kiln

---

name: kiln description: Build a GoFastr web app live by calling Kiln over HTTP. Use ONLY on explicit Kiln signals — $KILN_URL env var set, the user names Kiln ("kiln serve", "the kiln world", "kiln freeze"), or IR-mutation phrasing against a running Kiln. Do NOT trigger on "GoFastr" alone or on generic "build me an app" requests: a user building with the framework directly writes Go against framework/ and this skill would mis-route them into HTTP IR mutations.

You are driving a live GoFastr Kiln server. Mutate the application only through Kiln tools at $KILN_URL; do not edit the repository or start another server.

Workflow

1. Call world_get before changing anything.
2. Make the smallest coherent tool calls that satisfy the user's request.
3. Read the returned structured result. On a conflict or validation error, follow its hint and retry; never claim success after a failed call.
4. Read world_get again and verify the exact entity/page/config state.
5. For a destructive delete, propose a plan with the exact target and wait for approval before calling the delete tool with that plan_id.

The HTTP form is:

curl -sS -X POST "$KILN_URL/kiln/tool/add_entity" \
  -H 'Content-Type: application/json' \
  -d '{"entity":{"name":"notes","fields":[
    {"name":"text","type":"string","required":true}
  ]}}'

Prefer native tool calling when available; HTTP and MCP reach the same typed dispatcher.

Current routing contract

Entity CRUD defaults to /api/<entity>; HTML screens use bare paths. An entity posts and a screen /posts intentionally coexist. Forms targeting the entity must post to /api/posts, not /posts.

set_app_config replaces app config. Its HTTP payload must wrap every field under config; a flat payload is invalid:

curl -sS -X POST "$KILN_URL/kiln/tool/set_app_config" \
  -H 'Content-Type: application/json' \
  -d '{"config":{"name":"my-app","module":"example.com/my-app","db_driver":"sqlite","db_url":"app.db","api_prefix":"api"}}'

Include a name and module before freeze. An omitted or empty api_prefix inside config resolves to api.

Entities

Use the current declaration fields: fields, relations, endpoints, soft_delete, owner_field, cross_owner_read, search_fields, access, timestamps, crud, mcp, cursor_field/cursor_fields, indices, and properties.

For per-user data, set owner_field to the user foreign-key column. Do not set multi_tenant: true: Kiln cannot choose a tenant resolver and will reject it. That integration belongs in owned Go after freeze.

Screens

Send a complete, non-empty tree in add_page. Use design-system kinds for layout and styling:

• page_header, hero, section, card
• stack, cluster, grid, stat_row, stat_grid, stat_card
• link_button, callout, divider

Use semantic leaf kinds only for their HTML meaning: heading, paragraph, text, link, form, label, input, button, list and table elements. Never send class, style, or on* props. They are rejected because styling and interaction belong to GoFastr's shared component/runtime surfaces.

Example:

{
  "page": {
    "path": "/",
    "name": "home",
    "title": "Home",
    "layout": {"name": "marketing"},
    "tree": {
      "kind": "stack",
      "props": {"gap": "xl"},
      "children": [
        {"kind": "hero", "props": {
          "eyebrow": "GoFastr",
          "title": "Build the app you can own",
          "subtitle": "Live first, plain Go when you freeze."
        }},
        {"kind": "section", "props": {
          "heading": "What ships", "description": "One current blueprint"
        }, "children": [
          {"kind": "grid", "props": {"min": "16rem", "gap": "lg"},
           "children": [
            {"kind": "card", "props": {"heading": "REST + OpenAPI"}},
            {"kind": "card", "props": {"heading": "SSR + hydration"}}
          ]}
        ]}
      ]
    }
  }
}

Kiln assigns _id values and a page version. Use update_page_element for later surgical edits; pass the current version as if_match when possible.

Scaffold surfaces

Use set_scaffold to replace navigation and owned-Go stubs:

{
  "nav": [{"label":"Dashboard","href":"/dashboard"}],
  "endpoints": [{"name":"health","method":"GET","path":"/healthz"}],
  "middleware": [{"name":"request_logger"}],
  "plugins": [{"name":"metrics"}],
  "helpers": [{"name":"slug"}]
}

Navigation renders live. Endpoint/middleware/plugin/helper declarations become editable Go stubs in the generated scaffold.

Behavior: hooks, routes, seeds

Declarative behavior uses these tools (same dispatcher as everything else):

• add_hook(hook) / delete_hook(id) — entity lifecycle hooks. when is one of before_create, after_create, before_update, after_update, before_delete, after_delete, before_list, after_list. A hook has an id, an entity, a when, an optional condition (expression), and an action.
• add_route(route) / delete_route(method, path) — declarative HTTP routes.
• add_seed(seed) — insert seed rows: {"entity":"posts","rows":[{...}]}.
• undo — revert the most recent journal entry.

Action kinds (params are action-specific): noop; validate { expression, message } — errors with the message when false; set_field { field, value } (expression) or { field, value_literal }; audit { channel, message }; emit_event { topic, data }; respond_json (routes only) { status, body }.

The expression language covers condition, value, message, and string-typed body: literals (numbers, strings, true/false/null, lists), operators + - * / %, == != < > <= >=, && || !, member access (entity.title, ctx.user.role, result.id), and built-ins len, lower, upper, contains, starts_with, ends_with, abs, min, max, now(). Hook scope: entity (the row), ctx (request), result (after_* only).

curl -sS -X POST "$KILN_URL/kiln/tool/add_hook" \
  -H 'Content-Type: application/json' \
  -d '{"hook":{"id":"posts-slug","entity":"posts","when":"before_create",
    "action":{"kind":"set_field","params":{"field":"slug","value":"lower(entity.title)"}}}}'

Theme

set_theme accepts semantic light color tokens such as primary, primary-fg, background, surface, surface-soft, text, text-muted, border, accent, success, warning, danger, and info. Prefer the default adaptive theme unless the user requested a brand palette. Dark tokens are part of set_app_config.config.theme_dark.

Freeze boundary

When the user wants source, tell them to run:

kiln freeze --diff
kiln freeze --dir build
gofastr validate build/gofastr.yml
gofastr generate --from=build/gofastr.yml --out=app

Freeze emits gofastr.yml and the lossless world.json; it does not emit the removed entities/*.json format. Declarative behaviors that need a Go function graduate as named owned-Go stubs, with the exact IR retained in world.json.