OpenAI Platform 免费吗？价格、免费额度与海外可用性

OpenAI 开发者平台：GPT 系列模型 API、Playground 调试、微调、批量任务与 Assistants 能力，文档质量与生态是行业标杆。

文档和 SDK 体验好到可以照抄，模型更新节奏快；价格不算便宜但能力强，用量大了记得设预算告警。模型弃用节奏偏快，生产环境建议锁定版本并关注迁移公告，账单监控需自建面板。参考单价（OpenRouter 数据，美元/百万 tokens）：GPT-6.1 Terra 输入 1/输出 5，旗舰 GPT-5.5 输入 5/输出 30，Pro 档 30/180，低价档 GPT-6 Luna 低至 0.1/0.5。

OpenAI's developer API and platform: the GPT-6 family, embeddings, image generation, speech, fine-tuning, assistants and structured outputs, all behind one key. The reference implementation that most other providers are API-compatible with, which makes it the default integration target.

The pragmatic default for building, with clear trade-offs.

Where it winsBreadth and compatibility — everything is here, the documentation is thorough, and because it is the de facto standard, libraries and examples exist for every language and framework. Structured outputs and tool calling are mature.

Where to be carefulCost adds up fast at volume, and rate limits on lower tiers will constrain a growing product. Model deprecations force migrations on OpenAI's schedule, not yours.

VerdictStart here to get something working. Once you understand your token profile, evaluate cheaper providers for the high-volume paths — that is usually where the meaningful savings are.