> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Ledger operations

> Reference the Midaz Ledger operation fields — balances, transaction routes, operation routes, and metadata indexes used in postings.

This page covers fields specific to Midaz ledger operations, including balances, transaction routes, operation routes, and metadata indexes.

## 1. Balances

***

| Field          | Description                                                                 | Used in |
| -------------- | --------------------------------------------------------------------------- | ------- |
| key            | Unique identifier for the balance within the account context                | Midaz   |
| available      | Amount available for transactions                                           | Midaz   |
| onHold         | Amount currently reserved or on hold                                        | Midaz   |
| version        | Balance version, updated with each transaction (for optimistic concurrency) | Midaz   |
| accountType    | Type of account that holds this balance                                     | Midaz   |
| allowSending   | Whether the balance can be used to send transactions                        | Midaz   |
| allowReceiving | Whether the balance can be used to receive transactions                     | Midaz   |
| assetCode      | Asset or currency code (ISO 4217, 3 characters)                             | Midaz   |
| alias          | Account alias for quick identification                                      | Midaz   |

## 2. Transaction routes

***

| Field           | Description                                                           | Used in |
| --------------- | --------------------------------------------------------------------- | ------- |
| title           | Short text summarizing the route's purpose (max 50 characters)        | Midaz   |
| description     | Detailed description of the transaction route (max 250 characters)    | Midaz   |
| operationRoutes | Array of operation route IDs that define source and destination logic | Midaz   |

## 3. Operation routes

***

| Field         | Description                                            | Used in |
| ------------- | ------------------------------------------------------ | ------- |
| operationType | Route direction: source or destination                 | Midaz   |
| code          | External reference code for the operation route        | Midaz   |
| account       | Account selection rule for the operation               | Midaz   |
| ruleType      | Account selection method: alias or account\_type       | Midaz   |
| validIf       | Condition that must be satisfied for the rule to match | Midaz   |

## 4. Metadata indexes

***

| Field       | Description                                                                       | Used in |
| ----------- | --------------------------------------------------------------------------------- | ------- |
| metadataKey | Metadata key to index (max 100 characters, must match the field name in entities) | Midaz   |
| unique      | Whether the index enforces uniqueness (duplicate values rejected when true)       | Midaz   |
| sparse      | Whether the index is sparse (only indexes entities containing the field)          | Midaz   |
| indexName   | Name of the created index                                                         | Midaz   |
| entityName  | Name of the entity collection the index applies to                                | Midaz   |