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Email Send API

Official registry Productivity

Send emails programmatically via Resend. Text and HTML. x402 micropayment.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (sse)
Claude Code 
claude mcp add --transport sse email-send-api 'https://email-send.api.klymax402.com/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "email-send-api": {
            "type": "sse",
            "url": "https://email-send.api.klymax402.com/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Email Send API
  2. Quickstart -- MCP
  3. Quickstart -- HTTP (x402)
  4. Tools
  5. Example agent prompts
  6. Payment
  7. Part of klymax402
  8. License

Email Send API

Send emails programmatically via Resend -- text or HTML body, delivery status, message ID. Transactional email. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "email-send": {
      "url": "https://email-send.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://email-send.api.klymax402.com/api/send" \
  -H "Content-Type: application/json" \
  -d '{"to":"...","subject":"...","body":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

ToolMethodPathPriceDescription
email_send_messagePOST/api/send$0.008Send an email message
email_send_message

Use this when you need to send an email to one or more recipients. Returns delivery confirmation in JSON.

Parameters

NameTypeRequiredDescription
tostringyesRecipient email address
fromstringnoSender email address (default: noreply@x402.dev)
subjectstringyesEmail subject line
bodystringyesEmail body content (plain text)
htmlstringnoEmail body content (HTML, optional — overrides body)

Example response:

{"messageId":"msg_01abc123","status":"sent","timestamp":"2026-04-13T14:30:00Z","to":"user@example.com","from":"noreply@x402.dev","subject":"Your Report"}

When to use: sending transactional emails, notifications, alerts, password resets, order confirmations, and automated reports.

Not for: email validation (use email_verify_address), finding email addresses (use email_find_by_name), person data enrichment (use person_enrich_from_email).

Example agent prompts

  • "Send an email to one or more recipients"

Payment

  • Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
  • Network: Base L2 (eip155:8453)
  • Asset: USDC
  • Facilitator: Coinbase CDP (primary), PayAI (fallback)
  • Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

License

MIT

Frequently asked questions

What is Email Send API?

Send emails programmatically via Resend. Text and HTML. x402 micropayment.

How do I install Email Send API?

It runs as a remote server. In Claude Code: claude mcp add --transport sse email-send-api 'https://email-send.api.klymax402.com/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Email Send API need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Email Send API open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Email Send API?

It is published by Br0ski777. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.