@webcontextinterface/bridge API

Typed action dispatch with ActionResult feedback and optional PolicyEngine enforcement.

WciBridge

Session-scoped bridge: history, convenience methods, wci:state-change subscription.

constructor(root?: Element, options?: WciBridgeOptions)

Option	Type	Description
root	Element	Search root for [data-wci-id] targets. Default: document.body
options.policy	PolicyEngine	Enforce wci.txt rules on every dispatch

Subscribes to wci:state-change on document.

setPolicy(policy?: PolicyEngine): void

Attach or replace site policy (typically ctx.policy from WciContextLoader).

getPolicy(): PolicyEngine | undefined

dispatch(req: ActionRequest): Promise<ActionResult>

Runs policy checks when a PolicyEngine is set, then mutates the DOM.

Convenience methods

Method	Signature
fill	(nodeId, value: string)
click	(nodeId)
check	(nodeId, checked?: boolean)
select	(nodeId, value: string)

History and events

Method	Description
onStateChange(handler)	Subscribe; returns unsubscribe function
getHistory()	Copy of all session ActionResults
clearHistory()	Reset history

dispatchAction(req, root?, policy?): Promise<ActionResult>

Stateless dispatcher without history. Optional third argument applies the same policy rules as WciBridge.

Policy helpers

Function	Description
resolveScopeId(target, fallbackNodeId)	Scope from data-wci-scope or landmark ancestry
enforcePolicyForDispatch(policy, req, target)	Returns blocking ActionResult or null
checkPolicyBeforeDispatch(policy, req, root)	Resolve target in root, then enforce

Types

ActionRequest

interface ActionRequest {
  nodeId: string;
  action: 'click' | 'fill' | 'select' | 'check' | 'upload' | 'submit' | 'navigate' | 'focus' | 'clear';
  value?: string | boolean | number;
}

ActionResult

interface ActionResult {
  success: boolean;
  nodeId: string;
  action: string;
  value?: unknown;
  stateChange?: { before: Record<string, unknown>; after: Record<string, unknown> };
  sideEffects?: SideEffect[];
  error?: ActionError;
  timestamp: string;
}

ActionError.code

Code	When
NODE_NOT_FOUND	No [data-wci-id] match in root
SCOPE_DENIED	Scope denied or not on allow list
AUTH_REQUIRED	Scope requires authentication
HUMAN_CONFIRMATION_REQUIRED	Scope requires explicit user approval
PRECONDITION_UNMET	data-wci-precondition / disabled element
ACTION_NOT_SUPPORTED	Verb not supported for element type
VALIDATION_FAILED	Input validation failed
RATE_LIMITED	Rate limit exceeded
UNKNOWN_ERROR	Other failure

Other types

• SideEffect — { nodeId, change }
• StateChangeHandler — callback for wci:state-change
• WciBridgeOptions — { policy?: PolicyEngine }

Policy enforcement flow

1. Resolve target element by data-wci-id.
2. If policy is set, resolve scope and check deny / auth / human-confirmation.
3. Check data-wci-precondition and element disabled state.
4. Execute action; update data-wci-state; collect side effects.

Install

npm install @webcontextinterface/bridge

import {
  WciBridge,
  dispatchAction,
  resolveScopeId,
  type ActionResult,
  type WciBridgeOptions,
} from '@webcontextinterface/bridge';

Dependencies: @webcontextinterface/spec, @webcontextinterface/context

See also

• Action protocol
• Site policy