Model card

Claude Fable 5.1

lx1-fable-5.1FrontierMax planLive in the catalog

Anthropic's latest flagship, served from Anthropic's own cloud. Same $10/$50 card as Fable 5, with cheaper cache reads, a million-token window, and adaptive thinking for long-running agent and research work. Capacity is limited and the meter drains fast — reserved for Max.

Context window1M tokens

Input · per Mtok$10

Output · per Mtok$50

Served byLayer X1 engine

Where it earns its keep[01/03]

01Served direct from Anthropic cloud, not a reseller
02Long-horizon agentic coding, research, and document work
031M context and 128K output — Max plan only

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 5.1 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-5.1",
    "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 · Launch from $2/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.