# @emailens/mcp MCP server for email compatibility analysis. Analyze, preview, diff, and fix HTML emails across 15 email clients — plus capture real screenshots and create shareable links with an optional API key. Built on [`@emailens/engine`](https://github.com/emailens/engine). ## Install ```bash npx -y @emailens/mcp ``` ## Setup ### Claude Desktop Add to `claude_desktop_config.json`: ```json { "mcpServers": { "emailens": { "command": "npx", "args": ["-y", "@emailens/mcp"] } } } ``` ### Claude Code ```bash claude mcp add emailens -- npx -y @emailens/mcp ``` ### With API Key (optional — unlocks screenshots + sharing) ```json { "mcpServers": { "emailens": { "command": "npx", "args": ["-y", "@emailens/mcp"], "env": { "EMAILENS_API_KEY": "ek_live_..." } } } } ``` Get your free API key at [emailens.dev/settings/api-keys](https://emailens.dev/settings/api-keys). ## Tools ### Local Tools (no account needed) #### `preview_email` Full email compatibility preview — transforms HTML for 15 clients, analyzes CSS, generates scores, simulates dark mode, checks inbox preview and email size. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML source | | `clients` | string[] | No | Filter to specific client IDs | | `format` | enum | No | `"html"`, `"jsx"`, `"mjml"`, `"maizzle"` | #### `analyze_email` Quick CSS compatibility analysis — returns per-client scores and warnings. Faster than `audit_email` when you only need CSS compatibility. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML source | | `format` | enum | No | Input format | #### `audit_email` Comprehensive quality audit — CSS compatibility, spam scoring, link validation, accessibility, images, inbox preview, size (Gmail clipping), and template variables. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML source | | `format` | enum | No | Input format | | `skip` | string[] | No | Checks to skip (e.g. `["spam", "images"]`) | #### `fix_email` Generate a structured fix prompt for compatibility issues. Returns markdown with fix instructions that the AI can apply directly. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML to fix | | `format` | enum | No | Controls fix syntax | | `scope` | enum | No | `"all"` or `"current"` | | `selectedClientId` | string | No | Client ID for scoped fixes | #### `list_clients` List all 15 supported email clients with IDs, names, engines, and dark mode support. #### `diff_emails` Compare two email HTML versions — shows score changes, fixed issues, and introduced issues per client. | Parameter | Type | Required | Description | |---|---|---|---| | `before` | string | Yes | Original email HTML | | `after` | string | Yes | Modified email HTML | | `format` | enum | No | Input format | #### `check_deliverability` Check email deliverability for a domain — SPF, DKIM, DMARC, MX, BIMI records with a score and actionable issues. | Parameter | Type | Required | Description | |---|---|---|---| | `domain` | string | Yes | Domain to check (e.g. `"company.com"`) | ### Hosted Tools (require `EMAILENS_API_KEY`) #### `capture_screenshots` Capture real email screenshots across 15 clients in real browsers. Screenshots are hosted on CDN. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML source | | `format` | enum | No | Input format | | `clients` | string[] | No | Filter clients | | `modes` | string[] | No | `["light"]`, `["dark"]`, or `["light", "dark"]` | | `title` | string | No | Name for the preview | Free plan: 30 previews/day. [Sign up](https://emailens.dev?ref=mcp) #### `share_preview` Create a shareable link. Recipients see the full analysis without an account. | Parameter | Type | Required | Description | |---|---|---|---| | `html` | string | Yes | Email HTML source | | `title` | string | No | Display title | | `format` | enum | No | Input format | Requires Dev plan ($9/mo). Share links expire after 7 days (Dev) or never (Pro). ## Supported Email Clients (15) | Client | ID | Dark Mode | Notes | |---|---|---|---| | Gmail | `gmail-web` | Yes | | | Gmail Android | `gmail-android` | Yes | | | Gmail iOS | `gmail-ios` | Yes | | | Outlook 365 | `outlook-web` | Yes | | | Outlook Windows | `outlook-windows` | No | | | Outlook Windows Legacy | `outlook-windows-legacy` | No | Deprecated Oct 2026 | | Outlook iOS | `outlook-ios` | Yes | New in v0.4.0 | | Outlook Android | `outlook-android` | Yes | New in v0.4.0 | | Apple Mail | `apple-mail-macos` | Yes | | | Apple Mail iOS | `apple-mail-ios` | Yes | | | Yahoo Mail | `yahoo-mail` | Yes | | | Samsung Mail | `samsung-mail` | Yes | | | Thunderbird | `thunderbird` | No | | | HEY Mail | `hey-mail` | Yes | | | Superhuman | `superhuman` | Yes | | ## Development ```bash bun install bun run build bun test bun run typecheck ```