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

# Update Transaction

> Update selected fields of an existing transaction. Only metadata, tags, and internal notes are editable. Line items and transaction type cannot be changed.

Use this endpoint to append custom metadata or correct auxiliary fields for an existing transaction.

**Path Parameter:**

* `id` – ID of the transaction to update

**Editable Fields in Body:**

* `metadata`
* `internal_notes`
* `tags`

**Response:**

Returns the updated `Transaction` object. If the transaction is locked for tax purposes, an error will be thrown.


## OpenAPI

````yaml PATCH /transactions/{id}
openapi: 3.0.1
info:
  title: Antei API Reference
  description: >-
    Programmatic access to Antei’s platform. Use this API to manage core objects
    and retrieve taxation insights.
  version: 1.0.0
  license:
    name: MIT
  contact:
    name: Antei Developer Support
    email: support@antei.com
    url: https://antei.com
servers:
  - url: https://api.antei.com
security:
  - bearerAuth: []
paths:
  /transactions/{id}:
    patch:
      summary: Update Transaction
      description: Update specific fields of a transaction.
      parameters:
        - name: id
          in: path
          required: true
          description: ID of the transaction to update
          schema:
            type: string
      requestBody:
        description: Fields to update
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/NewTransaction'
      responses:
        '200':
          description: Updated transaction
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Transaction'
components:
  schemas:
    NewTransaction:
      allOf:
        - $ref: '#/components/schemas/Transaction'
    Transaction:
      type: object
      required:
        - id
        - transaction_type
        - amount
        - currency
        - timestamp
      properties:
        id:
          type: string
          description: Unique identifier for the transaction
        transaction_type:
          type: string
          enum:
            - inflow
            - outflow
          description: Direction of the transaction
        amount:
          type: number
          format: float
          description: Transaction amount
        currency:
          type: string
          description: Currency code (e.g., USD, EUR)
        timestamp:
          type: string
          format: date-time
          description: Time of transaction
        description:
          type: string
          description: Optional description of the transaction
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````