Desktop harness · Google
Chrome WebMCP origin trial
Experimental Chrome surface for websites and WebMCP-aware browser agents.
- Surface
- Desktop
- Execution
- local
- Target type
- release
- Default environment
- preview enabled
- Tracks
- Current
- Latest current evidence
- 2026-08-28
Description and scope
About this harness
This profile represents one exact product surface—not every product from Google.
This exact column represents the Chrome WebMCP origin trial documented by the Chrome team. It does not claim that WebMCP is enabled by default in stable Chrome or available to every Gemini in Chrome user.
Current-track snapshot
Support at a glance
7 of 114 atomic capabilities have a reviewed current status.
- Supported
- 3 Public evidence supports the current claim.
- Partial
- 4 Supported with a documented condition or limit.
- Unsupported
- 0 A current source explicitly says no.
- Unknown
- 107 No sufficiently scoped public evidence is published yet.
Provider and standards provenance
Reviewed public references
These links support individual capability cells. They are not a product-wide certification.
- Chrome for Developers — WebMCP and AI agents Google Chromedocumented · 2026-08-28
- WebMCP Draft Community Group Report W3C Web Machine Learning Community Groupdocumented · 2026-08-28
- Chrome for Developers — WebMCP Imperative API Google Chromedocumented · 2026-08-28
- Chrome for Developers — WebMCP Google Chromedocumented · 2026-08-28
- Chrome for Developers — WebMCP tool security Google Chromedocumented · 2026-08-28
Atomic capability ledger
Capability support
Open a capability record for its full notes, qualifiers, targets, and source links.
Try a broader term or include every current status.
| Capability | Current | Current evidence and conditions |
|---|---|---|
| InterfacesAgent Plugins failure isolation Reject invalid components narrowly without disabling valid components in the same package. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesAgent Plugins packaged MCP Load MCP server configuration contained in an Agent Plugins package. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesAgent Plugins packaged skills Load portable Agent Skills contained in an Agent Plugins package. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesAgent Plugins portable manifest Load the published portable plugin.json manifest and its core components. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeAgent Skills core and discovery Recognize, discover, and load reusable instruction packages centered on SKILL.md. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeAgent Skills manual invocation Let a user or agent explicitly select and activate a named skill. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeAgent Skills progressive loading Load skill metadata first and defer full instructions or resources until relevant. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeAgent Skills references and assets Resolve supporting reference files, templates, and assets from a skill package. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeAgent Skills scripts Resolve and execute optional scripts included with an Agent Skill under explicit runtime policy. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesAGENTS.md root instructions Discover and apply the cross-agent AGENTS.md convention at repository scope. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| CollaborationArtifact export Download generated files and other documented outputs. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaAudio file input Upload recorded audio for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyAudit logs Record security-relevant activity in an administrative audit log. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextAutomatic context compaction Continue long sessions by automatically summarizing or pruning older context. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeBackground agents Keep a run going after the operator leaves the session. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsBrowser automation Control a browser for navigation, clicks, forms, and page reading. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsCode execution Run generated code in a documented execution environment. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeComputer use Inspect and act on a visual interface through screenshots and input actions. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeConcurrent subagents Run multiple child-agent tasks concurrently with explicit queue and fan-out limits. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsConnectors Connect to external services authorized by the user or organization. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextContext compaction controls Trigger, inspect, configure, or disable context compaction. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextContext usage Inspect consumed or remaining context budget during a conversation or run. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextContext window Record the documented context-window limit by product, model, and mode. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| CollaborationConversation export Export conversation history in a documented format. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| CollaborationConversation sharing Share a conversation through a documented link or invitation. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesCustom instructions Persist instructions at user or project scope. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyData residency Select or document geographic storage or processing regions. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyData retention controls Configure or document retention and deletion for covered product data. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsDiffs and patches Propose or apply file changes as diffs or patches. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaDocument input Upload common document formats for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyEncryption key management Record documented encryption key ownership, scope, rotation, and revocation. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaFile upload limits Record numeric attachment size, count, page, duration, storage, and rolling quotas. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeHuman approval Pause before a tool action or file change until a person confirms. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaImage input Attach, paste, or select an image for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextLocal models Run against a model hosted on the operator's machine. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeLong-term memory Persist notes across sessions. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP Apps Render an interactive interface returned by an MCP server inside the product. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP cancellation Cancel an in-flight MCP request and handle cancellation correctly. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP client role Consume capabilities exposed by MCP servers. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP elicitation Handle structured user-input requests initiated by an MCP server. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP legacy HTTP and SSE Connect through the superseded HTTP plus SSE transport when migration compatibility is required. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP list-changed notifications Refresh capability lists when a server announces dynamic changes. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP logging Receive structured log messages emitted by an MCP server. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP OAuth authorization Complete the MCP authorization flow for protected remote servers. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP progress notifications Receive progress updates for long-running requests. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP prompt-list notifications Refresh prompt templates after a server announces changes. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP prompts Invoke reusable MCP prompt templates. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP Registry metadata Discover MCP servers and metadata through the official registry model. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP resource subscriptions Subscribe to resource changes and receive update notifications. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP resources Read MCP resources as live context. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP revision compatibility Implement or negotiate the exact dated MCP revision. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP roots Provide filesystem or workspace roots to an MCP server. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP sampling Handle server requests for model sampling through the client. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP server instructions Consume server-provided instructions during initialization. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP server role Expose capabilities from the harness as an MCP server. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP stdio transport Connect to a local MCP server over standard input and output. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP Streamable HTTP Connect to an MCP server over the current Streamable HTTP transport. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP task listing List and page through tasks exposed by the task utility. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP tasks Create, inspect, and manage long-running MCP tasks. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesMCP tools Invoke operations exposed by a Model Context Protocol server. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextModel fallback Switch to another model after a documented failure condition. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextModel selection Choose the model or documented model class used for a run. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsMulti-file edit Edit multiple files during one task. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesNative plugin system Install and load a product-specific extension package. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesNested AGENTS.md instructions Apply nested AGENTS.md files with directory-sensitive precedence. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeNested subagents Allow a child agent to delegate further work to another child agent. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyOffline operation Run a documented workflow without a required network connection. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyOrganization policy controls Centrally configure and enforce product settings for an organization. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextOutput token limit Record the maximum generated response budget by exact model and harness mode. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaPDF input Upload a PDF for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimePer-subagent model selection Choose or constrain each child agent's model independently of the parent. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Pricing, usage, and limitsPlans and pricing Compare documented plan, seat, included-usage, credit, and overage pricing by exact product. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesPlugin marketplace Discover and install extensions through a documented registry or marketplace. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesPlugin vendor extensions Preserve namespaced host-specific behavior without representing it as portable core support. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesProject rules Load persistent or path-scoped instructions from a documented product rule format. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeProject-scoped Agent Skills Discover skills installed for a repository or workspace. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextPrompt cache controls Mark, retain, refresh, or invalidate cached prompt context. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextPrompt cache telemetry Inspect cache hits, misses, token counts, latency, or billing effects. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextPrompt caching Reuse eligible repeated prompt content under documented caching behavior. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsPull request integration Open or review pull requests through a documented integration. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Pricing, usage, and limitsRate limits and quotas Record documented product usage limits and reset periods. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaRealtime voice Speak and listen over a live audio session. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Models and contextReasoning effort controls Choose a documented reasoning depth, effort, or budget for a run. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| CollaborationRole-based access control (RBAC) Assign and enforce permissions through documented roles. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSandbox network access Allow, deny, or restrict outbound network access from a tool sandbox. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeScheduled runs Start a task on a schedule without a new human prompt. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaScreenshots Capture a screen, window, or browser page for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacySecrets management Store and provide credentials through a documented secrets feature. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Pricing, usage, and limitsSession resume Continue a previously saved product session. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| CollaborationShared projects Share a product-defined project workspace with other people. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesStreaming output Show text or tool events as they arrive during a run. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesStructured outputs Return JSON or schema-constrained output through a documented product feature. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent context Define which conversation, instructions, files, memory, and tools a child receives. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent delegation Delegate a bounded task to another agent process. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent management List, inspect, and control child-agent tasks. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent MCP access Allow a child agent to use MCP tools or declare its own MCP servers. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent permissions Control child-agent tools, inherited permissions, and approval behavior. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent results Return a child agent's findings or work to the parent. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeSubagent write access Allow a child agent to create or modify project files. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsTerminal commands Propose or execute shell commands in a project environment. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Security and privacyTraining data controls Control or document model-training and service-improvement use of product content. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Pricing, usage, and limitsUsage metering Inspect documented product usage such as requests, tokens, or cost. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| RuntimeUser-scoped Agent Skills Discover personal or global skills outside the current project. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| Files and mediaVideo input Upload or select a video for use as model input. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsWeb fetch Retrieve live web pages or APIs during a run. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| InterfacesWebMCP declarative form tools Expose semantic HTML forms as structured tools through WebMCP annotations. | PPartialexperimental | 1 public referenceLatest evidence 2026-08-28dated documentation · Chrome WebMCP origin-trial documentation
|
| InterfacesWebMCP execution cancellation Cancel pending tool registration or execution through abort signals and lifecycle rules. | YSupportedexperimental | 2 public referencesLatest evidence 2026-08-28dated documentation · Chrome 153 WebMCP origin-trial documentation
|
| InterfacesWebMCP imperative tools Register JavaScript-backed tools through document.modelContext.registerTool(). | PPartialexperimental | 1 public referenceLatest evidence 2026-08-28dated documentation · Chrome WebMCP origin-trial documentation
|
| InterfacesWebMCP permissions policy Gate tool exposure across documents and origins through the tools permissions policy. | YSupportedexperimental | 3 public referencesLatest evidence 2026-08-28dated documentation · Chrome 153 WebMCP origin-trial documentation
|
| InterfacesWebMCP security annotations Communicate read-only and untrusted-content hints across the site-to-agent boundary. | YSupportedexperimental | 3 public referencesLatest evidence 2026-08-28dated documentation · Chrome 153 WebMCP origin-trial documentation
|
| InterfacesWebMCP tool discovery Expose the active page tool list and schemas to a WebMCP-aware agent. | PPartialexperimental | 1 public referenceLatest evidence 2026-08-28dated documentation · Chrome WebMCP origin-trial documentation
|
| InterfacesWebMCP tool execution Invoke a page tool with structured arguments and return its result to the agent. | PPartialexperimental | 1 public referenceLatest evidence 2026-08-28dated documentation · Chrome WebMCP origin-trial documentation
|
| ToolsWorkspace files Read or edit files inside a user-selected project. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |
| ToolsWorkspace search Search file names, text, or symbols across a workspace. | ?Unknown | No reviewed current evidenceThis remains unknown; it is not an unsupported claim.Open capability record → |