MODELS / ANTHROPIC

Claude Opus 4.8 (Fast)

Opus 4.8 is a focused upgrade to Opus 4.7 and is Anthropic's best generally available model for coding, agentic tasks, and enterprise workflows. It builds on the strengths of previous Opus models with stronger performance on complex, multi-step coding tasks. Anthropic…

TEXTREASONINGTOOL-USEREASONINGVISIONFILE-INPUTEXPLICIT-CACHINGWEB-SEARCHFAST
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-opus-4.8-fast",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": true
  }'
SPECIFICATIONS

The full spec sheet.

Context, pricing, modalities, routing, and deployment: everything Claude Opus 4.8 (Fast) supports, in one table.

MODEL ID
blackboxai/anthropic/claude-opus-4.8-fast
DEVELOPED BY
Anthropic
MODEL TYPE
Text
RELEASED
May 28, 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