v1, alpha

Template + data source,
one declarative file.

Canvakit is the open standard for agent-rendered UIs that update from live data without re-emitting HTML. Declare tools, files, queries, or static values in YAML frontmatter. Render with Mustache, MDX, or any engine that speaks (body, context) => string.

npm i -g canvakit

A canvakit template

---
template: true
name: hello
version: 0.1.0
dataSources:
  flights:
    kind: tool
    ref: searchFlights
    params: { origin: LHR, destination: JFK }
  header:
    kind: static
    value: "Welcome back"
---
<h1>{{header}}</h1>
<ul>
  {{#flights.flights}}
    <li>{{airline}} — {{price}}</li>
  {{/flights.flights}}
</ul>

The template declares its tool dependencies. Any runtime that can resolve tool names — Mastra, MCP clients, Vercel AI SDK, or a CI job with fixtures — can render it. Re-run a tool → re-render the template → the UI updates. No new HTML emission. No new agent turn.