MODELS / OPENAI

GPT 5.4 (Fast)

GPT-5.4 is OpenAI's best general-purpose model, part of the GPT-5 flagship model family. It's their most intelligent model yet for both general and agentic tasks.

TEXTREASONINGFILE-INPUTIMPLICIT-CACHINGREASONINGTOOL-USEVISIONWEB-SEARCHWEBSOCKET-REALTIMEFAST
1.1M
CONTEXT WINDOW
128K
MAX OUTPUT TOKENS
$5
INPUT PRICE / 1M TOKENS
$30
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/openai/gpt-5.4-fast",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": true
  }'
SPECIFICATIONS

The full spec sheet.

Context, pricing, modalities, routing, and deployment: everything GPT 5.4 (Fast) supports, in one table.

MODEL ID
blackboxai/openai/gpt-5.4-fast
DEVELOPED BY
OpenAI
MODEL TYPE
Text
RELEASED
Mar 5, 2026
CONTEXT WINDOW
1.1M
MAX OUTPUT TOKENS
128K
INPUT MODALITIES
text, image, pdf
OUTPUT MODALITIES
text
INPUT PRICE
$5 / 1M tokens
OUTPUT PRICE
$30 / 1M tokens
CACHE READ
$0.5 / 1M tokens
REASONING
Supported
DATA RETENTION
Standard retention
DEDICATED DEPLOYMENT
Not available (closed-weight model)
SUPPORTED PARAMETERS
max_tokenstemperaturestoptoolstool_choicereasoninginclude_reasoning