Ask your agent to "build a landing page and put it online" and it comes back with https://link.3ceng.cn/view/a1b2c3d4. No git repo, no build pipeline, no deploy config.

Kuailian is a Chinese-language hosting service. Account registration currently requires a mainland-China mobile number.

Setup

Sign in at link.3ceng.cn, open the MCP tab, and generate an API key.
Add the snippet below to your MCP client config (mcp.json for Cursor). The key is shown only once — store it somewhere safe.

{
  "mcpServers": {
    "kuailian": {
      "command": "npx",
      "args": ["-y", "@kuailian/mcp-server"],
      "env": {
        "KUAILIAN_API_KEY": "kl_live_xxx"
      }
    }
  }
}

Nothing to install and no service to keep running — your client spawns the server as a child process on demand over stdio and shuts it down afterwards. Publishing itself calls the Kuailian API, so an internet connection is required.

Environment variables

Variable	Required	Default
`KUAILIAN_API_KEY`	yes	—
`KUAILIAN_API_URL`	no	`https://link.3ceng.cn/api`
`KUAILIAN_SITE_URL`	no	`https://link.3ceng.cn`

Tools

Tool	What it does
`kuailian_publish_html`	Create and publish a page from `html` / `css` / `js`
`kuailian_update_page`	Update an existing code page (partial updates are safe)
`kuailian_publish_dir`	Zip and publish a local static directory such as `dist/`
`kuailian_update_dir`	Overwrite a folder site from a local directory
`kuailian_list_pages`	List your sites with view counts and origin
`kuailian_get_page`	Fetch one project's details and source
`kuailian_delete_page`	Move a project to trash
`kuailian_get_quota`	Check membership status and remaining quota
`kuailian_get_stats`	Traffic stats for a short link (paid feature)
`kuailian_check_slug`	Check custom `name.sites.3ceng.cn` availability (paid)
`kuailian_set_site_slug`	Set or clear custom subdomain (paid)

Publish tools accept optional slug (paid). Responses include url (/view/{shortId}) and share_url / custom_url when a slug is set.

Examples

Single page. kuailian_publish_html takes name plus any of html, css, js. Pass a full HTML document or just body markup. The whole request body is capped at 2 MB; beyond that you get CODE_SIZE_EXCEEDED and should switch to kuailian_publish_dir.

Partial updates. kuailian_update_page merges rather than replaces. Sending only js leaves the existing html and css untouched, so an agent iterating on one part of a page can't accidentally blank the rest.

Static build output. kuailian_publish_dir takes a path to a directory containing index.html; node_modules and .git are skipped automatically. On kuailian_update_dir the server refreshes the CDN cache for changed files — including CSS, JS, and images — so you don't need cache-busting query strings of your own.

Resources

The server also exposes reference documents your agent can read before acting:

kuailian://docs/limits — size and quota limits
kuailian://docs/kv-api — the key-value API available to published pages
kuailian://docs/publish-guide — how to choose between the publish tools

Errors and quotas

Failures come back as structured errors with a machine-readable code, so an agent can react instead of retrying blindly:

Code	Meaning
`CODE_SIZE_EXCEEDED`	Request body over 2 MB — use `kuailian_publish_dir`
`QUOTA_EXCEEDED`	Site or traffic quota used up
`FEATURE_LOCKED`	Paid-only feature; includes an `upgrade_url`
`NOT_MCP_PROJECT`	Site was created in the web app; delete it there instead
`INVALID_ID`	`project_id` is not a 24-character hex string

An API key can create, read, and update sites, but it may only delete sites that were created through MCP. Anything a user made by hand in the web app is off limits, which keeps an over-eager agent from destroying work it didn't create. Upgrades always happen in the browser — MCP cannot make a payment on the user's behalf.

Development

cd mcp-server && npm i && npm run dev

To point a client at your working copy, set command to npx and args to ["-y", "tsx", "<absolute path to mcp-server/src/index.ts>"], then override KUAILIAN_API_URL and KUAILIAN_SITE_URL to your local server.