GPT-5.5 Pro

A heavy-reasoning tier: expensive and available only on /v1/responses — not recommended outside specialist workloads.

Specifications

Item	Value
Model ID	`gpt-5.5-pro`
Vendor	OpenAI
Available on APIYI	2026-05-03
Knowledge cutoff	2025-12
Input modalities	Text, Image
Output modalities	Text
Context window	1,050,000 tokens
Max output	128,000 tokens
Billing	Usage-based

Pricing

Prices in USD per 1M tokens ($/1M).

Input	Cached input	Output
$30	$3	$180

The table shows list prices. Recharge promotions and group discounts stack; the console reflects the actual charge in real time. See Pricing and Recharge promotions.

Tiered pricing

This model is tier-priced by the token size of each request (output price = tier input price × output multiplier):

0 – 278,528 tokens: $30/1M input
Above 278,528 tokens: $60/1M input

Endpoints

Endpoint	Path	Supported
`OpenAI Chat Completions`	`POST /v1/chat/completions`	—
`OpenAI Responses`	`POST /v1/responses`	✅
`Anthropic Messages`	`POST /v1/messages`	—
`Gemini Generate Content`	`POST /v1beta/models/{model}:generateContent`	—
`Image Generations`	`POST /v1/images/generations`	—
`Embeddings`	`POST /v1/embeddings`	—

Billing groups

Group	Multiplier	Notes
`Default`	1×	List price
`SVIP`	1×	List price

Some groups carry extra discounts, stackable with recharge bonuses. See Tokens and groups.

Supported features

Feature	Supported
Streaming	✅
Tool calling	✅
Structured outputs	✅
Vision	✅
Prompt caching	✅
Extended thinking	On by default

Example request

The example below calls gpt-5.5-pro through OpenAI Responses (/v1/responses). Point base_url at https://api.apiyi.com/v1 — everything else matches the official API.

curl https://api.apiyi.com/v1/responses \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $APIYI_API_KEY" \
  -d '{
    "model": "gpt-5.5-pro",
    "input": "Hello"
  }'

Read the key from an environment variable, never hard-coded. In production, issue separate tokens per use case so you can revoke and attribute usage individually.

Launch announcement

Background, benchmarks and migration notes for GPT-5.5 Pro

Compatible Mode

Parameters, usage and best practices

Model pricing directory

Live pricing, endpoints and groups for all 308 models

Specs on this page are maintained by hand in models/data/model-details.json; pricing and endpoints come from the live pricing API, updated 2026-07-31 01:30 (UTC+8), specs last verified 2026-07-31.

Pricing Table

OpenAI

Anthropic

Google

xAI

Alibaba

ByteDance

Moonshot

Zhipu

MiniMax

Specifications

Pricing

Tiered pricing

Endpoints

Billing groups

Supported features

Example request

Launch announcement

Compatible Mode

Model pricing directory

​Specifications

​Pricing

​Tiered pricing

​Endpoints

​Billing groups

​Supported features

​Example request

​Related docs

Launch announcement

Compatible Mode

Model pricing directory

Specifications

Pricing

Tiered pricing

Endpoints

Billing groups

Supported features

Example request

Related docs