--- updatedAt: 2026-08-30T09:50:43.000Z agentTools: projectIndex: https://developer.unimaze.com/llms.txt --- # Get message envelope Returns information about a specific message using the unique message identifier (GUID). The returned object contains details about the message and the documents that are wrapped in the message. See the example response to the right. Each document is identified by an index or name. The binary payload of message attachments can be retrieved through the following calls: * [`GET /messages/:mid/documents/:idx`](/reference/GetMessageDocumentByIndex):\ Relies on the document index number to locate the document. * [`GET /messages/:mid/documents/:name`](/reference/GetMessageDocumentByName):\ Uses the document name to fetch the document. * [`GET /messages/:mid/documents/core`](/reference/GetCoreMessageDocument):\ Gets the message core document. * [`GET /messages/:mid/documents/original`](/reference/GetOriginalMessageDocument):\ If the core document has been transformed to another document specification, this call retrieves the original business document. * [`GET /messages/:mid/documents/transformed`](/reference/GetTransformedMessageDocument):\ In cases where the core document had to be transformed to another syntax format, use this call to get the transformed document. # OpenAPI definition ```json { "openapi": "3.0.1", "info": { "title": "MAPI Messaging v1.0", "description": "

\n \"Dev\n

\n\n## 🚧 Documentation has moved!\n\n| | |\n|---|---|\n| The MAPI documentation is now available on our new developer portal:

👉 **[https://developer.unimaze.com](https://developer.unimaze.com)** | • You’ll find up-to-date guides, authentication details, integration instructions, and client generation guidance there.

• This Swagger UI remains available for API exploration and testing, but the new developer portal is now the primary source of truth.

• The new site will provide a better Developer Experience for testing. |\n", "termsOfService": "https://www.unimaze.com/terms-of-use/", "contact": { "name": "Unimaze Software", "url": "https://www.unimaze.com", "email": "info@unimaze.com" }, "license": { "name": "Unimaze Software", "url": "https://www.unimaze.com" }, "version": "v1" }, "servers": [ { "url": "https://mapi-sandbox.unimaze.com", "description": "SANDBOX" }, { "url": "https://mapi-dsp-uat.unimaze.com", "description": "UAT" }, { "url": "https://mapi-partner-qa.unimaze.com", "description": "QA" } ], "paths": { "/api/v1/messages/{id}": { "get": { "tags": [ "Message" ], "summary": "Get message envelope", "description": "Returns information about a specific message using the unique message identifier (GUID).", "operationId": "MessageGetById", "parameters": [ { "name": "id", "in": "path", "description": "The identifier of the message in the format of a valid Universally unique identifier (GUID).", "required": true, "schema": { "type": "string", "format": "uuid" } }, { "name": "showEmbeddedAttachments", "in": "query", "description": "Can optionally show embedded attachments", "schema": { "type": "boolean", "default": false } } ], "responses": { "400": { "description": "Invalid input parameters.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ValidationProblemDetails" } }, "application/xml": { "schema": { "$ref": "#/components/schemas/ValidationProblemDetails" } } } }, "422": { "description": "The request was understood but could not be processed.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SimpleHttpErrorResult" }, "example": { "statusCode": "422", "statusText": "UnprocessableEntity", "message": "Message could not be processed. Missing lines." } }, "application/xml": { "schema": { "$ref": "#/components/schemas/SimpleHttpErrorResult" }, "example": "\r\n 422\r\n UnprocessableEntity\r\n Message could not be processed. Missing lines.\r\n" } } } } } } }, "components": { "schemas": { "SimpleHttpErrorResult": { "type": "object", "properties": { "statusCode": { "type": "string", "nullable": true }, "statusText": { "type": "string", "nullable": true }, "message": { "type": "string", "nullable": true } }, "additionalProperties": false }, "ValidationProblemDetails": { "type": "object", "properties": { "type": { "type": "string", "nullable": true }, "title": { "type": "string", "nullable": true }, "status": { "type": "integer", "format": "int32", "nullable": true }, "detail": { "type": "string", "nullable": true }, "instance": { "type": "string", "nullable": true }, "errors": { "type": "object", "additionalProperties": { "type": "array", "items": { "type": "string" } }, "nullable": true } }, "additionalProperties": {} } }, "securitySchemes": { "Bearer": { "type": "http", "description": "The Messaging API supports **Bearer authentication** as defined in\r\n[RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750).\r\n\r\nTo authenticate requests, include an API token in the `Authorization` header:\r\n\r\n`Authorization: Bearer {token}`\r\n\r\nThe token is an opaque value (Base64-encoded GUID) and must be treated as a\r\ncredential. Anyone in possession of the token is granted access.", "scheme": "bearer", "bearerFormat": "Opaque" }, "Basic": { "type": "http", "description": "⚠ **Legacy authentication method**\r\n\r\nThe Messaging API historically supported **HTTP Basic Authentication** as defined in\r\n[RFC 7617](https://datatracker.ietf.org/doc/html/rfc7617).\r\n\r\nTo authenticate requests, include a username and password encoded using\r\nBase64 in the `Authorization` header.\r\n\r\nThis method is retained for backward compatibility only and **must not be used\r\nfor new integrations**. New consumers should use **Bearer authentication** instead.", "scheme": "basic" } } }, "security": [ { "Bearer": [] }, { "Basic": [] } ] } ```