, Streaming |
| Claude 3.5 Sonnet | 200K | $3 | $15 | Vision, Tools, JSON mode, Streaming |
| Claude Fable 5 | 1M | $10 | $50 | Vision, Tools, Streaming |
Questions
- What does Claude Fable 5.1 cost?
- $10 per million input tokens and $50 per million output tokens — the same as Fable 5. Cache reads dropped 75% to $0.25 per million tokens; cache writes are $12.50 (5-minute) and $20 (1-hour).
- When should I pick Fable 5.1 over Claude Opus 5?
- Anthropic recommends starting with Opus 5 for most workloads. Pick Fable 5.1 for demanding reasoning and long-horizon agentic work, or when your evals on Opus 5 at higher effort still fall short.
- What is the difference between Fable 5.1 and Mythos 5.1?
- They are the same underlying model with different safeguard levels. Mythos 5.1 is in limited availability; Fable 5.1 is the generally available endpoint.
- Can I switch from Fable 5 to Fable 5.1 without code changes?
- Yes. Through odnoga you change the pinned model in the managed prompt version or pass claude-fable-5-1 as the model parameter — the API shape is unchanged.
All models · Pricing · Docs · Compare models in the evaluation lab
Sources: Anthropic — Introducing Claude Fable 5.1 and Mythos 5.1, Claude Platform Docs — Fable 5.1 overview, Claude Platform Docs — Pricing