OpenAI: GPT-5.5

Coming soonQuick Start

GPT-5.5 is OpenAI's frontier model for complex professional workloads, released 2026-04. It succeeds GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. The model suits large-scale coding, multimodal workflows, and long-document analysis.

This model is not routed on MirAPI yet — prices shown are the official list prices. Create an account to get notified when it goes live.

Modalities
inFileinImageinTextoutText
Price / 1M
$5.00 / $30.00
Context
1.05M
Knowledge cutoff
2025-12-01

Capabilities

ReasoningVisionTool useLong contextPrompt cachingStructured output

Benchmarks

bar = score (0–100) · ▏ median

Scores from vendor reports and public leaderboards. No private evals.

Intelligence Index
General ability
56.3
#11
Coding Index
Code
74.9
#8
Agentic Index
Agentic
47.4
#16
GPQA Diamond
Science QA
93.3
#3
τ-bench (airline)
Agentic tool use
78.0
#8

Showcase

Three fixed prompts, identical for every chat model. Outputs are archived verbatim — copy the prompt to reproduce.

Task prompt · identical for all models
Build a single-file HTML page using three.js from a CDN: a low-poly planet with a tilted ring of ~200 orbiting particles, a soft key light plus rim light, slow auto-rotation, and drag-to-orbit controls. No build tools — one file only.
Archived output
Archive not published yet

Every model will run this exact prompt; the output lands here verbatim, with tokens and per-run cost.

Quick Start

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.mirapi.ai/v1",   # changed
    api_key=os.environ["MIRAPI_API_KEY"],   # changed
)

resp = client.chat.completions.create(
    model="openai/gpt-5.5",
    messages=[{"role": "user", "content": "Hello"}],
)
Wire GPT-5.5 into your product

1M free tokens to start · no card · OpenAI-compatible, one base_url change

Start free