Set up Claude Code or Codex with Nullprint

A step-by-step guide from zero: get the account, install the agent, connect it to Nullprint, and run your first command. About ten minutes. For the full tool reference see the MCP docs.

Pick an agent and get an account

Agent	Account you need
Claude Code (Anthropic)	A claude.ai Pro, Max, Team or Enterprise plan, or an Anthropic Console account with API credit. The free claude.ai plan does not include Claude Code.
Codex (OpenAI)	A ChatGPT plan that includes Codex, or an OpenAI API key.

Either works the same way with Nullprint. You only need one.

Prepare

1. Install Nullprint and keep it running

Install Nullprint from the download page (Windows or macOS), open it and sign in. Leave it running while the agent works (minimized is fine). The MCP server finds its port and API key automatically.

2. Install uv

uv downloads and runs nullprint-mcp on first use. Open a terminal (macOS: Terminal; Windows: PowerShell) and run:

# macOS
curl -LsSf https://astral.sh/uv/install.sh | sh

# Windows (PowerShell)
powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

Close the terminal, open a new one and check with uvx --version.

Prefer Node.js? If you already have Node 18+, skip uv and replace uvx nullprint-mcp with npx -y nullprint-mcp in every command below. Same server, same tools.

Claude Code

1. Install

# macOS
curl -fsSL https://claude.ai/install.sh | bash

# Windows (PowerShell)
irm https://claude.ai/install.ps1 | iex

Open a new terminal and check with claude --version.

2. Sign in

Run claude, follow the browser prompt to sign in with your Claude account, then type /exit.

3. Connect Nullprint

claude mcp add --scope user nullprint -- uvx nullprint-mcp

--scope user makes Nullprint available in every folder you start Claude Code from. Check it:

claude mcp list

You should see nullprint: uvx nullprint-mcp - ✓ Connected. The first run takes a few seconds while uv downloads the package.

4. Try it

Start claude and type:

List my Nullprint profiles and tell me which are running.

Claude asks before it uses a tool for the first time; approve it. Inside a session, /mcp shows the server and its 17 tools.

OpenAI Codex

1. Install

# macOS (Homebrew)
brew install --cask codex

# Any system with Node.js 18+
npm install -g @openai/codex

2. Sign in

Run codex and choose Sign in with ChatGPT (or use an API key), then exit.

3. Connect Nullprint

codex mcp add nullprint -- uvx nullprint-mcp

Check with codex mcp list. Or add it by hand to ~/.codex/config.toml:

[mcp_servers.nullprint]
command = "uvx"
args = ["nullprint-mcp"]

4. Try it

Start codex and ask:

List my Nullprint profiles and tell me which are running.

What to ask

You say	The agent does
Create a profile called shop-01 with proxy socks5://user:pass@host:port	Creates the profile; the fingerprint is generated and frozen
Test these five proxies and give me country and latency	Checks each proxy's exit IP, country and latency
Open shop-01 and go to example.com	Launches the browser window and navigates
Type "headphones" in the search box and press Enter	Reads the page, fills, clicks and presses keys
Run a check-up on shop-01	Consistency check, lists anything that fails
Which profiles are running? Close the idle ones	Lists status and stops browsers
Delete shop-01 / what's in the trash / restore it	Moves to the recycle bin (recoverable), lists, restores

Use exact profile names (case-sensitive). For sites that need a login, have the agent open the page, type your password and 2FA code yourself in the window, then hand control back.

Troubleshooting

"The Nullprint daemon is not running." Open the Nullprint app and sign in, then retry.

uvx or claude not found. Open a new terminal after installing so the PATH is refreshed.

claude mcp list shows "Failed to connect". Run uvx nullprint-mcp --help in a terminal to see the real error; usually uv cannot reach PyPI or Python is missing (uv installs it if allowed).

The agent says a session must be started first. Page actions need an open profile: ask it to open the profile first.

Using Cursor, Windsurf, Cline or Claude Desktop? See the config snippets in the MCP docs.

Stay safe

The agent acts inside profiles that are already signed in. Review anything involving payments, password changes or deletion.
Ask it to close profiles when it is done.
Permanent deletion (emptying the recycle bin) is never exposed to agents.
nullprint-mcp runs on your computer and talks only to your local Nullprint app; your prompts still go to the model provider you chose.