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

# Tags and journal entries

> Tag dimensions and values, apply or merge tags, and post custom journal entries.

Tags and custom journal entries are business bookkeeping tools. List reads for tags are in `core` and `accounting` (platform and business). Writes and journal mutations are business `accounting`.

Amounts on journal lines are integer cents.

## Tags

### Sequence

<Steps>
  <Step title="Discover dimensions and values">
    `list_tag_dimensions`, `list_tag_values`.
  </Step>

  <Step title="Create or update the taxonomy">
    `create_tag_dimension`, `update_tag_dimension`, `create_tag_value`, `update_tag_value`.
  </Step>

  <Step title="Attach or remove tags on entities">
    `apply_tags`, `remove_tags` (destructive).
  </Step>

  <Step title="Merge duplicate values if needed">
    `merge_tag_values` (destructive).
  </Step>
</Steps>

Tag filters on reports are **not** universal. Layer applies them before aggregation only for P\&L, P\&L summaries, balance sheet, AP aging, and bank transactions. Do not send tag filters on cash flow, AR aging, trial balance, tax, or Schedule C.

## Custom journal entries

| Tool                                                                 | Notes               |
| -------------------------------------------------------------------- | ------------------- |
| `list_custom_journal_entries` / `get_custom_journal_entry`           | Reads               |
| `create_custom_journal_entry` / `bulk_create_custom_journal_entries` | Writes              |
| `update_custom_journal_entry`                                        | Write               |
| `reverse_custom_journal_entry`                                       | Destructive reverse |

Search phrases: custom journal entry, reverse.

REST shapes: [Custom journal entries](/api-reference/custom-journal-entries/custom-journal-entry).