Marsell MCP server

Marsell’s MCP server lets the AI you already use work on your Marsell projects: Claude Code, Codex, or any client that speaks the Model Context Protocol. It sees what you see, and anything that posts still waits for your yes.

Make a key

Open Your own AI

In the app, open a project and go to Agents. The section Your own AI is on that page.

Name the key

Give it a name you’ll recognise, such as “Claude on my laptop”. Turn on Can act if the agent may do things for you. Without it, the key only reads.

Make it and copy it

Click Make a key. The key starts with mk_ and shows only once: copy it, then click I’ve copied it.

Treat a key like a password: whoever has it acts as you. To stop a key, revoke it from the Keys list in the same section. It stops working straight away, even halfway through a task.

You can have up to 10 keys at a time. In an organisation, only administrators can make or revoke keys.

Connect your agent

The server is at https://getmarsell.com/mcp. Put your key where mk_… is.

Claude Code
Codex
Any MCP client

claude mcp add --transport http marsell https://getmarsell.com/mcp \
  --header "Authorization: Bearer mk_…"

export MARSELL_KEY=mk_…
codex mcp add marsell --url https://getmarsell.com/mcp --bearer-token-env-var MARSELL_KEY

Or in ~/.codex/config.toml:

[mcp_servers.marsell]
url = "https://getmarsell.com/mcp"
bearer_token_env_var = "MARSELL_KEY"

URL     https://getmarsell.com/mcp
Header  Authorization: Bearer mk_…
Kind    Streamable HTTP

Then ask your agent something like “What needs me on Marsell this week?”

What your agent can do

Tool	What it does	Needs Can act
`list_projects`	Lists your projects: name, website and kind.	No
`get_overview`	Where a project stands: Marsell’s latest line, what needs you, the week’s plan, the numbers that move and what Marsell did lately.	No
`list_decisions`	The decisions waiting for your yes, with each one’s options.	No
`get_brand`	What Marsell knows about the brand: what it is, who it’s for, how it talks, its colours, type and look, and what it never does.	No
`get_market`	The communities your buyers gather in, live conversations worth joining, questions people keep asking, and your rivals with their prices.	No
`list_people`	Everyone the project has talked to, with their stage and last touch.	No
`get_tokens`	Your Marsell plan, the tokens left this month and when they renew.	No
`answer_decision`	Answers one waiting decision with one of its options. Posting, publishing and sending happen only as that option says.	Yes
`update_brand`	Rewrites what the brand is, who it’s for, or how it talks. Every plan, post and page reads these.	Yes
`make_pictures`	Makes 1 to 4 pictures in the project’s look. It quotes the price in tokens first, and only starts when the agent confirms.	Yes
`ask_marsell`	Talks to Marsell in the project’s chat: ask what it is doing and why, or tell it what to change. Answers can take a minute and spend tokens.	Yes

When you have more than one project, the agent names the project it means; with one project it can leave it out.

Limits and safety

A key acts as you. It uses the role of the person who made it, checked on every call. If that person leaves the organisation, their key stops working.
Your plan applies. Work that costs tokens, such as make_pictures and ask_marsell, spends your Marsell plan’s tokens, the same as in the app.
Approvals still apply. An agent can answer a decision only when the key has Can act, and only with the options the decision offers.
Rate limit. Up to 120 calls a minute per key.

Technical details

POST https://getmarsell.com/mcp, Streamable HTTP. Each request carries one JSON-RPC message, or a batch of up to 20, and gets JSON back. There is no event stream or session: GET /mcp answers 405.
Methods: initialize, ping, tools/list and tools/call. Protocol versions 2025-11-25, 2025-06-18, 2025-03-26 and 2024-11-05.
A call without a valid key gets 401: “Use an agent key from Marsell: Authorization: Bearer mk_…”.

Not the same as the docs’ search server

https://docs.getmarsell.com/mcp searches these docs and needs no key. It can’t see your projects. See Use these docs with AI.

Build with Marsell

These docs

Marsell MCP server

Make a key

Connect your agent

What your agent can do

Limits and safety

Technical details

Not the same as the docs’ search server

​Make a key

​Connect your agent

​What your agent can do

​Limits and safety

​Technical details

​Not the same as the docs’ search server

Make a key

Connect your agent

What your agent can do

Limits and safety

Technical details

Not the same as the docs’ search server