HTML/CSS to Image API for AI agents
Let AI agents capture live website screenshots, render HTML/CSS, and populate reusable templates as images or PDFs—without managing a browser.
This repository is a portable Agent Plugin package with client-specific manifests for the hosted HCTI MCP server at https://mcp.hcti.io. Authentication uses HCTI's browser-based OAuth flow; no API key or access token is stored in this repository.
Repository layout
| Path | Purpose |
|---|---|
plugin.json | Portable Agent Plugins manifest. |
mcp.json | Portable MCP configuration. |
.mcp.json | Claude Code, GitHub Copilot, and Grok-compatible MCP configuration. |
llms-install.md | Agent-readable installation guidance for Cline and other MCP clients. |
.codex-plugin/plugin.json | Native ChatGPT and Codex plugin manifest. |
.app.json | Maps the package to the official published OpenAI plugin. |
.claude-plugin/plugin.json | Claude Code plugin manifest. |
.cursor-plugin/plugin.json | Cursor Marketplace manifest. |
.grok-plugin/plugin.json | Grok Build marketplace manifest. |
gemini-extension.json | Gemini CLI extension manifest. |
kimi.plugin.json | Kimi Code plugin manifest. |
skills/hcti-image-generation/ | Image generation and template workflow guidance. |
skills/hcti-open-graph-images/ | Dynamic Open Graph image configuration guidance. |
clawhub/html-css-to-image/ | Standalone OAuth/MCP rendering skill for ClawHub. |
clawhub/hcti-open-graph-images/ | Standalone OAuth/MCP Open Graph skill for ClawHub. |
ChatGPT and Codex
Install the official HTML/CSS to Image plugin from the Plugins Directory in ChatGPT or Codex. This is the preferred OpenAI integration and uses HCTI's registered MCP connection with browser-based OAuth.
The native .codex-plugin/plugin.json manifest packages the shared HCTI skill, while .app.json maps the package to the published OpenAI plugin.
Kimi Code
Install the plugin directly from GitHub in Kimi Code:
/plugins install https://github.com/htmlcsstoimage/agent-plugins
/reload
Run /mcp-config login hcti and complete authorization in your browser. Then use /mcp to confirm that the HCTI tools are connected.
To test a local checkout, use /plugins install /path/to/agent-plugins. Kimi copies installed plugins into its managed plugin directory, so reinstall after changing the local source.
Gemini CLI
Install the extension directly from GitHub:
gemini extensions install https://github.com/htmlcsstoimage/agent-plugins
Restart Gemini CLI, run /extensions list to confirm the extension is enabled, then run /mcp auth hcti and complete authorization in your browser. Use /mcp list to confirm the HCTI tools are connected. Gemini CLI automatically discovers the included HCTI Agent Skills.
To test a local checkout during development, run gemini extensions link /path/to/agent-plugins, restart Gemini CLI, and inspect it with /extensions list.
GitHub Copilot
Install a local checkout
Install this repository directly:
copilot plugin install /path/to/agent-plugins
Start Copilot CLI and use /plugin list, /skills list, and /mcp to confirm that the plugin, skill, and HCTI server are available. Connect hcti from /mcp and complete authorization in your browser.
Cline
Give Cline the repository's llms-install.md to configure the hosted HCTI server, or add it manually as a remote Streamable HTTP server at https://mcp.hcti.io. Complete the OAuth authorization in your browser; no API key or local server installation is required.
Claude Code
Install from the Claude community marketplace
After the plugin is published, add Anthropic's community marketplace and install the plugin:
/plugin marketplace add anthropics/claude-plugins-community
/plugin install html-css-to-image@claude-community
/reload-plugins
Run /mcp, select hcti, and complete authorization in your browser. Claude can invoke the HCTI skill automatically when relevant; it is also available as /html-css-to-image:hcti-image-generation.
Test a local checkout
Validate and load this repository directly:
claude plugin validate . --strict
claude --plugin-dir .
In the test session, run /mcp to connect hcti, then try an image request. Use /reload-plugins after changing the manifest, skill, or MCP configuration.
Cursor
Install from the Cursor Marketplace
After the plugin is published, open Customize in Cursor, search for HTML/CSS to Image API, select Install, and choose the desired scope.
Open Cursor's MCP settings, find hcti, select Connect, and complete authorization in your browser. Start a new Agent chat after connecting so the HCTI tools are available.
Test a local checkout
Copy this repository into Cursor's local plugin directory:
mkdir -p ~/.cursor/plugins/local
cp -R /path/to/agent-plugins ~/.cursor/plugins/local/html-css-to-image
Restart Cursor or run Developer: Reload Window, then confirm that HTML/CSS to Image API appears in Customize. Connect the hcti MCP server from Cursor's MCP settings before testing an image request.
For another test cycle, replace the copied html-css-to-image directory with the current checkout and reload Cursor.
Grok Build
The xAI plugin marketplace points to this repository at a pinned commit. Its Grok manifest reuses the root skill, MCP endpoint, and assets.
After the marketplace entry is available, install HTML/CSS to Image in Grok Build, connect the hcti MCP server when prompted, and complete authorization in your browser.
ClawHub / OpenClaw
The ClawHub skill supports HTML/CSS rendering, website screenshots, PDF output, and saved-template rendering through the hosted MCP server. Users connect to https://mcp.hcti.io using browser-based OAuth; no API keys are required. Rendering requires an HCTI account and available credits.
The separate Open Graph skill creates persistent dynamic social-preview configurations and integrates their image URLs into website metadata. It includes the webpage integration reference and uses the same OAuth connection.
These standalone distributions live outside skills/ so other clients do not discover duplicate skills. Their setup instructions register the server in OpenClaw and complete OAuth; installing a skill alone does not establish the connection. Publish only the skill folder, not the whole plugin repository.
From this repository's root, with the current ClawHub CLI installed:
clawhub login
clawhub skill publish ./clawhub/html-css-to-image \
--slug html-css-to-image \
--name "HTML/CSS to Image" \
--categories integrations,creative \
--topics "screenshots,html,css,pdf,images" \
--dry-run
Preview the Open Graph skill separately:
clawhub skill publish ./clawhub/hcti-open-graph-images \
--slug hcti-open-graph-images \
--name "HTML/CSS to Image — Dynamic Open Graph Images" \
--categories integrations,development \
--topics "open-graph,social-previews,seo,images,html" \
--dry-run
After reviewing each preview, run its publish command without --dry-run. To publish under an organization, add --owner <your-clawhub-owner-handle> to both commands; otherwise the authenticated user owns the listing. Publication is separate from committing this repository, and new releases may wait for automated review.
ClawHub distributes published skills under MIT-0. Review those terms before the first publication; the hosted HCTI service remains subject to its own terms. See ClawHub publishing and skill format.
Included capabilities
The core rendering and template tools are:
| Tool | Purpose |
|---|---|
create_image | Render HTML and CSS as an image or PDF. |
create_url_image | Capture a public URL or selected page element. |
create_templated_image | Render a saved HCTI template with variable values. |
create_batch_images | Generate multiple image variations in one request. |
get_max_batch_size | Check the account's current batch limit. |
create_template | Save a reusable HTML/CSS template. |
update_template | Update an existing template. |
list_templates | List templates in the authorized account. |
list_template_versions | Inspect a template's version history. |
Managing resources with MCP
Beyond generating images, the HCTI MCP server can manage supporting resources in the connected organization:
| Resource | Tools | Purpose |
|---|---|---|
| Usage | check_usage | Check the organization's current image usage and limits. |
| Open Graph configurations | create_og_config, update_og_config, get_og_config, list_og_configs, delete_og_config | Manage dynamic social-preview images for pages on a website. |
| Proxies | create_proxy, update_proxy, get_proxy, list_proxies, delete_proxy | Manage proxies used when HCTI accesses source websites. |
| Storage destinations | create_storage_destination, update_storage_destination, get_storage_destination, list_storage_destinations, delete_storage_destination, get_aws_storage_external_id | Manage external destinations for generated images and retrieve the external ID needed for AWS setup. |
Dynamic Open Graph image configurations are an especially useful integration point. An agent can resolve an existing HCTI template, map page metadata into its variables, optionally select a configured proxy or storage destination, and create a persistent configuration for serving cached social images.
Resource tools operate on the HCTI organization selected during OAuth authorization, and available tools depend on the permissions granted to that connection. Listing and retrieval are read-only; create, update, and delete operations change the account. In particular, update_og_config replaces the complete configuration, so agents should retrieve the current configuration and preserve unchanged settings before updating it.
Example requests
- "Create a 1200×630 Open Graph image with this title and color palette."
- "Capture the pricing table on
https://example.com/pricing." - "List my HCTI templates and render the social-card template with this headline."
- "Create five product-card variations with different accent colors."
- "Create a dynamic Open Graph configuration for
https://example.comusing my social-card template and map its title and description from page metadata."
Data handling
Requests sent through the plugin are processed by the hosted HTML/CSS to Image service. HTML, CSS, template values, target URLs, rendering options, and resource configuration supplied to HCTI are sent to that service; persistent resources are stored in the connected HCTI organization. Do not provide cookies, authorization headers, private URLs, or other secrets unless intentionally configuring an authorized rendering workflow and you understand that HCTI will process that data.
License and service terms
The plugin files in this repository are available under the MIT License. The license applies to this repository's source code, configuration, and documentation; it does not license the hosted HTML/CSS to Image service. Use of the service is governed separately by the Terms of Use and Privacy Policy.
Validate
Run the repository checks:
node scripts/validate-template.mjs
Validate the Claude adapter with Claude Code's official strict validator:
claude plugin validate . --strict
Verified compatibility
The plugin runtime, shared HCTI skills, MCP discovery, and browser-based OAuth flow were tested with Claude Code 2.1.258. Use Claude Code 2.1.281 or newer for strict validation of directory listing metadata such as privacyPolicyUrl.
The Grok adapter is validated by the xAI marketplace's catalog and component-index checks against the pinned commit.
HOL Registry
Our AI agent plugins are registered in the HOL Plugin Registry, where you can review installation details, security findings, provenance, and the current trust score.
Documentation and support
- HTML/CSS to Image MCP documentation
- Official ChatGPT and Codex plugin
- OpenAI plugin packaging documentation
- Kimi Code plugin documentation
- Gemini CLI extension documentation
- GitHub Copilot plugin documentation
- Cline MCP installation instructions
- Cursor plugin documentation
- Cursor plugin reference
- Claude Code plugin documentation
- Claude Code plugin reference
- Support: support@htmlcsstoimage.com