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Quickstart

You need an API key from console.gmjroaming.com and some account balance.

Code
export GMJ_KEY="your-api-key"
export GMJ="https://api.gmjroaming.com/api/v1"

1. Check your account

Code
curl "$GMJ/user" -H "X-API-KEY: $GMJ_KEY" -H "Accept: application/json"

data.balance is your balance in USD.

2. Find a destination

Code
curl "$GMJ/list-country?search=japan" -H "X-API-KEY: $GMJ_KEY"

Code
{ "status": "success", "code": 200, "data": [
  { "country_name": "Japan", "country_code": "jp", "image": "https://gmjroaming.com/img/country/jp.svg" }
] }

Pass country_code as locationCode in the next step. Regions such as asia or europe work too.

3. Pick a package

Code
curl "$GMJ/list-esim?locationCode=jp" -H "X-API-KEY: $GMJ_KEY"

Each package has a packageCode, a name, priceUsd (your price) and volume (bytes).

4. Buy it

The body is an array. Generate your own transaction_id and store it: it's your reference for this purchase. The call waits until the eSIM is ready, so allow up to 60 seconds.

Code
curl -X POST "$GMJ/checkout" -H "X-API-KEY: $GMJ_KEY" -H "Content-Type: application/json" \
  --max-time 60 \
  -d '[{"packageCode":"JC016","count":1,"transaction_id":"order-20261111-0001"}]'

Code
{
  "status": "success",
  "code": 200,
  "message": "Checkout successful",
  "currency": "USD",
  "current_balance": "95.80",
  "transaction_id": "order-20261111-0001"
}

5. Get the eSIM

Code
curl -X POST "$GMJ/myesim" -H "X-API-KEY: $GMJ_KEY" \
  -H "Content-Type: application/json" -d '{"transaction_id":"order-20261111-0001"}'

Send your customer qrCodeUrl (a QR to scan) or publicUrl (an install page). ac is the activation code for manual entry.

Next

• Set up webhooks to hear when your customer installs the eSIM and uses data.
• Read Buying eSIMs for retries and top-ups.