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Use MISSIN in your AI chats

Connect Claude, Codex, Cursor and other AI assistants to MISSIN with a secret API key, so they can find partners, file posts and run captures for you.

Ask your AI assistant to do the work in MISSIN for you: "make a partner for @test11 and add their posts to my spring campaign". It connects to MISSIN's own server with a secret API key, and the key decides what it may do. Pick your assistant to jump to its steps.

How it works

claude — The assistant asks, the server checks the key, and the work happens in your workspace. Revoke the key and the assistant stops at once.

MISSIN runs one server for every assistant, at https://api.missin.co.uk/mcp. It speaks MCP, the Model Context Protocol, which is how AI apps plug into other services.
Your assistant sends a secret API key with every request. There is no sign-in screen: MISSIN does not offer OAuth sign-in yet, so an assistant that can only connect by signing in cannot connect today.
The key belongs to one workspace and acts as the member who created it, never above that member's role.

Create a key

Open the Developers panel.
Create a secret key. Pick Write to let the assistant change partners, campaigns and posts and start captures, or Read to let it look only.

The key starts with sk_live_ and is shown once. Copy it now, and keep it out of chats, documents and code repositories.

Level	What the assistant can do
Read	Look up campaigns, partners, posts, forms, orders and more, and get a capture quote.
Write	Also create and change partners, campaigns, posts, discounts and forms, and start captures.
Admin	Also change connections, integration settings, the brand and workspace settings.

No key can create or revoke other keys. That stays in the app.

Connect your assistant

Claude Desktop

The MISSIN extension is one file, and your key goes in a form, so there is nothing to edit.

Download missin.mcpb.
In Claude Desktop, open Settings, then Extensions, and drag the file onto the page. You can also open the file directly.
Select Install and confirm.
Paste your key when Claude Desktop asks for it. It is stored as a secret.

The extension has one more setting, Toolsets: which groups of tools Claude loads. The default, core, is the everyday set, and all loads everything. More on Claude, including the Claude Code plugin, is on the Claude page.

Claude.ai

A custom connector sends your key with every request, from the web app or the desktop app.

Open Customize, then Connectors, then Add custom connector. On a Team or Enterprise plan, an Owner adds it instead, under Organization settings, then Connectors, then Add, then Custom.
Enter the server address https://api.missin.co.uk/mcp.
Set Authentication to No sign-in.
Open Request headers, choose authorization, and enter Bearer followed by your key, with the space: Bearer sk_live_....
Select Add.

Claude Code

Run one command in your terminal, with your key in place of sk_live_...:

bash

claude mcp add --transport http --scope user missin https://api.missin.co.uk/mcp --header "Authorization: Bearer sk_live_..."

Then type /mcp inside Claude Code: missin shows as connected. Keep --scope user. A project-scoped server is written into your repository, and the key goes with it. To install the plugin, which also teaches Claude the MISSIN workflows, see the Claude page.

ChatGPT

ChatGPT cannot connect to MISSIN yet. Its custom MCP servers offer two kinds of authentication, OAuth sign-in or none, and neither can carry a MISSIN key. MISSIN does not offer OAuth sign-in yet, and the server refuses every request without a key.

Codex, OpenAI's coding agent, can send a key. OpenAI's docs say the ChatGPT desktop app, the Codex CLI and the Codex IDE extension share one MCP configuration, so set up Codex as in the next section.

Codex, Cursor and VS Code

Codex reads the key from an environment variable, so it never sits in a file. Put your key in MISSIN_API_KEY in your shell, then run:

bash

codex mcp add missin --url https://api.missin.co.uk/mcp --bearer-token-env-var MISSIN_API_KEY

Run codex mcp list to check that missin is there. Cursor and VS Code each take a short config entry that reads the key from your environment or asks for it once: Connect Cursor, VS Code and Codex has the files to copy.

Other assistants

Any assistant that connects to remote MCP servers and can send a header works: the address https://api.missin.co.uk/mcp and the header Authorization: Bearer sk_live_.... An assistant that starts programs on your computer can run npx -y @missin/cli mcp with MISSIN_API_KEY set instead. MISSIN is listed in the MCP Registry as uk.co.missin/mcp.

Let an AI agent install it for you

If you use a coding agent such as Claude Code, Codex or Cursor, copy this prompt into it. The agent checks the server, asks you for the key without repeating it, adds MISSIN with its own setup command, and checks that it works.

Install with an AI assistant

Copy this prompt into the AI assistant you're using.

Install the MISSIN MCP server for me and check that it works.

About the server
- MISSIN's hosted MCP server is https://api.missin.co.uk/mcp (Streamable HTTP, JSON responses).
- It takes a MISSIN secret API key as the header "Authorization: Bearer sk_live_...". It has no OAuth sign-in, so do not start one.
- Guides: https://docs.missin.co.uk/integrations/ai-assistants and https://developer.missin.co.uk/mcp/connect-claude

Steps
1. Check the server is reachable, without a key: POST {"jsonrpc":"2.0","id":1,"method":"initialize"} to https://api.missin.co.uk/mcp with Content-Type: application/json. Expect 401 with the header WWW-Authenticate: Bearer realm="missin".
2. Ask me for my secret API key. If I do not have one, tell me to create one in MISSIN under Settings, then Developers, at Read or Write. Never print the key back, never write it into a file under version control, and leave it out of your report.
3. Add a server named "missin" with this client's own command, at user level, never project level:
- Claude Code: claude mcp add --transport http --scope user missin https://api.missin.co.uk/mcp --header "Authorization: Bearer <the key>"
- Codex: have me export MISSIN_API_KEY, then run: codex mcp add missin --url https://api.missin.co.uk/mcp --bearer-token-env-var MISSIN_API_KEY
- Cursor: in ~/.cursor/mcp.json, "missin": { "url": "https://api.missin.co.uk/mcp", "headers": { "Authorization": "Bearer ${env:MISSIN_API_KEY}" } }
- Any other client: its user-level MCP config, Streamable HTTP, the same header.
4. Reload the MCP servers if this client needs it, then call the missin tool "whoami".
5. Report: which config you changed and where, whether whoami answered, and the workspace and access level it reported (as created and as it acts now). If it failed, give the status code: 401 means the key is missing, revoked or expired; 403 with secret_key_required means a publishable key was used.

Check it works

Ask your assistant: "Which MISSIN workspace are you connected to, and what can you change?" It answers with the workspace, the key's name and level, and who created it. It shows two levels: the one the key was created with, and the one it acts with now, which is capped by its creator's current role. The second is the one that counts.

What it can do

The everyday tools load by default. Your assistant picks them for you, so ask for the outcome, not the tool.

Tool	What it does	Level
`whoami`	Says which workspace and level the key has.	Read
`save_partner`	Creates or updates a partner and their social handles.	Write
`quote_capture`	Prices a capture before anything is spent.	Read
`start_capture`	Starts the capture at the price you approved.	Write
`get_capture_status`	Checks how a running capture is going.	Read
`save_campaign`	Creates or updates a campaign.	Write
`assign_posts_to_campaign`	Files posts into a campaign.	Write
`save_discount_code`	Creates or updates a discount code.	Write
`find_in_app`	Says where to click in MISSIN when a job needs the app.	Read

More toolsets, such as forms and waitlists, load on request. The developer guide lists them and every tool behind them: Load more tools.

Keep it safe

Spending credits. A capture costs credits, so the assistant first gets a quote and tells you the cost. It starts only at the price you approved, and if the price changes it asks again.
The lowest level that works. Use a Read key for an assistant that only answers questions.
One workspace. A key works in the workspace it belongs to and no other.
Revoke any time. Revoke the key in and it stops working at once, everywhere it was used.

Will the assistant spend my credits without asking?

No. It gets a quote first and tells you the cost, and it starts a capture only at the price you approved.

Can I use more than one assistant?

Yes. Create a key for each one, so you can revoke one without the others.

Why is there no Sign in with MISSIN button?

MISSIN's server accepts secret API keys only. Sign-in through OAuth is not offered yet, which is why ChatGPT and Claude's one-click connectors cannot connect today.