For agents

Each component ships with rules for when to use it and when not to. Your coding agent can read them as text, over MCP, or from the install itself.

Docs as text

/llms.txt is the index. It links one markdown page per component and block.
/md/button.md is one component's page. Each one says when to use the component, when not to, its props, its accessibility notes, and examples.
/llms-full.txt has every page and the theme rules in one file.

MCP server

A read-only MCP server lives at https://txbrendan.dev/mcp. It speaks Streamable HTTP and has three tools:

list_components lists every component with a one-line description.
get_component returns one component's rules, props, install steps, and examples.
get_theme_rules returns the tones, tokens, and contrast pairs.

The tools do not list blocks yet. For blocks, use llms.txt.

To add it to Claude Code:

claude mcp add --transport http txbrendan https://txbrendan.dev/mcp

Other clients take the same URL as an HTTP server.

To give your agent your own theme, add it to the URL. A theme ID is your brand color as six lowercase hex digits, then round, soft, or sharp corners. Add -pill at the end for pill buttons and fields. The server then tells your agent to install your theme in place of ours. To pick yours and get the commands, go to Set up your agent.

claude mcp add --transport http txbrendan "https://txbrendan.dev/mcp?theme=0f766e-soft"

To install the same theme without an agent:

npx shadcn@latest add https://txbrendan.dev/r/themes/0f766e-soft.json

Each theme is checked against the same contrast pairs as ours.

Rules in every install

Each registry item carries the same rules as its page. So an agent that installs a component gets its rules from the same command. The install steps are the same for people and agents.

Some rules are in the types, too. For example, an icon-only button fails to compile without an aria-label.

Rules for your repo

To keep these rules in front of your agent on every task, paste them into your repo's AGENTS.md or CLAUDE.md. Change them to fit.

## UI

- Build UI with txbrendan/ui. Read https://txbrendan.dev/llms.txt before you start.
- Install in this order: the registry, the theme, then each component.
- Read a component's "Use it for" and "Avoid it for" lists before you use it.
- Use theme tokens for color. Never use palette classes, raw colors, or dark: classes.
- Look at each page in light and dark, at desktop and phone width.