> ## Documentation Index > Fetch the complete documentation index at: https://moengage.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Update OSM Template > This API updates an OSM template as per your requirements. #### Rate Limit The rate limit is 100 RPM. ## OpenAPI ````yaml /api/osm-templates/osm-templates.yaml put /custom-templates/osm openapi: 3.0.3 info: title: MoEngage On-Site Messaging (OSM) Template API version: '1.0' description: >- API for creating, updating, and searching On-Site Messaging (OSM) templates within the MoEngage platform. servers: - url: https://api-{dc}.moengage.com/v1.0 description: MoEngage Custom Templates API Server variables: dc: default: '01' description: >- The ‘dc’ in the API Endpoint URL refers to the MoEngage Data Center (DC). MoEngage hosts each customer in a different DC. You can find your DC number and replace the value of ‘dc’ in the URL by referring to the DC and API endpoint mapping [here](/api/introduction#data-centers). Your MoEngage Data Center (DC) can be 01, 02, 03, 04, 05, 06, or 101. security: - basicAuth: [] tags: - name: OSM Templates description: Operations to manage On-Site Messaging (OSM) templates. paths: /custom-templates/osm: put: tags: - OSM Templates summary: Update OSM Template description: This API updates an OSM template as per your requirements. requestBody: required: true description: The updated details for the OSM template. content: application/json: schema: $ref: '#/components/schemas/UpdateOsmTemplateRequest' example: external_template_id: 81e1a740-3e57-4c70-8ec7-ffc84d576498 update_campaigns: false basic_details: payload:

Updated HTML Content

meta_info: template_name: AD template updated API 1 template_id: '133434477456' template_version: '2' updated_by: testuser@moengage.com responses: '200': description: Template updated successfully. content: application/json: schema: type: object properties: external_template_id: type: string format: uuid description: The unique ID of the updated template. example: external_template_id: 4a1afbc5-4c31-4f19-8c23-793e27af01aa '400': description: Bad Request. Validation failed or missing parameters. content: application/json: schema: $ref: '#/components/schemas/StandardErrorResponse' example: error: code: 400 Bad Request message: Validation failed because of invalid request data details: - code: MissingValue target: external_template_id message: >- external_template_id value is required but value is passed empty. request_id: cTRlnJaG 5XX: description: Internal Server Error. content: application/json: schema: $ref: '#/components/schemas/SimpleErrorResponse' example: title: Internal Server Error message: >- An unexpected error was encountered while processing this request. Please contact MoEngage Team components: schemas: UpdateOsmTemplateRequest: type: object required: - external_template_id - basic_details - meta_info properties: external_template_id: type: string format: uuid description: >- The unique identifier generated by MoEngage during template creation. update_campaigns: type: boolean default: false description: > Flag to update all campaigns currently using this template to the newer version. * **`true`**: All campaigns running with this template will be updated. * **`false`**: A new version of the template is created; existing campaigns remain unchanged. basic_details: type: object description: Details about the template payload. required: - payload properties: payload: type: string description: | The updated HTML content. * Payload type must be HTML. * No limit restriction on field length. meta_info: type: object description: >- Updates template information such as name, version, and updater details. required: - template_name - template_id - updated_by properties: template_name: type: string description: The name of the template being updated. template_id: type: string description: A unique ID for the template provided by you. template_version: type: string description: >- Optional new version for the template. The version will be increased by 1 automatically after every update. updated_by: type: string format: email description: The email ID of the person updating the template. StandardErrorResponse: type: object description: Standard error structure used for 400 and 429 responses. properties: error: type: object properties: code: type: string description: A brief explanation of the error. example: 4XX Bad Request message: type: string description: >- Describes why the request failed (e.g., Duplicate - template_id). example: Duplicate - template_id and template_version details: type: array description: >- A list of error detail objects containing code, target, and specific messages. items: type: object properties: code: type: string description: Descriptive Error Code. example: InvalidValue target: type: string description: Denotes the field causing the issue. example: Duplicate - template_id and template_version message: type: string description: Descriptive Error Message. example: >- template_id:BasicTemplate1 template_version:1 is already present. request_id: type: string description: Unique identifier for the request. example: cLCcgLQj SimpleErrorResponse: type: object description: Simplified error structure used for 401, 415, and 5xx responses. properties: title: type: string description: The title of the error. example: Authentication required description: type: string description: A description of the error (used in 401/415). example: MOE-APPKEY missing in Authentication Header message: type: string description: A message describing the error (used in 5xx). example: An unexpected error was encountered. securitySchemes: basicAuth: type: http scheme: basic description: > Authentication is done via Basic Auth. This requires a base64-encoded string of your credentials in the format 'username:password'. - **Username**: Use your MoEngage workspace ID (also known as the App ID). You can find it in the MoEngage dashboard at **Settings** > **Account** > **APIs** > **Workspace ID (earlier app id)**. - **Password**: Use your API Key, which you can find within the **Campaign report/Business events/Custom templates/Catalog API/Inform Report** tile. For more information on authentication and getting your credentials, refer [here](https://www.moengage.com/docs/api/introduction#getting-your-credentials). ````