> For the complete documentation index, see [llms.txt](https://docs.omypayments.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.omypayments.com/api/api-endpoints/assets.md).

# Assets

An **asset** is one currency on one network enabled on your merchant account - say USDT on Tron, or ETH on Ethereum. Assets are what invoices are paid into, what balances are held in, and what withdrawals are sent from. Everything else in this API refers to them by `assetId`.

This page documents the HTTP endpoints you'll call from your backend. Authentication and the error-envelope format follow the public API style.

> **Base URL**: `https://api.omypayments.com`\
> **Version**: `v1` (all endpoints below start with `/1.0/...`)\
> **Auth**: add your API key in the header: `apiKey: <yourApiKey>`\
> **Permission**: the API key must have the **invoice** permission enabled, otherwise requests are rejected with `403 Forbidden`.

**What you get from an asset**

* `assetId` - the identifier every other endpoint expects: creating invoices, requesting withdrawals, filtering transactions.
* `crypto.decimals` - how many decimals the token has. You need it for every amount you send us or read from us, because all amounts travel as integer strings in minimal units.
* Balances - what is available to spend, what is still awaiting confirmations, and what is held.
* The default withdrawal wallet, if one is set for the asset.

**Prerequisites**

* Assets are enabled in the merchant dashboard, not through the API. This section is read-only.
* Only **active** assets are returned. An asset switched off in the dashboard disappears from these responses, and invoices can no longer be created for it.

**Typical flow**

1. `assets` once at integration time - cache the `assetId` and `decimals` values you need.
2. `asset` whenever you need a fresh balance for one asset.

Balances change as payments arrive and withdrawals leave, so don't cache them. Identifiers and decimals are stable and safe to cache.

**A word on amounts**

Every amount in this API - invoice totals, withdrawal amounts, balances, fees - is an integer string in the token's minimal units, never a decimal number. For a token with 6 decimals, `"100000000"` means 100 tokens. Divide by `10^decimals` for display, and never parse these values as floats: at 18 decimals a float silently loses precision.

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