Writing code is cool, but wouldn't it be cooler to type "build me a plugin showing populations around the world" and it Just Worked?
Now you can.
Requirements
This feature is in public beta.
Agent currently requires an API Key from OpenRouter. You can load credits on their billing portal.
Alternatively, if you have a Claude API account with higher rate limits you can buy credits directly and use an Anthropic API Key.
Optionally, a free Tavily API key can give your agent access to web search and web page fetching, enhancing your agents capabilities.
In the near future you'll be able to purchase credits directly from TRMNL.
Quickstart
How it works
TRMNL has developed a comprehensive system prompt written in plain English, which describe our platform's capabilities and design patterns in depth.
Whenever you interface with the Agent inside our private plugin interface, the agent has access to this context, which you may even ask it about.
In addition, the agent has been given access to a range of tools, including markup editing, settings updates, data refreshing, internet search, and a list of API endpoints to name a few. This empowers and grounds the agent in the "real world" to add value to your experience.
MCP Server (Advanced)
Prefer building plugins from your own editor with Claude, Cursor, or another AI tool?
TRMNL exposes an MCP (Model Context Protocol) server that gives your local agent the same powers as our built-in Agent: reading and writing your plugin's markup, refreshing live data, taking screenshots, viewing merge variables and logs, searching recipes, and consulting our design system docs.
Get your MCP API Key
Claude Code (CLI)
Run this in your terminal, substituting your key:
Start a Claude Code session and type /mcp — you should see trmnl listed as connected. Then just ask: "show me my plugin's markup," "refresh my data and screenshot the full layout," and so on.
By default this registers the server for your current project folder only; add --scope user to make it available everywhere. The Claude Code desktop app reads the same
configuration, so no extra setup is needed there.
Claude Desktop (chat app)
Your key goes in the URL here because Claude Desktop's connector form doesn't reliably pass custom auth headers. If you'd rather keep the key in a header, use the config file instead: Settings > Developer > Edit Config, add the snippet below (requires Node.js 18+), then fully restart Claude Desktop.
Good to know
Frequently Asked Questions
Which models does this feature support?
Gemini, Codex, Claude Sonnet, Kimi, and even OSS models (e.g. Llama). Set a preferred model from your Account > Agent configuration.
How much does it cost to build a plugin?
We're seeing an average of $1-3 per plugin.
For example, plugin can be created with a single sentence prompt: make a daily deal plugin for meh.com. After thinking and developing for a couple minutes, Agent required us to provide a free Meh.com API Key, then we requested that the daily deal item's image be included. Total cost: $2.20 USD.
Can I publish plugins with this feature?
Not currently. Our team reviews several plugin submissions per day and we need to scale internal tools before we can handle the inevitable Agent-driven volume bump.
Can I use other llm models (including free ones)?
Yes, even though Claude Sonnet 4.6 was used in developing this Agent, other state-of-the-art models like Gemeni 3.1 Pro are excellent replacements. Feel free to experiment with any OpenRouter model ID. The free models on OpenRouter tend to be less capable and slower.
Troubleshooting
Agent isn't perfect. Send us a live chat or email [email protected] if (when) you discover bugs or quirks.