KosmoKrator

productivity

Mailtrap MCP Integration for LangGraph

Connect Mailtrap to LangGraph 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 LangGraph

Run KosmoKrator integration calls from LangGraph nodes while preserving local credentials and permissions.

Use a graph node that calls the KosmoKrator CLI for deterministic steps or an MCP client for dynamic tool selection. The gateway is local, scoped to this integration, and starts with --write=deny so LangGraph can inspect read-capable tools without receiving write access by default.

Mailtrap MCP Config for LangGraph

Headless CLI calls fit repeatable graph edges; MCP fits exploratory agent nodes.

{
  "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 LangGraph

LangGraph 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 LangGraphClient-level gateway setup.