Text Generation (Chat Completions)

Text generation is the gateway’s core capability, unified through the Chat Completions interface (for parameter reference, see Chat Completions); when switching models, only the model field needs to be changed.

Quick Start

curl https://api.4allapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIPROXY_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.5",
    "messages": [{"role": "user", "content": "Write a product introduction"}]
  }'

Available Series

Series	Positioning	Details
GPT	General-purpose mainstay, code	GPT Series
Claude	Long-form writing, complex reasoning	Claude Series
Gemini	Multimodal, cost-effective, web-connected	Gemini Series
Free Models	Zero-cost trials and lightweight tasks	Free Models

General Capabilities

All series support: streaming output, multi-turn dialogue, FC function calling, cached billing; for reasoning tiers and thinking modes, see Reasoning Model Output.

Selection Path

1. For general scenarios, start with gpt-5.5 or claude-sonnet-5;
2. For cost-sensitive use, switch to gpt-5.4-mini / gemini-3.5-flash / claude-haiku-4-5;
3. For complex reasoning, use the -high / -thinking tier;
4. Make the model name a configuration item, compare performance and cost in a gray release; see Popular Models Now.