Browser WebMCP playground

The playground exposes browser tools that an agent can call on the page. It creates only fixed synthetic wallet requests; the browser tools do not return presentation tokens, identity claims, or verification details. This is a browser integration and does not connect to the remote MCP server used by IDE clients.

Enable WebMCP in Chrome

WebMCP is experimental. For local testing, Chrome documents a browser flag:

1. On macOS, open the flag page from Terminal:

   open -a "Google Chrome" "chrome://flags/#enable-webmcp-testing"

2. Set the flag to Enabled, then relaunch Chrome.

3. No extension is required to use the demo. The playground includes an in-page Ask this page panel. To inspect registered tools separately, install the optional Model Context Tool Inspector extension.

4. Open the playground in Chrome:

   open -a "Google Chrome" "https://playground.dlbr.app/"

Open the playground after enabling the flag. Its Ask this page panel should report that WebMCP tools are connected. Enter a prompt to list the available profiles:

Show me the available DLBR wallet request profiles.

The in-page client calls list_oid4vp_playground_profiles and displays the tool result. Then try creating a request:

Create a PID compatibility request using mDOC.

The in-page client calls create_oid4vp_session and displays its response, including an inline QR code and a wallet link. Scan it with a synthetic test wallet while keeping the page open. Ask the page to check the latest session; it calls get_oid4vp_session_result and displays only the redacted outcome.

The Ask this page prompt also supports optional voice dictation in browsers that provide on-device speech recognition and have a local language pack available. Audio is not sent to an online recognition service. Other browsers can use the text field as usual. See Chrome's on-device Web Speech API notes.

The built-in UI routes the supported sample prompts to fixed tool inputs. It does not send prompts to an external model. To experiment with a separate agent, use the optional Inspector extension or another WebMCP-enabled client.

If the tools do not appear, confirm the flag is enabled, relaunch Chrome, and reload the playground. The manual wallet flow remains available in browsers without WebMCP support.

Staging origin trial

Chrome also requires a WebMCP Origin Trial token registered for the exact playground origin. https://playground.dlbr.app uses WEBMCP_ORIGIN_TRIAL_PLAYGROUND. The https://try.dlbr.app microsite does not expose WebMCP or need a token. The playground token is never included in the browser bundle, and the response header is limited to its matching HTTPS origin. Register the playground host and configure its token before relying on WebMCP there. Production is not enabled.

Local apps/try/.dev.vars values are read by Wrangler but cannot authorize localhost; local browser testing still uses Chrome's WebMCP testing flag.

Available browser tools

Tool	Purpose	Data returned
list_oid4vp_playground_profiles	List fixed request profiles and formats	Profile metadata
create_oid4vp_session	Create a five-minute synthetic wallet request	Session ID, expiry, and wallet request link
get_oid4vp_session_result	Read a session's lifecycle outcome	Status and expiry only

Use only synthetic credentials. Do not paste real identity data into an agent prompt. Review the Chrome WebMCP documentation for current browser API details.

Browser WebMCP and remote MCP

Browser WebMCP exposes tools from the open playground page. For native clients such as IDEs that connect to a server endpoint, see the CLI's staging MCP instructions. The remote endpoint is staging-only; production has not been deployed.