API Reference

Blend exposes two API surfaces from the same backend. They share the same data and schemas but differ in authentication and how they identify the account.

Frontend API

For browser apps. Auth with a publishable key and SIWE wallet signature. The account is implicit from the signed session.

Server API

For backends. Auth with an API key. The account type and account ID are explicit in the URL path.

Which one do I use?

	Frontend API	Server API
Runs in	Browser	Your backend (Node.js, Python, etc.)
Auth	`X-Publishable-Key` + SIWE bearer JWT	`X-API-Key`
Account scoping	Automatic from the signed session	Explicit via `{accountTypeId}` and `{accountId}` in the URL
Auth endpoints	Yes (`/auth/challenge`, `/auth/verify`, `/auth/sign-out`)	No
Account lookup	No (account resolved from JWT)	Yes (`GET /account?address=...`)
SDK	`@blend-money/fe`	`@blend-money/node`
Base URL	`https://api.portal.blend.money/extern/fe`	`https://api.portal.blend.money/extern/svr/{accountTypeId}`

Both surfaces return the same response shapes. A balance response from the frontend API is identical to one from the server API.

Common patterns

Most successful responses wrap data in a standard envelope:

{
  "status": "success",
  "data": { ... }
}

Sign-out returns the same status field with a top-level message instead of data. Errors follow the same shape:

{
  "status": "error",
  "code": "INTENT_WRONG_STATUS",
  "message": "Human-readable error description"
}

code is optional. Use it for programmatic handling when present.

Frontend API

Browse all 21 frontend endpoints

Server API

Browse all 19 server endpoints

Frontend API

Server API

​Which one do I use?

​Common patterns

Frontend API

Server API

Which one do I use?

Common patterns