Model Context Protocol

Give any AI agent a real inbox

OTPBox's MCP server puts a disposable email inbox one tool call away. Any agent that speaks MCP — Claude Code, Cursor, Codex, Gemini CLI, and a growing list of others — can create an inbox, wait for a real email to arrive, and read back the extracted OTP code or verification link, all mid-task.

Get a free key Full MCP reference

Connect in one step

OTPBox is a remote, streamable-HTTP MCP server at https://otpbox.io/mcp. Authenticate with the same bearer token as the REST API — no separate MCP credential, no install:

{
  "mcpServers": {
    "otpbox": {
      "url": "https://otpbox.io/mcp",
      "headers": { "Authorization": "Bearer <your-otpbox-key>" }
    }
  }
}

That exact shape works for Cursor, Claude Code (via .mcp.json), Trae, Kimi Code CLI and most MCP clients that support remote servers. A few use a slightly different key name or file — see the per-client pages below for the exact syntax of each.

Mint the key first — POST /api/v1/keys/free, no account or card needed, 200 requests/month. See Get a key.

13 tools, the full loop

Every tool mirrors a REST endpoint 1:1 — same data, same quota accounting, callable directly mid-task instead of through a fetch call your agent has to write itself.

create_test_inbox wait_for_email get_otp get_verification_link get_latest_email search_emails delete_inbox create_batch create_test_identity create_bulk_test_identities delete_test_identity register_webhook get_usage

Full argument/return shape for each: the MCP section of the docs.

What you get

No custom tools to write

An agent gets create/wait/read/delete for inboxes and test identities out of the box — nothing to hand-roll against the REST API.

Extraction built in

OTP codes and verification links are parsed server-side. get_otp and get_verification_link return the field directly, not a raw body to regex.

wait_for_email blocks

No polling loop needed — the tool call blocks server-side until a message arrives or a timeout elapses (up to 25s).

Free tier, no card

200 requests/month, one call to mint a key. Pro is $9/month for 5,000 pooled across a team.

Per-client setup

Exact config file and syntax for each agent, since a few use a different key name (httpUrl vs url) or file format (TOML, not JSON):

Limits

Each tool call counts as one request against the key's monthly quota, same as REST. Separately, MCP is capped at 60 tool calls/minute per key to catch a runaway agent loop before it burns through quota. Full detail: Rate limits and quota.

Not just for coding agents

A standing MCP server, a Skill, and an SDK all cover the same ground from different angles — pick what fits how your agent is built:

API docs Pricing All guides Changelog

← Back to OTPBox