HTML hosting · API for agents
Go live straight from Claude Code or Codex in under a minute.
To get started, ask Claude Code or Codex to deploy your HTML file with https://ht-ml.app. Optimized for deploying prototypes, rich architecture diagrams, code reviews, decks, illustrations, and more straight from agentic environments. POST a single HTML document and get a public URL back instantly. No accounts, no dashboards, no API keys to provision.
Agent skill
Prefer a turnkey setup? The open html Agent Skill teaches your agent the whole workflow — create, update, assets, password protection — and bundles 20 ready-made page templates. One command installs it for Claude Code and Codex.
curl -fsSL https://raw.githubusercontent.com/nsmith/html/main/install.sh | sh
npx skills add nsmith/html
Open format (agentskills.io) · source & per-client install paths on GitHub.
Quickstart
Send your HTML to the API. The response hands you the public URL and the secret key you'll use for any later edits.
curl -X POST https://api.ht-ml.app/v1/sites \ -H "Content-Type: application/json" \ -d '{"html_content": "<h1>Hello from my agent</h1>"}'
{
"site_id": "{site_id}",
"url": "https://{site_id}.ht-ml.app/",
"update_key": "{update_key}",
"status": "active"
}
Read the live URL from the url field of your response — each site gets its own subdomain, https://{site_id}.ht-ml.app/, so relative asset paths just work (<img src="images/logo.png">). Keep the update_key secret — it's returned only once and grants write access.
The flow
POST html_content to /v1/sites. The HTML is scanned for unsafe content, then stored. You get back a site_id and an update_key.
GET /v1/sites/{site_id} to enumerate the assets your HTML references (images, video) and which are still missing.
For each missing asset, POST the file to /v1/sites/{site_id}/assets with your update_key as a Bearer token. Paths mirror the src in your HTML.
Reference
Base URL: https://api.ht-ml.app/v1. A machine-readable summary lives at /v1/help.
/v1/sites{"html_content": "<...>", "password": "<optional>"}site_id, update_key, url, statuspassword to make it private — use a unique, non-personal password (never the user's own), and remember it's a shared secret you'll give to everyone who should see the site./v1/sites/{site_id}status, the list of referenced assets, and helpful next-step endpointsAuthorization: Bearer <update_key>, or it returns 404./v1/sites/{site_id}Authorization: Bearer <update_key>{"html_content": "<...>", "password": "<optional>"}password to set it, "" to remove it, or omit to leave it unchanged./v1/sites/{site_id}/assetsrelative_path — the path exactly as it appears in your HTMLAuthorization: Bearer <update_key>multipart/form-data with the file/v1/helpConversational errors
Errors don't just fail — they tell an agent how to recover. Every error response includes an actionable message.
| Code | Name | Meaning & recovery |
|---|---|---|
| 401 | Unauthorized (write) | Missing or invalid update_key. Send Authorization: Bearer <update_key>. |
| 401 | Unauthorized (read) | The site is password-protected. Send the password as a cookie ht_ml_pwd=<password> to read it. |
| 403 | Forbidden | The asset path isn't referenced in the HTML, or the key is wrong. |
| 422 | Unprocessable | The HTML failed a safety scan. Read message and revise. |
Agent-native
WebMCP
If you're an in-browser agent, this page registers a WebMCP tool named publish_html_site via navigator.modelContext / document.modelContext. Call it with html_content and it publishes the site and returns the URL — no manual HTTP required.
/llms.txt — a concise, LLM-optimized reference you can read in one fetch./v1/help — the API describes itself in JSON.schema.org/WebAPI + HowTo) is embedded in this page for crawlers and answer engines./robots.txt.