MCP client integration

Twin Browser + Cursor

Cursor is an AI-native code editor with a built-in agent that can call MCP tools. Servers are registered in `.cursor/mcp.json` for a project or `~/.cursor/mcp.json` globally, and their tools become available to the agent while you work.

Get an API key Read the docs

MCP client4-step setupBearer key auth

How Twin plugs into Cursor

Add the Twin MCP server and Cursor’s agent gains a real browser: check that a deployed page renders, pull the data behind a login into the file you are editing, or reproduce a bug on staging. Project-level config is usually the right choice — the server ends up scoped to the repo it is useful in, and the key stays out of your global settings.

Twin is the browser execution layer your stack calls. The first run cold-compiles a skill via skill compilation; every similar request after that is matched from the cache and replayed deterministically, so your marginal cost per run trends toward zero rather than climbing with usage.

app.example.com

Cursor → Twin

Receive goal from Cursordone
Compile DOM → token-efficient indexed statedone
Match the semantic dispatch cacherunning
Replay compiled skill — 0 LLM callsqueued

What you get through Cursor

Every integration is a thin wrapper over the same execution layer, so the cache, the replay, and the corpus apply no matter how you call in.

Semantic dispatch cache

A re-phrased goal fuzzy-matches an already-compiled skill, so most calls never touch the LLM.

Deterministic replay

A compiled skill replays the exact action path with zero LLM calls — fast, repeatable, cheap.

Cross-tenant skill corpus

A skill compiled once can be safely reused across tenants, so the hit rate climbs as the network runs.

One Bearer key

Auth, usage-based billing, and an audit log run on every call — the same key works from every integration.

Wire it up

Drop Twin into Cursor.

Copy, paste, and swap in your Bearer key. The first run compiles a skill; repeats match the semantic dispatch cache and replay deterministically.

.cursor/mcp.jsonjson

{
  "mcpServers": {
    "twin-browser": {
      "command": "npx",
      "args": ["-y", "twin-browser-mcp"],
      "env": { "TWIN_API_KEY": "ab_live_…" }
    }
  }
}

// In Cursor's chat:
//   "Use twin-browser to sign into staging and confirm the new banner renders."

Base URL https://twin-browser.com/api/v1 · auth Authorization: Bearer ab_live_… · over MCP the same engine is run_goal, compile_skill and run_skill — the full tool table.

Get an API key
Create an ab_live_ key in the Twin dashboard under Keys & Secrets.
Create the config
Add .cursor/mcp.json in the project (or ~/.cursor/mcp.json for every project).
Add the server
Use command npx with args -y twin-browser-mcp and TWIN_API_KEY in env.
Ask the agent
Prompt Cursor to do a web task — it calls the twin-browser tools under the hood.

Read the Cursor docs API reference

FAQ

Cursor on Twin — common questions

Do I need a plugin to use Twin in Cursor?

No. Twin is a standard stdio MCP server, so Cursor’s native MCP support is all you need — add the config and the tools appear.

Can Cursor reuse a skill I compiled elsewhere?

Yes. Skills are stored against your tenant, so one compiled from the REST API, from CI, or from another MCP client is available to Cursor’s agent too.

Go deeper

Windsurf

MCP client

Windsurf is Codeium’s AI-native editor, whose Cascade agent supports MCP servers. Servers are registered in `~/.codeium/windsurf/mcp_config.json` in the same `mcpServers` shape most clients use.

Visual Studio Code

MCP client

VS Code’s Copilot agent mode supports MCP servers, configured in `.vscode/mcp.json` for a workspace or in your user profile. Note the shape difference: VS Code uses a top-level `servers` key where most other clients use `mcpServers`.

MCP (Model Context Protocol)

Protocol

MCP is an open protocol that lets an LLM application discover and call external tools over a standard interface. An MCP client — Claude Desktop, Claude Code, Cursor, Windsurf, VS Code, Cline — launches or connects to an MCP server, lists its tools, and invokes them on the model’s behalf, with no bespoke glue per app.

Wire up Cursor in minutes.

Free to start. Usage-based credits from $29/mo — each call billed the higher of its flat action price or its metered cost.

Get an API key See pricing