MCP server

this site, not the package

This site answers to agents as well as to people. One read-only endpoint, its tools and four resources, over the same bytes the pages render.

Public, unauthenticated and read-only Every tool is annotated readOnlyHint, so a client that honours the hint calls them without prompting, and there will never be a tool that writes — enforced by a test.

Add it

One URL. Streamable HTTP, no key, no install.

Any MCP client

The endpoint is https://www.sedna-ui.com/mcp. It is stateless, so a client may reconnect or fan out across processes without leaving sessions behind.

{
  "mcpServers": {
    "sedna-ui": {
      "type": "http",
      "url": "https://www.sedna-ui.com/mcp"
    }
  }
}

Claude Code

Or add it to a project's .mcp.json with the block above.

claude mcp add --transport http sedna-ui https://www.sedna-ui.com/mcp

The tools

One verb each, no overlap, shaped around one workflow: an agent writing a page in a consuming app and needing the exact markup plus enough semantics to pick the right variant — then checking what it wrote, and upgrading the app later.

Tool	What it answers
`search`	“What is there for a sortable table with status badges?” Ranks examples, classes, tokens and pages together. Returns references, never markup.
`get_example`	The markup for up to five examples, byte-for-byte what this site renders. Valid in a `.razor` page and an `.html` file alike.
`describe_class`	What a class actually does: the declarations from the shipped stylesheet, its cascade layer, its modifiers, and which examples use it. Also the way to check a class your app already styles before upgrading; a class a release renamed comes back with the classes that replace it.
`get_page`	Every example on one page — one call instead of five. With no id, the page list.
`get_tokens`	The tokens as an ordered array of blocks, media condition included, for writing `brand.css`.
`get_integration_guide`	The host page and its load order, the branding recipe, the JavaScript and C# surface, the rules a consuming app follows, the graph's or the rich-text editor's reference, or — with `"upgrade"` — every class each release renamed, old name to the classes that look the same.
`check_markup`	For markup the agent wrote: every class the stylesheet does not declare, with the nearest library class in case it is a typo; every class a release renamed or removed, judged against the installed version; every class newer than it; and every icon the font does not have. Classes only — it does not judge structure.
`get_changes`	What two releases differ by: every class, token and public C# member added and removed, every rename, and each release in between with a link to its notes, where the breaking changes are listed first. `to: "main"` includes what is merged and in no release yet.
`describe_api`	The C# and script API, member by member: a type's members, a member's signatures, its documentation, the release it first shipped in and the examples that use it — `ISednaUi.ShowModalAsync`, or `sednaUi.toast`.

The whole loop

search → get_example → describe_class. Nothing else is needed to write a page; check_markup then checks it.

search { "query": "filter bar above a sortable table", "installedVersion": "0.2.0" }

  → hits: [ { kind: "page",    ref: "/toolbar", title: "Toolbar",    score: 78 },
            { kind: "example", ref: "Toolbar/FilterBar",   classes: ["toolbar", "toolbar-field", …] },
            { kind: "example", ref: "Table/SortableTable", classes: ["table", "table-sortable", …] },
            { kind: "class",   ref: ".table-sticky", blurb: "In layer sedna.paint. Used by 2 example(s)." } ]

get_example { "ids": ["Toolbar/FilterBar", "Table/SortableTable"] }

  → the markup, byte-for-byte what this site renders, plus every class it uses
    and the release each one first shipped in.

describe_class { "names": ["table-sortable", "col-num"] }

  → the declarations the shipped stylesheet holds for each, its cascade layer,
    its modifiers, and which examples use it.

`describe_class`

Up to ten class names per call. The declarations come from the stylesheet the running app serves, and usedByExamples points at the pages that show the class in context.

describe_class { "names": ["health-badge", "stat-target"], "installedVersion": "0.4.0" }

{
  "meta": {
    "branch": "main",
    "commit": "9ac438c",
    "builtUtc": "2026-08-03T11:20:44Z",
    "latestRelease": "0.4.0",
    "installedVersion": "0.4.0",
    "warning": "2 of these are not in 0.4.0: .health-badge, .stat-target. Upgrade Sedna.UI, or use something else."
  },
  "classes": [
    {
      "name": ".health-badge",
      "layer": "sedna.paint",
      "declarations": ["display: inline-flex", "align-items: center", "gap: var(--space-3)", "…"],
      "modifiers": [".health-badge--live", ".health-badge--streaming", ".health-badge--down"],
      "usedByExamples": ["/status#a-connection-s-state"],
      "since": "unreleased"
    },
    {
      "name": ".stat-target",
      "layer": "sedna.paint",
      "declarations": ["font-size: var(--text-2)", "color: var(--muted)"],
      "modifiers": [],
      "usedByExamples": ["/stat#target-link-and-unavailable"],
      "since": "unreleased"
    }
  ],
  "notFound": []
}

# `declarations` is read from the stylesheet the running app serves, so it is
# what ships rather than a transcription. `since` comes from the git tags via
# build/class-history.sh, and `meta.warning` names everything in the answer
# that the version you passed does not have — so an agent can tell "copy this"
# from "upgrade first" without asking. At most ten names per call.

The four resources

Whole artefacts, addressable by URI. A resource is attached by the person rather than pulled by the model. Nothing is resource-only: get_tokens and get_integration_guide duplicate two of these, because clients vary widely in resource support.

URI	Type	What it is
`sednaui://stylesheet`	`text/css`	The whole shipped stylesheet, exactly as the package delivers it.
`sednaui://tokens`	`application/json`	The token export, as an ordered array of blocks.
`sednaui://version`	`application/json`	What this catalogue was built from, and the latest released version.
`sednaui://docs/{name}`	`text/markdown`	Any file in the repository's `docs/`, by name without `.md` — `getting-started`, `architecture`, `CLAUDE.consuming-app` and the rest. A wrong name is answered with the list.

Say which version you have

This site is built from main and can be ahead of any release, so every tool that answers with classes, tokens, examples or API takes installedVersion. Pass it and the meta.warning block names everything in the answer your version does not have — including anything with no since at all, which is in no release yet. The results still come back.

Limits

They apply to /mcp alone, never globally — a global limiter would also count this site's own SignalR upgrades. A rejected call answers 429 with Retry-After: 60.

Limit	Value	Why
Concurrent requests	64, plus 32 queued	The actual control. Not partitioned, so there is nothing to spoof around.
Per caller	240 burst, 120/min	Fairness, not security: behind a proxy whose addresses we do not control, per-IP limiting is not a security measure.
Request body	256 KB	JSON-RPC calls here are a few hundred bytes.
Per call	25 / 5 / 10	Hits from `search`, ids per `get_example`, names per `describe_class`. Markup is capped at 8 KB per example and cut at a tag boundary, so a truncated response still parses. `describe_api` takes 10 names, and `check_markup` up to 64 KB of markup.

Then give the agent the rules

The server answers questions. It does not stop an agent inventing a class name or wrapping a table in a component — so copy docs/CLAUDE.consuming-app.md (opens in a new tab) into your app's own CLAUDE.md, or fetch it through get_integration_guide { "section": "rules" }.