> ## Documentation Index > Fetch the complete documentation index at: https://developers.gonitro.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Create Envelope > The **Create Envelope** endpoint creates a new **sign envelope** in Nitro. A **sign envelope** is the container for signature processes in Nitro. It can include assets such as documents, participants, signature fields, and configuration settings that define how the signing process should behave. With the Create Envelope endpoint, you will create an empty sign envelope you can later add assets to. ## OpenAPI ````yaml https://api.gonitro.dev/openapi.json post /sign/envelopes openapi: 3.1.0 info: title: Nitro Sign Public API description: REST API for Nitro Sign version: '0.1' servers: - url: https://api.gonitro.dev security: - bearerAuth: [] paths: /sign/envelopes: post: tags: - Sign summary: Create Envelope description: > The **Create Envelope** endpoint creates a new **sign envelope** in Nitro. A **sign envelope** is the container for signature processes in Nitro. It can include assets such as documents, participants, signature fields, and configuration settings that define how the signing process should behave. With the Create Envelope endpoint, you will create an empty sign envelope you can later add assets to. operationId: createEnvelope requestBody: content: application/json: schema: $ref: '#/components/schemas/EnvelopeCreate' required: true responses: '201': description: > When an envelope is created you will get a unique ID for it. You can add assets to the envelope later by referencing its unique ID using other endpoints in this API. content: application/json: schema: $ref: '#/components/schemas/ExtendedEnvelope' '400': description: Invalid envelope or document name content: application/problem+json: schema: $ref: '#/components/schemas/BadRequestProblemDetail' '401': description: Unauthorized - Invalid or missing JWT token content: application/problem+json: schema: $ref: '#/components/schemas/UnauthorizedProblemDetail' components: schemas: EnvelopeCreate: type: object properties: name: type: string description: The Envelope's name. It doesn't have to be unique. minLength: 1 notification: $ref: '#/components/schemas/Notification' description: > The `notification` object defines the email sent to participants when an envelope is delivered for signing. It contains a `subject` and a `body` as nested parameters, and both fields support dynamic variables. **Dynamic Variables** You can personalize notification emails by referencing dynamic variables in the subject or body. Available variables: `envelope_name`: The name of the envelope being signed. `sender_name_or_email`: The sender’s name, or their email address if the name is not available. Syntax: To reference the variables, wrap them with `$()` in your message. Example: `$(envelope_name)` `notification` object example: ``` json { "notification": { "subject": "$(sender_name_or_email) is requesting your signature", "body": "Hi,\nPlease sign the $(envelope_name)\nThank you,\n$(sender_name_or_email)" } } ``` mode: type: string description: > The Signing Mode in an enum that defines the signing order. It has two possible values: - `sequential`: Participants receive notifications one at a time, in the order they were added to the envelope. Each new notification is triggered once the previous participant has completed their signing. - `parallel`: All participants are notified at the same time and can sign the documents in the envelope independently, without waiting for others. enum: - sequential - parallel required: - mode - name - notification ExtendedEnvelope: type: object properties: ID: type: string format: uuid description: >- A unique UUIDv4 string that identifies the envelope in the Nitro system. createdAt: type: string format: date-time description: UTC timestamp indicating when the envelope was created. lastModifiedAt: type: string format: date-time description: >- UTC timestamp indicating the last time the envelope was updated. Matches `createdAt` at the time of creation. name: type: string description: The name of the envelope. status: type: string description: >- The internal status of the envelope. Defaults to drafted on creation. enum: - drafted - sent - processing - sealed - rejected - cancelled - deleted mode: type: string description: Signing mode for the envelope. enum: - sequential - parallel notification: $ref: '#/components/schemas/Notification' description: Notification settings for the envelope. BadRequestProblemDetail: type: object description: Bad Request error details example: type: https://developers.gonitro.com/docs/build-nitro/errors#400-bad-request title: Bad Request status: 400 detail: Request validation failed instance: /sign/envelopes validation_errors: name: must not be blank properties: type: type: string description: A URI reference that identifies the problem type title: type: string description: A short, human-readable summary of the problem type status: type: integer format: int32 description: The HTTP status code detail: type: string description: A human-readable explanation specific to this occurrence instance: type: string description: A URI reference that identifies the specific occurrence extensions: type: object additionalProperties: {} description: Additional problem-specific properties UnauthorizedProblemDetail: type: object description: Unauthorized error details example: type: >- https://developers.gonitro.com/docs/build-nitro/errors#401-unauthorized title: Unauthorized status: 401 detail: Missing or invalid Authorization header instance: /sign/envelopes properties: type: type: string description: A URI reference that identifies the problem type title: type: string description: A short, human-readable summary of the problem type status: type: integer format: int32 description: The HTTP status code detail: type: string description: A human-readable explanation specific to this occurrence instance: type: string description: A URI reference that identifies the specific occurrence extensions: type: object additionalProperties: {} description: Additional problem-specific properties Notification: type: object properties: subject: type: string description: The subject line of the notification email. minLength: 1 body: type: string description: The body content of the notification email. minLength: 1 required: - body - subject securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT ````