feat(resend-mcp): add Resend email API integration

package.json

@@ -21,8 +21,8 @@
   },
   "workspaces": [
     "apify",
-    "content-scraper",
     "blog-post-generator",
+    "content-scraper",
     "data-for-seo",
     "datajud",
     "deco-llm",
@@ -52,6 +52,7 @@
     "reddit",
     "registry",
     "replicate",
+    "resend-mcp",
     "shared",
     "slack-mcp",
     "sora",

resend-mcp-spec.md

@@ -0,0 +1,187 @@
+# Resend MCP Tool Specification
+
+This document describes all functionality from the Resend app that should be implemented as MCP tools.
+
+## Overview
+
+Resend is an email platform API for sending transactional and marketing emails. This MCP implementation should provide tools to interact with the Resend API.
+
+## Authentication & Configuration
+
+### API Configuration
+- **Base URL**: `https://api.resend.com`
+- **Authentication**: Bearer token in Authorization header
+  - Format: `Authorization: Bearer {API_KEY}`
+- **Content-Type**: `application/json`
+
+### Default Configuration (Optional)
+These can be set as defaults but should be overridable per-tool invocation:
+- **Default Sender Name**: e.g., "Contact"
+- **Default Sender Email/Domain**: e.g., "onboarding@resend.dev"
+- **Default Recipients**: Array of email addresses
+- **Default Subject**: Default email subject line
+
+## Tools
+
+### Tool 1: Send Email
+
+**Purpose**: Send an email via the Resend API
+
+**API Endpoint**: `POST /emails`
+
+**Input Parameters**:
+
+All parameters are optional if defaults are configured, but at minimum `to`, `subject`, and either `html` or `text` should be provided:
+
+- **from** (string, optional): Sender email address
+  - Format: Can be just email or "Name <email@domain.com>"
+  - Falls back to configured default sender if not provided
+
+- **to** (string | string[], required): Recipient email address(es)
+  - Can be a single email string or array of emails
+  - Falls back to configured default recipients if not provided
+
+- **subject** (string, required): Email subject line
+  - Falls back to configured default subject if not provided
+
+- **html** (string, optional): HTML content of the email
+  - Mutually usable with `text`, can send both
+
+- **text** (string, optional): Plain text content of the email
+  - Mutually usable with `html`, can send both
+
+- **bcc** (string | string[], optional): Blind carbon copy recipient(s)
+  - Can be a single email string or array of emails
+
+- **cc** (string | string[], optional): Carbon copy recipient(s)
+  - Can be a single email string or array of emails
+
+- **reply_to** (string | string[], optional): Reply-to address(es)
+  - Can be a single email string or array of emails
+
+- **headers** (object, optional): Custom email headers
+  - Key-value pairs of header names and values
+
+**Success Response**:
+```typescript
+{
+  data: {
+    id: string  // The ID of the newly created email
+  },
+  error: null
+}
+```
+
+**Error Response**:
+```typescript
+{
+  data: null,
+  error: {
+    message: string,
+    name: string  // Error code key (see Error Codes below)
+  }
+}
+```
+
+**Error Codes**:
+Map of error code keys to HTTP status codes:
+
+| Error Code Key | HTTP Status | Description |
+|----------------|-------------|-------------|
+| `missing_required_field` | 422 | Required field is missing |
+| `invalid_access` | 422 | Invalid access |
+| `invalid_parameter` | 422 | Invalid parameter value |
+| `invalid_region` | 422 | Invalid region |
+| `rate_limit_exceeded` | 429 | API rate limit exceeded |
+| `missing_api_key` | 401 | API key not provided |
+| `invalid_api_Key` | 403 | API key is invalid |
+| `invalid_from_address` | 403 | From address is invalid |
+| `validation_error` | 403 | Validation error |
+| `not_found` | 404 | Resource not found |
+| `method_not_allowed` | 405 | HTTP method not allowed |
+| `application_error` | 500 | Application error |
+| `internal_server_error` | 500 | Internal server error |
+
+**Implementation Notes**:
+1. The tool should accept all parameters and merge them with any configured defaults
+2. Parameters provided to the tool should override defaults
+3. The API request body should be JSON encoded
+4. The response should be parsed as JSON and returned in the format specified above
+
+## Additional Features & Context
+
+### React Email Template Support
+The original app supports rendering React email templates to HTML using `@react-email/render`. For the MCP implementation:
+- Users can use external tools to generate HTML from templates
+- The MCP tool should accept pre-rendered HTML via the `html` parameter
+- No need to implement React rendering in the MCP itself
+
+### Use Cases
+1. **Transactional Emails**: Order confirmations, password resets, notifications
+2. **Marketing Emails**: Newsletters, promotional campaigns
+3. **Form Submissions**: Contact forms, feedback forms
+
+### API Key Generation
+Users need to:
+1. Create account at https://resend.com/signup
+2. Generate API key at https://resend.com/api-keys
+3. Store the API key securely (it cannot be viewed again after creation)
+
+### Domain Configuration
+- Default sender domain is `onboarding@resend.dev` (Resend's domain)
+- For production use, users should configure their own domain through Resend's dashboard
+- Custom domains require DNS verification
+
+## Example Usage Scenarios
+
+### Scenario 1: Simple Text Email
+```json
+{
+  "to": "user@example.com",
+  "subject": "Welcome to our service",
+  "text": "Thank you for signing up!"
+}
+```
+
+### Scenario 2: HTML Email with Multiple Recipients
+```json
+{
+  "to": ["user1@example.com", "user2@example.com"],
+  "subject": "Monthly Newsletter",
+  "html": "<h1>Hello!</h1><p>Here's our monthly update...</p>"
+}
+```
+
+### Scenario 3: Full-Featured Email
+```json
+{
+  "from": "Support Team <support@mycompany.com>",
+  "to": "customer@example.com",
+  "subject": "Your Order #12345",
+  "html": "<html><body><h1>Order Confirmation</h1>...</body></html>",
+  "text": "Order Confirmation - Your order #12345 has been received",
+  "cc": "manager@mycompany.com",
+  "reply_to": "support@mycompany.com"
+}
+```
+
+## Implementation Checklist
+
+For your TypeScript MCP implementation:
+
+- [ ] Configure Resend API client with base URL and authentication
+- [ ] Implement `send_email` tool with all parameters
+- [ ] Handle optional default configuration (from, to, subject)
+- [ ] Parameter validation (at least one of html/text must be provided)
+- [ ] Proper error handling and error code mapping
+- [ ] Return structured response with data/error format
+- [ ] Support both single string and array formats for to/cc/bcc/reply_to
+- [ ] Document tool usage and parameters for MCP consumers
+
+## Security Considerations
+
+1. **API Key Storage**: Store API keys securely, never expose in logs or error messages
+2. **Rate Limiting**: Implement appropriate rate limiting to avoid hitting API limits
+3. **Email Validation**: Consider validating email formats before sending to API
+4. **Content Sanitization**: If accepting user input for email content, ensure proper sanitization
+5. **HTTPS Only**: All API communication must use HTTPS

resend-mcp/.gitignore

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+.dev.vars