TempJar

Free temporary email for agents and apps: create and read temp inboxes via MCP, REST API, or CLI. Custom handles, password reclaim, 6-month retention, free plan 1,000 emails received per account per month. Receives mail only, not for banking or important accounts.

View on tempjar.com

Hosted MCP Server

npx add-mcp 'https://tempjar.com/api/mcp'

Installs into Claude Code, Codex, Cursor and more

Documentation

Free plan only (no paid plan yet): 1,000 emails received per account per calendar month, across all your API keys. When the quota is reached, further mail to your API inboxes is not stored until the next month. API reads and inbox creation are not counted.

1 · Create an account

Complete the captcha, then register. Your API key is shown exactly once — save it, TempJar stores only its hash and can never show it again.

Create account + API key

2 · REST API

Base: https://tempjar.com/api/v1 — clean URLs, no .php shown. Send X-API-Key: tj_live_... (or Authorization: Bearer tj_live_...).

Inboxes

GET /inboxes
POST /inboxes
DELETE /inboxes/{id}

Messages

GET /inboxes/{id}/messages
GET /inboxes/{id}/messages/{message_id}

Account

GET /domains
GET /usage

curl -H "X-API-Key: tj_live_..." https://tempjar.com/api/v1/domains
curl -H "X-API-Key: tj_live_..." https://tempjar.com/api/v1/usage
curl -X POST -H "X-API-Key: tj_live_..." -H "Content-Type: application/json" \
  -d '{"handle":"my-test","domain":"jarinbox.com"}' \
  https://tempjar.com/api/v1/inboxes
curl -H "X-API-Key: tj_live_..." "https://tempjar.com/api/v1/inboxes/1/messages?limit=20"

Create with handle, domain, optional password (generated if omitted, shown once), and lifespan 24h or 6mo (default 6mo).

3 · MCP server

URL: https://tempjar.com/api/mcp (Streamable HTTP, JSON-RPC 2.0). Tools: list_domains, list_inboxes, create_inbox, list_messages, get_message, get_usage.

{
  "mcpServers": {
    "tempjar": {
      "url": "https://tempjar.com/api/mcp",
      "headers": { "X-API-Key": "tj_live_..." }
    }
  }
}

4 · CLI

Download: tempjar-cli.py — Python 3.8+, no extra packages. Your key is stored locally with permissions 600 when you use set-key.

python3 tempjar-cli.py set-key
python3 tempjar-cli.py domains
python3 tempjar-cli.py create my-test jarinbox.com
python3 tempjar-cli.py messages 1
python3 tempjar-cli.py usage
python3 tempjar-cli.py register --email you@example.com

Or: TEMPJAR_API_KEY=tj_live_... python3 tempjar-cli.py inboxes

Rules

  • One API key is enough to start; create more, or revoke old ones, while signed in on this page's account session. A revoked key stops working immediately.
  • Never share your API key. TempJar staff will never ask for it.
  • Temp mail is for low-stakes sign-ups only — never banking or accounts you cannot afford to lose. Some sites block disposable domains.