Install

Use CommonPlace, connect your agent, or run Theorem on your own Railway account.

Pick the path by intent. CommonPlace installs as a browser app or native desktop app. The harness connects to Claude Code, Claude Desktop, Cursor, Codex, or raw MCP over one authenticated endpoint.

Use CommonPlace

Install the web app without signing, or use the native desktop build when you want the local node bundled with the shell.

In Chrome or Edge, the install button appears when the browser confirms the app shell is ready.

Open latest release

Looking up the latest GitHub Release asset for this device.

Run your own

Self-host the harness and graph engine. Provider keys stay in your Railway project.

Open template source

The template source is ready. Publishing it to Railway turns this into a one-click deploy button.

Connect your agent

One terminal command registers the remote MCP endpoint.

Bearer keyThe value stays in this browser tab and is used only to complete the copy block and Cursor link.

Replace <your-key> with a bearer from the Harness console

claude mcp add --transport http theorems-harness \
  https://api.theoremharness.com/mcp \
  --header "Authorization: Bearer <your-key>"

Create keyPaste a bearer key to generate the Cursor install link.

Ask your agent to call remember with: My install proof is working across sessions.
Start a fresh agent session and ask it to recall: install proof working across sessions.

Open CommonPlace Read the Theseus project