# MCP connector PayBox speaks the **Model Context Protocol**. Add one URL to your agent's connector list, sign in once, and the agent gets scoped, passkey-gated access to your wallets, cards, and secrets. ## The URL ```txt https://api.paybox.sh/mcp ``` It's a **streamable HTTP** MCP endpoint (protocol version `2025-06-18`). ## Steps ::::steps ### Add the URL At `claude.ai/new#settings/customize-connectors` (Customize → Connectors), or your agent's equivalent, paste the MCP URL above as a custom connector. At `grok.com` it's `grok.com/connectors` → **New Connector** → **Custom** → paste the URL above, then complete the sign-in it opens. That path is **Grok**, not Grok Bots. **Grok Bots** is a different client. It has no `grok.com/connectors` screen. A hosted bot runs on its own box, so the way in is the [CLI](/sdk-cli) on that machine (`npm install -g @paybox-sh/sdk`, then the package `SKILL.md`). Same API, same grants, same passkey approvals. If that host later asks for a custom MCP URL, paste `https://api.paybox.sh/mcp`. Do not invent a Settings → Plugins path. **Grok Computer** and other agents on a computer follow the same CLI path — no connector screen on the machine where the agent runs. Not every other agent host has a connector screen either. Chat products built on the same model often do not. There too, install the CLI on the machine the agent runs on. ### Sign in Your agent opens PayBox in a tab. Sign in (email + passkey) and **approve a scoped grant** on just the credentials you want this agent to use, with an approval mode per credential. ### Stay in control Above-threshold and sensitive operations pause for your passkey. Every operation is an audit event. Revoke the connector from the app's **Clients** screen at any time. :::: ## Signing: in the chat, or in your browser PayBox never holds your wallet key. Anything that spends or signs is confirmed by you in the **PayBox signing window**, which holds your key and signs there and nowhere else. Agents render that window inside the chat. It appears next to the conversation and signs as soon as your key is connected to it — you take no separate action. What differs is *when* it appears. Most agents draw it the moment the tool runs. Grok draws it only after the agent finishes replying, so there's a gap where nothing is on screen yet. That's expected: let the reply finish, the window shows up, you sign, and the agent reports the outcome on its next message. Your agent is told which applies to it, so you don't have to work it out. ## How it works The MCP endpoint is the agent's whole interface to PayBox. Adding the URL drives an **[OAuth 2.1 + PKCE](/connect/oauth)** flow under the hood: the client registers dynamically, you consent to a scoped grant, and the client receives an access token it presents as `Authorization: Bearer …` on every call. From there the agent calls the **[MCP tools](/reference/mcp-tools)** — `list_credentials`, `request_payment`, `claim_payment_credentials`, `request_wallet_sign`, `request_secret`, `request_swap`, `get_portfolio`, `verify_solana_balance`, `get_buy_link`, the x402 tools (`discover_services`, `pay_x402`, `use_service`), `request_account_change`, `get_request`, and `list_requests` — plus [`discover_plugins`](/reference/mcp-tools#plugin-tools), `get_contract`, and `use_plugin` for **[plugin tools](/reference/mcp-tools#plugin-tools)** the user has enabled (they also appear on MCP `tools/list`). All the same approval, policy, and audit rules apply, and wallet signing happens in an in-chat **[signing window](/concepts/requests#the-signing-window)** so the key never leaves MoonX MPC. :::tip New to the flow? **[Request lifecycle](/concepts/requests)** explains the submit → approve → poll pattern every tool follows. :::