Model card

Claude Sonnet 4.5

lx1-sonnet-4.5PremiumLive in the catalog

The Sonnet generation before 4.6: vision, tools, documents, and a 200K window at the same $3/$15 card. Reach for it when you want that generation's behavior by name.

Context window200K tokens

Input · per Mtok$3

Output · per Mtok$15

Served byLayer X1 engine

Where it earns its keep[01/03]

01Premium Claude quality
02Vision, tools, and documents
03200K context

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 Sonnet 4.5 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-sonnet-4.5",
    "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 · 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.