GPT-5.5 is OpenAI's most capable model for real-world work, understanding what users are trying to do faster and carrying more of the work itself. It excels at writing and debugging code, researching online, analyzing data, creating documents and spreadsheets, operating software, and moving across tools until a task is finished. With a 1M token context window and vision support, GPT-5.5 covers reasoning, tool use, structured output, web search, and computer use. It performs better than GPT-5.4 across nearly every measured evaluation while matching GPT-5.4's real-world serving latency, so it is more capable without being slower. Rather than requiring careful management of every step, GPT-5.5 accepts messy multi-part tasks and handles planning, tool selection, verification, and navigation through ambiguity more autonomously. That combination makes it well suited to developers building agentic systems.
GPT-5.5 runs on 2 different routes through the Opper gateway. Compare residency, ZDR, and training posture at a glance β full data-handling detail per route below.
Training posture across routes: No training on prompts by default.
Each route hosting GPT-5.5 has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention is available via Opper Enterprise contract. No training on customer data. EU; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Independent benchmark scores β composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call GPT-5.5 through the Opper gateway with one API key. Let your coding agent set it up, or call it directly β Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into your coding agent β Claude Code, Cursor, Codex, and more β and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/v3/compat",});const completion = await client.chat.completions.create({model: "openai/gpt-5.5",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
