Stunt Double MCP Server

Deploy AI user personas to validate user journeys at scale. Find UX friction before real users do.

Stunt Double deploys AI agents with realistic user personas to validate user journeys at scale. Create actors, run automated workflows and checklists against any web app, and surface friction points before real users encounter them. Integrates with Claude, Linear, GitHub, and Slack.

This repository

This repo holds plugin and MCP configuration (.cursor-plugin/plugin.json, root mcp.json, server.json), plus skills, agents, and Cursor rules. There is no package.json and no runnable server here — the MCP endpoint is hosted at https://app.stuntdouble.io/api/mcp from the main Stunt Double codebase. See CONTRIBUTING.md for how to validate edits and avoid confusing this folder with a Node package.

Quick Start

Claude Code

claude mcp add --transport http stuntdouble https://app.stuntdouble.io/api/mcp

Claude Desktop

Go to Settings → Connectors → Add and paste:

https://app.stuntdouble.io/api/mcp

Cursor / Windsurf

Add the mcpServers block below to an MCP config file:

• Project-local (recommended for this repo clone): .cursor/mcp.json at the root of your project.
• Global (all projects): ~/.cursor/mcp.json on macOS/Linux (see Cursor MCP docs for your OS).

{
  "mcpServers": {
    "stuntdouble": {
      "url": "https://app.stuntdouble.io/api/mcp"
    }
  }
}

Use only url for remote servers (Streamable HTTP is negotiated automatically). Extra keys such as "type": "streamable-http" are not part of Cursor's documented mcp.json shape and can break plugin validation.

Cursor marketplace (one-click install) expects a plugin layout: .cursor-plugin/plugin.json plus root mcp.json. Those files are in this repo. The plugin logo path is assets/logo.png (bundled in this repository). The server.json file is the separate MCP registry manifest for mcp-publisher and directory listings; Cursor's installer does not use it.

Authentication

Authentication is handled automatically via OAuth 2.1 with PKCE. The first time your AI client connects, a browser window will open for you to sign in and authorise access to your Stunt Double account. No API keys or tokens required.

For Cursor, the OAuth redirect URI is fixed to cursor://anysphere.cursor-mcp/oauth/callback (docs).

Available Tools

Account

Notification channel and timezone are account settings rather than workspace ones, so they are the same answer in every workspace. Pass the timezone when creating a scheduled workflow, or "every weekday at 9" becomes nine in UTC.

Workspaces

get_workspace reports the workspace security controls under settings: public sharing, the feedback widget, self-hosted workers, and the network policy. They are ceilings set by an admin, so a feature switched off there cannot be switched back on for a single project.

Search

search takes a workspace_id plus an optional query, types filter, project_id filter and limit (max 50). Terms are matched as prefixes, so a partial word is enough. Omit query to browse the most recently updated items. Results carry the id you need for the matching getter, so it is usually cheaper than listing an entity type and filtering the list yourself. Reach for it before creating anything, to find the actor or checklist that already covers the job.

Projects

A project is archived, never deleted, and an archived project reads as missing from every tool here. Registering an MCP server and attaching it to a project are workspace-admin actions in the dashboard; list_project_mcp_servers is how you check what tools a run will actually have before writing a checklist that depends on one.

Guidelines

Standing rules the team holds the product to: design system, tone of voice, brand, content, accessibility, compliance, security, performance, or shared knowledge. A guideline is owned by the workspace and attached to the projects it applies to, so one rule can hold for every project without being retyped. Whatever is in force is rendered into every checklist run, design review, interview and triage for that project.

Two switches decide whether a rule is in force for a project: the library's enabled and the attachment's. list_project_guidelines folds them into one enabled so you never have to reason about both. A rule with apply_to_design_reviews set also holds for design reviews raised from Slack or Linear, which carry no project to attach it through.

Codify a standard as a guideline rather than repeating it in each checklist, and search the library before writing a new rule: attaching the one that already exists keeps the team's standard in a single place to edit.

Actors

Knowledge

Conversations

Checklists