)]}'
{"id": 5117755740913664, "name": "WebMCP", "summary": "WebMCP is a proposal for a web API that enables web pages to provide agent-specific paths in their UI. With WebMCP, agent-service interaction takes place via app-controlled UI, providing a shared context available to app, agent, and user.", "markdown_fields": [], "blink_components": ["Blink>Agentic Platform>WebMCP"], "star_count": 176, "search_tags": ["WebMCP"], "created": {"by": "bokan@chromium.org", "when": "2025-07-08 19:29:42.615078"}, "updated": {"by": "fbeaufort@google.com", "when": "2026-08-12 05:43:50.470558"}, "category": "Miscellaneous", "category_int": 2, "feature_notes": null, "web_feature": "document-modelcontext", "is_official_web_feature": true, "webdx_usecounter_enum": null, "enterprise_feature_categories": [], "enterprise_product_category": 0, "is_releasenotes_content_reviewed": false, "is_releasenotes_publish_ready": false, "stages": [{"id": 5122802059051008, "created": "2025-07-08 19:29:43.335515", "feature_id": 5117755740913664, "stage_type": 110, "display_name": null, "intent_stage": 7, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 5184746627530752, "created": "2025-07-08 19:29:43.413010", "feature_id": 5117755740913664, "stage_type": 120, "display_name": null, "intent_stage": 1, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": "https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CANMmsAtRdyRw1WtO5va0K%3D_adYH-FRh01xvw5%2BosSd_DAq%3D%3DUQ%40mail.gmail.com", "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 5129728364904448, "created": "2025-07-08 19:29:43.545324", "feature_id": 5117755740913664, "stage_type": 130, "display_name": null, "intent_stage": 2, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": "https://groups.google.com/a/chromium.org/g/blink-dev/c/bhhOmTGzD5Y/m/PGdM8lF6AQAJ", "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": 146, "android_first": 146, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 5100883867860992, "created": "2025-07-08 19:29:43.622657", "feature_id": 5117755740913664, "stage_type": 140, "display_name": null, "intent_stage": 4, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 5111811472621568, "created": "2025-07-08 19:29:43.693452", "feature_id": 5117755740913664, "stage_type": 150, "display_name": "WebMCP", "intent_stage": 3, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": "https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a076b26.050a0220.3377b4.05fa.GAE%40google.com", "announcement_url": null, "experiment_goals": "For the experiment we are  focused on understanding the API ergonomics for agentic workflows across various verticals such as web commerce and productivity. We expect the site owners to implement WebMCP tools in their sites to automate high-value workflows for them and will seek feedback on the functionality of WebMCP. We also plan to gather metrics for tool usage and latency, and assess opportunities for improvements. \n", "experiment_risks": "No risks when the experiment finishes. We expect WebMCP tools to continue to be available in Chrome stable, with no loss in data.  Browser agents in Chrome can continue to actuate sites as before by simulating user behaviors. ", "origin_trial_id": "4163014905550602241", "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": "WebMCP", "ot_description": "Origin trial for WebMCP, which allows websites to register tools for use by agents hosted by the site or in Chrome.  More information can be found at https://developer.chrome.com/docs/ai/webmcp", "ot_display_name": "WebMCP", "ot_documentation_url": "https://docs.google.com/document/d/1ZaQvuj4YnUnoqOfEhbfgFynpDRKk2zZZHavTNJ151gM/edit?tab=t.0#heading=h.ggi78l861caa", "ot_emails": ["pjmclachlan@google.com", "bengr@google.com", "skmanickam@google.com", "mfoltz@google.com", "khushalsagar@google.com", "domfarolino@google.com"], "ot_feedback_submission_url": "https://issues.chromium.org/issues?q=componentid:2021259", "ot_has_third_party_support": true, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": "bengr@google.com", "ot_requester_email": "skmanickam@chromium.org", "ot_require_approvals": false, "ot_use_counter_bucket_number": 5791, "ot_webfeature_use_counter": "kModelContextRegisterTool", "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": 149, "android_first": 149, "ios_first": null, "webview_first": 149, "desktop_last": 156, "android_last": 156, "ios_last": null, "webview_last": 156, "ot_setup_status": 6}, {"id": 5083005395402752, "created": "2025-07-08 19:29:44.443453", "feature_id": 5117755740913664, "stage_type": 160, "display_name": null, "intent_stage": 5, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}], "accurate_as_of": "2025-07-08 19:29:42.614770", "creator_email": "bokan@chromium.org", "updater_email": "fbeaufort@google.com", "owner_emails": ["khushalsagar@chromium.org", "yhkumar@google.com", "bengr@chromium.org", "masonf@chromium.org", "dom@chromium.org", "mfoltz@chromium.org", "fbeaufort@google.com"], "editor_emails": ["bengr@chromium.org", "masonf@chromium.org", "dom@chromium.org", "mfoltz@chromium.org"], "cc_emails": ["bengr@chromium.org", "chrishtr@chromium.org", "khushalsagar@chromium.org", "pjmclachlan@chromium.org", "skmanickam@chromium.org", "masonf@chromium.org", "mfoltz@chromium.org"], "spec_mentor_emails": [], "unlisted": false, "deleted": false, "editors": ["bengr@chromium.org", "masonf@chromium.org", "dom@chromium.org", "mfoltz@chromium.org"], "cc_recipients": ["bengr@chromium.org", "chrishtr@chromium.org", "khushalsagar@chromium.org", "pjmclachlan@chromium.org", "skmanickam@chromium.org", "masonf@chromium.org", "mfoltz@chromium.org"], "spec_mentors": [], "creator": "bokan@chromium.org", "feature_type": "New or changed feature", "feature_type_int": 0, "intent_stage": "None", "intent_stage_int": 0, "active_stage_id": 5083005395402752, "bug_url": "https://crbug.com/445637567", "launch_bug_url": "https://launch.corp.google.com/launch/4460611", "new_crbug_url": "https://bugs.chromium.org/p/chromium/issues/entry?components=Blink>Agentic Platform>WebMCP&blocking=445637567&cc=khushalsagar@chromium.org,yhkumar@google.com,bengr@chromium.org,masonf@chromium.org,dom@chromium.org,mfoltz@chromium.org,fbeaufort@google.com", "screenshot_links": [], "first_enterprise_notification_milestone": null, "enterprise_impact": 1, "breaking_change": false, "confidential": false, "shipping_year": 2026, "flag_name": "Experimental Web Platform features", "finch_name": "WebMCP", "non_finch_justification": null, "ongoing_constraints": "No technical constraints for the experiments. ", "rollout_plan": 0, "rollout_plan_displayname": "Will ship enabled for all users", "motivation": "The web platform's ubiquity and popularity have made it the world's gateway to information and capabilities. Its ability to support complex, interactive applications beyond static content, has empowered developers to build rich user experiences and applications. As AI agents become more prevalent, the potential for even greater user value is within reach.\n\nFor the Web to succeed, it needs to APIs to interact with Agents beyond UIs written for humans.", "devtrial_instructions": "https://docs.google.com/document/d/1rtU1fRPS0bMqd9abMG_hc6K9OAI6soUy3Kh00toAgyk/edit?tab=t.0", "activation_risks": "There are no activation requirements to register WebMCP tools.  To execute WebMCP tools does require an agent, either provided by the browser or site author, to formulate and orchestrate tool calls.  There are several Chrome extensions already available that allow cloud-LLM-based agents to discover and call WebMCP tools. It is also possible to use the Prompt API to call WebMCP tools using on-device models.", "measurement": null, "availability_expectation": null, "adoption_expectation": null, "adoption_plan": null, "initial_public_proposal_url": "https://github.com/explainers-by-googlers/script-tools", "explainer_links": ["https://github.com/webmachinelearning/webmcp"], "requires_embedder_support": true, "spec_link": "https://webmachinelearning.github.io/webmcp", "api_spec": true, "automation_spec": false, "interop_compat_risks": "Given this is a new space and new API - there's no compatibility risk.\n\nUsual risk related to other browser vendors not adopting the API apply. This API is meant to augment capabilities provided by browser add-ons and so non-adoption in other engines would have limited user-impact and thus we consider the risk to be low.", "all_platforms": true, "all_platforms_descr": null, "non_oss_deps": null, "anticipated_spec_changes": null, "security_risks": "Sites may consume and expose sensitive information when their WebMCP tools are called by agents.  Agents should implement safeguards to ensure that sensitive information is passed to sites and between origins only under the consent of the user that is supervising them.\n\nLLM-based agents are susceptible to attacks such as indirect prompt injection, which can cause an exploited agent to exfiltrate sensitive information in its context to an attacker.  Agents should implement safeguards against prompt injection and related attacks. ", "ergonomics_risks": "There is a risk that site authors that wish to incorporate WebMCP tools into their sites will need to duplicate functionality that currently exists to drive the user interface.  We're hoping that most imperative WebMCP tools are just thin wrappers around existing code that drives actions on the site, but we are working with framework developers like React to ensure that WebMCP tools can be added without rearchitecting the site logic.  We are also offering a declarative version that requires only adding attributes to existing form elements, which is much lighter weight to deploy and does not require any refactoring of existing site functionality. ", "wpt": null, "wpt_descr": "The IDL and basic usage is tested via WPTs.\n\nSince the API provides the user agent with the ability to call certain tools, we might need to extend the WPT harness to support this.", "webview_risks": null, "devrel_emails": ["devrel-chromestatus-all@google.com"], "debuggability": "Explicit debugging support through a new WebMCP Chrome DevTools Protocol domain. The domain supports listing registered tools, invoking tools, and logging all calls by agents. Registration issues for declarative tools (e.g., missing names or descriptions) are reported through the Audits domain.", "doc_links": ["https://docs.google.com/document/d/1ZaQvuj4YnUnoqOfEhbfgFynpDRKk2zZZHavTNJ151gM/edit?tab=t.0#heading=h.ggi78l861caa", "https://docs.google.com/document/d/1ycdzuXA-VE8lRDFSArh0Um3PChHV0Hq6Om1MSMG8qPE/edit?tab=t.0#heading=h.edohi3f5z12h"], "sample_links": [], "prefixed": null, "tags": ["WebMCP"], "tag_review": "Spec is being incubated. We will request TAG review before shipping. ", "tag_review_status": "Pending", "tag_review_status_int": 1, "security_review_status": "Pending", "security_review_status_int": 1, "privacy_review_status": "Pending", "privacy_review_status_int": 1, "security_continuity_id": null, "security_launch_issue_id": null, "updated_display": null, "resources": {"samples": [], "docs": ["https://docs.google.com/document/d/1ZaQvuj4YnUnoqOfEhbfgFynpDRKk2zZZHavTNJ151gM/edit?tab=t.0#heading=h.ggi78l861caa", "https://docs.google.com/document/d/1ycdzuXA-VE8lRDFSArh0Um3PChHV0Hq6Om1MSMG8qPE/edit?tab=t.0#heading=h.edohi3f5z12h"]}, "comments": null, "ff_views": 5, "safari_views": 5, "web_dev_views": 4, "browsers": {"chrome": {"bug": "https://crbug.com/445637567", "blink_components": ["Blink>Agentic Platform>WebMCP"], "devrel": ["devrel-chromestatus-all@google.com"], "owners": ["khushalsagar@chromium.org", "yhkumar@google.com", "bengr@chromium.org", "masonf@chromium.org", "dom@chromium.org", "mfoltz@chromium.org", "fbeaufort@google.com"], "origintrial": false, "prefixed": null, "flag": false, "status": {"text": "Proposed", "val": 2, "milestone_str": "Proposed"}, "announced": false, "desktop": null, "android": null, "webview": null, "ios": null}, "ff": {"view": {"url": null, "notes": null, "text": "No signal", "val": 5}}, "safari": {"view": {"url": null, "notes": null, "text": "No signal", "val": 5}}, "webdev": {"view": {"text": "No signals", "val": 4, "url": null, "notes": "Web Framework developers: \nHave shown a great deal of interest during the developer trial, as evidenced here: https://www.star-history.com/?repos=webmachinelearning%2Fwebmcp&type=date&legend=bottom-right\nChrome web store features about 9 different extensions with WebMCP on their title and 4* or more ratings. \nhttps://chromewebstore.google.com/search/WebMCP?minimalRating=4\n"}}, "other": {"view": {"text": null, "val": null, "url": null, "notes": null}}}, "standards": {"spec": "https://webmachinelearning.github.io/webmcp", "maturity": {"text": "Specification being incubated in a Community Group", "short_text": "Incubation", "val": 3}}, "is_released": false, "is_enterprise_feature": false, "experiment_timeline": null, "ai_test_eval_report": null, "ai_test_eval_run_status": null, "ai_test_eval_status_timestamp": null}