For developers

REST API documentation

Publish and update HTML pages straight from code and AI pipelines. Publish and update static sites and HTML pages from code and AI pipelines. Available on every plan, including Free, with an API key.

Create an API key →Download OpenAPI

Authentication

Every request needs an API key in the Authorization header. Create the key in your dashboard on the “API keys” page — it is shown only once. A request without a valid key is rejected with 401 invalid_api_key.

The base address of every endpoint is https://htmlkin.io/api/v1. Add this header to each request:

"Authorization: Bearer <api_key>"

The API is available on every plan, including Free. Create a key in your dashboard on the “API keys” page — it is shown only once.

Rate limits

Request rates are limited by plan, per account: all its keys share one counter. Over the limit you get 429 rate_limit_exceeded with a Retry-After header.

Plan	Limit
Free	10 requests per minute, up to 60 site uploads an hour together with the dashboard, one update per site a minute
Pro	60 requests per minute
Business	120 requests per minute

Endpoints

POST/api/v1/pages

Publish a page

Uploads an HTML file or a static site ZIP and publishes it on its own subdomain. Send exactly one of html_file and site_archive. A random subdomain is assigned by default; set your own in the subdomain field.

Request body multipart/form-data

Field	Type	Required	Description
html_file	file	no	A single HTML file, saved as index.html. Exactly one content source.
site_archive	file	no	A static site ZIP: the entry page is the root index.html or the first HTML file in the archive root. The unpacked site must be up to 200 MB and fit in the free storage space.
subdomain	string	no	Preferred subdomain ({subdomain}.htmlkin.io), 3–63 characters a-z, 0-9, “-” (not at the ends). 409 if taken.
pin	string	no	A 4-digit PIN (0000–9999) to protect viewing. On paid plans.
visibility	string	no	Who can open the site: public — anyone, search engines index it; link — anyone with the link, not indexed; team — the account's team members after signing in, on the Business plan; private — only the account owner after signing in. Defaults to public.

Example request

curl -X POST https://htmlkin.io/api/v1/pages \
  -H "Authorization: Bearer $HTMLKIN_API_KEY" \
  -F "html_file=@index.html" \
  -F "subdomain=mypage"

Response 201

{
  "id": "abc123",
  "url": "https://mypage.htmlkin.io",
  "expires_at": null,
  "created_at": "2026-06-14T07:00:00Z",
  "updated_at": "2026-06-14T07:00:00Z",
  "file_count": 1,
  "entry_path": "index.html",
  "visibility": "public"
}

PUT/api/v1/pages/{id}

Update a page

Replaces the whole site with new HTML or ZIP at the same address and/or changes the PIN and visibility. The page URL stays the same. Send at most one of html_file and site_archive; you can send only pin and/or visibility to change just protection or visibility.

Request body multipart/form-data

Field	Type	Required	Description
html_file	file	no	A new HTML file (optional; not together with site_archive).
site_archive	file	no	A new complete site ZIP; all previous files are replaced.
pin	string	no	4 digits set or change the PIN; an empty string removes it.
visibility	string	no	Who can open the site: public — anyone, search engines index it; link — anyone with the link, not indexed; team — the account's team members after signing in, on the Business plan; private — only the account owner after signing in.

Example request

curl -X PUT https://htmlkin.io/api/v1/pages/abc123 \
  -H "Authorization: Bearer $HTMLKIN_API_KEY" \
  -F "html_file=@index.html"

Response 200

{
  "id": "abc123",
  "url": "https://mypage.htmlkin.io",
  "expires_at": null,
  "created_at": "2026-06-14T07:00:00Z",
  "updated_at": "2026-06-14T07:10:00Z",
  "size_bytes": 12345,
  "file_count": 8,
  "entry_path": "index.html",
  "pin_protected": false,
  "visibility": "public"
}

GET/api/v1/pages/{id}

Get page details

Returns page metadata: address, site size, file count, entry point, lifetime, PIN protection and visibility.

Path parameters

Parameter	Description
id	Page ID.

Example request

curl -X GET https://htmlkin.io/api/v1/pages/abc123 \
  -H "Authorization: Bearer $HTMLKIN_API_KEY"

Response 200

{
  "id": "abc123",
  "url": "https://mypage.htmlkin.io",
  "expires_at": null,
  "created_at": "2026-06-14T07:00:00Z",
  "updated_at": "2026-06-14T07:10:00Z",
  "size_bytes": 12345,
  "file_count": 8,
  "entry_path": "index.html",
  "pin_protected": false,
  "visibility": "public"
}

DELETE/api/v1/pages/{id}

Delete a page

Deletes the page permanently. If a custom domain was attached to the page, the domain stays in the account — only its link to this page is removed.

Path parameters

Parameter	Description
id	Page ID.

Example request

curl -X DELETE https://htmlkin.io/api/v1/pages/abc123 \
  -H "Authorization: Bearer $HTMLKIN_API_KEY"

Response 200

{
  "id": "abc123",
  "deleted": true
}

Error codes

The error body is always the same: { "error": "<code>", "message": "<description>" }.

HTTP	error	Description
400	invalid_file	The single file doesn't look like HTML.
400	invalid_site	Invalid combination of sources or an invalid set of site files.
400	invalid_archive	The ZIP is damaged, encrypted or uses an unsupported format.
400	invalid_path	Invalid, unsafe or duplicate file path.
400	missing_entry_file	There is no HTML file in the site root.
400	too_many_files	The site has more than 500 useful files.
400	banner_removal	A site file contains code that removes the htmlkin promo bar; the bar goes away on a paid plan.
400	invalid_pin	The PIN is not 4 digits.
400	invalid_visibility	visibility is not one of public, link, team, private.
400	invalid_subdomain	The subdomain has invalid characters (allowed: a-z, 0-9, “-”).
401	invalid_api_key	Invalid or missing API key.
403	account_banned	The account has been blocked for violating the terms of service.
403	team_visibility_requires_plan	team is available on the Business plan.
403	content_blocked	The entry page (index.html) is byte-for-byte identical to a page of a site blocked for violating the terms of service.
403	dangerous_link	The page links to a URL that Google Web Risk flags as phishing or malware.
403	page_limit_exceeded	The plan's active site limit has been reached.
404	not_found	The page was not found or belongs to another owner.
409	subdomain_taken	The requested subdomain is already taken.
413	file_too_large	The unpacked site is larger than 200 MB, the limit for a single upload.
413	storage_limit_exceeded	The site doesn't fit in the storage: together with the account's other active sites it would exceed the plan's storage. On update, the space of the site's current version counts as free.
429	rate_limit_exceeded	Too many requests; the response has a Retry-After header.

Testing and client generation

The API is described by a machine-readable OpenAPI 3.1 spec. Import it to send requests interactively and generate a ready-made client for your language:

Swagger UI / Postman — paste https://htmlkin.io/api/v1/openapi.json, set the Bearer key and call endpoints right from your browser.
openapi-generator — generate an SDK for Python, TypeScript, Go and other languages with a single command from the same spec.

Publishing from AI assistants (MCP)

The same API is available through the MCP server https://htmlkin.io/mcp — Claude and other assistants publish and update sites right from the chat, with your API key. Nothing to install or run.

Set up the MCP server →