# XRP Ledger Trust Lines

A trust line is an XRP Ledger account-level setting that authorizes the
account to hold a specific Trust Line Asset (also called an Issued Token, and
historically, an IOU) from a given issuer. Without a trust line, an account
cannot receive that asset.

Fordefi exposes a dedicated transaction type for creating a trust line, built
on the XRP Ledger's `TrustSet` transaction.

## Trust line limits

The XRP Ledger's `TrustSet` transaction accepts a `LimitAmount` parameter that
caps the maximum amount of the asset the account is willing to hold. Fordefi
**always creates trust lines with the protocol-maximum limit**, which makes
them effectively unlimited.

## No rippling by default

Every account Fordefi creates leaves the account-level `DefaultRipple` setting
off (the protocol default), so every trust line the account opens
automatically has `NoRipple` set. This is configured once, at account
creation. There is no per-trust-line setting to manage, and no option to
change this behavior.

## Create a trust line

Following is an illustrative example of the body of a
[Create Transaction](https://docs.fordefi.com/api/openapi/transactions/create_transaction_api_v1_transactions_post)
request for creating a trust line.

```json
{
  "signer_type": "api_signer",
  "type": "ripple_transaction",
  "details": {
    "type": "ripple_create_trustline",
    "asset_identifier": {
      "type": "ripple",
      "details": {
        "type": "trust_line_asset",
        "currency": "USD",
        "issuer": {
          "chain": "ripple_mainnet",
          "base58_repr": "rEXAMPLE1111111111111111111111111"
        }
      }
    }
  },
  "note": "Establish a trust line for USD",
  "vault_id": "your_xrp_vault_id"
}
```

Once the trust line is established, the vault can receive that asset directly
using standard transfers. No claimable balance fallback is needed.