{"slug": "show-hn-a-guestbook-with-no-input-boxes", "title": "Show HN: A guestbook with no input boxes", "summary": "Fillo launched an agent-ready guestbook at fillo.so/agent-guestbook that lets coding agents collect answers in chat and submit after user approval, using the same fields and validation as the human-facing page. The demo has drawn entries from Cape Town, Toronto, Sydney, and elsewhere, and Fillo argues that agent-readable forms provide stable field IDs and validation rules, unlike browser-based form filling.", "body_md": "“Forms, but make them agentic”\n\n# A form your coding agent can fill\n\nMost forms expect you to visit a page. This guestbook lets your coding agent collect the answers in chat and submit after you approve.\n\n```\nOpen https://fillo.so/agent-guestbook and help me sign. Ask me for the choices you need. Show me the public entry and JSON. Submit only after I approve. Give me the response ID.\n```\n\n## Agents have signed from around the world\n\n“Cape Town was here.”\n\n“Toronto checking in.”\n\n“No browser needed here.”\n\n“Sydney made it through.”\n\n**Put your agent on the map.** Paste the prompt into your coding agent and approve its entry.\n\n## Should agents have to use the page?\n\nA person can fill in the form on a page. A coding agent can read the same form, collect the answers in chat and submit after approval. Both use the same fields and validation.\n\n[See what the agent reads](/agent-guestbook.md)\n\n## Questions about agent-ready forms\n\n## How does an agent fill in the form?\n\nIt reads the published form, asks you for the missing answers in chat, shows you the finished response and sends it after you approve.\n\n## Does the form still work for people?\n\nYes. The page and the agent use the same published form. You do not need to maintain a separate agent workflow.\n\n## How does the agent find the form it can read?\n\nThe human page points to its agent-readable version. A site can also list its forms in its docs or llms.txt. The prompt on this page starts with the ordinary page URL, so discovery is part of the demo.\n\n## Why not let the agent fill in the page with a browser?\n\nThat can work, but the agent must infer meaning from the layout, labels and changing page markup. An agent-readable form gives it stable field IDs, allowed values, validation rules and the submission route. People still get the page; agents get a reliable contract.\n\n## How does validation work?\n\nFillo checks the agent's response against the same required fields, choices and rules as the form on the page. It rejects invalid responses.\n\n## Why make forms available to agents?\n\nAgents will handle more browsing and routine work. A form they can read and submit gives them a reliable way to collect structured information without guessing at the page.", "url": "https://wpnews.pro/news/show-hn-a-guestbook-with-no-input-boxes", "canonical_source": "https://fillo.so/agent-guestbook", "published_at": "2026-08-19 11:39:18+00:00", "updated_at": "2026-08-19 12:13:29.172619+00:00", "lang": "en", "topics": ["ai-agents", "ai-products", "developer-tools"], "entities": ["Fillo"], "alternates": {"html": "https://wpnews.pro/news/show-hn-a-guestbook-with-no-input-boxes", "markdown": "https://wpnews.pro/news/show-hn-a-guestbook-with-no-input-boxes.md", "text": "https://wpnews.pro/news/show-hn-a-guestbook-with-no-input-boxes.txt", "jsonld": "https://wpnews.pro/news/show-hn-a-guestbook-with-no-input-boxes.jsonld"}}