Model card

Claude Fable 5

lx1-fable-5FrontierMax planLive in the catalog

Anthropic's top-of-line model for the work that demands the most: intricate long-form writing, subtle multi-step reasoning, and judgment calls where the difference between good and great is the whole job. Frontier reasoning, vision, and a full million-token window. Reserved for Max — it is the dearest model in the catalog and earns its place only where nothing else will do.

Context window1M tokens

Input · per Mtok$10

Output · per Mtok$50

Served byLayer X1 engine

Where it earns its keep[01/03]

01Frontier reasoning for long-form, high-stakes work
02Vision: reads screenshots, diagrams, and UI states
031M context holds an entire codebase in view

Capabilities

Tool callingYes

Strict, schema-faithful tool calls, enforced by the engine on every request — safe to build an agent loop on.

ReasoningYes

Thinks before it answers. Budget max_tokens generously — hidden reasoning counts against it.

VisionYes

Reads images — screenshots, diagrams, and UI states — inline in the conversation.

Behind the endpoint[02/03]

One endpoint. Served by our engine.

Claude Fable 5 is served through the Layer X1 engine — zero-downtime serving is the design target, not a status-page apology. You request it by name; everything else is our problem.

Call it by name

curl https://api.layerx1.com/v1/messages \
  -H "x-api-key: lx1_your_key" \
  -H "content-type: application/json" \
  -d '{
    "model": "lx1-fable-5",
    "max_tokens": 1024,
    "messages": [{ "role": "user", "content": "Hello" }]
  }'

OpenAI-style clients work too — send the same model name to /v1/chat/completions with a Bearer key. See the docs for both dialects.

Your agent stays the same.
Its inference gets better.

$export ANTHROPIC_BASE_URL=https://api.layerx1.com

Get a key Read the docs

Start free · no card · Starter from $5/mo

One endpoint. Served by our engine.

Your agent stays the same.Its inference gets better.

Your agent stays the same.
Its inference gets better.