{
  "description": "Minimal working calls to claude-fable-5. Recommended defaults: adaptive thinking on, effort high.",
  "model_id": "claude-fable-5",
  "endpoint": "https://api.anthropic.com/v1/messages",
  "required_headers": {
    "content-type": "application/json",
    "x-api-key": "$ANTHROPIC_API_KEY",
    "anthropic-version": "2023-06-01"
  },
  "request_body": {
    "model": "claude-fable-5",
    "max_tokens": 16000,
    "thinking": {"type": "adaptive"},
    "output_config": {"effort": "high"},
    "messages": [{"role": "user", "content": "Explain CRDTs like a fable."}]
  },
  "python": {
    "install": "pip install anthropic",
    "code": "import anthropic\n\nclient = anthropic.Anthropic()  # reads ANTHROPIC_API_KEY\n\nresponse = client.messages.create(\n    model=\"claude-fable-5\",\n    max_tokens=16000,\n    thinking={\"type\": \"adaptive\"},\n    output_config={\"effort\": \"high\"},\n    messages=[{\"role\": \"user\", \"content\": \"Explain CRDTs like a fable.\"}],\n)\nfor block in response.content:\n    if block.type == \"text\":\n        print(block.text)"
  },
  "python_streaming": {
    "when": "Required above ~16K output tokens; 128K max output is reachable only via streaming",
    "code": "with client.messages.stream(\n    model=\"claude-fable-5\",\n    max_tokens=64000,\n    thinking={\"type\": \"adaptive\"},\n    messages=[{\"role\": \"user\", \"content\": \"Write the design doc.\"}],\n) as stream:\n    for text in stream.text_stream:\n        print(text, end=\"\", flush=True)"
  },
  "typescript": {
    "install": "npm install @anthropic-ai/sdk",
    "code": "import Anthropic from \"@anthropic-ai/sdk\";\n\nconst client = new Anthropic();\nconst response = await client.messages.create({\n  model: \"claude-fable-5\",\n  max_tokens: 16000,\n  thinking: { type: \"adaptive\" },\n  output_config: { effort: \"high\" },\n  messages: [{ role: \"user\", content: \"Explain CRDTs like a fable.\" }],\n});"
  },
  "source": "https://fableguide.com/#first-call",
  "last_verified": "2026-06-10"
}