@sqlrooms/app-runtime

@sqlrooms/app-runtime defines the iframe runtime bridge used by generated HTML apps in SQLRooms. It owns the protocol between a sandboxed app iframe and the SQLRooms host; it does not own project authoring, bundling, or WebContainer startup.

Runtime Scope

The first supported app surface is the html-app stateful block. The same bridge contract can also be reused by artifact shells and WebContainer previews, but the block remains the durable v1 state model.

The app-facing API is intentionally small:

const result = await window.sqlrooms.query(
  'select region, sum(revenue) as revenue from sales group by region',
);
console.log(result.rows);

TypeScript apps may use the client entrypoint:

import {createAppClient} from '@sqlrooms/app-runtime/client';

const app = createAppClient();
const result = await app.query('select * from sales limit 100');

Threat Model

Generated apps are treated as untrusted code. They run in a sandboxed iframe and must not receive direct access to DuckDB connectors, the room store, filesystem APIs, host DOM nodes, command execution, or mutation-capable host services.

The host grants explicit capabilities and handles every request. The initial capability set is deliberately narrow:

read-only query
optional table/schema discovery
optional initial data payloads

The v1 runtime explicitly excludes:

write queries
filesystem access
host DOM access
room store mutation
command execution
network access as an app-runtime capability

Read-only query handling starts with state.db.sqlSelectToJson as the SQL classification gate. Hosts should additionally enforce single-statement input, row limits, timeout handling, and JSON-serializable result bounds before data crosses into the iframe.

Relation To WebContainer

@sqlrooms/webcontainer answers how a generated project is authored, edited, built, and served. @sqlrooms/app-runtime answers what a rendered app can ask the SQLRooms host to do.

WebContainer previews can attach the same host bridge to their preview iframe, and generated Vite apps can import the client entrypoint or use an injected window.sqlrooms global. WebContainer should not grow its own separate data bridge.

Revision history follows the same boundary. The v1 revision model belongs to persisted html-app runtime state and does not migrate or version legacy WebContainer app project records such as appProject.config.appsByArtifactId. Those projects can be migrated to html-app state later, but they should not drive the shared runtime history API.

HTML App Blocks

The html-app block stores a small source file map instead of one opaque HTML string:

{
  "/index.html": "<!doctype html>...",
  "/src/app.js": "..."
}

entryHtmlPath points at the HTML file rendered through iframe.srcdoc; the default is /index.html. The host injects the app-runtime prelude before user scripts run, so generated apps can call:

HtmlAppState.intent can store the durable natural-language objective for a generated or edited app. Prefer this over storing raw model input in app state.

const {rows, columns, truncated} = await window.sqlrooms.query(
  'select category, count(*) as n from events group by category',
);

queryRows(sql) is available when an app only needs the plain object rows.

Dependencies are persisted as structured package/version entries:

[
  {
    package: 'd3',
    version: '7.9.0',
    entry: 'dist/d3.min.js',
    kind: 'script',
    global: 'd3',
  },
];

The v1 resolver turns these into jsDelivr URLs at render time. Persisted state keeps the structured entries so a future resolver can use import maps, bundling, local caching, or another dependency policy without rewriting app state.

Revision History

html-app state persists source revisions alongside the current source:

type HtmlAppRevision = {
  id: string;
  name: string;
  description?: string;
  sourcePrompt?: string;
  source: 'assistant' | 'user' | 'restore' | 'system';
  sessionId?: string;
  toolCallId?: string;
  commitGroupId?: string;
  parentRevisionId?: string;
  createdAt: number;
  title: string;
  intent?: string;
  files: Record<string, string>;
  entryHtmlPath: string;
  requestedCapabilities?: AppCapability[];
  grantedCapabilities?: AppCapability[];
  dependencies: HtmlAppDependency[];
};

Persisted HtmlAppState includes revisions, activeRevisionId, and redoRevisionIds. Older app states parse with empty history by default, so hosts can adopt revision-aware writes without a separate storage migration. Diagnostics are not stored in revisions because they describe current runtime observations and can be regenerated after restore or preview.

Query results are JSON-serializable:

type QueryResult = {
  rows: Record<string, unknown>[];
  columns: {name: string; type?: string}[];
  rowCount: number;
  truncated: boolean;
  executionMs?: number;
};

The host enforces read-only SELECT parsing, a single statement, row limits, and request timeouts before returning data to the iframe.

Later Capability Boundaries

The v1 bridge intentionally stops at bounded JSON query results. The following capabilities should remain out of the runtime until the read-only query path has proven useful and each addition has an explicit capability contract:

queryArrow() or streaming query results
selected artifact or block context reads
command invocation through SQLRooms command registries
generated asset save/export
mutation or write queries with user confirmation
dependency bundling, import maps, or local dependency caching

Those features should reuse the same request/response and diagnostic protocol rather than adding a second app-to-host channel.

Classes

AppRuntimeError

Type Aliases

Variables

Functions

References

AppCapabilityType

Renames and re-exports AppCapability

AppDiagnosticType

Renames and re-exports AppDiagnostic

AppDiagnosticLevelType

Renames and re-exports AppDiagnosticLevel

AppDiagnosticSourceType

Renames and re-exports AppDiagnosticSource

QueryColumnType

Renames and re-exports QueryColumn

QueryRequestType

Renames and re-exports QueryRequest

QueryResultType

Renames and re-exports QueryResult

RuntimeDiagnosticMessageType

Renames and re-exports RuntimeDiagnosticMessage

RuntimeErrorCodeType

Renames and re-exports RuntimeErrorCode

RuntimeErrorPayloadType

Renames and re-exports RuntimeErrorPayload

RuntimeMessageType

Renames and re-exports RuntimeMessage

RuntimeRequestMessageType

Renames and re-exports RuntimeRequestMessage

RuntimeRequestMethodType

Renames and re-exports RuntimeRequestMethod

RuntimeResponseMessageType

Renames and re-exports RuntimeResponseMessage

HtmlAppDependencyType

Renames and re-exports HtmlAppDependency

HtmlAppRevisionType

Renames and re-exports HtmlAppRevision

HtmlAppRevisionSourceType

Renames and re-exports HtmlAppRevisionSource

HtmlAppRuntimeConfigType

Renames and re-exports HtmlAppRuntimeConfig

HtmlAppSourceFileMapType

Renames and re-exports HtmlAppSourceFileMap

HtmlAppStateType

Renames and re-exports HtmlAppState

@sqlrooms/app-runtime ​

Runtime Scope ​

Threat Model ​

Relation To WebContainer ​

HTML App Blocks ​

Revision History ​

Later Capability Boundaries ​

Classes ​

Type Aliases ​

Variables ​

Functions ​

References ​

AppCapabilityType ​

AppDiagnosticType ​

AppDiagnosticLevelType ​

AppDiagnosticSourceType ​

QueryColumnType ​

QueryRequestType ​

QueryResultType ​

RuntimeDiagnosticMessageType ​

RuntimeErrorCodeType ​

RuntimeErrorPayloadType ​

RuntimeMessageType ​

RuntimeRequestMessageType ​

RuntimeRequestMethodType ​

RuntimeResponseMessageType ​

HtmlAppDependencyType ​

HtmlAppRevisionType ​

HtmlAppRevisionSourceType ​

HtmlAppRuntimeConfigType ​

HtmlAppSourceFileMapType ​

HtmlAppStateType ​