> ## Documentation Index > Fetch the complete documentation index at: https://docs.inflection.io/llms.txt > Use this file to discover all available pages before exploring further. # Set a personalized email version > Stores the personalized version of a [Personalized Email Asset](/agents/personalized-email) for one contact. One version per contact per asset; re-posting for the same contact replaces their version. At send time the contact receives their version if it's ready; contacts without one get the asset's default email. Validation on arrival: `email` must resolve to an existing contact, and `html` must contain the literal `{{unsubscribe_url}}` token, contain no other `{{…}}` tokens, and stay within 500 KB. A version that fails validation is rejected with a reason (visible on the asset's **Activity** tab) and the default email sends instead. ## OpenAPI ````yaml /api-reference/openapi.yaml post /v1/email-versions openapi: 3.1.0 info: title: Inflection Developer API version: '1.0' description: >- A REST API for reading and writing the people in your Inflection workspace: their profiles, product and marketing activity, static lists, and emails. servers: - url: https://api.inflection.io description: Production security: - bearerAuth: [] paths: /v1/email-versions: post: tags: - Email Versions summary: Set a personalized email version description: >- Stores the personalized version of a [Personalized Email Asset](/agents/personalized-email) for one contact. One version per contact per asset; re-posting for the same contact replaces their version. At send time the contact receives their version if it's ready; contacts without one get the asset's default email. Validation on arrival: `email` must resolve to an existing contact, and `html` must contain the literal `{{unsubscribe_url}}` token, contain no other `{{…}}` tokens, and stay within 500 KB. A version that fails validation is rejected with a reason (visible on the asset's **Activity** tab) and the default email sends instead. operationId: setEmailVersion requestBody: required: true content: application/json: schema: type: object required: - assetId - email - subject - preheader - html properties: assetId: type: string description: >- ID of the Personalized Email Asset. Copy it from the asset URL (`…/assets/email/per-user//versions`) or its **How to add versions** tab. email: type: string format: email description: The contact's email. Must match an existing contact. subject: type: string description: The personalized subject line. preheader: type: string description: The inbox preview text. html: type: string description: >- Full HTML of the personalized email. Must include the literal `{{unsubscribe_url}}` token; no other `{{…}}` tokens are allowed. Max 500 KB. expiresAt: type: string format: date-time description: >- Optional ISO-8601 expiry. After this moment the contact falls back to the default email. Omit for a version that never expires. example: assetId: 6a60ee387b78bbc9a263aba0 email: contact@example.com subject: A note just for you preheader: Personalized for you html: …Unsubscribe… expiresAt: '2030-01-01T00:00:00Z' responses: '200': description: Version stored. content: application/json: schema: allOf: - $ref: '#/components/schemas/Envelope' - type: object properties: data: type: object properties: status: type: string example: stored '400': description: >- Validation failed: malformed JSON, unknown `assetId`, contact not found, missing `{{unsubscribe_url}}`, a disallowed `{{…}}` token, or HTML over 500 KB. '401': description: Missing or malformed bearer token. components: schemas: Envelope: type: object properties: data: description: 'Payload: object or array, shape depends on the endpoint.' pagination: type: object description: Present only on paged list endpoints. properties: pageNumber: type: integer example: 1 pageSize: type: integer example: 20 totalElements: type: integer example: 151 totalPages: type: integer example: 8 errors: type: array items: type: object properties: errorCode: type: string message: type: string detail: type: string meta: type: object properties: status: type: string enum: - SUCCESS - FAILURE timestamp: type: string format: date-time securitySchemes: bearerAuth: type: http scheme: bearer description: >- Personal Access Token or OAuth 2.1 access token, sent as a bearer credential. READ permission for GET, WRITE for POST/PATCH/DELETE. ````