# Source: https://getlago.com/docs/api-reference/credit-notes/metadata/update-metadata-cn.md

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

# Udpate metadata

> This endpoint merges the provided metadata with existing metadata on the credit note.
Existing keys not in the request are preserved. New keys are added, existing keys are updated.



## OpenAPI

````yaml PATCH /credit_notes/{lago_id}/metadata
openapi: 3.1.0
info:
  title: Lago API documentation
  description: >-
    Lago API allows your application to push customer information and metrics
    (events) from your application to the billing application.
  version: 1.41.0
  license:
    name: AGPLv3
    identifier: AGPLv3
  contact:
    email: tech@getlago.com
servers:
  - url: https://api.getlago.com/api/v1
    description: US Lago cluster
  - url: https://api.eu.getlago.com/api/v1
    description: EU Lago cluster
security:
  - bearerAuth: []
tags:
  - name: activity_logs
    description: Everything about Activity logs
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/audit-logs/activity-logs-object
  - name: analytics
    description: Everything about Analytics
  - name: api_logs
    description: Everything about API logs
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/audit-logs/api-logs-object
  - name: billable_metrics
    description: Everything about Billable metric collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/billable-metrics/object
  - name: features
    description: Everything about Feature collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/features/object
  - name: entitlements
    description: Everything about Entitlement collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/entitlements/object
  - name: billing_entities
    description: Everything about Billing Entities
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/billing-entities/object
  - name: customers
    description: Everything about Customer collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/customers/object
  - name: plans
    description: Everything about Plan collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/plans/object
  - name: subscriptions
    description: Everything about Subscription collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/subscriptions/subscription-object
  - name: events
    description: Everything about Event collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/events/event-object
  - name: organizations
    description: Everything about Organization collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/organizations/organization-object
  - name: taxes
    description: Everything about Tax collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/taxes/tax-object
  - name: coupons
    description: Everything about Coupon collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/coupons/coupon-object
  - name: add_ons
    description: Everything about Add-on collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/add-ons/add-on-object
  - name: fees
    description: Everything about Fees
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/invoices/invoice-object#fee-object
  - name: invoices
    description: Everything about Invoice collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/invoices/invoice-object
  - name: wallets
    description: Everything about Wallet collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/wallets/wallet-object
  - name: credit_notes
    description: Everything about Credit notes collection
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/credit-notes/credit-note-object
  - name: webhooks
    description: Everything about Webhooks
    externalDocs:
      description: Find out more
      url: >-
        https://doc.getlago.com/api-reference/webhooks/format---signature#1-retrieve-the-public-key
  - name: webhook_endpoints
    description: Everything about Webhook Endpoints
    externalDocs:
      description: Find out more
      url: >-
        https://doc.getlago.com/api-reference/webhook-endpoints/webhook-endpoint-object
  - name: payment_receipts
    description: Everything about Payment receipts
    externalDocs:
      description: Find out more
      url: >-
        https://doc.getlago.com/api-reference/payment-receipts/payment-receipt-object
  - name: payment_requests
    description: Everything about PaymentRequests
    externalDocs:
      description: Find out more
      url: >-
        https://doc.getlago.com/api-reference/payment-requests/payment-request-object
  - name: payments
    description: Everything about Payments
    externalDocs:
      description: Find out more
      url: https://doc.getlago.com/api-reference/payments/payment-object
externalDocs:
  description: Lago Github
  url: https://github.com/getlago
paths:
  /credit_notes/{lago_id}/metadata:
    patch:
      tags:
        - credit_notes
      summary: Merge credit note metadata
      description: >-
        This endpoint merges the provided metadata with existing metadata on the
        credit note.

        Existing keys not in the request are preserved. New keys are added,
        existing keys are updated.
      operationId: mergeCreditNoteMetadata
      parameters:
        - name: lago_id
          in: path
          description: The credit note unique identifier, created by Lago.
          required: true
          schema:
            type: string
            format: uuid
            example: 1a901a90-1a90-1a90-1a90-1a901a901a90
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreditNoteMetadataResponse'
      responses:
        '200':
          description: Credit note metadata merged
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CreditNoteMetadataResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '422':
          $ref: '#/components/responses/UnprocessableEntity'
components:
  schemas:
    CreditNoteMetadataResponse:
      type: object
      required:
        - metadata
      properties:
        metadata:
          $ref: '#/components/schemas/MetadataObject'
    MetadataObject:
      type:
        - object
        - 'null'
      description: >-
        Custom metadata stored as key-value pairs.

        Keys are strings (max 100 characters), values can be strings (max 255
        characters) or null.
      additionalProperties:
        type:
          - string
          - 'null'
      example:
        external_id: ext-123
        synced_at: '2024-01-15'
        source: null
    ApiErrorUnauthorized:
      type: object
      required:
        - status
        - error
      properties:
        status:
          type: integer
          format: int32
          example: 401
        error:
          type: string
          example: Unauthorized
    ApiErrorNotFound:
      type: object
      required:
        - status
        - error
        - code
      properties:
        status:
          type: integer
          format: int32
          example: 404
        error:
          type: string
          example: Not Found
        code:
          type: string
          example: object_not_found
    ApiErrorUnprocessableEntity:
      type: object
      required:
        - status
        - error
        - code
        - error_details
      properties:
        status:
          type: integer
          format: int32
          example: 422
        error:
          type: string
          example: Unprocessable entity
        code:
          type: string
          example: validation_errors
        error_details:
          type: object
  responses:
    Unauthorized:
      description: Unauthorized error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorUnauthorized'
    NotFound:
      description: Not Found error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorNotFound'
    UnprocessableEntity:
      description: Unprocessable entity error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiErrorUnprocessableEntity'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````