Four AI APIs, four completely different citation formats. Getting the data out was harder than the analysis.

【核心亮点】一篇开发者的实测文章揭示了AI行业一个尴尬现状：四大AI助手的引用格式各搞一套，提取数据比分析数据还难，这让人有点意外。【通俗解读】四个主流AI服务商，比如OpenAI和Anthropic，它们的AI在回答问题时都会附上信息来源链接。但问题是，每家返回链接的方式完全不一样，有的藏在回答的注释里，有的单独打包，字段名称、数据结构都各不相同。开发者想把四个AI的引用放在一起对比，就得挨个适配，像翻译四种语言一样折腾，光提取数据就耗费了一个周末。【实际影响】这件事短期看是开发者头疼的事，但长期对普通用户也有影响。AI引用格式不统一，意味着跨平台工具难以呈现标准化的信息来源，用户想核实AI说的对不对会很麻烦。如果各家能形成统一的引用标准，以后用任何AI查资料，都能清楚看到引用了哪个网站、哪篇文章，信息透明度会大大提升，AI回答的可信度也会更容易验证。

I've been running a <a href="https://greaterthanservices.com/blog/ai-search-study-aesthetic-clinics" rel="noopener noreferrer">small monthly study</a>: take ten buyer-intent questions from one industry, ask four AI assistants the identical question, and record every source each one actually read. The analysis is the easy bit. Set overlap, count the domains, done. Getting the citations out of four different APIs in a shape you can compare — that's where I lost a weekend. Writing it up because I couldn't find this anywhere when I needed it. <h2> The problem </h2> All four providers will tell you which URLs they used. None of them agree on where to put that, what to call it, or even what a "URL" is. Here's roughly what each one gives you. (Shapes as of mid-2026 — they move, check the docs before you copy this.) OpenAI, Responses API with the web search tool. Citations ride along as annotations on the text output: <div class="highlight js-code-highlight"> <pre class="highlight javascript"><code>const urls = []; for (const item of resp.output ?? []) { for (const block of item.content ?? []) { for (const a of block.annotations ?? []) { if (a.type === "url_citation") urls.push(a.url); } } } </code></pre> </div> Anthropic, Messages API with the web search tool. Search results come back as their own content block type, separate from the text: <div class="highlight js-code-highlight"> <pre class="highlight javascript"><code>const urls = []; for (const block of msg.content ?? []) { if (block.type === "web_search_tool_result") { for (const r of block.content ?? []) { if (<s