{"version":1,"type":"story","url":"https://digestai.news/story/zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo","json":"https://digestai.news/story/zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo.json","markdown":"https://digestai.news/story/zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo.md","slug":"zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo","headline":"Zapier finds Claude Code uses Markdown mirrors and hidden Haiku 4.5 model","summary":"Zapier built a tool to test how AI agents like Claude Code interpret its integration pages. By comparing production and preview versions of the Slack integration page, they discovered Claude’s WebFetch tool first requests Markdown mirrors—even when HTML is stripped—before passing content to a separate Haiku 4.5 model for summarization. This hidden processing layer applies its own rules, like a 125-character quote limit, altering what reaches the final response. The findings reveal agents don’t always use the raw page content and that Markdown versions are already part of the request path, not just an optimization.\n\nThe experiment used a Docker-based proxy to isolate variables, running the same Claude Code prompt against both versions. When the HTML variant was emptied, the agent still returned detailed integration data, traced back to the Markdown mirror. The Haiku 4.5 model’s instructions—such as paraphrasing rules—further filtered the content before it reached the top-level Claude model. Zapier now plans to study how document structure and page depth affect agent behavior across other page types and agent tools.","keyPoints":["Claude Code’s WebFetch fetches Markdown mirrors first, even if HTML is empty, revealing hidden request paths","Haiku 4.5 processes fetched content under its own instructions before returning results to Claude Code","Quote limits and paraphrasing rules in Haiku’s instructions alter what agents ultimately share with users"],"whyItMatters":"This shows how AI agents process content in layers, with hidden models and instructions shaping responses. Websites must test both HTML and Markdown versions to predict agent behavior, and content creators need to account for unseen processing steps.","category":{"slug":"agents","name":"Agents & Tools","url":"https://digestai.news/category/agents"},"entities":{"companies":["Zapier"],"models":["Claude Code","Opus 5","Haiku 4.5"],"people":[]},"firstPublishedAt":"2026-11-06T05:00:00Z","updatedAt":"2026-11-06T05:00:00Z","sourceCount":1,"hasPrimarySource":false,"sources":[{"outlet":"Zapier Blog","title":"What we learned by watching Claude read Zapier.com","url":"https://zapier.com/blog/what-we-learned-watching-claude-read-zapier","publishedAt":"2026-11-06T05:00:00Z","type":"press","primary":false,"lead":true}],"sourceNotes":null,"discussions":[],"thread":{"title":"AI Tools Empower Non‑Coders to Build Games","url":"https://digestai.news/thread/user-builds-and-publishes-browser-rpg-in-one-day-using-claude-code-pixai-and","storyCount":6},"cite":{"text":"Digest AI, \"Zapier finds Claude Code uses Markdown mirrors and hidden Haiku 4.5 model\", 6 November 2026, https://digestai.news/story/zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo","publisher":"Digest AI","title":"Zapier finds Claude Code uses Markdown mirrors and hidden Haiku 4.5 model","datePublished":"2026-11-06T05:00:00Z","url":"https://digestai.news/story/zapier-finds-claude-code-uses-markdown-mirrors-and-hidden-haiku-4-5-mo"},"generatedBy":"Written by Digest AI's editorial model from the linked sources; the sources are the record.","license":"Headlines, digests and key points are written by Digest AI and may be quoted with a link to the story page. Linked articles belong to their publishers. Terms: https://digestai.news/terms#reuse"}