Customer-facing API requests use secret API keys from trusted server environments.
Keep secret keys on your server. Do not place them in browsers, mobile apps, hosted checkout pages, or logs.
Create and rotate merchant keys in Developers → API keys and platform keys
in Connect → API keys.
Browser credentials
Ionic Blocks uses a publishable key and an intent’s
client secret. Your backend creates the intent and returns those two values to
the browser. For Connect, the browser also selects the receiving merchant with
the account option, and the platform secret key stays on your server.
Choosing key permissions
In Developers → API keys, choose a restricted secret key when an integration
needs a specific set of permissions. The picker shows the permissions currently
available to you. Select all selects those current choices; Read only and
Write only select the available actions of that kind. You can also select
individual actions independently.
A restricted key keeps the permissions selected when you create it. New Ionic
permissions are not added to that key automatically. Standard secret keys follow
Ionic’s managed standard policy and can receive permissions explicitly added to
that policy.
Platform credentials in Connect → API keys offer permissions approved for
your Platform Program and environment. A permission available to a Platform may
be unavailable for an Account key or a connected account’s consent. If access
changes while a form is open, reload the inventory and review the selection;
the server checks the current policy when creating the key.
An authorized Platform can act for one connected account by adding that
Account’s Ionic Merchant ID to a server-side request:
Use this header only when the endpoint’s API reference lists
Ionic-Account. The header is not a global account switch and does not make an
unsupported endpoint delegable. Omit it when the key owner is accessing its
own Account.
A request selects exactly one connected account. PaymentIntents, SetupIntents,
and customers accept the header. Platform payment domains and platform webhook
endpoints belong to the platform itself, so those requests carry no
Ionic-Account. See How Connect works.
Never accept an Account ID from an untrusted browser and forward it with a
Platform secret key. Choose the connected account on your server after
authenticating and authorizing your own user.
Hosted checkout
Your backend creates checkout sessions and payment links. Ionic-hosted checkout handles buyer payment collection and confirmation without requiring you to send raw card data to the API.
Create checkout resources on your server, redirect the buyer, and retrieve the
completed session from your server before fulfilling the order.
Retry behavior
Authentication identifies the caller. Idempotency identifies a retryable operation. For create and refund calls, send the same Idempotency-Key when retrying the same operation. See Idempotency for the retry model. 
