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Mailtrap MCP Integration for Claude Agent SDK

Connect Mailtrap to Claude Agent SDK through the local KosmoKrator MCP gateway with scoped tools, credentials, and write policy.

7 functions 6 read 1 write API token auth
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Connect Mailtrap to Claude Agent SDK

Give Claude Agent SDK workflows access to KosmoKrator integrations through a local MCP server.

Add a KosmoKrator stdio MCP server to the Claude Agent SDK options. The gateway is local, scoped to this integration, and starts with --write=deny so Claude Agent SDK can inspect read-capable tools without receiving write access by default.

Mailtrap MCP Config for Claude Agent SDK

Use a narrow integration list so the agent does not load unrelated tools.

{
  "mcpServers": {
    "kosmokrator-mailtrap": {
      "type": "stdio",
      "command": "kosmo",
      "args": [
        "mcp:serve",
        "--integration=mailtrap",
        "--write=deny"
      ]
    }
  }
}

Run the Gateway Manually

kosmokrator mcp:serve --integration=mailtrap --write=deny

Why Use KosmoKrator Here

Scoped tools

Expose only Mailtrap instead of a broad multi-service tool list.

Local credentials

Reuse credentials already configured for the KosmoKrator CLI and Lua runtime.

Write policy

Start read-only, then opt into ask or allow for trusted workspaces.

Mailtrap Tools Visible to Claude Agent SDK

Claude Agent SDK sees stable MCP tool names generated from the Mailtrap integration catalog.

MCP toolSource functionTypeDescription
integration__mailtrap__mailtrap_list_inboxes mailtrap.mailtrap_list_inboxes Read List all inboxes in the Mailtrap account. Returns inbox IDs, names, and email addresses.
integration__mailtrap__mailtrap_get_inbox mailtrap.mailtrap_get_inbox Read Get details for a specific Mailtrap inbox by ID, including its email address, settings, and message counts.
integration__mailtrap__mailtrap_list_messages mailtrap.mailtrap_list_messages Read List messages in a Mailtrap inbox with optional search and pagination.
integration__mailtrap__mailtrap_get_message mailtrap.mailtrap_get_message Read Get a single message from a Mailtrap inbox by its ID, including subject, sender, recipient, and body.
integration__mailtrap__mailtrap_send_test_email mailtrap.mailtrap_send_test_email Write Send a test email through Mailtrap. Provide sender, recipient(s), subject, and either text or HTML body.
integration__mailtrap__mailtrap_list_suppressions mailtrap.mailtrap_list_suppressions Read List suppressions (blocked recipients) for a Mailtrap inbox.
integration__mailtrap__mailtrap_get_current_user mailtrap.mailtrap_get_current_user Read Get the current Mailtrap user profile and account info. Useful as a health check.

Related Mailtrap Pages

Mailtrap CLIUse direct JSON commands instead of MCP discovery. Mailtrap MCPFull gateway reference and MCP tool names. KosmoKrator for Claude Agent SDKClient-level gateway setup.