> ## Documentation Index
> Fetch the complete documentation index at: https://breadbox-mintlify-7401d007.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Tag read MCP reference

> MCP read tool for listing tags. Tag writes live on the Tag writes page; tagging transactions lives on Transaction writes.

Tags are open-ended labels attached to transactions. Each tag has a stable `slug` (for queries and rules) and a `display_name` (for humans). The review queue is just transactions tagged `needs-review` — a system-seeded rule auto-tags every new transaction during sync, and agents close reviews by removing the tag via [`update_transactions`](/mcp/reference/transactions-write#update_transactions).

The same read surface is also exposed over REST at [`GET /api/v1/tags`](/api/overview).

***

## list\_tags

Returns all tags registered in the system. Filter transactions by tag via the `tags` / `any_tag` parameters on `query_transactions`.

**Scope:** Read

**Mirrors:** [`GET /api/v1/tags`](/api/overview)

### Parameters

None. Pass an empty object.

### Example input

```json theme={null}
{}
```

### Example output

```json theme={null}
[
  {
    "id": "t1Xm9pQ2",
    "slug": "needs-review",
    "display_name": "Needs Review",
    "description": "Automatically added by sync; removed when a human or agent closes the review.",
    "color": "#F59E0B",
    "icon": "inbox",
    "created_at": "2026-01-01T00:00:00Z",
    "updated_at": "2026-01-01T00:00:00Z"
  },
  {
    "id": "t2Yn0qR3",
    "slug": "subscription:monthly",
    "display_name": "Monthly Subscription",
    "description": "Recurring monthly charge.",
    "color": "#8B5CF6",
    "icon": "refresh-cw",
    "created_at": "2026-02-14T14:30:00Z",
    "updated_at": "2026-02-14T14:30:00Z"
  }
]
```

<Note>
  **Tag discovery.** When agents add a tag via [`add_transaction_tag`](/mcp/reference/transactions-write#add_transaction_tag) or [`update_transactions`](/mcp/reference/transactions-write#update_transactions) with a slug that doesn't exist yet, Breadbox auto-registers it as a persistent tag with the slug as the display name. Use [`create_tag`](/mcp/reference/tags-write#create_tag) up front only when you need to set a custom display name, color, or icon.
</Note>