Lumail Plugin

Lumail plugin — MCP basics

The Lumail plugin connects Claude Code and Codex to one Lumail organization over an OAuth MCP connection at https://lumail.io/mcp. There is no API token to create, paste, or store: the host runs the browser OAuth flow, the user picks the organization, and the access token stays in the host's credential store.

Before the first tool call

Confirm the server is connected and authenticated.

Claude Code:

claude mcp get plugin:lumail:lumail

Codex:

codex mcp list

Expected: status connected, URL https://lumail.io/mcp. If the status is "needs authentication", run the login command for the host — claude mcp login plugin:lumail:lumail or codex mcp login lumail — and tell the user a browser window will open. Do not ask the user for an API token; this connection does not use one.

What the connection can and cannot do

The OAuth connection exposes a deliberately narrowed tool set. It is scoped to the single organization the user picked during consent, and to that user's membership — only owners and admins can authorize it.

Read (lumail.read scope): list_subscribers, get_subscriber, list_tags, list_campaigns, get_campaign, render_campaign, get_campaign_analytics, get_campaign_progress, list_workflows, get_workflow, list_workflow_groups, get_workflow_group, get_org_stats, get_subscriber_stats, get_subscriber_growth, get_email_senders, get_custom_fields, get_email_snippets, get_writing_style, get_available_variables, get_skill.

Write (lumail.write scope): add_subscriber, get_or_create_tags, bulk_add_tags, bulk_remove_tags, create_campaign, edit_campaign, duplicate_campaign, auto_fit_campaign_images, create_workflow, configure_workflow_draft, update_workflow_draft, create_workflow_group, update_workflow_group, set_workflow_group.

Not available over OAuth at all: sending a campaign, scheduling a send, publishing or activating a workflow, unsubscribing someone, and every delete. These are not permission-gated — the tools are not registered on this endpoint. If the user asks for one, say so plainly and point them at the Lumail app, or at the API-token MCP endpoint if they want the full catalog in an agent.

Working rules

• Read before you write. Call the matching list_* or get_* tool before creating or editing anything, so you edit the record the user means.
• Campaigns start as drafts. create_campaign and edit_campaign produce drafts. Never imply a campaign was sent — it was not, and it cannot be from here.
• Workflows are configured as one graph. Call get_skill with type workflow first, read the current state with get_workflow, then call configure_workflow_draft passing the exact updatedAt value you read. A stale updatedAt is rejected, which is the intended optimistic lock.
• Tags are resolved, not invented. get_or_create_tags returns the ids that bulk_add_tags and bulk_remove_tags expect.
• Bulk tag operations are real and immediate. Confirm the target set with list_subscribers and repeat the count back to the user before running one.

Rate limits

Per organization, per minute: 100 on Free, 700 on Premium, 2,000 on Business. A 429 carries Retry-After; wait it out rather than retrying immediately.

Errors

• 401 with a WWW-Authenticate header — the access token expired or was revoked. Re-run the host's login command.
• "Only Lumail organization owners and admins can authorize the plugin" — the user is a member, not an owner or admin, of the org they selected. They need to re-authorize picking an org where they are owner or admin.
• "Tool not found" — either the tool is one of the send/delete tools that this endpoint intentionally omits, or it is gated off for the organization's plan. Check list_* availability before assuming a bug.

When to use the CLI instead

The lumail skill covers npx lumail, which reaches the full API surface including sending. It authenticates separately with npx lumail auth login (same browser OAuth, lumail.cli scope). Use it when the user explicitly wants an action this MCP connection does not expose, and only after they ask for it.