Set up Plain for a person

You are an agent setting up Plain, a customer support platform, for the person you’re working with. You do the setup through Plain’s Model Context Protocol (MCP) server at https://mcp.plain.com/mcp, which signs in as that person with OAuth. Don’t ask the person for an API key: the MCP server needs none, and an API key belongs to a machine user, not to them. Follow the steps in order. Steps 1 to 4 only read. In step 5, nothing in the workspace changes until the person agrees to it. When the person has to choose, such as which labels to create or which Slack channels to connect, use your host’s question tool if it has one, such as AskUserQuestion in Claude Code. Otherwise ask in chat. When you’ve handed the person something to do, such as signing up or approving Slack, and they say they’re done, check it with a tool if you can, then move straight on to the next step. Related resources:

MCP server reference: MCP server lists every tool and host-specific troubleshooting
Docs index: https://www.plain.com/docs/llms.txt
OAuth metadata: https://mcp.plain.com/.well-known/oauth-protected-resource/mcp

1. Check for an existing connection

If Plain tools are already loaded in your session, call getMyWorkspace. When it returns a workspace, tell the person its name and ID and ask whether it’s the workspace they want to set up. A connection is bound to one workspace, so it might be the wrong one. If it is the right one, go to step 4. If no Plain tools are loaded, ask whether the person already has a Plain workspace. If they do, or they gave you a workspace ID (it starts with w_), go to step 3 and check after connecting that getMyWorkspace returns that workspace. Otherwise, or if getMyWorkspace fails with No workspace ID provided, start at step 2. The person signs up themselves. You can’t create an account or a workspace for them. Send them this link and wait for them to say they’re done:

https://app.plain.com/get-started

Tell them to:

Sign up with Google or their work email
Name their workspace when Plain asks
Come back to you once the workspace exists

Don’t connect the MCP server before the workspace exists. The connection gets bound to an account with no workspace, every tool fails with No workspace ID provided, and the person has to reconnect.

3. Connect the Plain MCP server

Add the server for the host you’re running in. Every host opens a browser window for the person to sign in to Plain and pick the workspace. The person must finish that sign-in themselves.

Claude Code

Run this command, then ask the person to run /mcp, select plain, and choose Authenticate:

claude mcp add --transport http --scope user plain https://mcp.plain.com/mcp

Claude Code loads the Plain tools once authentication finishes. If they don’t appear, ask the person to restart Claude Code.

Codex

Run this command. Codex detects that the server uses OAuth and opens the browser sign-in:

codex mcp add plain --url https://mcp.plain.com/mcp

Cursor

Add the server to ~/.cursor/mcp.json, or to .cursor/mcp.json in the project:

{
  "mcpServers": {
    "plain": {
      "url": "https://mcp.plain.com/mcp"
    }
  }
}

Cursor shows a Needs login prompt next to Plain. Ask the person to click it.

Claude and Claude desktop

You can’t add a connector from inside a chat. Ask the person to:

Go to Customize → Connectors
Click +, then Add custom connector
Name it Plain and set the URL to https://mcp.plain.com/mcp
Click Connect next to the new connector and sign in

On a Team or Enterprise plan, only an admin can add custom connectors. If the person isn’t an admin, they need to ask theirs.

ChatGPT

Ask the person to:

Turn on Developer Mode in Settings → Apps → Advanced settings
Click Create app, name it Plain, and set the URL to https://mcp.plain.com/mcp
Set authentication to OAuth, click Create, and sign in

If Advanced settings is missing, the person’s ChatGPT admin has to allow custom apps.

Other hosts

Any host that supports remote MCP servers over HTTP with OAuth works. Point it at https://mcp.plain.com/mcp. If your host can’t connect to remote MCP servers, tell the person you can’t set up Plain from here and send them to Claude or ChatGPT with the steps above. When the connection is up, call getMyWorkspace and confirm the workspace name with the person.

Find Plain’s apps

Some Plain tools open an app: an interactive Plain view inside the chat where the person reviews and edits what you set up. Hosts that render MCP Apps show the view. Other hosts get the same result as text.

Find them: search your Plain tools for ones whose description says they show the person a view, such as suggestLabels and showWorkflow
Always use one when it exists: after you make a change, or to propose one, open the app for it so the person can check and change your work
Don’t repeat the view: when an app shows the result, don’t list the same details again in chat

4. Read the setup checklist

Call workspaceSetup. It returns the same onboarding checklist the person sees in the Plain app, with a steps list of key and isComplete. Also call getLabels, workflows and workspaceSlackChannelIntegrations so you know what already exists. Tell the person in a sentence what’s done and what’s left. If workspaceSetup returns a not-yet-implemented error, the checklist isn’t available for this workspace. Work through step 5 from what the other reads returned, and treat each step’s status as unknown. Any other error goes to If something fails.

5. Walk the person through each step

Go through the steps that aren’t complete one at a time, in the order of the table below, which follows the onboarding in the Plain app. Two steps don’t go by the checklist: include CONNECT_CHANNELS while connectedSlackChannels is empty, and always include SET_UP_WORKFLOWS. Leave out email and SET_UP_TIERS for now, even if the checklist lists them. Finish each step before you start the next, and don’t save steps for a list at the end:

A step you can do with tools: tell the person exactly what you’ll create, wait for a yes, do it, then show the result
A step the person does in the app: give them that step’s link, wait for them to say they’re done, check it with a tool if you can, then move on
A step the person wants to skip: move on

Step key	What to do
`CONNECT_CHANNELS`	The checklist marks this complete once Slack is installed, even with no channels connected, so judge it by `connectedSlackChannels` instead. If `workspaceSlackChannelIntegrations` returns none, give the person the Slack install link, which takes them straight to Slack to approve. When they say they’re done, call `workspaceSlackChannelIntegrations` and `connectedSlackChannels` to confirm Slack is connected and which channels are. Installing Plain doesn’t join any channels, so if `connectedSlackChannels` is empty, ask the person to add the Plain app to a channel in Slack, then check again when they say they’re done. Move on once a channel is connected or the person skips it. Don’t set up channel rules unless the person asks.
`INVITE_TEAM`	The person invites teammates in the app. Give them the invite link.
`CREATE_LABEL_TYPES`	Call `suggestLabels` with labels that fit the person’s support, so they can review and create them in the app. If it isn’t available, check `getLabels` so you don’t duplicate any, then create the agreed labels with `createLabelType`.
`SET_UP_SIDEKICK`	The person picks the Sidekick Agent’s tools in the app. Give them the Sidekick Agent integrations link.
`SET_UP_WORKFLOWS`	Do this step even when the checklist marks it complete. Plain creates workflows with every workspace. Show them with `showWorkflow`, or list them if it isn’t available, as the premade workflows for auto-labeling, priority and investigation. Tell the person to ask if they have questions, or say done to move on. If they want more detail about a workflow or want to change one, read `workflowBuilderGuide` first: it explains the triggers and every step. Change a workflow only if the person asks.

Once the checklist steps are done, offer test threads: createAllTestThreads fills the inbox with example conversations from test customers, so the person can practice replying. If you change a workflow, watch for 2 traps:

Unpublished by default: createWorkflow creates a draft, and the checklist only counts a published workflow. If the person doesn’t approve publishing with updateWorkflow, report it as a draft.
Steps get replaced: bulkUpsertWorkflowSteps deletes every step you don’t pass it. Never run it on an existing workflow without the complete list of steps.

Some hosts, such as Claude, ask the person to approve each tool call, so batch your writes within a step where a tool allows it.

Links

Replace workspace_id_here with the ID from getMyWorkspace, which starts with w_. Never send a link with a placeholder in it.

Page	Link
Slack install	`https://app.plain.com/workspace/workspace_id_here/install/slack`
Invite teammates	`https://app.plain.com/workspace/workspace_id_here/settings/members/add`
Sidekick Agent integrations	`https://app.plain.com/workspace/workspace_id_here/sidekick/integrations`

If the workspace syncs its members from a directory, the invite page redirects to the members list. The person adds teammates in their identity provider instead.

6. Finish in the Plain app

When every step is done or skipped, give the person:

What you set up: a short list, grouped by checklist step
What they skipped: each with its link, so they can come back to it
Their workspace: https://app.plain.com/workspace/workspace_id_here

If something fails

Error	What to do
`No workspace ID provided`	The connection was made before a workspace existed. Have the person create one (step 2), then re-authenticate the MCP server.
`403` after OAuth completes	The token is missing the `openid offline_access` scopes. Have the person disconnect and reconnect the MCP server. If your host lets you set scopes, request both.
A tool is missing	The host cached an old tool list. Disconnect and reconnect the MCP server.
A permission error	The person’s role in Plain doesn’t allow that action. An admin can do it, or change their role.
Anything else	Tell the person to email help@plain.com with their workspace ID, the error, and the host they’re using.

Agents

Channels

Platform

Integrations

Workflows

Broadcasts

Help center

Security

Plans & Billing

Set up Plain for a person

1. Check for an existing connection

3. Connect the Plain MCP server

Claude Code

Codex

Cursor

Claude and Claude desktop

ChatGPT

Other hosts

Find Plain’s apps

4. Read the setup checklist

5. Walk the person through each step

Links

6. Finish in the Plain app

If something fails

​1. Check for an existing connection

​2. Have the person sign up and create a workspace

​3. Connect the Plain MCP server

​Claude Code

​Codex

​Cursor

​Claude and Claude desktop

​ChatGPT

​Other hosts

​Find Plain’s apps

​4. Read the setup checklist

​5. Walk the person through each step

​Links

​6. Finish in the Plain app

​If something fails

1. Check for an existing connection

2. Have the person sign up and create a workspace

3. Connect the Plain MCP server

Claude Code

Codex

Cursor

Claude and Claude desktop

ChatGPT

Other hosts

Find Plain’s apps

4. Read the setup checklist

5. Walk the person through each step

Links

6. Finish in the Plain app

If something fails