> ## Documentation Index > Fetch the complete documentation index at: https://kernel.sh/docs/llms.txt > Use this file to discover all available pages before exploring further. # Discover WebMCP tools across the browser > Returns a snapshot of native WebMCP tools available across every open tab and embedded frame in the browser. Each tool includes an opaque tool_ref for invoking that exact live registration. Tools disappear when their document closes or navigates away. ## OpenAPI ````yaml https://api.onkernel.com/spec.json get /browsers/{id_or_name}/webmcp/tools openapi: 3.1.0 info: description: Developer tools and cloud infrastructure for AI agents to use web browsers title: Kernel API version: 0.1.0 servers: - description: API Server url: https://api.onkernel.com security: - bearerAuth: [] tags: - description: Create and manage browser sessions. name: Browsers - description: Control mouse, keyboard, and screen on the browser instance. name: Browser Computer Controls - description: Execute Playwright code against the browser instance. name: Browser Playwright - description: Discover and invoke native page tools across the browser instance. name: Browser WebMCP - description: Read, write, and manage files on the browser instance. name: Browser Filesystem - description: Execute and manage processes on the browser instance. name: Browser Processes - description: Record and manage browser session video replays. name: Browser Replays - description: Stream logs from the browser instance. name: Browser Logs - description: >- Stream live telemetry events from a browser session, and manage the destinations sessions export them to. name: Browser Telemetry - description: Create, list, retrieve, and delete browser profiles. name: Profiles - description: Create and manage proxy configurations for routing browser traffic. name: Proxies - description: Create, list, retrieve, and delete browser extensions. name: Extensions - description: Create and manage browser pools for acquiring and releasing browsers. name: Browser Pools - description: Inspect the identity and authorization context for the current request. name: Authentication - description: >- Create and manage auth connections for automated credential capture and login. name: Managed Auth - description: Create and manage credentials for authentication. name: Credentials - description: Configure external credential providers like 1Password. name: Credential Providers - description: List applications and versions. name: Apps - description: Create and manage app deployments and stream deployment events. name: Deployments - description: Invoke actions and stream or query invocation status and events. name: Invocations - description: Read and manage organization-level limits. name: Organization - description: | Create and manage projects for resource isolation within an organization. When projects are disabled for the organization, project operations return `404` with code `projects_disabled`. name: Projects - description: Create and manage API keys for organization and project-scoped access. name: API Keys - description: Read audit log records for the authenticated organization. name: Audit Logs - description: Resolve browser and proxy recommendations for bot-protected sites. name: Config Registry paths: /browsers/{id_or_name}/webmcp/tools: get: tags: - Browser WebMCP summary: Discover WebMCP tools across the browser description: > Returns a snapshot of native WebMCP tools available across every open tab and embedded frame in the browser. Each tool includes an opaque tool_ref for invoking that exact live registration. Tools disappear when their document closes or navigates away. operationId: listWebMCPTools parameters: - description: Browser session ID or name example: htzv5orfit78e1m2biiifpbv in: path name: id_or_name required: true schema: type: string responses: '200': content: application/json: schema: $ref: '#/components/schemas/WebMCPToolsResponse' description: Current browser-wide WebMCP tool snapshot '404': $ref: '#/components/responses/NotFound' '500': $ref: '#/components/responses/InternalError' default: $ref: '#/components/responses/BrowserProxyError' security: - bearerAuth: [] components: schemas: WebMCPToolsResponse: additionalProperties: false properties: tools: items: $ref: '#/components/schemas/WebMCPTool' type: array required: - tools type: object WebMCPTool: additionalProperties: false properties: annotations: $ref: '#/components/schemas/WebMCPToolAnnotations' description: type: string input_schema: additionalProperties: true type: object name: type: string source: $ref: '#/components/schemas/WebMCPToolSource' tool_ref: description: >- Opaque reference for invoking this exact live registration. It becomes invalid when its document or browser process is replaced. type: string required: - tool_ref - name - description - input_schema - source type: object Error: properties: code: description: Application-specific error code (machine-readable) example: bad_request type: string details: description: Additional error details (for multiple errors) items: $ref: '#/components/schemas/ErrorDetail' type: array inner_error: $ref: '#/components/schemas/ErrorDetail' message: description: Human-readable error description for debugging example: 'Missing required field: app_name' type: string required: - code - message type: object InstanceProxyError: properties: code: $ref: '#/components/schemas/InstanceProxyErrorCode' message: description: Human-readable error description for debugging type: string required: - code - message type: object WebMCPToolAnnotations: additionalProperties: false description: >- Page-provided behavioral hints. These values are untrusted and are not enforced by Kernel. properties: autosubmit: type: boolean consequential: type: boolean read_only: type: boolean untrusted_content: type: boolean required: - read_only - untrusted_content - consequential - autosubmit type: object WebMCPToolSource: additionalProperties: false properties: frame: allOf: - $ref: '#/components/schemas/WebMCPToolFrame' description: >- Embedded frame that registered the tool, or null when the top-level page registered it. nullable: true page_title: description: Current title of the top-level page. type: string page_url: description: Current URL of the top-level page with the fragment omitted. type: string tab_id: description: >- Monotonically increasing identifier for the tab during the current browser process. minimum: 1 type: integer window_id: description: >- Monotonically increasing identifier for the browser window during the current browser process. minimum: 1 type: integer required: - window_id - tab_id - page_title - page_url - frame type: object ErrorDetail: properties: code: description: Lower-level error code providing more specific detail example: invalid_input type: string message: description: Further detail about the error example: Provided version string is not semver compliant type: string type: object InstanceProxyErrorCode: description: Canonical error code returned by browser instance API proxy routes enum: - invalid_request - unauthorized - forbidden - session_not_leased - not_found - conflict - session_gone - rate_limit_exceeded - internal_error - browser_unavailable type: string WebMCPToolFrame: additionalProperties: false properties: frame_id: description: >- Monotonically increasing identifier for this embedded frame during the current browser process. minimum: 1 type: integer url: description: Current frame URL with the fragment omitted. type: string required: - frame_id - url type: object responses: NotFound: content: application/json: schema: $ref: '#/components/schemas/Error' description: Resource not found InternalError: content: application/json: schema: $ref: '#/components/schemas/Error' description: Internal Server Error BrowserProxyError: content: application/json: schema: $ref: '#/components/schemas/InstanceProxyError' description: Error returned by the browser or its proxy securitySchemes: bearerAuth: scheme: bearer type: http ````