Apps and tools

Bring your own tools over MCP, and test them first

Custom MCP servers in Brainwrite add tools from Model Context Protocol servers you choose, run as a command on your Mac or reached at a URL over Streamable HTTP or SSE. Every compatible bot can then use those tools under your normal approval settings. New servers are saved switched off, so you test the connection and see the tool list before turning one on.

Download for Mac Read the docs

Ask your own data

Using the analytics MCP server, how many sign-ups came from the October newsletter?

Your Chief of Staff put a team on it

Nova· Chief of Staff
Dash· Triage bot
Atlas· Rigel, QA and Release Engineer

Called the analytics server's query tool after your approval.
October newsletter: 214 sign-ups, 31% of the month.
September's newsletter brought 168.
The tool call and result are in the Inspector.

DoneDone. Nothing was sent.

An illustrated example. Your team works on your own files and apps.

An operations manager checks a printed list in a warehouse office while AI agents Dash, Penny and Nova stand beside her.

See it in the app

Custom MCP servers in Brainwrite.

Apps → MCP servers with the Add MCP server form: Connect to a URL, server name northwind-crm and a Streamable HTTP connection.

How it works

How Custom MCP servers works.

01
Open the tab
Choose Connected apps in the sidebar, then the MCP servers tab, then Add server, and give it a Server name.
02
Say how to reach it
Run a command: enter the Executable command, one argument per line, and KEY=value variables. Or Connect to a URL: enter the Server URL, pick Streamable HTTP or SSE, and add Headers.
03
Save and test
Choose Save; the server is saved switched off. Choose Test to complete the MCP handshake and list the tools it offers.
04
Turn it on
Choose Turn on when you are happy with it. New threads pick up the change.

Good to know

The details.

Paste a config

Paste config accepts the mcpServers block from Claude Code, Cursor or Claude Desktop. Each server arrives switched off; test it, then turn it on.

Values are write-only

Brainwrite never shows a saved environment variable or header value again, only its name. Leave a value blank when editing to keep it.

Predictable Claude bots

Claude bots get only these servers plus a project's own .mcp.json, not your personal Claude Code setup. Loading that setup cost one measured desktop about 407 extra tools and 10k tokens per call.

Opt in to your Claude Code servers

Turn on Also use my Claude Code MCP servers to give Claude bots those servers too, on every turn.

Off without deleting

Turn off keeps a server saved without offering its tools. Remove it with its remove button when you are done.

The edges, plainly

Command servers run on your Mac with the variables you provide, and URL servers receive the headers you provide. Only add software and addresses you trust.
Changes apply to new threads, not to ones already running.

Full reference in the documentation

Use cases

Jobs this feature does for you.

Works with

Apps it's often used with.

FAQ

Questions about Custom MCP servers

What is an MCP server?

An MCP server offers tools to AI agents over the Model Context Protocol. It can be a program that runs on your computer or a service at a URL. In Brainwrite, once you add and turn on a server, every compatible bot can call its tools, subject to your approval settings.

Can I use my Claude Code MCP servers in Brainwrite?

Yes, two ways. Paste the mcpServers block from Claude Code, Cursor or Claude Desktop with Paste config, then test and turn each server on. Or turn on Also use my Claude Code MCP servers to give Claude bots your existing servers on every turn. It is off by default to save tokens.

Does Brainwrite support remote MCP servers?

Yes. Choose Connect to a URL, enter the Server URL, and pick Streamable HTTP for most servers or SSE for older ones. Put tokens in Headers, one Name: value per line. Brainwrite never shows a saved header value again.

Do MCP tool calls need approval?

MCP tool calls follow your normal approval settings, the same as any other tool. Adding a server makes its tools available to compatible bots; it does not pre-approve them. Test each server before turning it on so you know exactly which tools it offers.

Works well with