Plain

MCP server for the Plain customer support platform. Provides tools for managing threads, help center articles, and more via the Model Context Protocol.

Setup

With Claude Code

Add to your project's .claude/settings.json:

{
  "mcpServers": {
    "plain": {
      "command": "npx",
      "args": ["-y", "@orbitlogistics/mcp-plain@latest"],
      "env": {
        "PLAIN_API_KEY": "${PLAIN_API_KEY}"
      }
    }
  }
}

Then set PLAIN_API_KEY in your shell environment (e.g. .zshrc, .envrc, or a secrets manager).

With other MCP clients

Run the server directly:

PLAIN_API_KEY=plainApiKey_xxx npx @orbitlogistics/mcp-plain@latest

Tools

Note: This server does not cover the full Plain API — only the endpoints we actively use. If you need additional methods, PRs are welcome!

Threads

• list_threads - List threads with filters (status, priority, labels, customer, tenant)
• get_thread - Get full thread details by ID (includes timeline)
• get_thread_by_ref - Get thread by reference number (e.g. T-510)
• get_thread_fields - Get custom field values for a thread
• create_thread - Create a new thread (auto-creates customer by email if needed)
• reply_to_thread - Send a reply through the original channel
• mark_thread_as_done - Mark a thread as resolved
• upsert_thread_field - Set/update custom field values
• add_internal_note - Post an internal note (not visible to customer)
• add_labels - Add category labels to a thread
• get_label_types - List available label types

Thread links

• link_threads - Link a thread to another Plain thread, a Linear issue, a Jira issue, or a generic source
• get_thread_links - List the links on a thread
• unlink_thread - Remove a link by its link ID

get_thread and get_thread_by_ref also return the first 25 links of a thread in a links array.

Attachments

• get_attachment_download_url - Get a temporary download URL
• get_attachment_content - Fetch attachment content (text or base64)

Help Center

• list_help_centers - List all help centers
• get_help_center - Get help center structure (groups and articles)
• list_help_center_articles - List articles with full content
• get_help_center_article - Get article by ID
• get_help_center_article_by_slug - Get article by URL slug
• upsert_help_center_article - Create or update an article (new articles default to DRAFT; updates keep the article's current status, group and slug unless you pass them, and always keep its icon and labels)
• create_help_center_article_group - Create an article group
• delete_help_center_article_group - Delete an empty article group

Development

pnpm install
pnpm test
pnpm build

License

MIT