Sendblue

Send customer messages, read replies, and check delivery from your Sendblue workspace in Claude, Grok Bot, and Cursor.

The plugin connects to Sendblue's hosted MCP server using Streamable HTTP and OAuth. Sign in with your Sendblue account, choose the workspace, and grant the permissions you want to use.

Connect in Claude

Open Customize > Connectors and select Add > Add custom connector.
Enter Sendblue as the name and https://api.sendblue.co/mcp as the server URL.
Review the detected OAuth configuration. Use Register automatically for the OAuth client and leave request headers empty.
Complete setup, connect, and sign in to Sendblue. Select the workspace and approve the read and/or send permissions you need.
Start a conversation with Sendblue enabled and ask Claude to check the connection.

Team and Enterprise owners add the connector in their organization settings first. Members then connect their own Sendblue accounts from Customize > Connectors.

The custom connector is available now. The Claude directory listing is being prepared for review.

Connect in Grok Bot

Open Connect apps and choose Add a custom connector.
Enter Sendblue as the name and select Remote HTTPS.
Enter https://api.sendblue.co/mcp as the server URL.
Leave HTTP headers and Client ID empty. Choose Add plugin.
Complete the browser authorization. If the connector shows an initial error, choose Reconnect and complete authorization.
Return to Grok Bot and verify Connected with 6 of 6 enabled.

This is the custom-connector installation flow. Marketplace distribution is pending review.

Connect in Cursor

Add this server to your MCP configuration, then complete its OAuth sign-in.

{
  "mcpServers": {
    "sendblue": {
      "url": "https://api.sendblue.co/mcp"
    }
  }
}

For local plugin development, copy this plugin directory into ~/.cursor/plugins/local/sendblue, reload Cursor, and inspect the discovered components in Customize. Follow your team's plugin policy.

Available tools

Tool	Purpose
`ping`	Check connectivity and echo a supplied message
`list_lines`	Find sending numbers assigned to the connected account
`list_messages`	Read recent messages, with contact and direction filters
`send_message`	Send one text message from the connected account
`get_message_status`	Check a message using the UUID returned by Sendblue
`evaluate_service`	Summarize recent outbound messaging health over a bounded window

Example requests

Check my Sendblue connection and list my available sending numbers.
Show the three most recent messages for the contact I specify.
Send the exact text I provide to the recipient I specify, then check its status.
Summarize outbound messaging health over the past 24 hours, including sampling and denominators.

Permissions and sending

messages:read permits message-history and account-health reads. messages:send permits message sending. Send-only access can check the status of a send made by the connected app. Access follows the workspace and permissions authorized in Sendblue.

Use a fresh UUID idempotency_key for each intentional send. Retry the same send with identical inputs and the same key. Check the returned message UUID when the outcome is uncertain.

Free-plan accounts must specify a sending line and use a recipient whose shared-line routing is already established. Follow the Sendblue dashboard's recipient setup flow before testing sends on such accounts.

evaluate_service samples at most the newest 100 messages in the requested window. Include the window, sample size, total count, and relevant denominators when reporting its results. SMS lacks delivery receipts, so confirmed-delivery rates need to be interpreted alongside the service mix.

Disconnect or revoke access through Sendblue Connected Apps. Grok Bot connections are account-wide and may be used by the other Bots on that account.

Support and terms

Platform references

Official MCP Registry

The hosted messaging connector is described in server.json as io.github.sendblue-api/sendblue. It uses the same OAuth-protected HTTPS endpoint documented above. The manually dispatched Publish official MCP Registry metadata GitHub Actions workflow publishes metadata using short-lived GitHub OIDC credentials; no repository secret or additional DNS record is needed. The repository contains client configuration and listing metadata; the remote service is operated by Sendblue.

sendblue

Documentation