Pricing, context window, capabilities, and release date — pulled from each provider's public docs. Both are available via the same AIgateway OpenAI-compatible endpoint; flip the model string to switch.
Both models stream in parallel through your own AIgateway key. Tokens, latency, and cost update as they arrive.
| FLUX 3 Image Klein black-forest-labs/flux-3-image-klein | GPT-5.5 Pro openai/gpt-5.5-pro | |
|---|---|---|
| Provider | Black Forest Labs | OpenAI |
| Family | FLUX | GPT-5 |
| Modality | image | text |
| Context window | — | 1,000,000 tok |
| Max output | — | 16,384 tok |
| Released | 2026-10-16 | 2026-05-22 |
| Input price | $0.0090 /img | $30.00 /1M |
| Output price | — | $180.00 /1M |
| Cache read | — | — |
| Tools | — | yes |
| Streaming | — | yes |
| Vision | — | yes |
| JSON mode | — | yes |
| Reasoning | — | yes |
| Prompt caching | — | — |
FLUX 3 Image Klein is Black Forest Labs' 5.6B-parameter image model for text-to-image, image editing, and multi-reference generation with up to 10 reference images. It supports native 4K output and bounding-box layout control.
GPT-5.5 pro uses OpenAI's Responses API with built-in tools, improved reasoning, and stateful context management.
# pip install aigateway-py openai
# aigateway-py: sub-accounts, evals, replays, jobs, webhook verify.
# openai SDK: chat/embeddings/images/audio — drop-in compat per our SDK's own guidance.
from openai import OpenAI
client = OpenAI(
base_url="https://api.aigateway.sh/v1",
api_key="sk-aig-...",
)
# Try FLUX 3 Image Klein
client.chat.completions.create(
model="black-forest-labs/flux-3-image-klein",
messages=[{"role":"user","content":"hello"}],
)
# Try GPT-5.5 Pro — same client, same key
client.chat.completions.create(
model="openai/gpt-5.5-pro",
messages=[{"role":"user","content":"hello"}],
)