Integrate SendKit MCP server

Overview

Connect your MCP-capable client (agent framework, IDE, or custom integration) to the SendKit MCP server to access SendKit tools, resources, and prompts over the Model Context Protocol.

The SendKit MCP server exposes a single MCP endpoint, uses OAuth for authentication, and communicates over the Streamable HTTP transport defined in the MCP specification.

Endpoint, auth, and transport

MCP endpoint

Use this URL as the MCP endpoint in your client configuration:

https://mcp.sendkit.ai/mcp

The endpoint exposes MCP capabilities such as tools, resources, and prompts to your client once the session is authenticated.

Authentication model

SendKit uses OAuth-based authentication for its MCP server.

1. Your MCP client or integration obtains an OAuth access token from SendKit.
2. The client connects to https://mcp.sendkit.ai/mcp using the MCP Streamable HTTP transport, including the access token according to the transport and client conventions.
3. The server authorizes the session based on the provided token.

Transport: MCP Streamable HTTP

SendKit uses the MCP Streamable HTTP transport for the MCP endpoint.

According to the MCP specification, Streamable HTTP:

• Uses HTTP POST and GET requests to transport MCP messages
• Allows the MCP server to handle multiple client connections over HTTP
• Replaces the older HTTP+SSE transport from protocol version 2024-11-05, although servers may host both for backwards compatibility

You connect your MCP client to https://mcp.sendkit.ai/mcp as a Streamable HTTP endpoint; the client handles the underlying GET and POST calls according to the MCP spec.

For the full transport details, see the official MCP specification:
Streamable HTTP transport specification

Configure your MCP client

Configure your MCP-capable client or framework with the SendKit endpoint, OAuth details, and token handling.

{
  "mcpServers": {
    "sendkit": {
      "transport": "streamable-http",
      "endpoint": "https://mcp.sendkit.ai/mcp",
      "auth": {
        "type": "oauth",
        "tokenSource": "sendkit-oauth",
        "clientId": "YOUR_SENDKIT_CLIENT_ID",
        "redirectUri": "https://your-app.example.com/oauth/callback"
      }
    }
  }
}

# Placeholder example showing the overall flow conceptually.

# 1. Run your own OAuth client against SendKit to obtain an access token.
#    Replace these variables with values from your SendKit dashboard/admin.
SENDKIT_CLIENT_ID="your-sendkit-client-id"
SENDKIT_REDIRECT_URI="https://your-app.example.com/oauth/callback"
SENDKIT_ACCESS_TOKEN="access-token-from-sendkit-oauth-flow"

# 2. Start or configure your MCP client so it uses:
#    - Endpoint: https://mcp.sendkit.ai/mcp
#    - Transport: Streamable HTTP
#    - Auth: the SENDKIT_ACCESS_TOKEN above according to your client's conventions

Test connectivity

After configuration, verify that your MCP client can connect to the SendKit MCP endpoint using Streamable HTTP.

Use an MCP client that supports Streamable HTTP

Use an IDE, agent framework, or custom client that explicitly supports the MCP Streamable HTTP transport and allows you to:

• Configure a Streamable HTTP endpoint URL
• Provide or reference an OAuth access token for that endpoint

Start your MCP client and connect to the sendkit server entry you configured earlier.

Look for a successful initialization

A successful connection typically includes:

• The client establishing a Streamable HTTP session against https://mcp.sendkit.ai/mcp
• An initial MCP handshake or initialization exchange defined by your client and the MCP spec
• The client listing SendKit tools, resources, or prompts as available capabilities

Your client’s logs should show a successful connection or session initialization without authentication errors.

Troubleshooting

If your client cannot connect or authenticate, use these common checks.

401 or 403 errors

Authentication or authorization failures often appear as generic HTTP 401 or 403 responses at the transport layer or as client-side “unauthorized” errors.

Check:

• The access token is present in the request according to your client’s MCP configuration
• The token has not expired and is issued by SendKit for this client
• You used the correct endpoint: https://mcp.sendkit.ai/mcp over HTTPS

If you rotate credentials or change OAuth configuration in SendKit, restart or reconfigure your MCP client to use a fresh token.

Invalid redirect URI during OAuth

If your OAuth flow fails with an “invalid redirect URI” or similar message:

• Confirm the redirect URI your OAuth client uses matches exactly (including scheme and path) the value registered in SendKit
• Update the registered redirect URIs in the SendKit dashboard or via your admin if they changed
• Avoid using temporary or local URIs unless SendKit explicitly supports them

After correcting the redirect URI, rerun the OAuth flow to obtain a new access token.

Token expired or revoked

When tokens expire or are revoked, new MCP sessions fail to authenticate and existing sessions may be terminated.

To recover:

• Trigger your client’s token refresh or re-auth flow
• Confirm that refreshed tokens are propagated to the MCP configuration for https://mcp.sendkit.ai/mcp
• Retry the connection and confirm your client lists SendKit capabilities again

If issues persist, capture the client logs and share them with your SendKit admin or support contact, including timestamps and the type of OAuth flow you are using.