API Partner Terms

Version 2026-10-02

These terms govern your use of the eSIMCenter partner API. They are written for businesses and developers integrating our eSIM catalogue into their own product. Plain language is used where the law allows; nothing here limits mandatory rights you may have under the law of your country of residence.

Preamble

1. Parties: This agreement is between eSIMCenter LLC, 1300 S Watson Rd Ste A-114 #946, Buckeye, AZ 85326, US ("we", "us", "the seller"), and the company or individual that accepts these terms in the developer panel ("you", "the partner"). It governs your use of the eSIMCenter partner API, including live and sandbox keys, pricing, billing terms, webhook delivery and any data your integration sends or receives through the API.
2. Acceptance: You accept these terms with the I accept the API partner terms button on the API keys page of the developer panel, or with the same button on the Partner account screen of the eSIMCenter mobile app. We record the version you accepted, the date and time, and the channel you accepted through. A new key, live or sandbox, can only be created after you have accepted the version shown at the top of this page. Keys you already hold keep working without a new acceptance. A live key also requires a complete billing profile: legal name, postal address, billing email, and a tax ID or a statement that you have none.

Terms

1. Account types: We offer two types of partner account. A prepaid account is topped up before use and you buy eSIMs from the balance; a postpaid account is invoiced monthly. The account type is set on your account and shown on the developer dashboard; switching between them is handled by us on request.
2. Postpaid billing: On a postpaid account we issue one invoice per calendar month covering all charges, refunds, profit share and adjustments from that month. The invoice is due 15 days after issue (or, if your account has its own payment term, that many days after issue). We send a notice when the invoice is issued and reminders three days before the due date, on the due date, and three days after. An invoice that is still unpaid seven days after the due date puts your account on hold for non-payment: new purchases stop and no new profit share accrues while you are on hold. The non-payment hold is lifted as soon as the overdue amount reaches zero. A hold we set for a different reason does not lift on payment; it stays until we review it.
3. Pricing: Your partner price for a product never exceeds the price we charge the customer on the public site (list price). The discount is a share of our margin on that product, not a flat percentage off the list, and is capped at the share limit set on your account. A rule resolves at one of four levels — product, provider, country or region, then your account default — and the most specific wins. If a fixed price on a product falls below the floor the share cap allows, that rule is ignored at read time and resolution moves one level up: the provider, country or region rule covering that product applies, and your account default is used only when none of them exists. The old rule is never silently applied. Your price ladder is shown on the developer dashboard.
4. Profit share: If profit share is enabled on your account, you receive a share of the cost of the data your customers did not use. Unlimited plans are excluded, because unused data cannot be measured on them. The share is calculated per sale after the eSIM has expired and a short grace window on top of the expiry date, so that late usage figures are settled on a number that has stopped moving. The grace window is set by us and is the same for every partner. On a prepaid account the share is credited to your wallet; on a postpaid account it is written off against your outstanding balance, and any remainder is credited to your wallet. Profit share is never paid out as cash or as a bank transfer: it always sits in your site balance or reduces what you owe us. No new profit share accrues while your account is on hold.
5. Rate limits: Every API endpoint belongs to a tier with a request limit per 60-second window: 900 for catalog reads, 360 for account and order reads, 150 for purchases, 30 for wallet top-ups and 18 for outbound probes and webhook tests. Limits are applied per key; two keys on the same account do not share a quota. Exceeding a limit returns 429 with a Retry-After header.
6. Webhooks: We sign every webhook with an HMAC-SHA256 signature over the timestamp and the raw request body, joined by a dot: sha256=hex(hmac_sha256(secret, timestamp + "." + body)). The signature is sent in the X-Signature header, alongside the X-Webhook-Timestamp, X-Webhook-Event and X-Webhook-Id headers. We recommend that your receiver reject anything whose timestamp is more than five minutes off its own clock; a captured body could otherwise be replayed forever. Delivery is at-least-once: any 2xx counts as delivered, anything else (including a timeout) is retried on a fixed schedule of 1 minute, 5 minutes, 30 minutes, 2 hours and 12 hours. We wait up to 10 seconds for a 2xx response. After 5 unsuccessful attempts the event is moved to a dead-letter queue that we can re-queue by hand. After 10 consecutive failures the endpoint is disabled so we stop hammering a dead host; fixing the endpoint and reactivating it in the panel gives the subscription one more attempt — full credit returns only after that attempt succeeds. A URL that resolves to a private or link-local address is refused before any request is opened; the same gate runs when you save a subscription and again at delivery time, and only HTTPS on port 443 is accepted.
7. Sandbox: A sandbox key starts with esk_test_ followed by a random string of hex characters and calls the same endpoints with the same field names. No money moves and no provider is called. A sandbox purchase does not touch your wallet, does not open a real order, does not send email and does not earn profit share. Sandbox events carry livemode: false and the eSIM returned is fake (it cannot be installed on a phone). You can hold up to 2 active sandbox keys. Top-ups are not supported on sandbox keys.
8. Key security: Each key can be locked to a list of allowed source addresses (IPv4 or IPv6, CIDR ranges supported, up to 20 entries). A request from an address outside that list is refused with 403 ip_not_allowed and the address is recorded on the key. Leaving the list empty allows any address, which is how a key works by default. A key that leaks — by being committed to a public repository, logged in clear text or shared with a third party — is treated as compromised and the partner is responsible for any spend it generated. Revoke a compromised key immediately from the developer dashboard and create a new one; revoking stops further use but does not undo spend already made.
9. Customer data: You are the controller of the customer data you collect through your integration, and you decide what you collect and why. We act as a processor for the data the API call carries (recipient details, installation records, delivery status) under our Privacy Policy. We do not use that data to market our own products to your customers. You are responsible for your own privacy notice, your lawful basis and your retention period for the customer data you hold.
10. Liability: To the extent permitted by mandatory law, our aggregate liability to you under this agreement is limited to the amount we invoiced you (or, for a prepaid account, the amount you loaded onto your wallet) in the period covered by the agreement. We are not liable for lost profits, lost business or consequential damages. The cap does not apply to liability that cannot be excluded for fraud, wilful misconduct or personal injury. Mandatory rights you have are not affected.
11. Termination: We may suspend or terminate your access to the API at any time for a material breach of this agreement that is not cured within a reasonable time of notice, including an unpaid invoice, repeated policy violations or a misuse of the integration. You may stop using the API at any time by revoking your keys. Revoking a key does not cancel an invoice already issued; payment of an issued invoice is still due.
12. Changes: When we change this text we publish a new version at the same URL and update the version line at the top of the page. A new version applies to you once you accept it: the developer panel asks for that acceptance before your next new key, and keys you already hold keep working in the meantime under the version you last accepted.