MODELS / ANTHROPIC

Claude Fable 5

Claude Fable 5 is a Mythos-class model with robust safeguards. It can handle long-running, complex, and asynchronous tasks where previous models would have needed more frequent check-ins.

TEXTREASONINGREASONINGTOOL-USEEXPLICIT-CACHINGFILE-INPUTVISION
1M
CONTEXT WINDOW
128K
MAX OUTPUT TOKENS
$10
INPUT PRICE / 1M TOKENS
$50
OUTPUT PRICE / 1M TOKENS
QUICKSTART

Call it in one request.

OpenAI-compatible: change the base URL, and the setup is complete.

curl https://enterprise.blackbox.ai/v1/chat/completions \
  -H "Authorization: Bearer $BLACKBOX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "blackboxai/anthropic/claude-fable-5",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": true
  }'
SPECIFICATIONS

The full spec sheet.

Context, pricing, modalities, routing, and deployment: everything Claude Fable 5 supports, in one table.

MODEL ID
blackboxai/anthropic/claude-fable-5
DEVELOPED BY
Anthropic
MODEL TYPE
Text
RELEASED
Jul 1, 2026
CONTEXT WINDOW
1M
MAX OUTPUT TOKENS
128K
INPUT MODALITIES
text, image, pdf
OUTPUT MODALITIES
text
INPUT PRICE
$10 / 1M tokens
OUTPUT PRICE
$50 / 1M tokens
CACHE READ
$1 / 1M tokens
CACHE WRITE
$12.50 / 1M tokens
REASONING
Supported
DATA RETENTION
Standard retention
DEDICATED DEPLOYMENT
Not available (closed-weight model)
SUPPORTED PARAMETERS
max_tokenstemperaturestoptoolstool_choicereasoninginclude_reasoning