Can I use Mailtrap as a CLI?

Yes. KosmoKrator exposes a Mailtrap CLI through kosmo integrations:call and the provider shortcut command. Commands can return JSON for scripts, CI, and coding agents.

Can I expose Mailtrap through MCP?

Yes. The KosmoKrator MCP gateway can expose selected Mailtrap tools to clients such as Claude Code, Cursor, Codex, and other MCP-compatible tools.

Where are Mailtrap credentials stored?

Mailtrap credentials are configured in KosmoKrator's local integration settings and reused by CLI, Lua, and MCP gateway surfaces.

Can I deny write access for Mailtrap MCP tools?

Yes. Start the gateway with --write=deny for read-only clients, or use ask/allow only for trusted workspaces.

productivity

Mailtrap MCP Integration for LangChain

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

7 functions 6 read 1 write API token auth

Submit Mailtrap feedback View package source

Connect Mailtrap to LangChain

Bridge LangChain agents to local KosmoKrator integration tools through MCP or headless CLI calls.

Use the MCP gateway when the agent should discover tools, or wrap kosmo integrations:call for fixed chains. The gateway is local, scoped to this integration, and starts with --write=deny so LangChain can inspect read-capable tools without receiving write access by default.

Mailtrap MCP Config for LangChain

Keep the gateway scoped to the integration and operation class needed by the chain.

{
  "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 LangChain

LangChain sees stable MCP tool names generated from the Mailtrap integration catalog.

MCP tool	Source function	Type	Description
`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 LangChainClient-level gateway setup.