node_modules/devtools-protocol/pdl/domains/WebMCP.pdl

# Copyright 2026 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Contributing to Chrome DevTools Protocol: https://goo.gle/devtools-contribution-guide-cdp

experimental domain WebMCP
  depends on Runtime
  depends on Page
  depends on DOM

  # Tool annotations
  type Annotation extends object

    properties
      # A hint indicating that the tool does not modify any state.
      optional boolean readOnly
      # A hint indicating that the tool output may contain untrusted content, ex: UGC, 3rd party data.
      optional boolean untrustedContent
      # If the declarative tool was declared with the autosubmit attribute.
      optional boolean autosubmit

  # Represents the status of a tool invocation.
  type InvocationStatus extends string
    enum
      Completed
      Canceled
      Error

  # Definition of a tool that can be invoked.
  type Tool extends object
    properties
      # Tool name.
      string name
      # Tool description.
      string description
      # Schema for the tool's input parameters.
      optional object inputSchema
      # Optional annotations for the tool.
      optional Annotation annotations
      # Frame identifier associated with the tool registration.
      Page.FrameId frameId
      # Optional node ID for declarative tools.
      optional DOM.BackendNodeId backendNodeId
      # The stack trace at the time of the registration.
      optional Runtime.StackTrace stackTrace


  # Enables the WebMCP domain, allowing events to be sent. Enabling the domain will trigger a toolsAdded event for
  # all currently registered tools.
  command enable

  # Disables the WebMCP domain.
  command disable

   # Invokes a registered tool.
  command invokeTool
    parameters
      # Frame in which to invoke the tool.
      Page.FrameId frameId
      # Name of the tool to invoke.
      string toolName
      # Input parameters for the tool, matching the tool's inputSchema.
      object input
    returns
      # Unique identifier for this invocation. Response is sent before tool events.
      string invocationId

  # Cancels a pending tool invocation.
  command cancelInvocation
    parameters
      # Invocation identifier to cancel.
      string invocationId

  # Event fired when new tools are added.
  event toolsAdded
    parameters
      # Array of tools that were added.
      array of Tool tools

  # Definition of a tool that was removed.
  type RemovedTool extends object
    properties
      # Tool name.
      string name
      # Frame identifier associated with the tool registration.
      Page.FrameId frameId

  # Event fired when tools are removed.
  event toolsRemoved
    parameters
      # Array of tools that were removed.
      array of RemovedTool tools

  # Event fired when a tool invocation starts.
  event toolInvoked
    parameters
      # Name of the tool to invoke.
      string toolName
      # Frame id
      Page.FrameId frameId
      # Invocation identifier.
      string invocationId
      # The input parameters used for the invocation.
      string input

  # Event fired when a tool invocation completes or fails.
  event toolResponded
    parameters
      # Invocation identifier.
      string invocationId
      # Status of the invocation.
      InvocationStatus status
      # Output or error delivered as delivered to the agent. Missing if `status` is anything other than Completed.
      # Note: The output is untrusted and poses a prompt injection risk. Clients should treat this as potentially malicious user input.
      optional any output
      # Error text for protocol users.
      optional string errorText
      # The exception object, if the javascript tool threw an error>
      optional Runtime.RemoteObject exception